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This rare group of carcinomas are derived from the eccrine sweat glands of the skin. In general, most have a poor prognosis. The pathologist must exclude a cutaneous metastasis from a visceral malignancy before making an unequivocal diagnosis of an eccrine carcinoma. Many of these tumors may resemble primary carcinomas from the lung, salivary glands, and breast.


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Genetic changes in sweat gland carcinomas

MinoruTakata, KenHashimoto, PariusMehregan, Min W.Lee, AkifumiYamamoto, ShinobuMohri, KuniakiOhara and KazuhikoTakehara

J Cutan Pathol 2000;27 (1), 30-35 Abstract quote

The molecular pathogenesis of malignant appendageal tumors is poorly understood.

Immunohistochemical staining, polymerase chain reaction (PCR)-based loss of heterozygosity (LOH) and sequencing analyses were performed in a mixed group of 21 sweat gland carcinomas.

LOH was mostly confined to the chromosome arm 17p. None of the remaining 17 tumors showed LOH at any loci. Nuclear accumulation of p53 protein was observed in 3 tumors, all of which also showed LOH of 17p. One eccrine gland adenocarcinoma showed allelic loss of 17p and a Cys 176 Arg mutation in the p53 gene. The other three tumors that showed LOH of 17p, however, had wild-type p53 genes. A clear transition from benign eccrine poroma to porocarcinoma that was associated with p53 protein stabilization and allelic loss was observed in one tumor. One eccrine porocarcinoma/undifferentiated adnexal carcinoma showed prominent microsatellite instability, probably reflecting an underlying defect in DNA mismatch repair. Overexpression of erbB-2 was observed in three tumors.

The low frequencies of LOH and p53 alterations in sweat gland carcinomas contrasted with the multiple genetic defects normally observed in cutaneous squamous cell carcinomas, and may be partly explained by the relative protection of cutaneous appendages from ultraviolet light and other environmental mutagens.


Primary sweat gland carcinosarcoma of the scrotal skin.

Lin TP, Pan CC, Huang WJ, Murphy GF.

Division of Urology, Department of Surgery, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan, ROC.

J Cutan Pathol. 2004 Nov;31(10):678-82. Abstract quote  

Background: Carcinosarcoma is a biphasic tumor composed of malignant epithelial and mesenchymal elements. Although the tumors have been reported in different locations, they rarely occur in the skin and have not been reported in the skin of external genitalia.

Case report: We present such a case in a 71-year-old Taiwanese man. He had had a long-term indolent nodule on scrotal skin, but it enlarged rapidly in 2 weeks. Wide excision of the tumor was performed.

Results and Discussion: The pathologic examination revealed a sweat gland carcinosarcoma consisting of admixed mucin-producing adenocarcinoma and solid spindle cell sarcoma. The two components exhibited contrasting immunohistochemical profiles with the epithelial component diffusely positive for epithelial markers and S-100 protein, while the sarcomatous component positive for vimentin and smooth muscle actin but negative for epithelial markers and S-100 protein. The immunoreactivity for S-100 protein in the epithelial component supports sweat gland origin. The tumor behaved aggressively. Local recurrence and distant metastases to lungs and brain occurred 6 months and 18 months later. The patient died of the disease 20 months after the initial diagnosis.

Mucinous adenocarcinoma of ectopic breast tissue of the vulva.

Chung-Park M, Zheng Liu C, Giampoli EJ, Emery JD, Shalodi A.

Department of Pathology and Obstetrics/Gynecology, Case Western Reserve University at MetroHealth Medical Center, Cleveland, Ohio.

Arch Pathol Lab Med 2002 Oct;126(10):1216-8 Abstract quote

Ectopic breast tissue has been described rarely in the vulva and is known to develop a variety of pathologic changes. Our review of the literature found a total of 11 reported cases of primary infiltrating ductal adenocarcinoma arising in ectopic breast tissue of the vulva.

We report what we believe is the first case of primary mucinous adenocarcinoma arising in ectopic breast tissue of the vulva diagnosed by characteristic histopathologic features and immunohistochemical stain results.

We discuss the criteria used in diagnosis of primary breast carcinoma of the vulva and review previously reported cases.



Carcinomas of Sweat Glands Report of 60 Cases

Carmelo Urso, etal.

Arch Pathol Lab Med 2001;125:498–505. Abstract quote

Context.—Several aspects of sweat gland carcinomas (incidence, classification, diagnosis, and behavior) have not been definitively clarified and need to be studied further.

Objective.—The clinicopathologic findings of a large series of sweat gland carcinomas, collected during a period of 15 years, are presented. Methods.—Sixty sweat gland carcinomas (41 porocarcinomas, 3 syringomatous carcinomas, 8 ductal carcinomas, 5 adenoid cystic carcinomas, and 3 mucinous carcinomas) were analyzed histologically and immunohistochemically.

Results.—Porocarcinomas were composed of eosinophilic and clear atypical cells arranged in solid-cystic lobular masses. These tumors were divided into 2 subgroups: horizontal porocarcinomas, showing a prominent intraepidermal component, and nodular porocarcinomas, which demonstrated predominant nodular growth. Syringomatous carcinomas presented keratinizing and nonkeratinizing cysts, dilated tubules (sometimes with a “tadpole” appearance), small neoplastic ducts, solid islands, and cellular cords. Ductal carcinomas were characterized by a prominent formation of tubules, solid islands, and cellular cords. Adenoid cystic carcinomas presented a characteristic pattern, showing basaloid monomorphous cells with moderately atypical nuclei, arranged in cribriform or solid islands and in tubular structures. Mucinous carcinomas were composed of moderately atypical cells with eosinophilic vacuolated cytoplasm, forming solid and cystic islands floating in large mucin pools. Immunohistochemically, cytokeratin was found in neoplastic cells in all cases, carcinoembryonic antigen was detected in 73% of cases, and actin-positive (myoepithelial) cells were not found.

Conclusions.—Although numerous studies have been published in recent years, the histologic features, histogenesis, and classification of sweat gland carcinomas still remain controversial and need to be clarified by further studies.


Semin Diagn Pathol 1987;4:38–74.

Tubules, sometimes dilated or small with small lumina, variously mixed with solid islands, nests, and cords of neoplastic cells

Cells showed mild to marked nuclear atypia and a variable number of mitoses Lumina contained PAS-positive, diastase-resistant, CEA-positive material

Degree of differentiation based upon the presence of tubules and cytologic pleomorphism

Ductal carcinomas have to be distinguished from cutaneous metastases, especially from the breast


Am J Dermatopathol 1999;21:400
J Am Acad Dermatol 1999;40:640–642.
Arch Dermatol 1978;114:421–424.
Arch Dermatol 1984;120:774–777.

Very rare

May resemble adenoid basal cell carcinoma, but shows no epidermal contact or peripheral palisading in neoplastic islands

True neoplastic lumina containing PAS-positive material and common involvement of perineural spaces

Atypical and malignant hidradenomas: a histological and immunohistochemical study.

Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.


Mod Pathol. 2009 Apr;22(4):600-10 Abstract quote

The histological features of atypical hidradenoma are worrisome for increased risk of recurrence and possible malignant potential; however, earlier studies with immunohistochemistry or patient follow-up have not been reported. In addition, immunohistochemical analysis of hidradenocarcinoma exists in the literature mainly as case reports and as a single series of six cases.

