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Background
Melanoma is one of the deadliest skin cancers but with increasing awareness, it can be cured in its earliest stage. It is, however, one of the fastest growing cancers in the western world . Most melanomas are discovered as a suspicious changing mole. In fact, any change in a preexisting mole should prompt a visit to a physician. Increased sun exposure is certainly an important risk factor but melanoma is often a result of a complex interaction of race, sex, and genetics.
Melanoma can be recognized by following this simple chart.
THE ABCD's OF MELANOMA
A Assymetrical B Border irregularity C Color change D Diameter enlarging The outlines below have a detailed discussion of the disease.
The pathologist's task in diagnosing melanoma is first to distinguish it from benign moles (nevi) and other melanocytic proliferations. The dysplastic nevus has varying degrees of cytologic and architectural atypia that can sometimes histologically mimic a melanoma. There are a number of atypical melanocytic proliferations have been termed minimal deviation melanomas and nevoid melanomas. These latter two entities are indeed melanomas but have subtle histologic features that mimic benign nevi. If there is any doubt about the diagnosis, a review of the original tissue slide by a dermatopathologist should be sought. However, it must be stressed that even amongst experts, differences of opinion may occur. Sometimes additional consultation with several dermatopathologists is needed.
In an effort to sharpen the diagnostic criteria to distinguish between atypical moles and melanomas, numerous studies utilizing immunoperoxidase markers and other genetic probes have been undertaken. In general, there is no convincing evidence that any special stain or marker can definitely distinguish between benign and malignant.
The next task is to determine whether the melanoma is in the radial or vertical growth phase. All melanomas except nodular melanomas have a radial growth phase (see below). Melanomas confined to the epidermis are termed melanoma in-situ. In this stage, the melanoma is completely curable if it has been completely excised. At some point, the melanoma cells may invade into the underlying papillary dermis. Even in this early stage, the melanoma has a very limited potential for metastasis and some investigators have termed this stage an invasive radial growth phase. Key features which exclude this diagnosis include the presence of mitotic figures within these dermal melanocytes, a distinctly different cytologic appearance of these dermal melanocytes as compared to the intraepidermal melanocytes, and the formation of an expansile nodule within the papillary dermis. Once a melanoma has entered into the vertical growth phase, it definitely has the capacity to metastasize.
If the melanoma is in the vertical growth phase, measurements and staging must be given (see Clark's level and Breslow thickness below). In addition, parameters such as ulceration, regression, vascular-lymphatic invasion, satellite lesions, or perineural invasion should also be commented upon. Regression may not be a familiar term. This is the host body's response to the melanoma and may be observed clinically as a scar or depigmentation in a previously pigmented mole or melanoma. Histologically, the melanoma has areas replaced by a scar with a heavy lymphoplasmacytic inflammatory cell infiltrate. Some investigators believe that the presence of regression in thin melanomas (<1.5 mm thickness) portends a poorer prognosis. One explanation may be that regression may obscure the fact the melanoma was more deeply invasive in the past, and thus more aggressive. Satellite lesions are clinically distinct pigmented lesions located apart from the main tumor. These represent an intraepithelial or in-transit metastasis of the melanoma and thus are a poor prognostic factor.
Approximately 2% of melanomas may present with no recognizable primary skin lesion. A careful search of the patient, which can be aided with an ultraviolet lamp is necessary. Occasionally a history is elicited of a mole or pigmented lesion which had disappeared. In many cases, the assumption is a primary skin melanoma has undergone regression. In addition, there are a number of rare histologic variants of melanoma usually reserved for specialized textbooks of dermatopathology and case reports in pathology journals. Some of these variants produce some of the most challenging diagnoses in all of pathology. Indeed, these variants may mimic every known malignancy. The alert pathologist can rely upon a battery of immunoperoxidase stains to differentiate between these tumors. The skin is the most common site but melanoma has been described in almost every organ, including the eye. In these rare locations, a metastasis from a primary skin tumor must always be ruled out. Even this task may not be straightforward.
OUTLINE
Epidemiology Incidence
Age
Risk factors
Race and geographyDisease Associations Basal Cell Carcinoma
Dermatomyositis
HIV
Lichen sclerosus
Lymphoma
Melanoma associated retinopathy
Pancreatic cancer
Pregnancy
TraumaPathogenesis Ultraviolet light
Angiotropism
Animal models
APC Gene
Beta catenin
BRAF gene
Cadherin
Chromosomal abnormalities
Cyclin D1
Erzin
Insulin-Like Growth Factor Binding Protein 2
Ku
Loss of heterozygosity
p27
Protease-activated Receptors
PTEN
Regression
Retinoblastoma gene
Transforming Growth Factor-Beta
Tumor doubling time
Tyrosine kinase
Ultraviolet lightLaboratory/Radiologic/
Other Diagnostic TestingDermoscopy
CD95 circulating
Circulating melanoma cells in peripheral blood
HypercalcemiaGross Appearance and Clinical Variants Diffuse melanosis associated with metastatic disease
Multiple primary melanomas
Melanoma of unknown primary
Extracutaneous Melanomas
Small melanomas
Histopathological Features and Variants Special Stains/
Immunohistochemistry/
Electron MicroscopyDifferential Diagnosis Staging Prognosis
Treatment Commonly Used Terms Breslow thickness
Clark's level
Ocular melanoma
Pagetoid
Radial and vertical growth phaseInternet Links
DISEASE ASSOCIATIONS CHARACTERIZATION BASAL CELL CARCINOMA
- A Collision Tumor Involving Basal Cell Carcinoma and Lentigo Maligna Melanoma.
Belisle A, Gautier MS, Ghozali F, Plantier F, Wechsler J.
From the *Department of Pathology, Henri Mondor University Hospital, University Paris-Val-de-Marne, Creteil, France; dagger
Department of Dermatology,
Henri Mondor University Hospital, University Paris-Val-de-Marne, Creteil, France; and double daggerDepartment of Pathology, Tarnier-Cochin University Hospital, Paris, France.
Am J Dermatopathol. 2005 Aug;27(4):319-321. Abstract quote
Basal cell carcinomas (BCC) are known to co-exist with other cutaneous lesions, but the collision of BCC with malignant melanoma is rare.
We report on the case of an 82-year-old woman with a translucent papule set on a beige-brown plaque on the right side of the nose. Histologic examination showed lesions of lentigo maligna melanoma (LMM) in situ and invasive melanoma involving nests of BCC that invaded the dermis. Immunohistochemical studies with S100 protein, HMB-45, and Melan-A antibodies showed the melanocytic component in the epidermis and dense clusters of "atypical" melanocytes in the dermal nests of BCC.
On examination of the biopsy specimen, melanoma was still in situ because it was limited to the nests of BCC and not detectable between dermal collagen bundles. However, the re-excision of the lesion showed residual BCC and invasive LMM, level II, measuring 0.2 mm in thickness. The diagnosis, pathogenesis, and prognosis of this collision tumor are discussed.DERMATOMYOSITIS
J Am Acad Dermatol. 2006 Feb;54(2):221-6. Abstract quote
BACKGROUND: Dermatomyositis (DM) is an inflammatory connective tissue disorder well recognized as a paraneoplastic syndrome in adults.
OBJECTIVE: The objective of this study was to assess the prognosis of DM associated with malignant melanoma (MM).
PATIENTS AND METHODS: We systematically searched databases (PubMed, MEDLINE, and WEB OF SCIENCE) for articles reporting the concurrence of DM and MM. For the literature study, time of onset of DM in relation to diagnosis of MM (before, concomitant with, or after), stage of MM after restaging (according to the American Joint Committee on Cancer [AJCC] guidelines, 2001), and survival time after diagnosis of DM were recorded. Survival time studies and univariate statistical analyses were performed. Furthermore, we present our own clinical case of a patient with DM concomitantly occurring with regional lymph node metastasis of MM.
RESULTS: In 5 cases DM occurred before, in 6 cases concomitantly with, and in 6 cases after progression of MM. Univariate analysis identified the AJCC stage of MM as a significant prognostic factor. Gender, age, and the time interval between onset of DM and progression of melanoma were unrelated. The 1-year actuarial survival rate was 0% for patients with DM when occurring with MM at stage IV and 60% when occurring with MM at stage III (P < .05). The estimated mean survival time was 6.6 months for patients with MM stage IV and 57 months for stage III.
LIMITATIONS: The conclusions from this study are limited by the relatively small number of articles that reported the association of MM and DM.
CONCLUSION: DM occurring in patients with MM at stage IV is connected with an extremely poor prognosis, whereas the few reported patients with DM and MM at stage III, including our case, have a prognosis similar to stage III patients without DM.HIV-1 INFECTION
Altered Clinical Course of
Malignant Melanoma in
HIV-Positive Patients.Rodrigues LK, Klencke BJ, Vin-Christian K, Berger TG,
Crawford RI, Miller JR 3rd,
Ferreira CM, Nosrati M, Kashani-Sabet M.University of California, San Francisco, Melanoma Center,
UCSF Comprehensive Cancer
Center,
1600 Divisadero St,
San Francisco, CA 94115.