We compare the histological features and Ki-67, phosphorylated histone H3, epidermal growth factor receptor, and Her2/neu expression profiles of 15 atypical and 15 malignant hidradenomas with those of benign hidradenoma and metastasizing adnexal carcinomas. Infiltrative growth pattern, deep extension, necrosis, nuclear pleomorphism, and > or =4 mitoses per 10 high-power fields are specific features of hidradenocarcinomas. Significant difference in mean Ki-67% was observed between benign and malignant hidradenomas (P<0.001), benign and metastasizing adnexal carcinomas (0.002), atypical and malignant hidradenomas (P<0.001), and between atypical hidradenomas and metastasizing adnexal carcinomas (0.002). Significant difference in mean phosphorylated histone H3% was observed between benign and malignant hidradenomas (P<0.001), benign and metastasizing adnexal carcinomas (0.003), atypical and malignant hidradenomas (P<0.001), and between atypical hidradenomas and metastasizing adnexal carcinomas (P<0.001). Mean epidermal growth factor receptor total score was significantly different in benign and atypical hidradenoma when compared with that in metastasizing adnexal carcinoma (P=0.014 and 0.019, respectively). Equivocal or 2+ Her2/neu positivity was observed in one hidradenocarcinoma and in two metastasizing adnexal carcinomas. Receiver operating characteristic curve analysis for Ki-67 and phosphorylated histone H3% positivity reveals statistically significant criterion values of >11.425 and >0.7, respectively, for distinguishing malignant hidradenomas from atypical hidradenomas. Despite the presence of some worrisome histological features, the significantly different immunoprofile from the malignant counterpart suggests that atypical hidradenomas are likely to recur but are unlikely to metastasize.

A tumor with Ki-67>11% and/or phosphorylated histone H3>0.7% would likely be a malignant rather than an atypical hidradenoma. The infrequent Her2/neu overexpression in hidradenocarcinoma suggests its limited therapeutic role.
Metastatic hidradenocarcinoma with demonstration of Her-2/neu gene amplification by fluorescence in situ hybridization: potential treatment implications.

Departments of Pathology and Dermatology, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.


J Cutan Pathol. 2007 Jan;34(1):49-54. Abstract quote

A 44-year-old man was referred for a right chest nodule of 3 months duration. A 'benign' nodule had been excised from this location 8 years prior. On examination, palpable nodes were noted in the right axilla. Radiographic studies were significant only for right axillary lymphadenopathy. Histologically, a nodular dermal proliferation composed of poorly differentiated epithelioid cells in nests and focally forming ducts with pseudopapillary architecture comprised the primary tumor. Features of a clear cell hidradenoma were noted focally.

Immunohistochemical (IHC) analysis revealed reactivity for HMW cytokeratins, CK5 and CK7, p53, p63, CEA (focal), androgen receptor, EGFR, estrogen receptor (ER), MUC5AC, and strong/diffuse membranous staining for Her-2/neu. Negative stains included villin, TTF-1, CDX2, S-100 protein, vimentin, gross cystic disease fluid protein 15 (GCDFP-15), mammoglobulin, and MUC2. A wide local excision and axillary node dissection was performed. Metastatic tumor involved nine of 28 nodes.

Interphase fluorescence in situ hybridization (FISH) demonstrated chromosomal amplification of the Her-2/neu locus within the tumor and a nodal metastasis. The patient has completed adjuvant and radiotherapy, including trastuzumab, and is asymptomatic.

We believe this to be the first demonstration of Her-2/neu amplification in a malignant skin adnexal tumor. In analogy to breast carcinoma, these findings suggest the applicability of trastuzumab for patients with metastatic adnexal carcinomas demonstrating Her-2/neu amplification.
Hidradenocarcinoma: a histological and immunohistochemical study*.

Department of Dermatology, Drexel University College of Medicine, Philadelphia, PA, USA.


J Cutan Pathol. 2006 Nov;33(11):726-30 Abstract quote

The diagnosis of hidradenocarcinoma is difficult due to a combination of factors including inconsistent nomenclature/ classification, rarity of the neoplasm, and variable morphology of cells composing the neoplasm. Immunohistochemistry has not been previously performed on a series of hidradenocarcinomas.

We evaluated six cases of hidradenocarcinoma histologically and immunohistochemically using antibodies to gross cystic disease fluid protein-15 (GCDFP-15), carcino-embryonic antigen (CEA), epithelial membrane antigen (EMA), S-100 protein, keratin AE1/3, cytokeratin 5/6, p53, bcl-1, bcl-2, and Ki67. Histology suggested concurrent eccrine and apocrine differentiation of the cases. Ki67 and p53 staining was strongly positive in five of six tumors. The neoplasms stained with antibodies to CEA, S-100 protein, GCDFP-15, EMA, bcl-1, and bcl-2 in no consistent pattern.

All tumors studied stained positively for keratin AE1/3 and cytokeratin 5/6. In making the diagnosis of hidradenocarcinoma, it may be unnecessary to separate hidradenocarcinoma into eccrine and apocrine categories, and although Ki67 and p53 may be helpful, histological parameters remain paramount.

Low-grade malignant eccrine spiradenoma with systemic metastases.

Leonard N, Smith D, McNamara P.

Am J Dermatopathol. 2003 Jun;25(3):253-5. Abstract quote

Malignant eccrine spiradenoma (MES) is a very rare tumor. Tumors can be low grade or high grade.

There are nine cases in the literature with systemic metastases. Of these, only one was low grade; the others had obvious features of high-grade malignancy such as pleomorphism, increased mitoses, and abnormal mitoses. Low grade MESs are more difficult to diagnose and are said to have a better prognosis.

We report an additional case of low-grade MES with systemic metastases. It had a monotonous appearance with few mitotic figures and minimal pleomorphism. Vascular invasion was seen in both cases of low-grade MES and may be an important prognostic feature.

Spiradeno-cylindrocarcinoma: a malignant hybrid tumor.

Carlsten JR, Lewis MD, Saddler K, Reilly P, Pan T, Gnepp DR, Robinson-Bostom L.

Department of Pathology, Rhode Island Hospital, Brown Medical School, Providence, RI, USA.
J Cutan Pathol. 2005 Feb;32(2):166-71. Abstract quote  

Background: Eccrine spiradenomas and cylindromas are benign, slowly growing, cutaneous adnexal neoplasms, recently hypothesized to arise from a common pluripotential cell; malignant variants are rare. We found 48 cases of malignant spiradenomas and 33 cases of malignant cylindromas reported in the English literature. Benign tumors demonstrating both spiradenomatous and cylindromatous features have been infrequently reported. Recent immunohistochemical studies of these two tumors have provided compelling evidence that these two tumors may merely represent a single tumor type with a spectrum of histological features.

Case report: We describe two cases of a malignant variant of this rare hybrid tumor occurring in a 62-year-old male and a 72-year-old female.

Conclusion: We propose the term 'spiradenocylindrocarcinoma' to describe malignant tumors with features of both a spiradenoma and a cylindroma. In conjunction with histological features of malignancy, p53 and Ki-67 immunohistochemical staining may provide helpful clues in determining the malignant potential of this tumor. Further studies are needed to clarify the biologic behavior of such lesions.

Carcinoma and eccrine syringofibroadenoma: a report of five cases.

Bjarke T, Ternesten-Bratel A, Hedblad M, Rausing A.

Hallbecksgatan 3, Helsingborg, Department of Pathology, Sahlgrenska university hospital, Goteborg, Department of Dermatology, Karolinska hospital, Stockholm, and Medilab AB, Malmo, Sweden.


J Cutan Pathol. 2003 Jul;30(6):382-92 Abstract quote

BACKGROUND: In the literature, there are some reports of cases interpreted as carcinomatous transformation in eccrine syringofibroadenoma (ESFA).

RESULTS: We have studied five cases with a histological mixture of ESFA and carcinoma. The carcinoma had a partial squamous cell cytology in all cases. In two of them, there was partial poroma and porocarcinoma picture. However, the squamous cell parts had some features of porocarcinoma such as retiform configuration and funnel-like cavities with luminal carcinoembryonic antigen (CEA) positivity. Also, there was strong epithelial membrane antigen (EMA) positivity. Therefore, we interpret the cases as porocarcinomas with extensive squamous metaplasia. One case had a life-long precursor lesion with a histologic picture interpreted as ESFA, with progressing cytologic atypia. Another case had ectodermal dysplasia, a condition known to predispose to ESFA and a precursor lesion of long-standing, probably benign ESFA. In these two cases, we interpret the carcinoma as a secondary development in a benign ESFA. Three cases were otherwise healthy people with precursor lesions of 10-, 5-, and 2-year duration. We do not know for certain if the ESFA preceded the carcinoma in these cases but we think that it probably did.

CONCLUSIONS: We recommend that diagnosed ESFA shall be completely excised or followed, in view of the risk of developing carcinoma.

Carcinomatous transformation
of eccrine syringofibroadenoma.

Katane M, Akiyama M,
Ohnishi T, Watanabe S,
Matsuo I.

Department of Dermatology, Teikyo University School of Medicine, Ichihara Hospital, Ichihara; Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo; and Department of Dermatology, Teikyo University School of Medicine, Tokyo, Japan.


J Cutan Pathol 2003 Mar;30(3):211-214 Abstract quote

BACKGROUND: While squamous cell carcinoma and pseudocarcinomatous hyperplasia have been documented as pre-existing lesions in cases of reactive eccrine syringofibroadenoma (ESFA), to the best of our knowledge carcinoma occurring in a solitary ESFA has not yet been reported. We present one such case in a 91-year-old female who had a dome-shaped, reddish tumor on the extensor side of the left forearm.

METHODS: We review the histopathological, immunophenotypical and ultrastructural findings of this tumor, including the keratin expression profile.

RESULTS: Histopathologically, long, branching, anastomosing, thin and thick strands of small cuboidal epithelial cells were extending from the surface epidermis into the dermis. In the center of the tumor, there were irregular-shaped nests of atypical tumor cells invading downward into the dermis. Ultrastructurally, duct-like lumina lined with cuboidal tumor cells were present in the epithelial cords. From these findings, the present case was diagnosed as solitary eccrine syringofibroadenocarcinoma (ESFAC). Keratin expression studies revealed that cells of the thick strands, except for the luminal and basal cells, were positive for differentiation-specific keratins, keratins 1 and 10, and that cells of the thin strands were positive for keratins 5 and 14.

CONCLUSIONS: Histopathological, immunophenotypical and ultrastructural evidence, as well as the pattern of keratin expression, suggest differentiation of the present malignant tumor towards the eccrine dermal duct. This case is the first reported case of ESFAC as far as we know.


Am J Dermatopathol 2000;22:166–170.

Groups or sheets, solid or cystic, of neoplastic cells floating in large pools of mucins

Investigation excluding a metastasis from a visceral cancer is necessary

Mucinous Carcinoma
of the Skin, Primary,
and Secondary: A Clinicopathologic Study
of 63 Cases With
Emphasis on the Morphologic
Spectrum of Primary Cutaneous Forms: Homologies With
Mucinous Lesions
in the Breast.

Kazakov DV, Suster S,
Leboit PE, Calonje E,
Bisceglia M, Kutzner H,
Rutten A,
Mentzel T, Schaller J,
Zelger B, Baltaci M, Leivo I, Rose C, Fukunaga M,
Simpson RH,
Yang Y, Carlson JA,
Cavazza A, Hes O,
Mukensnabl P, Vanecek T, Fidalgo A, Pizinger K,
Michal M.

From *Sikl's Department of Pathology, Charles University, Medical Faculty Hospital, Pilsen, Czech Republic; daggerDepartment of Pathology, Ohio State University Medical Center, Columbus, OH; double daggerDermatopathology Section, University of California, San Francisco, CA; section signDepartment of Dermatopathology, St. John's Institute of Dermatology, St. Thomas's Hospital, London, UK; parallelDepartment of Pathology, IRCCS-Ospedale
"Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; paragraph sign
Dermatohistopathologische Gemeinschaftspraxis, Friedrichshafen, Germany;
#Unit of Dermatopathology, Department of Dermatology, St. Barbara Hospital, Duisburg, Germany; **Clinical Department of Dermatology and Venereology, Medical University Innsbruck, Innsbruck, Austria; daggerdaggerDepartment of Pathology, Haartman Institute, University of Helsinki, Finland; double daggerdouble daggerDepartment of Dermatology, University of Lubeck, Lubeck, Germany; section sign section signDepartment of Pathology, Jikei 3rd Hospital, Tokyo, Japan; parallel parallelDepartment of Histopathology, Royal Devon and Exeter Hospital, Exeter, UK; paragraph sign paragraph signDepartment of Pathology, Health Science Center, Peking University, Beijing, China; ##Division of Dermatopathology, Albany Medical College, Albany, NY; ***Department of Pathology, Arcispedale "S. Maria Nuova," Reggio Emilia, Italy; daggerdaggerdagger
Department of Dermatology, Hospital do Desterro, Lisbon, Portugal; and double daggerdouble daggerdouble daggerDepartment of Dermatology, Charles University, Medical Faculty Hospital, Pilsen, Czech Republic.
Am J Surg Pathol. 2005 Jun;29(6):764-782. Abstract quote  

We present the largest series of mucinous carcinoma involving the skin, describing the histopathologic, immunohistochemical, electron microscopic, and cytogenetic findings. Our aim was fully to characterize the clinicopathologic spectrum and compare it with that seen in the breast. In addition, we wished to reevaluate the differential diagnostic criteria for distinguishing primary mucinous carcinomas from histologically similar neoplasms involving the skin secondarily, and study some aspects of their pathogenesis.

We demonstrate that primary cutaneous mucinous carcinomas span a morphologic spectrum compatible to their mammary counterparts. Both pure and mixed types can be delineated morphologically, and some lesions have mucocele-like configurations. Most lesions seem to originate from in situ lesions that may represent, using mammary pathology terminology, ductal hyperplasia, atypical ductal hyperplasia, or ductal carcinoma in situ or a combination of the three. Inverse cell polarity appears to facilitate the progression of the changes similar to lesions in the breast.

The presence of an in situ component defines the neoplasm as primary cutaneous, but its absence does not exclude the diagnosis; although for such neoplasms, full clinical assessment is essential.

Mammary mucinous carcinoma involving the skin: all patients presented with lesions on chest wall, breast, axilla, and these locations can serve as clue to the breast origin. Microscopically, cutaneous lesions were of both pure and mixed type, and this correlated with the primary in the breast.