Arch Dermatol 2002 Jun;138(6):765-70 Abstract quote OBJECTIVE: To determine whether the natural history of melanoma is different in patients who test positive for human immunodeficiency virus (HIV) compared with matched control subjects.
DESIGN: Retrospective cohort analysis.
SETTING: Ambulatory care at 2 university-affiliated medical centers. PATIENTS: Each HIV-positive melanoma patient (n = 17) was randomly matched with 2 HIV-negative patients (HIV status unknown, but without risk factors for HIV) based on the melanoma subtype, tumor thickness, Clark level, tumor location, and sex and age of the patient.
MAIN OUTCOME MEASURES: Disease-free survival and overall survival of HIV-positive and HIV-negative melanoma patients were compared using a matched-pairs analysis. CD4 cell counts were recorded at the time of melanoma diagnosis and disease recurrence.
RESULTS: Melanoma patients who were HIV positive had a significantly shorter disease-free survival (P =.03) and overall survival (P =.045) compared with HIV-negative melanoma patients by matched-pairs analysis. There was an inverse relationship between CD4 cell counts and time to first melanoma recurrence.
CONCLUSIONS: The natural history of malignant melanoma in HIV-positive patients is more aggressive compared with matched HIV-negative melanoma patients. Altered immune response and comorbid disease may play a role in the poor clinical outcome of HIV-positive patients. These findings have important implications in the management of melanoma in the setting of HIV disease.
LICHEN SCLEROSUS Melanocytic Proliferations
Associated With Lichen SclerosusJ. Andrew Carlson, MD, FRCPC; Xiao C. Mu, MD, PhD; Andrzej Slominski, MD, PhD; Kaare Weismann, MD, PhD; A. Neil Crowson, MD; John Malfetano,
MD; Victor G. Prieto, MD, PhD;
Martin C. Mihm, Jr, MDArch Dermatol. 2002;138:77-87 Abstract quote
Objectives
To describe the clinicopathologic features of melanocytic proliferations associated with lichen sclerosus (LS) and to compare these findings with those in controls. Design Cohort study.Setting
Academic and private practice dermatology and dermatopathology services.Patients
Cases of melanocytic proliferations associated with LS and consecutive controls with persistent (recurrent) melanocytic nevi, persistent malignant melanomas, and compound melanocytic nevi.Main Outcome Measures
Diagnostic criteria and disease recurrence.Results
Eleven patients, all female, with a mean age of 40 years (range, 8-83 years), presented with pigmented lesions clinically suspected to be malignant melanoma or atypical melanocytic nevi affecting the vulva (7 patients), perineum (3 patients), or chest (1 patient). Lichen sclerosus was first identified in the biopsy specimen and subsequently confirmed clinically. In 10 cases, a melanocytic nevus was superimposed on LS (overlying or entrapped by sclerosis), whereas LS was found at the periphery of vulvar malignant melanoma. After complete excision, no recurrences have been reported for the melanocytic nevi in LS (mean follow-up, 29 months; range, 4-60 months). Compared with control lesions, the LS melanocytic nevi most closely resembled persistent melanocytic nevi and could be distinguished from persistent malignant melanoma histologically. Melanocytes, nevoid or malignant, proliferating contiguously with fibrotic or sclerotic collagen, contained abundant melanin, diffusely expressed HMB-45, and had a higher Ki-67 labeling index than ordinary melanocytic nevi. However, persistent malignant melanoma exhibited mitotic figures, significantly higher Ki-67 labeling index, and deep dermal HMB-45 expression compared with LS melanocytic nevi and persistent melanocytic nevi.Conclusions
Melanocytic nevi occurring in LS have features in common with persistent melanocytic nevi and can mimic malignant melanoma. An "activated" melanocytic phenotype is seen in LS melanocytic nevi, implicating a stromal-induced change.LYMPHOMA Monoclonal proliferation of
germinal center cells
(incipient follicular lymphoma)
in an axillary lymph node of a melanoma patientGiancarlo Pruneri, MD
Giovanni Mazzarol, MD
Michela Manzotti, BSc
Giuseppe Viale, MD, FRCPathHum Pathol 2002;32:1410-1413. Abstract quote
A monoclonal proliferation of germinal center cells within a lymph node follicle was incidentally discovered during the staging surgical procedures in a patient with Clark III–level cutaneous melanoma.
In one of the 19 axillary lymph nodes examined, we identified a single morphologically atypical lymphoid follicle, predominantly composed of medium-sized cells and immunoreactive for B-cell antigens and for the markers of germinal center origin CD10 and bcl-6. A monoclonal rearrangement of the immunoglobulins heavy chains (IgH) was documented by polymerase chain reaction after laser capture microdissection. The cells of the aberrant follicle expressed the bcl-2 protein at higher levels than the surrounding T lymphocytes in the absence of bcl-2 gene rearrangement.
We propose for this lesion the designation of incipient follicular lymphoma. The present findings also confirm the previously reported association between melanoma and lymphoproliferative disorders.
A single-institution case series of patients with cutaneous melanoma
and non-Hodgkin's lymphomaHensin Tsao, MD, PhD
Kimberly Kwitkiwskib
Arthur J. Sober, MD
Boston, MassachusettsJ Am Acad Dermatol 2002;46:55-61 Abstract quote
Background: Over the past two decades, cutaneous melanoma (CM) and non-Hodgkin's lymphoma (NHL) have both experienced unabated increases in incidence. Population-based studies have documented an elevated risk of subsequent NHL among patients with CM and vice versa.
Methods: To better characterize the clinical features of patients who have had both malignancies, we retrospectively identified all patients with CM at the Massachusetts General Hospital (MGH) who subsequently had NHL and all NHL patients who later developed CM.
Results: A total of 2461 CM and 2708 NHL patients were registered at MGH between 1973 and 1998. Out of these groups, 10 CM patients (0.4%) eventually developed NHL and 11 NHL patients (0.4%) subsequently had CM. The mean age at the first CM diagnosis was 56 years, wheras the mean age at the first NHL diagnosis was 67 years. The mean interval to NHL among the CM group was 119 months, whereas the mean interval to CM among the NHL patients was 36 months. All primary CMs were relatively thin (0.95 mm, first diagnosis; 1.07 mm, second diagnosis), and most NHL subtypes were indolent in nature.
Conclusion: The rates of developing a second NHL among CM patients and vice versa are low. Any interactions between CM and NHL may be due to factors such as detection bias, shared environmental ultraviolet carcinogenesis, or possibly, posttreatment effects.
MELANOMA ASSOCIATED RETINOPATHY Am J Ophthalmol 1988;106:307–11.
Invest Ophthalmol Vis Sci 2000;41:262–6.
Invest Ophthalmol Vis Sci 1993;34:91–100.Patients have autoantibodies that cross-react with the tumor cells and an unknown antigen in rod bipolar cells of the retina, leading to loss of rod function (night blindness)
Corticosteroid Treatment for Melanoma-Associated Retinopathy Effect on Visual Acuity and Electrophysiologic Findings
Caroline Jacobzone, MD ;Catherine ;
Cochard-Marianowski, MDIngrid Kupfer, MD ;Samia Bettembourg, MD ;Yves Dordain, MD ;Laurent Misery, MD ;Beatrice Cochener, MD ;Bruno Sassolas, MD
Arch Dermatol. 2004;140:1258-1261. Abstract quote Background Visual disturbance in the course of melanoma is rare. Specific localized metastases and drug toxic effects are frequently the cause. Recognition of a retinopathy raises several questions when the diagnosis of melanoma-associated retinopathy (MAR) can be confirmed. Descriptions of such patients in dermatologic literature are rare and deserve attention because therapeutic decisions are mandatory.
Observations A 70-year-old woman had a first melanoma in 1985 and a second primary melanoma in 1994. Axillary lymph node involvement occurred in November 2000, leading to surgery and chemotherapy. In December 2001, she had sudden bilateral visual loss, with shimmering blobs of color and flickering photopsias. Computed tomography and cerebral magnetic resonance imaging ruled out localized tumor on the eyes or optic nerves or evolution of disease. Ophthalmologic examination revealed a bilateral posterior uveitis, with hyalitis and progressive destruction of retinal pigment. The electrophysiologic data confirmed the diagnosis of MAR. Symptoms improved after systemic corticosteroid therapy, with no relapse after tapering doses despite worsening of melanoma.
Conclusions As a rare paraneoplastic visual syndrome possibly leading to blindness, MAR is characterized by bipolar cell involvement without photoreceptor cell impairment. Also, MAR is linked to the presence of autoantibodies directed against melanoma antigens that cross-react with the rod bipolar cells of the retina. Corticosteroid therapy is rarely beneficial. Our case of MAR is noteworthy because it involved a woman, was associated with an uveitis, and improved with corticosteroid therapy.
PANCREATIC CANCER
Pancreatic carcinoma surveillance in patients with familial melanoma.Parker JF, Florell SR, Alexander A, DiSario JA, Shami PJ, Leachman SA.
Department of Dermatology and Huntsman Cancer Institute and the Divisions of Gastroenterology and Oncology, University of Utah, Salt Lake City, Utah 84112, USA.
Arch Dermatol. 2003 Aug;139(8):1019-25. Abstract quote OBJECTIVE: To determine the optimal methods for pancreatic adenocarcinoma surveillance in high-risk patients with familial melanoma and cyclin-dependent kinase inhibitor 2A (CDKN2A) mutations.
DESIGN: Case report with pedigree analysis and literature review, with an emphasis on guideline development for high-risk kindreds with familial pancreatic adenocarcinoma.
SETTING: A university-affiliated familial melanoma research clinic.Patients The proband was referred as a participant in a research clinic protocol and was found to carry a germline CDKN2A mutation and have a history of melanoma and pancreatic adenocarcinoma. A total of 179 family members were identified through the Utah Population Database and underwent evaluation for history of melanoma and pancreatic adenocarcinoma.
Intervention/ METHODS: Comprehensive family history and pedigree analysis performed by means of personal interview, medical record review, and use of cancer registry and population database records. Mutation status was confirmed by results of DNA sequence analysis. Tumor identity was confirmed with immunohistochemical markers.
MAIN OUTCOME MEASURES: Estimated risk for pancreatic adenocarcinoma in a high-risk family with CDKN2A-positive melanoma. Guidelines for surveillance in these families were based on review of the literature.
RESULTS: Sequence analysis confirmed a CDKN2A mutation, and immunohistochemical evaluation confirmed the diagnoses of metastatic melanoma and metastatic pancreatic adenocarcinoma. Pedigree analysis showed an observed-expected ratio of 8.9 to 12.6 for pancreatic adenocarcinoma and 16.4 to 20.8 for melanoma in this family. Guidelines used for surveillance of kindreds at high risk for pancreatic adenocarcinoma were applied to families with CDKN2A melanoma.
Conclusion Patients with melanoma and a germline CDKN2A mutation should be considered for pancreatic adenocarcinoma surveillance that is based on the most recent published studies.
Phenotypic variation in eight extended CDKN2A germline mutation familial atypical multiple mole melanoma-pancreatic carcinoma-prone families: the familial atypical mole melanoma-pancreatic carcinoma syndrome.Lynch HT, Brand RE, Hogg D, Deters CA, Fusaro RM, Lynch JF, Liu L, Knezetic J, Lassam NJ, Goggins M, Kern S.
Department of Preventive Medicine, Creighton University School of Medicine, Omaha, Nebraska 68178, USA.
Cancer 2002 Jan 1;94(1):84-96 Abstract quote BACKGROUND: Hereditary pancreatic carcinoma shows extant phenotypic and genotypic heterogeneity as evidenced by its integral association with a variety of hereditary cancer syndromes inclusive of the familial atypical multiple mole melanoma (FAMMM) syndrome in concert with CDKN2A (p16) germline mutations.
METHODS: Creighton University's familial pancreatic carcinoma resource comprises 159 families of which 19 (12%) show the FAMMM cutaneous phenotypes. The authors describe eight families with the FAMMM-pancreatic carcinoma (FAMMM-PC) association in concert with a CDKN2A germline mutation. Each family was thoroughly educated about all facets of the study, including the molecular genetics, reduced penetrance of CDKN2A mutations, and their variable expressivity. Genetic counseling was provided to each patient.
RESULTS: Diversity in cancer presentation within and among the families was noteworthy, wherein melanoma predominated in certain of the families whereas pancreatic carcinoma predominated in others. Early-onset pancreatic carcinoma (at ages 35, 45, 46, and 49 years) appeared in some of the families whereas markedly later-onset pancreatic carcinoma occurred in others. There were four incidences of melanoma and pancreatic carcinoma as double primaries in the same individuals. One patient with melanoma and pancreatic carcinoma had a third primary of breast carcinoma. Another patient had sarcoma, esophageal carcinoma, and two melanoma primaries, whereas his daughter had sarcoma and was a carrier of a CDKN2A mutation.
CONCLUSIONS: The authors suggest that these tumors may collectively, in concert with CDKN2A mutations, constitute a "new" putative hereditary carcinoma syndrome referred to as FAMMM-PC. More clinical and molecular genetic research on additional families with pancreatic carcinoma in concert with the FAMMM will be required.
PREGNANCY
Department of Dermatology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
For many years, clinicians have been concerned about a potential adverse effect of pregnancy-associated hormones and exogenous hormones on melanocytic nevi and malignant melanoma.
Today, these issues are more significant as women have delayed childbearing into their 30's and 40's, and the likelihood of diagnosis with melanoma during pregnancy is enhanced.
More recent clinical, epidemiologic, and laboratory studies have shed some light on the relationship among hormones, nevi, and melanoma in pregnancy.TRAUMA Trauma and melanoma formation: a true association?
Kaskel P, Kind P, Sander S, Peter RU, Krahn G.
Department of Dermatology, University of Ulm, 89070 Ulm/Donau, Germany.
Br J Dermatol 2000 Oct;143(4):749-53 Abstract quote
BACKGROUND: Little is known about the role of mechanical trauma in the pathogenesis of malignant melanoma. In individual patients, traumatic events have been discussed as a causative factor for the induction of melanoma and diagnosis of melanoma following trauma may raise medico-legal questions.
OBJECTIVES: To evaluate the relationship between traumatic single or recurrent events and melanoma characteristics.
METHODS: Retrospective questionnaire in 369 melanoma patients.
RESULTS: A large number of patients (337 of 369; 91.3%) denied an association between a possible traumatic event and melanoma formation. Thirty-two of 369 patients (8.7%) considered an association of trauma and melanoma formation likely. Of these 32 patients, 22 patients (13 men, nine women) reported a single event, and 10 patients (four men, six women) a persisting irritation. An irritation of a pre-existing melanocytic naevus was reported by two patients with histologically confirmed melanoma on acquired or congenital naevus.
CONCLUSIONS: As most of the patients who mentioned a trauma in this study suffered from acral melanoma, or melanoma located on the extremities, a history of trauma should be expected more frequently at these body sites. A review of epidemiological, clinical and scientific research indicates that there seems to be no evidence for single or persistent traumatic events as a causative factor for melanoma formation.
PATHOGENESIS CHARACTERIZATION ANGIOTROPISM
Pericytic-like angiotropism of glioma and melanoma cells.Lugassy C, Haroun RI, Brem H, Tyler BM, Jones RV, Fernandez PM, Patierno SR, Kleinman HK, Barnhill RL.
Am J Dermatopathol 2002 Dec;24(6):473-8 Abstract quote We have identified in malignant melanoma an angiotumoral complex in which tumor cells occupy a pericytic location along the endothelium of microvessels without evidence of intravasation.
We have suggested that this pericytic-like angiotropism could be a marker of an extravascular migration of tumor cells along the abluminal surface of vessels. The extravascular migratory metastasis proposed for melanoma has close analogies with glioma migration.
To compare our hypothesis of extravascular migration by melanoma with the migration of glioma cells, we have used the B16 murine melanoma cell line and the GL26 murine glioma cell line in an in vivo murine brain tumor model and in vitro using endothelial cells that have formed capillary-like structures and have been cocultivated with tumor cells. In the brain tumors, a clear progression of glioma and melanoma cells was observed along the abluminal surface of vessels, where they occupied a pericytic location along the periendothelial laminin. In vitro, time-lapse videomicroscopy recorded the migration of tumor cells toward endothelial tubules. After 24 hours, both the melanoma cells and the glioma cells were localized along the external surfaces of the vascular tubules, occupying a pericytic-like location.
These similarities between glioma and melanoma support the hypothesis of an extravascular migration of melanoma cells, particularly along the abluminal surface of vessels.
ANIMAL MODELS
Malignant melanoma in the Sinclair miniature swine: an autopsy study of 60 cases.Oxenhandler RW, Adelstein EH, Haigh JP, Hook RR Jr, Clark WH Jr.
Am J Pathol 1979 Sep;96(3):707-20 Abstract quote Sinclair miniature swine spontaneously develop multiple cutaneous melanomas which have the ability to metastasize and regress.
This study, based on 60 necropsies, documents the similarity of the pathology of the cutaneous malignant melanomas and the organ distribution of metastasis to human melanoma. The invasive cutaneous melanomas have an intraepidermal component analogous to human superficial spreading melanoma. The pathology of the spontaneous regression, characterized by a series of cellular events beginning with a mononuclear inflammatory infiltrate and leading to depigmentation and fibrosis, is likewise similar to cutaneous regression in human melanoma. Just as with human melanoma,metastasis was correlated with deeply invasive cutaneous tumors.
Because of both the biologic and histologic similarity of this animal model to human melanoma, the Sinclair miniature swine should serve as an important resource in continuing the study of melanoma.