Dirty necrosis was a constant histologic finding in intestine mucinous carcinomas involving the skin, and this feature may serve as a clue to an intestinal origin.
A rare case of fatal primary cutaneous mucinous carcinoma of the scalp with multiple in-transit and pulmonary metastases.

Jih MH, Friedman PM, Kimyai-Asadi A, Goldberg LH.

DermSurgery Associates, Houston, Texas 77030, USA.
J Am Acad Dermatol. 2005 May;52(5 Suppl 1):S76-80. Abstract quote  

BACKGROUND: Primary cutaneous mucinous carcinoma is a rare neoplasm derived from the sweat glands. It is usually located in the head and neck region, with the eyelids being the most common site of presentation. Recurrence following primary excision is common but metastasis is rare.

CASE REPORT: We report a patient presenting with rapidly progressive cutaneous mucinous carcinoma on the right parietal scalp. Systemic work-up failed to reveal an occult primary source. The tumor was treated with Mohs micrographic surgery with clear margins. However, within two months, the patient developed new lesions on the scalp both adjacent to and separate from the original previously excised area, as well as metastasis to the right parotid gland. The patient received adjuvant radiation therapy both to the scalp lesions and to the parotid gland with apparent control of locoregional disease. However, two weeks after completing radiation therapy, the patient was found to have developed pulmonary metastases and died soon thereafter.

CONCLUSION: Primary mucinous carcinoma arising in the skin is rare and usually follows an indolent course. We report the rare occurrence of a mucinous carcinoma of the scalp that developed multiple cutaneous tumors caused by in-transit metastases, as well as parotid gland metastases and eventual fatal pulmonary metastases.
Primary cutaneous mucinous carcinoma: presence of myoepithelial cells as a clue to the cutaneous origin.

Qureshi HS, Salama ME, Chitale D, Bansal I, Ma CK, Raju U, Ormsby A, Lee MW.
Am J Dermatopathol. 2004 Oct;26(5):353-8. Abstract quote  

BACKGROUND:: Primary cutaneous mucinous carcinoma (PCMC) is a rare malignancy with probable apocrine differentiation. It is important to differentiate it from metastatic mucinous carcinoma (MMC), especially from the breast. The histologic and immunohistochemical features overlap between PCMC and breast mucinous carcinomas. In this study, we introduce the presence of myoepithelial component in PCMC as a new morphologic parameter to distinguish it from MMC from either breast or sites elsewhere in the body.

MATERIALS AND METHODS:: We studied 7 cases of PCMC. The possible in situ component in the tumor was assessed by the presence of a peripheral myoepithelial cell layer. Myoepithelial cell differentiation was confirmed with immunohistochemical stains for p63, CK 5/6, calponin, smooth muscle actin (SMA), HHF-35, and CD10. Estrogen and progesterone receptor (ER/PR), gross cystic disease fluid protein (GCDFP 15), CK7, CK20, and S-100 immunostains were also performed.

RESULTS:: Histologically, multiple small monomorphic epithelial islands floating in multilocular pools of mucin characterized the tumor. Focally, epithelial islands were bordered by dermal connective tissue at the periphery of mucin pools. Secretory snouts were apparent in all cases providing evidence for apocrine differentiation. In 5 of the 7 cases, an in situ component was identified as epithelial islands being bounded by a myoepithelial layer, which was highlighted by p63, CK 5/6, calponin, SMA, and HHF-35. ER/PR and CK7 were positive in all the cases. GCDFP-15 and CD10 were focally positive in the tumor cells and myoepithelial cells, respectively. All 7 cases were negative for S-100 and CK 20.

CONCLUSION:: We conclude that an in situ component is frequently present in PCMC (5/7) and may help in distinguishing this entity from MMC, especially of breast origin. Furthermore, it may provide insight into the pathogenetic mechanism of mucinous carcinoma evolving from in situ carcinoma with luminal mucinous distention to cellular tumor with a little surrounding mucin.

Mucinous carcinoma of the skin with apocrine-type differentiation: immunohistochemical studies.

Wako M, Nishimaki K, Kawamura N, Harima N, Kubota T, Yoneda K, Manabe M, Ansai S.

Am J Dermatopathol 2003 Feb;25(1):66-70 Abstract quote

We investigated the pathway of differentiation in a case of mucinous carcinoma of the skin (MCS) arising on the right temple of a 70-year-old man.

Histopathologic findings of the tumor showed evidence of apocrine-type differentiation such as distinctive decapitation secretion. Additionally, by employing a panel of antibodies, the immunohistochemical staining pattern of tumor cells was shown to be compatible with that of apocrine glands.

Although the differentiation of this neoplasm remains controversial, the findings in our case suggest apocrine differentiation.

Endocrine mucin-producing sweat gland carcinoma: report of a case and review of the literature.

Department of Tissue Pathology, Westmead Hospital, The University of Sydney, Westmead, New South Wales, Australia

J Cutan Pathol. 2006 Dec;33(12):812-6. Abstract quote

Mucinous carcinoma of skin (MCS) is an uncommon adnexal tumor of disputed differentiation. In 1995, Rahilly et al. reported a case of MCS with neuroendocrine differentiation (E-MCS).(1)

Since that report, seven additional cases have been published.

Here, we report on a case of E-MCS and discuss the differential diagnoses.
Sarcomatoid eccrine porocarcinoma: report of two cases and a review of the literature.

St John's Institute of Dermatology, St Thomas' Hospital, London, UK.


J Cutan Pathol. 2007 Jan;34(1):55-60. Abstract quote

Eccrine porocarcinoma is an uncommon sweat gland malignancy. To the best of our knowledge, there has been no report in the English literature of porocarcinoma with predominantly undifferentiated sarcomatous change.

We present two cases of sarcomatoid eccrine porocarcinoma associated with a benign poroma. Case 1 pertained to an 82-year-old woman with an ulcerated chest wall tumor, and Case 2 was that of a 74-year-old woman who presented with an ulcerated plaque in the lower leg. Case 1 showed an unusual pseudo-angiosarcomatous morphology with spindle cells dissecting through collagen bundles and forming vascular like channels. Case 2 revealed high-grade malignant spindle cells with focal evidence of ductal differentiation. In both the cases, benign poromatous elements were histologically evident. Immunohistochemistry performed showed pancytokeratin positivity in spindle cells of both lesions. Epithelial membrane antigen and carcino-embryonic antigen positivity in the malignant ductal elements and focal smooth muscle actin staining of the spindle cells were demonstrated in Case 2. A brief review of relevant literature is presented.
Porocarcinoma Arising in Pigmented Hidroacanthoma Simplex.

Ueo T, Kashima K, Daa T, Kondoh Y, Yanagi T, Yokoyama S.

From the *Department of Pathology, Faculty of Medicine, Oita University Oita, Japan; and daggerTakada Medical Center, Oita, Japan.

Am J Dermatopathol. 2005 Dec;27(6):500-503. Abstract quote  

Hidroacanthoma simplex (HAS) is a rare benign tumor that is also known as intraepidermal poroma. While there have been a few reports of HAS with malignant transformation (porocarcinoma), we report an unusual case of porocarcinoma, arising in a pigmented HAS, the latter also showing secondary amyloid deposits.

An 80-year-old Japanese man presented with a cutaneous tumor on his left buttock, which had first been noticed in his childhood. The tumor consisted of flat pigmented plaque and a depigmented papule with erosion.