Histopathology of regression in sinclair swine model of melanoma.
Greene JF Jr, Townsend JS 4th, Amoss MS Jr.
Department of Pathology, Scott & White Clinic, Temple, Texas.
Lab Invest 1994 Jul;71(1):17-24 Abstract quote BACKGROUND: Detailed histopathologic studies of melanomas occurring in neonatal Sinclair miniature swine have demonstrated a remarkable similarity to human melanoma. A significant difference is the predictable, complete regression of primary and metastatic tumors that occurs in all animals by early adulthood (1 to 2 years). Prior histopathologic descriptions of regression in this model have been incomplete with regard to the time of onset and chronologic sequence of events. This lack of data makes it difficult to plan studies of regression mechanisms especially when requiring the harvesting of tumor tissue.
EXPERIMENTAL DESIGN: By routine histologic methods, 94 tumors from 46 piglets were evaluated for the degree of regression, presence of pigment-laden macrophages, and presence of lymphocytes. One or more punch biopsies were performed on 51 tumors before excision, for a total of 256 biopsies.
RESULTS: Regression took place in two phases. The first phase began during the 4th week after birth; was preceded by a rapid, massive infiltration of pigment-laden macrophages; and was most active during the 2nd month. Significant numbers of lymphocytes were rarely seen in tumors during this phase of regression. In the vast majority of tumors, this initial regression activity was followed by regrowth of residual tumor usually appearing as emerging clones (intralesional transformation). The second phase of regression was characterized by asymmetrically distributed lymphocytic infiltration of the residual melanoma, and progressive regression of tumor over several months. Significant numbers of lymphocytes were not present in the majority of the tumors until the beginning of the 4th month.
CONCLUSIONS: We conclude that regression of melanoma in this animal model is a complex event in which the immune system participates differentially during the natural history of the disease.
Antimelanoma antibodies in swine with spontaneously regressing melanoma.Cui J, Chen D, Misfeldt ML, Swinfard RW, Bystryn JC.
Ronald O. Perelman Department of Dermatology, New York University Medical Center, New York, USA.
Pigment Cell Res 1995 Feb;8(1):60-3 Abstract quote Sinclair swine provide a unique model for studying mechanisms of tumor regression because they are born with melanomas that spontaneously regress approximately 10 weeks after birth.
To examine whether an antitumor immune response is present in these animals, and, if so, to study its relation to tumor regression, 38 sera specimens collected at different times from 13 swine born with melanomas were tested for melanoma antibodies by immunoprecipitation and SDS-PAGE analysis of 125I labelled swine melanoma macromolecules. Antibodies to melanoma were present in 13 (100%) of the swine versus 1 of 3 control swine. The antibodies were directed to antigens of approximately 45, 68-75, or 100 kDa. These antigens were also expressed on human melanomas and normal melanocytes but on only one of five unrelated tumors. The incidence and level of these antibodies increased with time. Antibodies to the 45, 68-75, and 100 kDa antigens were present in 36%, 55%, and 9%, respectively, of sera collected prior to 7 weeks of age, but in 80%, 100%, and 37% of sera collected between 7 and 20 weeks (P < 0.05). The rise in melanoma antibodies usually preceded or appeared together with tumor regression and loss of pigmentation.
These findings indicate that Sinclair swine with melanomas have antibodies to antigens preferentially expressed on pigment cells, and support the hypothesis that the regression phenomenon and the vitiligo-like skin depigmentation result from immune responses to common antigens shared by normal and malignant swine pigment cells.
ROLE OF APAF-1 GENE Inactivation of the apoptosis effector Apaf-1 in malignant melanoma.
Soengas MS, Capodieci P, Polsky D, Mora J, Esteller M, Opitz-Araya X, McCombie R, Herman JG, Gerald WL, Lazebnik YA, Cordon-Cardo C, Lowe SW.
Cold Spring Harbor Laboratory, New York 11724, USA.
Nature 2001 Jan 11;409(6817):207-11 Abstract quote
Metastatic melanoma is a deadly cancer that fails to respond to conventional chemotherapy and is poorly understood at the molecular level. p53 mutations often occur in aggressive and chemoresistant cancers but are rarely observed in melanoma.
Here we show that metastatic melanomas often lose Apaf-1, a cell-death effector that acts with cytochrome c and caspase-9 to mediate p53-dependent apoptosis. Loss of Apaf-1 expression is accompanied by allelic loss in metastatic melanomas, but can be recovered in melanoma cell lines by treatment with the methylation inhibitor 5-aza-2'-deoxycytidine (5aza2dC). Apaf-1-negative melanomas are invariably chemoresistant and are unable to execute a typical apoptotic programme in response to p53 activation. Restoring physiological levels of Apaf-1 through gene transfer or 5aza2dC treatment markedly enhances chemosensitivity and rescues the apoptotic defects associated with Apaf-1 loss.
We conclude that Apaf-1 is inactivated in metastatic melanomas, which leads to defects in the execution of apoptotic cell death. Apaf-1 loss may contribute to the low frequency of p53 mutations observed in this highly chemoresistant tumour type.
APF GENE Analysis of adenomatous polyposis coli gene expression, APC locus-microsatellite instability and APC promoter methylation in the progression of melanocytic tumours.
Korabiowska M, Schlott T, Siems N, Muller A, Cordon-Cardo C, Fischer G, Brinck U.
1Department of Cytopathology, University of Gottingen, Gottingen, Germany.
Mod Pathol. 2004 Dec;17(12):1539-44. Abstract quote
Adenomatous polyposis coli gene (APC) defects have been demonstrated for the first time in familial adenomatous polyposis. Recent reports indicate that the APC gene is an intermediary between cell adhesion molecules and the cytoskeleton and that it may function as a gatekeeper of colonic epithelial proliferation.
The objective of this study was to analyse APC's presence in lentigos, primary melanomas and melanoma metastases. By immunohistochemistry, APC was demonstrated in all lentigos, in 75 out of 88 primary melanomas and in 16 out of 28 melanoma lymphatic metastases. The percentage of immunolabelled tumour cells (APC index) in lentigos ranged between 5 and 69%, in primary melanomas between 0 and 98% and in melanoma metastases between 0 and 52%. Statistically significant differences between lentigos and primary melanomas and between lentigos and metastases in APC expression were found.
In a multivariate analysis, APC showed an independent prognostic impact. Analysis of microsatellite instability in the APC locus was performed on 29 melanomas. Microsatellite instability was found in 5/29 melanomas and loss of heterozygosity in 1/29 melanomas. Promoter methylation of APC was found in 6/10 APC-negative primary melanomas and in 9/10 APC-negative melanoma lymphatic metastases investigated.
We conclude about important role of APC alterations for melanoma progression.BETA CATENIN
Loss of membranous expression of beta-catenin is associated with tumor progression in cutaneous melanoma and rarely caused by exon 3 mutations.Demunter A, Libbrecht L, Degreef H, De Wolf-Peeters C, van den Oord JJ.
Department of Pathology, Laboratory of Morphology and Molecular Pathology, University Hospitals, Katholieke Universiteit Leuven, Belgium.
Mod Pathol 2002 Apr;15(4):454-61 Abstract quote beta-Catenin plays a fundamental role in the regulation of the E-cadherin-catenin cell adhesion complex. It also plays a role in the Wnt signaling pathway by activating T-cell factor- and lymphoid enhancer factor-regulated gene transcription. The level of beta-catenin in cells is tightly controlled in a multiprotein complex, and mutations in the glycogen synthase kinase 3beta (GSK-3beta) phosphorylation sites of the beta-catenin gene (CTNNB1) result in nuclear and/or cytoplasmic accumulation of beta-catenin and constitutive transactivation of T-cell factor and lymphoid enhancer factor target genes, a mechanism occurring in many cancers. Melanoma cell lines may harbor beta-catenin mutations; in vivo, however, cellular accumulation of beta-catenin is rarely caused by CTNNB1 mutations.
In our study, 43 primary cutaneous melanoma and 30 metastases were screened for CTNNB1 exon 3 mutations by using a denaturing gradient gel electrophoresis technique and sequencing. beta-Catenin mutations were found in 2 primary melanomas and 1 metastatic melanoma and were not correlated with nuclear accumulation of beta-catenin in these cases. Cellular expression of beta-catenin was evaluated by immunohistochemistry and by reverse polymerase chain reaction (RT-PCR) in 80 and 70 cases, respectively. Immunohistochemistry revealed a significant loss of membranous beta-catenin staining between the primary and metastatic melanomas as well as between radial and vertical growth phase. RT-PCR showed a significant inverse correlation between the amount of RNA and the proportion of cells with membranous expression of beta-catenin (P =.0015); no correlation existed between the amount of RNA and the number of cells with nuclear or cytoplasmic expression of beta-catenin.
In conclusion, nuclear expression of beta-catenin is seen in cutaneous melanoma but, in contrast to the case of many other cancers, does not correlate with tumor stage or mutation status. A combination of immunohistochemistry and RT-PCR showed that down-regulation of membranous beta-catenin was associated with an increased amount of beta-catenin RNA in primary or metastatic melanoma. Our results suggest that posttranslational events, rather than CTNNB1 mutations, are responsible for the altered distribution of beta-catenin in cutaneous melanoma.
BRAF GENE
- BRAF and c-kit gene copy number in mutation-positive malignant melanoma.
Willmore-Payne C, Holden JA, Hirschowitz S, Layfield LJ.
Department of Pathology, University of Utah, Salt Lake City, UT 84132, USA.
Hum Pathol. 2006 May;37(5):520-7. Abstract quote
Activating mutations in BRAF or c-kit have been reported in malignant melanoma. Because the activating mutations are dominant, it has been assumed that they are heterozygous in the affected tumors.
To test this, we have carefully examined the DNA sequencing electropherograms on 43 BRAF mutation-positive and 3 c-kit mutation-positive malignant melanomas to determine the ratio of the normal to mutant allele. Of the 43 BRAF mutation-positive tumors, we classified 26 as presumptive heterozygous. Eight cases were indeterminate. Surprisingly, 9 cases appeared to contain an excess of the mutant allele. BRAF fluorescence in situ hybridization on these 9 cases suggested the increased amount of the mutant BRAF allele was due to amplification (2 cases) or chromosome 7 polysomy (7 cases).
We have previously described the presence of the c-kit-activating mutation, L576P, in 2 of 100 malignant melanomas. In this report, we have evaluated an additional 53 cases and found 1 additional case that contained the L576P mutation. Evaluation of the DNA sequencing electropherograms from all 3 cases of L576P mutation-positive melanoma suggests a selective loss of the normal allele. Fluorescence in situ hybridization for c-kit on these 3 L576P mutation-positive tumors indicated that one showed slight amplification of the c-kit gene and the other 2 were present in a nonamplified diploid state.
These results have important implications concerning the mechanism of oncogenesis in melanoma as well as in the response of the tumor to anticancer drugs targeting BRAF or c-kit.
J Am Acad Dermatol. 2005 Jul;53(1):108-14. Abstract quote
High frequency of B-RAF gene mutations has recently been identified in benign melanocytic nevi and melanoma.
This review focuses on clinical studies that evaluate the role of B-RAF in melanocytic neoplasia.
- Human malignant melanoma: Detection of BRAF- and c-kit-activating mutations by high-resolution amplicon melting analysis.
Willmore-Payne C, Holden JA, Tripp S, Layfield LJ.
Hum Pathol. 2005 May;36(5):486-93. Abstract quote
Summary Activating mutations in the BRAF kinase have been reported in a large number of cases of malignant melanoma. This suggests that therapy with specific RAF kinase inhibitors may find use in treating this disease. If the response to RAF kinase inhibition is dependent on the presence of an activated BRAF protein, it will be necessary to evaluate cases of malignant melanoma for the presence or absence of BRAF mutations.
High-resolution amplicon melting analysis is able to detect single base-pair changes in DNA isolated from paraffin-embedded tissue sections and obviates the need for direct DNA sequencing. Results can be available within 48 hours.
In this report, we used high-resolution amplicon melting analysis to evaluate 90 cases of malignant melanoma for BRAF mutations. Of these 90 cases, 74 were metastatic melanomas, 12 were primary cutaneous melanomas, and 4 were in situ melanomas. BRAF activation mutations were found in 43 cases (48%). Forty-one of these mutations were in exon 15. The mutations in exon 15 included V600E (34 cases), V600K (6 cases), and V600R (1 case). Two activating mutations were found in exon 11, G469V and G469R. The presence or absence of a BRAF mutation in the junctional component of an invasive melanoma was maintained in the invasive component.
We also evaluated these 90 cases, as well as an additional 10 cases (total of 100) for the expression of c-kit. The majority of invasive and metastatic malignant melanomas did not express c-kit, although all in situ lesions and the junctional components of invasive lesions were strongly c-kit positive. Surprisingly, 2 cases of metastatic malignant melanoma (2%) showed strong and diffuse c-kit expression and contained a c-kit-activating mutation, L576P, as detected by high-resolution amplicon melting analysis and confirmed by direct DNA sequencing. These 2 c-kit mutation-positive cases did not contain BRAF mutations. The presence of a c-kit-activating mutation in metastatic malignant melanoma suggests that a small number of melanomas may progress by a somatic mutation of the c-kit gene.
The presence of BRAF- and c-kit-activating mutations in malignant melanoma suggests new approaches to treating this disease involving specific tyrosine kinase inhibitors may prove worthwhile and that mutation analysis by high-resolution melting analysis might help guide therapy.
BRAF mutation: a frequent event in benign, atypical, and malignant melanocytic lesions of the skin.
Uribe P, Wistuba II, Gonzalez S.
Department of Anatomic Pthology, Medical School, P.Universidad Catolica de Chile, Santiago, Chile.
Am J Dermatopathol. 2003 Oct;25(5):365-70. Abstract quote
BRAF mutations have recently been detected with a high frequency (66%) in cutaneous melanoma. All those mutations are activating, with a single substitution (T1796A) at codon 599 (V599E) accounting for over 90%.To investigate the stage in which those mutations occur in the currently proposed sequential malignant transformation of melanocytes, 22 benign melanocytic nevi, 23 melanocytic atypical nevi, and 25 primary cutaneous melanoma from 63 different patients were examined for BRAF mutations using DNA extracted from microdissected formalin-fixed and paraffin-embedded tissues, and a two-round PCR-RFLP-based strategy. A subset of samples was sequenced for mutation confirmation. Sixteen benign (73%) and eleven atypical (52%) melanocytic nevi, and thirteen melanoma (56%) demonstrated BRAF mutations at codon 599, and no statistically significant differences were detected among all three types of lesions. No mutations were demonstrated in microdissected epidermal keratinocytes adjacent to melanocytic lesions having BRAF mutations. No correlation was detected between BRAF mutational status and age, sun exposure, and Clark's level in malignant melanoma. However, comparing only atypical nevi and melanoma lesions the frequency of BRAF mutation is significantly greater in male (78%) than female (35%) patients (P = 0.0194). The previously described T1796A point mutation was detected in 17 of 18 mutated samples, and a novel mutation consisting of a substitution of valine for lysine (GT1795-96AA) was detected in one melanoma case.
Our findings of a high frequency of BRAF mutations at codon 599 in benign melanocytic lesions of the skin indicate that this mutation is not sufficient by itself for malignant transformation.
Mutations of the BRAF gene in human cancer.
Davies H, Bignell GR, Cox C, Stephens P, Edkins S, Clegg S, Teague J, Woffendin H, Garnett MJ, Bottomley W, Davis N, Dicks E, Ewing R, Floyd Y, Gray K, Hall S, Hawes R, Hughes J, Kosmidou V, Menzies A, Mould C, Parker A, Stevens C, Watt S, Hooper S, Wilson R, Jayatilake H, Gusterson BA, Cooper C, Shipley J, Hargrave D, Pritchard-Jones K, Maitland N, Chenevix-Trench G, Riggins GJ, Bigner DD, Palmieri G, Cossu A, Flanagan A, Nicholson A, Ho JW, Leung SY, Yuen ST, Weber BL, Seigler HF, Darrow TL, Paterson H, Marais R, Marshall CJ, Wooster R, Stratton MR, Futreal PA.
Cancer Genome Project, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SA, UK.
Nature 2002 Jun 27;417(6892):949-54 Abstract quote Cancers arise owing to the accumulation of mutations in critical genes that alter normal programmes of cell proliferation, differentiation and death. As the first stage of a systematic genome-wide screen for these genes, we have prioritized for analysis signalling pathways in which at least one gene is mutated in human cancer.
The RAS RAF MEK ERK MAP kinase pathway mediates cellular responses to growth signals. RAS is mutated to an oncogenic form in about 15% of human cancer. The three RAF genes code for cytoplasmic serine/threonine kinases that are regulated by binding RAS. Here we report BRAF somatic missense mutations in 66% of malignant melanomas and at lower frequency in a wide range of human cancers. All mutations are within the kinase domain, with a single substitution (V599E) accounting for 80%.
Mutated BRAF proteins have elevated kinase activity and are transforming in NIH3T3 cells. Furthermore, RAS function is not required for the growth of cancer cell lines with the V599E mutation. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation in human cancer, it may provide new therapeutic opportunities in malignant melanoma.
CADHERIN
Cadherin expression pattern in melanocytic tumors more likely depends on the melanocyte environment than on tumor cell progression.
Krengel S, Groteluschen F, Bartsch S, Tronnier M.
Department of Dermatology, Medical University Lubeck, Lubeck, and Department of Dermatology, Municipal Hospital Hildesheim, Hildesheim, Germany.
J Cutan Pathol. 2004 Jan;31(1):1-7 Abstract quote.