Histologic analysis revealed many pigmented and well-defined nests within the epidermis of the flat pigmented portion. The nests were composed of cuboidal to oval and occasionally elongated, bland, basaloid cells with numerous melanin granules. In addition, there were infrequently ductal structures and small clusters of sebocytes, and abundant amyloid deposits in the upper dermis. These findings were consistent with pigmented HAS with amyloid deposition. In the depigmented portion, markedly atypical cells with occasional ductal structures and intracytoplasmic lumina extended throughout the entire thickness of the epidermis, with minimal invasion of the dermis.

We considered this portion of the tumor to be a porocarcinoma. Since the two portions of the tumor were continuous, we made a final diagnosis of porocarcinoma arising in pre-existing pigmented HAS with amyloid deposition.

Semin Diagn Pathol 1987;4:38–74.

Elderly adults 50–80 years of age

Suggestion of a male bias in the literature while other studies find slight bias toward women

Site of predilection does not correlate with these areas of highest concentration of eccrine glands, unlike benign poromas

Preference for the trunk or head and neck and lower extremity

Vary greatly in size from <1 cm to 10 cm

Horizontal porocarcinomas showed a prominent intraepidermal component, extending horizontally, intraepidermal component involved at least 3 rete ridges adjacent to the dermal component

Nodular porocarcinomas presented as nodular dermal neoplasms, extending mainly in a vertical sense, when the intraepidermal component was absent or involved fewer than 3 adjacent rete

Eccrine Porocarcinoma (Malignant Eccrine Poroma) A Clinicopathologic Study of 69 Cases

A. Robson, etal.

Am J Surg Pathol 2001;25:710-720 Abstract quote

The clinicopathologic characteristics of 69 cases of eccrine porocarcinoma (EP) have been studied. Seven cases of purely in situ disease are included. Forty patients were female, 29 male with ages ranging from 29 to 91 years (mean 73 years). The lower extremity represented the single most common site (44%). Other common sites were the trunk (15 cases, 24%) and head (11 cases, 18%).

The histologic diagnosis of EP was predicated on the basis of an irregular tumor at least partly formed of characteristic poromatous basaloid epithelial cells displaying ductal differentiation, and significant cytologic atypia. Forty-seven tumors (68%) contained mature well-formed eccrine ducts having an eosinophilic luminal cuticle, with the remaining tumors containing small ill-formed ducts and/or intracytoplasmic lumina. All ducts were discernible via light microscopy and in 49 cases were highlighted with DPAS stain and/or CEA/EMA immunocytochemistry. A variant with a broad pushing tumor margin and marked nuclear pleomorphism showed some resemblance to proliferative bowenoid dysplasia. In 11 cases (18%) the tumors appeared to arise in continuity with a benign preexistent poroma. A variety of histologic patterns were displayed including clear, squamous, and spindle cell differentiation, mucus cell metaplasia, and colonization by melanocytes. Lymphovascular invasion was present in 9 cases (15%). Three cases showed pagetoid extension of malignant cells (epidermotropism) and appeared to be multifocal.

Follow-up was available in 54 patients (78%) with 9 (17%) experiencing local recurrence, 10 developing lymph node metastases (19%), and 6 (11%) experiencing distant metastases or death.

Mitoses, the presence of lymphovascular invasion, and tumor depth >7 mm were associated with a poorer prognosis. Dividing tumors into those with a ``pushing'' or ``infiltrating'' advancing margin was also predictive of outcome with the latter having an increased risk of local recurrence. This report, the largest series of EP to date, suggests that the incidence of aggressive behavior is less than popularly believed. Furthermore, EP can display a wide variety of histologic patterns that may lead to diagnostic error in the unwary. The large number of cases in this series enables a reliable evaluation of prognostic parameters. A more aggressive clinical course may be indicated by more than 14 mitoses per high power field (hazard ratio [HR] for death 17.0, 95% confidence interval [CI] 2.71–107), lymphovascular invasion by tumor (HR 4.41, CI 1.13–17.2), and depth >7 mm (HR 5.49, CI 1.0–30.3).

Thus, mitoses, lymphovascular invasion, and tumor depth should be evaluated in these tumors. We also suggest that tumors presenting an ``infiltrative'' advancing margin are particularly prone to local recurrence and require wide excision with close attention to the surgical margins by the reporting pathologist.

Aberrant expression of p16 and RB protein in eccrine porocarcinoma.

Gu LH, Ichiki Y, Kitajima Y.

Department of Dermatology, Gifu University School of Medicine, Gifu, Japan.

J Cutan Pathol 2002 Sep;29(8):473-9 Abstract quote

BACKGROUND: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland and very little is known about its etiology and molecular basis.

METHODS: To investigate the expression of p16 and retinoblastoma (RB) protein and their relationship, an immunohistochemical method was performed on nine eccrine porocarcinomas and five eccrine poromas. Furthermore, one case of eccrine porocarcinoma was analyzed for p16 gene mutation.

RESULTS: A striking inverse correlation between p16 and RB expression was noted in all of the eccrine porocarcinomas and poromas. Strong immunoreactivity for p16 protein was observed in both nuclei and cytoplasm of the tumor cells in eight out of nine cases of eccrine porocarcinomas, while RB expression was negative in these cases. Conversely, one case of eccrine porocarcinoma did not show immunoreactivity for p16 protein, whereas RB protein was positive in the scattered nuclei. On the other hand, immunostaining of p16 was negative in all cases of five poromas, whereas RB-positive nuclei were sparse. No p16 gene mutation was detected in the investigated eccrine porocarcinoma case.

CONCLUSIONS: These results indicate that detectable p16 protein and loss of RB protein are common occurrences in eccrine porocarcinoma lesions. Moreover, overexpression of p16 protein may be an additional, simple and useful diagnostic marker for eccrine porocarcinoma on routine laboratory screening.


Polymorphous sweat gland carcinoma.

Suster S, Wong TY.

Arkadi M. Rywlin Department of Pathology, MOunt Sinai Medical Center, Miami Bech, FL 33140.

Histopathology 1994 Jul;25(1):31-9 Abstract quote

We describe nine cases of a distinctive cutaneous neoplasm showing features of eccrine adnexal differentiation that were characterized by their variegated histological appearance and low-grade malignant behaviour.

The term polymorphous sweat gland carcinoma is proposed to designate these lesions. The tumours presented as large, long-standing, slow growing, dermal nodules showing a marked predilection for the extremities. Six patients were women. The patients were aged 42-70 years (mean, 59.8 years). Histologically, the lesions were characterized by a highly cellular proliferation displaying a variety of growth patterns, including solid, trabecular, tubular, pseudopapillary and cylindromatous, with prominent stromal changes including haemorrhage, hyalinization and cystic change, and displaying moderate cytological atypia and mitoses. Focal areas showing features associated with eccrine differentiation (i.e. tubular structures, small glandular lumina) could be identified in all cases.

Clinical follow-up in six cases showed that two of the lesions recurred locally over a period of 3-6 years, and one tumour metastasized to regional lymph nodes 3 years after excision. Polymorphous sweat gland carcinoma should be considered in the differential diagnosis of neoplastic epithelial dermal proliferations; complete but conservative surgical excision appears to be the treatment of choice for these lesions.

Recurrent polymorphous sweat gland carcinoma of the skin.

Ronnen M, Ben-Dor D, Huszar M.

Departments of Dermatology and Pathology, Barzilai Medical Center, Ashkelon, and the Kaplan Medical Center, Rehovot, Israel.