BACKGROUND: Adhesion molecules have been assigned an important role in melanocytic tumor progression. By the loss of E-cadherin, melanocytes might escape the control of neighbouring keratinocytes. Although in vitro data support this hypothesis, there are yet no conclusive immunohistochemical results on cadherin expression in melanocytic tumors.
OBJECTIVE: To gain detailed insight in the expression of cadherins and their cytoplasmic binding partners, the catenins, in various types of benign and malignant melanocytic neoplasms.
METHODS: Immunohistochemical analysis of the expression of E-, P-, and N-cadherin and alpha-, beta-, and gamma-catenin in compound and dermal nevi, Spitz nevi, blue nevi, ultraviolet B (UVB)-irradiated nevi, and malignant melanomas of various tumor thickness.
RESULTS: In both nevi and melanomas, E-cadherin expression in melanocytic cells decreased, following a gradient from junctional to deeper dermal localization. The pattern of E-cadherin expression was more heterogeneous in melanomas than in nevi. In some melanomas, E-cadherin was only weakly positive in the epidermal tumor cells. P-cadherin expression was similar to that of E-cadherin. N-cadherin expression in melanocytic lesions was a rare finding, however, a small percentage of melanomas showed expression in some cell nests. Some Spitz nevi exhibited strong N-cadherin immunoreactivity. Most melanocytic cells were alpha- and beta-catenin-positive and gamma-catenin-negative. UVB irradiation did not influence the expression of cadherins and catenins in melanocytic nevi in vivo.
CONCLUSIONS: It is presumed that the gradual loss of E-cadherin expression represents a reaction of melanocytic cells to altered conditions in the dermal environment, e.g. lack of contact to keratinocytes, or new contact with dermal extracellular matrix molecules, respectively. Melanoma cells apparently are less dependent on these environmental factors and, therefore, show a more heterogeneous expression pattern. This might be of importance for the adaptation of the tumor cells to local requirements. However, in view of our results, a causative role of (loss of ) E-cadherin or (gain of ) N-cadherin for melanocytic tumor progression still remains to be proven.CDKN2A
(Tumor suppressor gene)NEJM 1998;338:879-887
Non familial cases of multiple primary melanomas have germ-line mutations (5/33-15%)Prevalence of p16 and CDK4 germline mutations in 48 melanoma-prone families in France. The French Familial Melanoma Study Group.
Soufir N, Avril MF, Chompret A, Demenais F, Bombled J, Spatz A, Stoppa-Lyonnet D, Benard J, Bressac-de Paillerets B.
Unite des Marqueurs Genetiques des Cancers, Institut Gustave Roussy (IGR), 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
Hum Mol Genet 1998 Feb;7(2):209-16 Abstract quote
Germline mutations in the p16 and CDK4 genes have been reported in a subset of melanoma pedigrees, but their prevalence is not well known. We searched for such germline mutations in 48 French melanoma-prone families selected according to two major criteria: families with at least three affected members (n = 20) or families with two affected members, one of them affected before the age of 50 (n = 28), and one additional minor criterion. Sixteen different p16 germline mutations were found in 21 families, while one germline mutation, Arg24His, was detected in the CDK4 gene.
The frequency of p16 gene mutation in our sample (44%) is among the highest rates yet reported and the CDK4 mutation is the second mutation detected in this gene worldwide. In summary, our results show frequent involvement of the p16 gene in familial melanoma and confirm the role of the CDK4 gene as a melanoma-predisposing gene.
Low prevalence of germline CDKN2A and CDK4 mutations in patients with early-onset melanoma.
Tsao H, Zhang X, Kwitkiwski K, Finkelstein DM, Sober AJ, Haluska FG.
Department of Dermatology, Massachusetts General Hospital, Bartlett 622, 48 Blossom St, Boston, MA 02114.
Arch Dermatol 2000 Sep;136(9):1118-22 Abstract quote
BACKGROUND: In patients with cutaneous melanoma, early age at disease onset is characteristic in familial cases and in individuals with multiple primary melanomas. Both subsets of patients with melanoma are at risk for harboring germline CDKN2A or CDK4 mutations.
OBJECTIVE: We set out to prospectively determine the prevalence of CDKN2A and CDK4 mutations in a group of young patients with melanoma. DESIGN: We prospectively screened 913 patients over a 6-month period and identified 519 patients with invasive melanomas. We invited 172 patients with melanoma who were younger than 40 years to participate in the study, and 49 patients consented and donated peripheral blood samples. Forty-nine percent (n = 24) of our patients developed cutaneous melanoma before the age of 30 years.
SETTING: A melanoma clinic in the Boston, Mass, area.
MAIN OUTCOME MEASURE: We used a combination of single-strand conformation analysis and direct sequencing of samples of peripheral blood leukocyte DNA to search for mutations in exons 1alpha, 1beta, 2, and 3 of CDKN2A and in exon 2 of CDK4.
RESULTS: The mean and median ages at diagnosis in our group were 30 and 32 years, respectively. Among a group of 49 patients, we detected 1 (2%; 95% confidence interval, 0.07%-10.8%) Met 53 Ile CDKN2A mutation, which was found in a patient with a strong family history of melanoma. This alteration has been previously shown to impair p16 function. One patient had an Ala 148 Thr change in CDKN2A, which has also been shown to be a polymorphism. We also detected a sequence polymorphism (in the 3' untranslated region [3'UTR] of CDKN2A) in 27% of our patients. A similar incidence of this 3'UTR polymorphism was observed in a control population. We found no CDK4 mutations.
CONCLUSIONS: Germline CDKN2A and CDK4 mutations are not common in patients who develop melanoma at an early age. This finding contrasts with other cancer-predisposition syndromes, in which there is an increased incidence of germline mutations among young patients. Selection of patients with melanoma for genetic testing based solely on age at onset may not be warranted at the current time.
CHROMOSOMAL ABNORMALITIES Cancer Res 1988;58:2170-2175
Chromosome 9p21
Other candidates include 12q14 and 1p36
Increased risk of pancreatic cancerInterphase Cytogenetic Analysis of 1q 12 Satellite III DNA in Melanocytic Lesions Increased Aneuploidy With Malignant Histology
J. Dennis Lee, M.D.; Elizabeth R. Unger, Ph.D., M.D.; Cynthia Gittenger, B.S.; Daisy R. Lee, M.S.; Reneé Hebert, Ph.D.; John C. Maize, M.D.
Departments of Dermatology (J.D.L., J.C.M.), Pathology and Laboratory Medicine (C.G.), Biometry and Epidemiology (R.H.), Medical University of South Carolina, Charleston, South Carolina; Department of Health and Human Services Centers for Disease Control and Prevention, Atlanta, Georgia (E.R.U., D.R.L.).
Am J Dermatopathol 2001;23:176-180 Abstract quote
To examine the relationship of chromosome 1 copy number to melanocytic tumorigenesis, interphase cytogenetic analysis of 1q12 satellite III DNA was performed on the spectrum of melanocytic lesions comprising Clark's tumor progression model.
Results showed increased copy number in a ``step off'' pattern between melanoma in-situ and the intraepidermal component of invasive melanoma rather than a progression between each lesional group.
These findings support Clark's concept of independent clonal expansion of a cell population giving rise to the vertical growth phase and further demonstrates increased chromosome 1 copy number as a late event in melanoma tumor progression.
CD95 (FAS) Melanoma cell expression of Fas(Apo-1/CD95) ligand: implications for tumor immune escape.
Hahne M, Rimoldi D, Schroter M, Romero P, Schreier M, French LE, Schneider P, Bornand T, Fontana A, Lienard D, Cerottini J, Tschopp J.
Institute of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland.
Science 1996 Nov 22;274(5291):1363-6 Abstract quote Malignant melanoma accounts for most of the increasing mortality from skin cancer. Melanoma cells were found to express Fas (also called Apo-1 or CD95) ligand (FasL). In metastatic lesions, Fas-expressing T cell infiltrates were proximal to FasL+ tumor cells.
In vitro, apoptosis of Fas-sensitive target cells occurred upon incubation with melanoma tumor cells; and in vivo, injection of FasL+ mouse melanoma cells in mice led to rapid tumor formation. In contrast, tumorigenesis was delayed in Fas-deficient lpr mutant mice in which immune effector cells cannot be killed by FasL.
Thus, FasL may contribute to the immune privilege of tumors.
Human melanoma cells do not express Fas (Apo-1/CD95) ligand.Chappell DB, Zaks TZ, Rosenberg SA, Restifo NP.
Howard Hughes Medical Institute-NIH Research Scholars Program, Bethesda, Maryland 20814, USA.
Cancer Res 1999 Jan 1;59(1):59-62 Abstract quote A recent report described the expression of Fas ligand (FasL) by melanoma cells as an important mechanism involved in the immune evasion by tumors [M. Hahne et al., Science (Washington DC), 274: 1363-1366, 1996].