J Am Acad Dermatol 2002 Jun;46(6):914-6 Abstract quote

Polymorphous sweat gland carcinoma is an unusual, recently described variant of low-grade malignant adnexal neoplasm of the skin characterized by a prolonged clinical course and predilection for the extremities.

We describe a case of recurrent polymorphous sweat gland carcinoma in a 56-year-old man who presented with multiple large skin nodules distributed along the flexor surface of his left arm. The lesions were treated by surgical excision; multiple local recurrences, as well as the development of new lesions, were observed over a period of 5 years. No distant metastases have been observed so far. The clinical differential diagnosis and management of these unusual lesions are discussed.


Clear-cell porocarcinoma in situ: a cytologic variant of porocarcinoma in situ.

Rutten A, Requena L, Requena C.

Laboratory of Dermatohistopathology, Friedrichshafen, Germany (A.R.); and Department of Dermatology, Fundacion Jimenez Diaz, Universidad Autonoma, Madrid, Spain(L.R., C.R.).

Am J Dermatopathol 2002 Feb;24(1):67-71 Abstract quote

Poromas are benign neoplasms composed of poroid and cuticular cells. Four histopathologic variants of poromas are accepted, according to the architectural features of the neoplasm: hidroacanthoma simplex or intraepidermal poroma; eccrine poroma, which is a poroma connected to the epidermis that extends to superficial dermis; dermal duct tumor, which develops when the neoplasm is composed of small, solid aggregations of poroid and cuticular cells confined to the dermis with little or no connection with the epidermis; and poroid hidradenoma, which is a solid-cystic, dermal poroma. The malignant counterpart of hidroacanthoma simplex is named malignant hidroacanthoma simplex or porocarcinoma in situ.

This report describes an example of clear-cell malignant hidroacanthoma simplex, a cytologic variant of porocarcinoma in situ, which, to our knowledge, has not been previously reported. In contrast with other clear-cell neoplasms, a relation with diabetes mellitus could not be clearly established in this case.

SIGNET RING CARCINOMA Some studies suggest that this is an tumor derived from apocrine glands

Cutaneous Signet Ring Cell Carcinoma A Report of a Case and Review of the Literature

Carmen González-Lois, M.D. ; José Luis Rodríguez-Peralto, M.D.; Rosario Serrano-Pardo, M.D.; Miguel Angel Martínez-González, M.D.; Fernando López-Ríos, M.D.

Department of Pathology, University Hospital ``12 de Octubre,'' Madrid, Spain.

Am J Dermatopathol 2001;23:325-328 Abstract quote

Primary cutaneous signet-ring cell carcinoma (CSRCC) is a very unusual but distinctive clinicopathologic entity. It is defined as a diffuse malignant epithelial neoplasia localized in dermis and subcutis without epidermal involvement, showing variable amounts of signet ring cells, without evidence of a visceral adenocarcinoma.

We report a case of CSRCC in a 70-year-old man along with its histologic and ultrastructural characteristics, and review of previous cases.

We describe their main diagnostic features and discuss its wide differential diagnosis.

Primary Signet Ring Cell Carcinoma of the Eyelid: Report of a Case Demonstrating Further Analogy to Lobular Carcinoma of the Breast With a Literature Review

Desiree J. Langel, MD; R. Patrick Yeatts, MD; Wain L. White, MD

Departments of Pathology and Dermatology (D.J.L,W.L.W); Department of Ophthalmology (R.P.Y.), Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA and Greensboro Pathology Associates (W.L.W.), Greensboro, NC, U.S.A.

Am J Dermatopathol 2001;23:444-449 Abstract quote

Primary signet ring cell carcinoma of the eyelid is a rare neoplasm with less than ten cases described.

This report details another case, which shows further parallels to lobular carcinoma of the breast, and reviews the literature on this subject. A 73-year-old white female presented with diffuse induration of her left eyelids. Histopathology revealed a delicate infiltrate of epithelial cells scattered throughout the lid stroma in a non-destructive pattern. The cells were relatively monomorphous and showed only mild atypia and rare mitotic figures. Many had slightly granular amphophilic cytoplasms, others showed distinct signet ring cell morphology, and all were strongly positive for epithelial mucin.

Immunomicroscopy showed strong reactivity for estrogen receptor (ER), progesterone receptor (PR) and gross cystic disease fluid protein-15 (GCDFP-15), and was negative for Her-2/neu (erb-2) and cytokeratin 20. An extensive workup for other primary sites was negative. Orbital exenteration showed extensive involvement of both lids and soft tissue, including diffuse muscle and lacrimal gland infiltration. In the breast, signet ring cell carcinoma is considered a variant of lobular carcinoma. The delicate infiltrating pattern in our case and the ER+, PR+, GCDFP-15+, Her-2/neu-phenotype further strengthen this analogy.

Together, these data also support apocrine differentiation of primary eyelid signet ring cell carcinoma.


Clear cell syringoid carcinoma: an ultrastructural and immunohistochemical study.

Ramos D, Monteagudo C, Carda C, Montesinos E, Ferrer J, Peydro-Olaya A.

Department of Pathology, Hospital Clinico Universitario, University of Valencia, Spain

Am J Dermatopathol 2000 Feb;22(1):60-4 Abstract quote

Syringoid carcinoma (syringoid "eccrine" carcinoma or eccrine epithelioma) is a rare cutaneous tumor with some controversy regarding its correct definition. It may also be difficult to differentiate from its benign counterpart (syringoma), other adnexal carcinomas, and cutaneous metastasis from adenocarcinomas.

We present a case of a syringoid carcinoma of the clear cell variant complemented with an immunohistochemical and ultrastructural study, the latter revealing cytoplasmic accumulation of glycogen and presence of intercellular and intracellular lumina in clear tumor cells, as well as diverse hallmarks of malignancy (i.e., perineural invasion, tumor necrosis, and deep invasion). Clear tumor cells showed cytoplasmic and membranous immunoreactivity to epithelial membrane antigen, carcinoembryonic antigen, keratins, and S-100.

Our ultrastructural and immunohistochemical results support the ductal differentiation of the glycogen-filled clear cell tumor population

Syringoid eccrine carcinoma: report of a case with immunohistochemical analysis of cytokeratin expression.

Ohnishi T, Kaneko S, Egi M, Takizawa H, Watanabe S.

Am J Dermatopathol 2002 Oct;24(5):409-13 Abstract quote

Syringoid eccrine carcinoma is an extremely rare cutaneous malignant tumor, thought to be derived from eccrine sweat apparatus.

We report a case of syringoid eccrine carcinoma occurring on the scalp of a 66-year-old woman and analyzed its cytokeratin expression immunohistochemically to clarify its histogenesis. The tumor consisted mainly of numerous small cords and nests extending from the reticular dermis to the subcutaneous tissue, which formed luminal or tubular structures mimicking the nests of syringoma. Immunohistochemical analysis revealed that most tumor cells expressed simple epithelial cytokeratins (CKs 7, 8, 18, 19) suggesting their sweat secretory differentiation, and that a small number of tumor cells showed an expression of stratified epithelial cytokeratins (CKs 5, 14) suggesting their ductal differentiation.

We believe that the syringoid eccrine carcinoma of our case may differentiate mainly toward the sweat secretory cells rather than toward the dermal ductal cells.