To investigate the expression of FasL by melanomas, we screened a panel of early-passage cell lines by functional assay and reverse transcriptase-PCR. Using conditions designed to replicate those in the original report, we did not find functional FasL on any of the 19 human melanoma lines established at the National Cancer Institute. Furthermore, we additionally evaluated our melanoma lines using reverse transcriptase-PCR and found that 0 of the 26 human melanoma cell lines expressed FasL mRNA. FasL mRNA was abundantly expressed by anti-melanoma T-cell lines after activation.
These data do not support a role for FasL expression in the escape of melanoma cells from immune destruction.
Blockade of the Fas-triggered intracellular signaling pathway in human melanomas is circumvented by cytotoxic lymphocytes.Ferrarini M, Imro MA, Sciorati C, Heltai S, Protti MP, Pellicciari C, Rovere P, Manfredi AA, Rugarli C.
Laboratorio di Immunologia dei Tumori, Divisione di Medicina II, H San Raffaele Scientific Institute, Milan, Italy.
Int J Cancer 1999 May 17;81(4):573-9 Abstract quote Fas and Fas ligand (FasL) have been found both in lymphoid and in non-lymphoid malignancies, and are thought to play a role in the interplay between tumors and the immune system.
Here we investigated Fas/FasL expression, function and intracellular signalling pathways in human melanomas. Of 5 melanoma cell lines, 3 expressed Fas at their surface, and all of them expressed FasL. FasL was functional, since it triggered Fas-induced apoptosis of human T lymphocytes clones. Conversely, cross-linking of Fas molecule with a specific monoclonal antibody failed to induce apoptosis in any of the melanomas tested, or ceramide intracellular accumulation or caspase-3 activation, pointing to an early alteration in the Fas-triggered signaling cascade. All melanomas retained the ability to undergo apoptosis induced by cytotoxic lymphocytes, which was mediated by the granule exocytosis mechanism.
This suggests that melanoma cells evade immune-mediated Fas-triggered apoptosis via a selective blockade of the Fas apoptotic pathway. Cytotoxic lymphocytes, however, may circumvent tumor resistance to Fas-induced death via granzyme-mediated apoptosis, further supporting the development of immunotherapeutic strategies in the treatment of cancer.
Predominant expression of Fas (CD95) ligand in metastatic melanoma revealed by longitudinal analysis.Terheyden P, Siedel C, Merkel A, Kampgen E, Brocker EB, Becker JC.
Department of Dermatology, School of Medicine, Julius-Maximilians University, Wurzburg, Germany.
J Invest Dermatol 1999 Jun;112(6):899-902 Abstract quote The expression of Fas ligand has recently been proposed as a novel tumor escape mechanism for melanoma.
To establish the characteristics of Fas ligand expression during the course of melanoma progression we performed a longitudinal study analyzing primary tumors as well as subsequently evolving metastases. In primary melanoma Fas ligand was expressed in two of 20 lesions; this expression was weak and restricted to few parts of the tumors.
The Fas ligand positive primary melanomas were rather thick, i.e., 8.5 and 3.8 mm, versus a median of 2.4 mm of the remaining tumors. In contrast, for metastatic melanoma Fas ligand expression was present in six of 11 cases investigated. The metastases of primary tumors displaying Fas ligand maintained its expression. As Fas ligand positive melanoma cells are capable of inducing apoptosis in susceptible cells, e.g., Fas positive tumor infiltrating lymphocytes, we tested for the presence of apoptotic cells in situ by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. This analysis revealed that apoptotic cells were present within the Fas ligand positive tumors. The number of apoptotic cells, however, never exceeded 5% of the total cells.
Thus, Fas ligand mediated apoptosis does not seem to be a major immune escape mechanism for melanoma but its expression correlates with the stage of melanoma.
Alterations of Fas (Apo-1/CD95) gene in cutaneous malignant melanoma.
Shin MS, Park WS, Kim SY, Kim HS, Kang SJ, Song KY, Park JY, Dong SM, Pi JH, Oh RR, Lee JY, Yoo NJ, Lee SH.
Departments of Pathology, Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Am J Pathol 1999 Jun;154(6):1785-91 Abstract quote Fas (Apo-1/CD95) is a cell-surface receptor involved in cell death signaling. The key role of the Fas system in negative growth regulation has been studied mostly within the immune system, and somatic mutations of Fas gene in cancer patients have been described solely in lymphoid-lineage malignancies. However, many nonlymphoid tumor cells have been found to be resistant to Fas-mediated apoptosis, which suggests that Fas mutations, one of the possible mechanisms for Fas resistance, may be involved in the pathogenesis of nonlymphoid malignancies as well.
In this study, we have analyzed the entire coding region and all splice sites of the Fas gene for the detection of the gene mutations in 44 human malignant melanomas in skin by polymerase chain reaction, single-strand conformation polymorphism, and DNA sequencing. Overall, 3 tumors (6.8%) were found to have the Fas mutations, which were all missense variants and identified in the cytoplasmic region (death domain) known to be involved in the transduction of an apoptotic signal.
The data presented here suggest that somatic alterations of the Fas gene might lead to the loss of its apoptotic function and contribute to the pathogenesis of some human malignant melanomas.
A comparative study of Fas and Fas-ligand expression during melanoma progression.Soubrane C, Mouawad R, Antoine EC, Verola O, Gil-Delgado M, Khayat D.
Medical Oncology Department, Salpetriere Hospital, 47 boulevard de l'Hopital, 75013 Paris, France.
Br J Dermatol 2000 Aug;143(2):307-12 Abstract quote BACKGROUND: Impaired regulation of apoptosis is known to be associated with the development of various cancers. Fas receptor (APO-1/CD95) binding to its ligand, Fas-ligand (Fas-L), has been shown to trigger apoptosis in various cell types.
OBJECTIVES: In this study, we examined CD95 and Fas-L expression on primary and metastatic melanoma cells from patients to investigate a potential correlation between these measures of apoptosis and different disease stages.
PATIENTS AND METHODS: Primary melanoma cells were obtained after surgical resection from 19 patients and metastatic cells from fine-needle aspiration of lymph nodes or palpable subcutaneous lesions in 25 patients. Normal skin cells were obtained at skin biopsy of 10 healthy donors.
RESULTS: Flow cytometric analysis revealed that CD95 and Fas-L expression was detected in all the kinds of cell studied. In whole cell suspensions, CD95 expression was significantly higher (P < 0.0001) in normal skin cells than in melanoma cells, whatever the stage studied. By contrast, we observed an increase in Fas-L expression in melanoma cells compared with normal ones. Subsequently, using a double staining method, we studied these measures on HMB45+ cells, a specific marker for melanoma cells, and found that CD95 expression was significantly higher (P = 0.0005) in primary than in metastatic cells while Fas-L expression was significantly increased (P = 0. 0004) in metastatic compared with primary cells. Furthermore, a relationship was found between CD95 or Fas-L expression and Breslow thickness; as primary melanoma thickness progressively increased, the percentage of HMB45+ CD95+ cells decreased while that of HMB45+ Fas-L+ cells concurrently increased.
CONCLUSIONS: These results suggest that downregulation of CD95 and upregulation of Fas-L in melanoma might be considered as concomitant with disease progression.
Fas-mediated apoptosis of melanoma cells and infiltrating lymphocytes in human malignant melanomas.Shukuwa T, Katayama I, Koji T.
Department of Dermatology, Nagasaki University School of Medicine, Sakamoto, Japan.
Mod Pathol 2002 Apr;15(4):387-96 Abstract quote In a rodent system, melanoma cells expressing Fas ligand (FasL) could kill Fas-positive lymphocytes, suggesting that FasL expression was an essential factor for melanoma cell survival in vivo. These findings led us to investigate apoptosis, and to histochemically analyze involvement of Fas and FasL in the induction of apoptosis, in human malignant melanoma tissues.
The percentages of terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end-labeling (TUNEL)-positive melanoma cells and of proliferating cell nuclear antigen (PCNA)-positive melanoma cells in melanoma tissues (n = 22) were greater than those in melanocytes in uninvolved skin (n = 6) and nevus cells in nevi tissues (n = 9). The infiltrating lymphocytes around melanomas were also TUNEL positive. Immunohistochemistry revealed expression of Fas and FasL in melanoma cells and lymphocytes, whereas no Fas or FasL expression was detected in normal skin melanocytes and nevus cells. There was significant correlation between Fas-positive indices and TUNEL indices in melanoma tissues. Moreover, TUNEL-, Fas-, and FasL-positive indices of melanoma cells from patients with Stage 3 melanomas were significantly lower than those with Stage 2 melanomas. The PCNA index of Stage 1 melanoma was significantly lower than that of the other stages, although the difference of PCNA index was insignificant among Stages 2 to 4. Among Stages 1 to 4, there was no difference in the PCNA, TUNEL-, and Fas-positive indices of lymphocytes, although the FasL-positive index of lymphocytes from Stage 3 melanomas was significantly lower than in that from Stage 2.
These data reveal that melanoma cells and infiltrating lymphocytes have the potential to induce their own apoptosis regulated by Fas and FasL in an autocrine and/or paracrine fashion and that the decline of Fas-mediated apoptosis of melanoma cells, rather than the apoptosis of infiltrating lymphocytes, may affect the prognosis of melanoma patients, possibly through the accumulation of more aberrant cells acquiring metastatic activity.