Special stains  

Positive for cytokeratin

ICEA-positive material was found in neoplastic lumina and/or in tumor cells in majority of cases

Cytokeratin 5/6 immunostaining in cutaneous adnexal neoplasms and metastatic adenocarcinoma.

Plumb SJ, Argenyi ZB, Stone MS, De Young BR.

Departments of Pathology and Dermatology, University of Washington, Seattle, Washington, USA.

Am J Dermatopathol. 2004 Dec;26(6):447-51. Abstract quote

The differentiation of primary cutaneous adnexal neoplasms (CANs) from dermal-based metastatic lesions can be difficult. Cytokeratin 5/6 (CK 5/6) has a relatively limited expression profile, being relatively specific for mesothelium and other "pavement" type epithelium such as squamous epithelium. To date, the degree and distribution of CK 5/6 expression in cutaneous neoplasms has not been extensively studied.

We speculate that since most of CANs arise from similar epithelium, they should express CK 5/6 and, therefore, CK 5/6 could potentially be helpful in distinguishing these lesions from most of metastatic neoplasms, which usually do not express this marker. Formalin-fixed, paraffin-embedded tissue sections from 228 previously classified CANs and 27 metastatic adenocarcinomas (17 breast, 4 colon, 2 prostate, 2 ovary, 1 lung, and 1 esophagus) were immunostained with anti-CK 5/6. Anti-CK 5/6 labeled 2 of 2 proliferating trichilemmal tumors, 6 of 6 poromas, 4 of 5 hydrocystomas, 10 of 10 cylindromas, 10 of 10 eccrine acrospiromas, 8 of 10 pilomatricoma, 10 of 10 nevus sebaceus, 9 of 9 desmoplastic trichoepitheliomas, 7 of 7 nevus sebaceus with basal cell carcinomas, 10 of 10 pilar cysts, 14 of 14 trichilemmomas, 10 of 10 syringomas, 6 of 7 chondroid syringomas, 10 of 10 hidradenoma papilliferum, 9 of 9 sebaceus adenomas, 3 of 3 microcystic adnexal carcinomas, 10 of 10 eccrine spiradenomas, 4 of 4 syringocystadenoma papilliferum, 3 of 5 ocular sebaceous carcinomas, 28 of 28 basal cell carcinomas, 16 of 16 trichoepitheliomas, and 33 of 33 trichoepitheliomas with basal cell features. By contrast, 9 of 27 metastatic adenocarcinomas stained positively, although only two of these stained strongly. Cumulatively, CK 5/6 was expressed by most (97%) of CANs, while only 33% of metastatic adenocarcinomas showed positive expression.

The sensitivity of this marker in the malignant lesions (other than basal cell carcinoma) is 78%, while the specificity is 67%. If all lesions are considered, the sensitivity increases to 97%. Therefore, CK 5/6 may prove to be a useful adjunct marker in distinguishing CANs from metastatic lesions.

Her-2 expression in cutaneous eccrine and apocrine neoplasms.

Hiatt KM, Pillow JL, Smoller BR.

1Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Mod Pathol. 2004 Jan;17(1):28-32. Abstract quote  

Cutaneous eccrine and apocrine glands have many histologic and immunologic similarities to ducts and acini of the breast.

Thus, differentiating a primary cutaneous process from a metastatic breast carcinoma can be nearly impossible. In all, 10-34% of breast carcinomas overexpress HER-2 protein, a membrane-associated protein that functions in cell differentiation, adhesion and motility.

As expression of this gene in cutaneous neoplasms has not been well characterized, we sought to determine HER-2 expression in a sample of benign and malignant cutaneous eccrine and apocrine neoplasms and to determine if there is value in using this protein expression in differentiating primary cutaneous from metastatic breast lesions. Totally, 85 primary cutaneous neoplasms and 11 cutaneous metastases from HER-2-positive breast carcinomas were retrieved from archived material at our institute.

All cases were evaluated for HER-2 protein expression using the Dako Hercept Test kit. Membranous HER-2 staining was noted in three of the 85 cutaneous adnexal neoplasms: one hidrocystoma and two nodular hidradenomas. Seven of the 11 cutaneous metastases from HER-2-positive breast carcinomas maintained moderate-to-strong HER-2 expression.

In conclusion, while 10-34% of breast carcinomas overexpress the HER-2 protein, only 3.5% of cutaneous apocrine and eccrine neoplasms in this study stained with the HER-2 antibody. These HER-2-positive cutaneous neoplasms typically do not pose a diagnostic dilemma in the setting of differentiation from breast metastasis. Additionally, although histologically these breast and cutaneous lesions may have morphologic similarities, the relative lack of HER-2 overexpression suggests that they are different nosologically. Finally, this study suggests that HER-2 protein expression can be a useful tool in differentiating a primary cutaneous appendageal neoplasm from HER-2 expressing metastatic breast carcinoma.

Immunohistochemical analysis of cytokeratin and human milk fat globulin expression in mucinous carcinoma ofthe skin

Takamitsu Ohnishi, Hajime Takizawa and Shinichi Watanabe

J Cutan Pathol 2002;29:38 Abstract quote

Background: Mucinous carcinoma of the skin (MCS) is a rare epithelial tumor which arises primarily in the skin. Metastatic MC from extracutaneous sites, especially breast or colon, mimics MCS and cannot be differentiated from MCS by routine histology alone.

Methods: Nine cases of MCS were analyzed immunohistochemically using monoclonal antibodies against cytokeratins (CKs) and human milk fat globulin 1 (HMFG) in order to clarify their nature and compare the immunophenotypes with those of other MCs studied in the literature.

Results: Expression of simple epithelial CKs in most of the tumor cells of all cases studied and co-expression of simple and stratified epithelial CKs in some tumor cells of two cases were recognized. CK 20 expression could not detected in any tumor cells. Focal HMFG expression in the luminal or outer surface of the nests was observed in three cases.

Conclusion: From CKs expression, MCS was speculated to differentiated mainly toward the secretory cells of the sweat glands, and some tumor cells toward the transient portion between the dermal duct and the secretory portion. Focal HMFG expression suggested either a consequence of malignant transformation or apocrine differentiation. No expression of CK 20 in MCS suggests that we may exclude the diagnosis of metastatic colorectal MC which expressed CK 20.


P53 Protein Expression in Eccrine Poroma and Porocarcinoma

Taner Akalin, M.D.; Sait en, M.D.; Ayla Yücetürk, M.D.; Gülen Kandilolu, M.D.

Ege University School of Medicine, Department of Pathology, Bornova, Ízmir, Turkey.

Am J Dermatopathol 2001;23:402-406 Abstract quote

The role of p53 mutation has been shown in different human malignancies, including various skin cancers.

In this study, we examined p53 protein expression in 25 eccrine poromas and 11 porocarcinomas by immunohistochemistry. P53 expression was observed in 88% (22 of 25) of eccrine poromas and 73% (8 of 11) of porocarcinomas. In eccrine poromas, percentage of cells reactive for p53 was less than 5% (low expresser) in 6 cases, 5 to 50% (moderate expresser) in 14 and greater than 50% (high expresser) in 2 cases. In terms of intensity, 13 cases showed weak staining, 8 moderate, and 1 case showed strong reactivity. On the other hand, 2 cases of porocarcinoma were low expresser, 2 were moderate and 4 were high expresser. All of the high expressers had also strong staining.

This study has demonstrated that eccrine poromas showed significant p53 expression as much as porocarcinomas and, therefore, p53 positivity cannot be accepted as a valuable parameter for malignancy. P53 gene may involve in the carcinogenetic pathway of porocarcinoma but it is likely that other oncogenes may also have a role.


Eccrine Syringofibroadenoma of Clear Cell Variant: An Immunohistochemical Study.

Hu S, Bakshandeh H, Kerdel FA, Rongioletti F, Romanelli P.

From the *Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida; daggerCedars Medical Center, Miami, Florida; and double daggerDepartment of Dermatology, University of Genoa, Italy.
Am J Dermatopathol. 2005 Jun;27(3):228-231. Abstract quote  

Eccrine syringofibroadenoma is a rare eccrine tumor first described by Mascaro in 1963. The clear cell variant was reported by Fretzin in 1995.

We describe a hemorrhagic papule on the knee of a 64-year-old woman. Microscopic examination revealed epidermal-based anastomosing thin epithelial cords with ductal structures surrounded by a fibrovascular stroma. Multiple nests of glycogen-containing clear cells were also present. The tumor cells forming the epithelial cords expressed keratin. The eccrine ductal structures and clear cells additionally expressed gross cystic disease fluid protein-15 (GCDFP-15). Reactivity with antibodies against estrogen receptor or progesterone receptor was negative.

These results favor the dual differentiation of the clear cell variant of eccrine syringofibroadenoma toward ductal and secretory portions of the eccrine sweat gland.

Expression of p63 in primary cutaneous adnexal neoplasms and adenocarcinoma metastatic to the skin.

Ivan D, Hafeez Diwan A, Prieto VG.

1Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Mod Pathol. 2005 Jan;18(1):137-42 Abstract quote.

p63, a recently identified homologue of the p53 gene, has been reported to be essential in the development of epithelia and is mainly expressed by basal and myoepithelial cells. The purpose of this study was to investigate the pattern of p63 expression in cutaneous adnexal neoplasms and to assess its possible value in the differential diagnosis of primary cutaneous neoplasms vs adenocarcinomas metastatic to the skin.

Immunohistochemical analysis for p63 was performed on formalin-fixed, paraffin-embedded archival tissue from 20 benign adnexal tumors, 10 malignant adnexal tumors and 14 adenocarcinomas metastatic to the skin. The expression of p63 was evaluated in epidermal cells, skin appendages and metastatic tumor cells. p63 was consistently expressed in the basal and suprabasal cells of epidermis and cutaneous appendages, including the basal/myoepithelial cells of sweat glands. Out of 20 benign adnexal tumors, 13 (65%) showed strong (score 3) p63 expression; the remaining seven (35%) cases had score 2.

All primary cutaneous carcinomas, including adenocarcinomas, expressed p63. In contrast, none of the metastatic adenocarcinomas to the skin was positive for p63 (P<0.001).

Based on our findings, analysis of p63 expression may help in the differential diagnosis of primary vs metastatic cutaneous adenocarcinomas.

Estrogen and progesterone receptors and anti-gross cystic disease fluid protein 15 (BRST-2) fail to distinguish metastatic breast carcinoma from eccrine neoplasms.

Wallace ML, Longacre TA, Smoller BR.

Department of Pathology, Stanford University Medical Center, Stanford, CA, USA.

Mod Pathol 1995 Dec;8(9):897-901 Abstract quote

Cutaneous metastases of breast carcinoma can be histologically similar to primary skin tumors with eccrine differentiation.

We compared the immunohistochemical staining characteristics of 15 metastatic breast carcinoma skin lesions in 12 patients to those of a series of primary eccrine tumors using estrogen receptor, progesterone receptor, and anti-gross cystic disease fluid protein-15 markers.

Anti-gross cystic disease fluid protein-15 positivity was noted in 7 of 15 breast carcinoma skin metastases, 0 of 5 benign eccrine tumors, 1 of 6 microcystic adnexal carcinomas, and 1 of 1 metastatic sweat gland adenocarcinoma. Estrogen receptor positivity was found in 1 of 15 metastatic breast carcinoma skin lesions, 0 of 5 benign eccrine tumors, 2 of 8 microcystic adnexal carcinomas, and 1 of 1 metastatic sweat gland adenocarcinoma. Progesterone receptor positivity was identified in 15 of 15 metastatic breast carcinoma skin lesions, 2 of 5 benign eccrine tumors, 5 of 8 microcystic adnexal carcinomas, and 1 of 1 metastatic sweat gland adenocarcinomas.

These results indicate that standard immunohistochemical staining for estrogen receptors, progesterone receptors, and gross cystic fluid protein-15 markers will not reliably distinguish primary (or metastatic) eccrine tumors from cutaneous metastases of breast carcinoma.

Reactive syringofibroadenomatous hyperplasia in peristomal skin with formation of hybrid epidermal-colonic mucosa glandular structures, intraepidermal areas of sebaceous differentiation, induction of hair follicles, and features of human papillomavirus infection: a diagnostic pitfall.

Kazakov DV, Mikyskova I, Mukensnabl P, Brouckova M, Treska V, Hes O, Michal M.

Sikl's Department of Pathology, Charles University, Medical Faculty Hospital, Pilsen, Czech Republic.
Am J Dermatopathol. 2005 Apr;27(2):135-41. Abstract quote  

We report a case of reactive syringofibroadenomatous hyperplasia in peristomal skin. The patient was a 62-year-old woman who had undergone abdominoperineal resection of the rectum for rectal adenocarcinoma with subsequent colostomy 2 years earlier.

Clinically, a nodule and small, whitish, warty lesions developed at the outer margin of the stoma extending onto the adjacent skin. Following a clinical suspicion of adenocarcinoma, recurrent at the colostomy site, a 5 x 4 x 3-cm excision of the peristomal skin and the affected portion of the stoma was performed and submitted for histologic examination. The biopsy revealed a peculiar composite lesion of reactive syringofibroadenomatous hyperplasia and the excised part of the stoma. Several unusual histopathological features were detected in the syringofibroadenomatous part of the lesion such as the formation of plentiful hybrid epidermal-colonic mucosa glandular structures, intraepidermal areas of sebaceous differentiation, koilocytic changes, induction of rudimentary hair follicles, and intradermal mucinous lakes. The cellular composition of the glandular structures was mainly similar to that seen in a normal colonic mucosa epithelium. They also contained occasional Paneth cells. Being located at a distance from the stoma, these accentuated colonic mucosa epithelial glands reaching the epidermis may be a diagnostic pitfall prompting the consideration of adenocarcinoma involving the stoma.

The rudimentary follicles and sebaceous differentiation were probably induced by an altered stroma and/or human papillomavirus (HPV): HPV, type 36 was identified by PCR using consensus primers followed by sequencing of the PCR products.


Eccrine porocarcinoma

Br J Dermatol 1982;107:675–80.

Increased local recurrence and lymph node metastasis

Tumor stage appears to be highly significant in predicting prognosis
Positive regional lymph node involvement mortality is 65%,32 and 28% of patients

Epidermotropism is a poor prognostic factor, it may be impossible to distinguish primary multifocal tumors from epidermotropic metastases in some cases

Of 54 invasive malignancies with follow-up described herein, 9 (17%) locally recurred, 10 (19%) spread to regional lymph nodes, and 6 (11%) metastasized to distant sites and/or caused the death of the patient


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