CLAUDIN-1
J Cutan Pathol. 2005 Sep;32(8):533-6. Abstract quote
Claudins are a family of transmembrane proteins involved in cell-to-cell adhesion and are believed to be the main component of tight junctions. Recent studies have suggested that some metastatic solid tumors lack claudin expression. It is unknown whether claudins play a role in cutaneous melanoma.
Immunohistochemical studies were performed on tissue microarrays containing 19 benign melanocytic nevi (BN), 21 dysplastic nevi (DN), 23 primary malignant melanomas (MMs), and 31 metastatic melanomas (MMMs) using a polyclonal anti-claudin-1 antibody. Immunoreactivity in tumor cells and associated vessels was graded by intensity and by percentage of reactive cells. Normal epidermis served as internal control (3+ labeling). Cases with at least 2+ labeling in more than 25% of the cells were considered positive. Claudin-1 expression was present in 37% of BN, 24% of DN, 26% of MM, and 3.2% of MMM. Tumor-associated vessels showed the following results: 11 of 19 (58%) in BN, 14 of 21 (67%) in DN, 17 of 23 (74%) in MM, and 6 of 31 (19%) in MMM. A significant loss of expression was noted between MMM and all other lesions in tumor cells and associated vessels. There was no significant difference between BN, DN, and MM.
Within primary melanomas, there was a significant correlation between expression of claudin in tumor cells and Clark level/Breslow thickness. Also significant was a decreased expression of claudin in tumor vessels of lesions with higher Breslow thickness or Clark level. These data suggest that loss of claudin-1 may play a significant role in the acquisition of metastatic phenotype in cutaneous melanoma.CYCLIN D1
- Cyclin D1 expression in melanocytic lesions of the skin.
Ramirez JA, Guitart J, Rao MS, Diaz LK.
Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Ann Diagn Pathol. 2005 Aug;9(4):185-8. Abstract quote
BACKGROUND: Progression through the cell cycle is controlled by cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitory proteins. The role of cyclin D1 in the development and progression of melanomas is controversial. The goal of this study is to evaluate the role of cyclin D1 in benign and malignant melanocytic lesions of the skin.
METHODS: A total of 126 pigmented lesions of the skin including compound nevi (21), intradermal nevi (18), melanoma in situ (28), primary invasive melanomas (30), and metastatic melanoma (29) were evaluated for cyclin D1 expression. The following tiered system was used for scoring: 0% nuclear staining (score 0), 1% to 19% nuclear staining (score 1), 20% to 49% nuclear staining (score 2), and 50% or greater nuclear staining (score 3).
RESULTS: Average scores were significantly higher for primary melanomas compared with nevi and for in situ melanomas compared with primary invasive melanomas. The average score for metastatic melanomas was not significantly different compared with primary invasive melanomas. Scores for primary invasive melanomas did not correlate with depth of invasion or presence of metastases. Compound nevi exhibited a slightly higher level of cyclin D1 expression compared with intradermal nevi.
CONCLUSION: Although primary melanomas show a higher level of cyclin D1 expression compared with nevi, cyclin D1 appears to have little role in development of a metastatic phenotype. It is not clear why lesions localized near the dermal-epidermal junction express higher levels of cyclin D1. Further studies are indicated to ascertain the biologic role and practical utility of cyclin D1 in melanocytic lesions of the skin.EPIDERMAL GROWTH FACTOR
Association between functional polymorphism in EGF gene and malignant melanoma.Shahbazi M, Pravica V, Nasreen N, Fakhoury H, Fryer AA, Strange RC, Hutchinson PE, Osborne JE, Lear JT, Smith AG, Hutchinson IV.
Immunology Research Group, School of Biological Sciences, Stopford Building, University of Manchester, Manchester M13 9PT, UK.
Lancet 2002 Feb 2;359(9304):397-401 Abstract quote BACKGROUND: Malignant melanoma, the most serious cutaneous malignancy, has attracted substantial attention because of its rapidly increasing incidence and the poor prognosis of some tumours. Little is known of the genetic factors that mediate susceptibility to, and outcome of, sporadic malignant melanoma. Because of its role in mitogenesis, which is especially relevant to wound healing, tumorigenesis, and proliferation of epidermal tissues, epidermal growth factor (EGF) is an attractive candidate in which to look for genetic polymorphisms.
METHODS: We enrolled 135 white European patients with malignant melanoma and 99 healthy white European controls, and screened a selection of DNA samples for polymorphisms in the promoter and 5' untranslated region of the EGF gene by analysis. We then screened DNA samples from all participants for the identified polymorphism by restriction-fragment-length polymorphism (RFLP) analysis. In-vitro EGF production was measured in peripheral-blood mononuclear cells from 34 controls, and the results were compared with the individuals' EGF genotypes.
FINDINGS: We identified a single nucleotide substitution (G to A) at position 61 of the EGF gene. Allele frequencies in the controls were 56% EGF 61*A and 44% EGF 61*G. Cells from individuals homozygous for the 61*A allele produced significantly less EGF than cells from 61*G homozygotes (p=0.0004) or heterozygous A/G individuals (p=0.001). Compared with the A/A genotype, G/G was significantly associated with Breslow thickness (p=0.045) and with risk of malignant melanoma (odds ratio 4.9 [95% CI 2.3-10.2], p<0.0001).
INTERPRETATION: This study suggests that high EGF production might be important in the development of malignant melanoma.
ERZIN
- Ezrin in primary cutaneous melanoma.
Ilmonen S, Vaheri A, Asko-Seljavaara S, Carpen O.
1Department of Plastic Surgery, Helsinki University Hospital, Helsinki, Finland.
Mod Pathol. 2005 Apr;18(4):503-10. Abstract quote
Ezrin is a member of the ezrin-radixin-moesin family of proteins that link the actin-containing cytoskeleton to the plasma membrane. Ezrin is also connected to signaling molecules involved in the regulation of cell survival, proliferation and migration.
Here, we examined the expression of ezrin in 95 primary cutaneous melanomas and correlated ezrin expression with conventional prognostic factors and biomarkers. From 12 patients metastatic tissue samples were also examined. In addition to ezrin staining, Mib-1 proliferation antigen, p53 and Bcl-2 were evaluated. Ezrin immunoreactivity was seen in most tumors; only 19 (20%) melanomas were negative. A total of 48 (51%) tumors had weak immunoreactivity and 28 (29%) strong immunoreactivity. The intensity of ezrin immunoreactivity was associated with tumor thickness (Breslow, P=0.0008) and with tumor invasion level (Clark, P=0.004), thicker tumors having stronger immunoreactivity. Also, there was a correlation between higher Mib-1 index in tumors and strong ezrin expression. All metastatic samples (n=12) showed positive ezrin immunoreactivity. In univariate analysis of survival, patients (n=76) with positive ezrin immunoreactivity had worse clinical disease behavior than those (n=19) without ezrin immunoreactivity, but the difference was not significant (P=0.19). In multivariate analysis of survival, the ezrin immunoreactivity was not a significant marker.
The results indicate that ezrin is expressed in most primary melanomas of the skin and in all metastatic tumors. Ezrin expression correlates with tumor thickness and level of invasion suggesting an association between ezrin expression and tumor progression.Ets-1 PROTO-ONCOGENE
Expression of the ets-1 proto-oncogene in melanocytic lesions.Keehn CA, Smoller BR, Morgan MB.
Department of Pathology, University of South Florida College of Medicine, USA.
Mod Pathol. 2003 Aug;16(8):772-7. Abstract quote Ets-1 oncoprotein is a transcription factor known to regulate the expression of numerous genes important in extracellular matrix remodeling and angiogenesis. Up-regulation of Ets-1 has been shown to be important in a variety of human malignancies and to correlate with prognosis.
To our knowledge, this oncoprotein has not been examined in melanocytic lesions. A series of 10 cutaneous melanomas and 24 benign melanocytic lesions with patient records were independently examined for diagnosis confirmation and immunohistochemical expression by two dermatopathologists.
The immunohistochemical expression for Ets-1 (Novocastra, Newcastle upon Tyne, UK) was scored by an average of the mean labeling intensity; no nuclear staining = 0, weak nuclear staining = 1, moderate = 2, and intense = 3. Ets-1 expression was statistically assessed by the one-way analysis of variance (ANOVA) comparing the mean labeling intensity of melanoma to benign melanocytic nevi. All of the benign melanocytic lesions exhibited negative to weak nuclear staining, with an average mean labeling intensity of 0.4. Melanoma in situ exhibited moderate nuclear staining, for a mean labeling intensity of 2.0, whereas all conventional invasive melanomas exhibited moderate to strong nuclear staining, with a mean labeling intensity of 2.7. Metastatic melanoma exhibited very strong nuclear staining, with a mean labeling intensity of 3.0. Invasive desmoplastic