Orbital Inflammatory Pseudotumor

Background

This is a rare disease characterized by inflammation occurring within the orbit that simulates a neoplasm. Patients commonly present with an abrupt onset of diffuse or compartmentalized orbital pain associated with double vision (diplopia), a restricted range of motion of the eye, and swelling and reddening of the eyelid. Other causes of orbital inflammation must first be excluded before this diagnosis is established.

OUTLINE

Epidemiology

Disease Associations

Pathogenesis

Laboratory/Radiologic/Other Diagnostic Testing

Gross Appearance and Clinical Variants

Histopathological Features and Variants

Differential Diagnosis

Prognosis

Treatment

Commonly Used Terms

Internet Links

EPIDEMIOLOGY CHARACTERIZATION

SYNONYMS Sclerosing orbitis
I diopathic orbital inflammatory syndrome (IOIS)

INCIDENCE/PREVALENCE Rare

AGE Adults

SEX About equal

DISEASE ASSOCIATIONS CHARACTERIZATION

CHURG-STRAUSS SYNDROME

Orbital inflammatory pseudotumor and ischemic vasculitis in Churg-Strauss syndrome: report of two cases and review of the literature.

Takanashi T, Uchida S, Arita M, Okada M, Kashii S.

Department of Ophthalmology, Kurashiki Central Hospital, Kurashiki, Japan.
Ophthalmology 2001 Jun;108(6):1129-33 Abstract quote
OBJECTIVE: To clarify the characteristics of ocular manifestations in Churg-Strauss syndrome (allergic granulomatosis and angiitis).

DESIGN: Two interventional case reports and literature review.

PARTICIPANTS: Two patients with Churg-Strauss syndrome with ocular manifestations are described; 15 previously reported cases and the present 2 cases of Churg-Strauss syndrome with ocular manifestations are reviewed.

INTERVENTION: Ocular manifestations were divided into two groups: orbital inflammatory pseudotumor and ischemic vasculitis.

MAIN OUTCOME MEASURES: The onset, conjunctival involvement, orbital imaging, antineutrophil cytoplasmic antibodies (ANCA), and visual prognosis were evaluated.

RESULTS: The characteristics of the orbital inflammatory pseudotumor type (eight cases) are chronic onset, positive conjunctival involvement, abnormalities in orbital imaging studies, negative ANCA, and good visual prognosis. The ischemic type (nine cases) is characterized by sudden onset, no conjunctival involvement or abnormalities in imaging studies, positive ANCA, and occasional poor visual prognosis.

CONCLUSIONS: Orbital inflammatory pseudotumor and ischemic vasculitis may represent two essential characteristics of Churg-Strauss syndrome, granulomatosis and angiitis, respectively. The clinical features of the two types are so distinct that differentiation may be meaningful for diagnosis and treatment of Churg-Strauss syndrome with ocular manifestations.

PATHOGENESIS CHARACTERIZATION

GENERAL

Idiopathic orbital inflammation: ocular mechanisms and clinicopathology.

Yuen SJ, Rubin PA.

Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA.
Ophthalmol Clin North Am 2002 Mar;15(1):121-6 Abstract quote
Pathogenesis of idiopathic orbital inflammation remains elusive but several lines of evidence point to immune-mediated processes as the likely underlying ocular mechanism. The exact nature of the immunological process and possible role of infection need to be elucidated in greater depth. There is an obvious need for a more satisfactory animal model for orbital pseudotumor.

Given the prevalence of recurrent and persistent orbital inflammation, therapeutic alternatives to corticosteroids need to be further explored and systematically investigated.

LABORATORY/RADIOLOGIC/
OTHER TESTS
CHARACTERIZATION

RADIOLOGIC

Pseudotumor of the orbit. Clinical, pathologic, and radiologic evaluation.

Weber AL, Romo LV, Sabates NR.

Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA.

Radiol Clin North Am 1999 Jan;37(1):151-68 Abstract quote
Pseudotumor, Graves' disease, and lymphoproliferative disease are the most common ophthalmologic disease entities requiring evaluation by CT and MR imaging. A history of acute onset, pain, swelling, proptosis, and response to steroids are the classical findings.

The radiologic findings are categorized according to location into dacryoadenitis, myositis, and sclerouveitis, with and without associated infiltrations. The inflammatory infiltrate, which is composed of polymorphic leukocytes, lymphocytes, and plasma cells interspersed with a variable amount of fibrovascular tissue, may be diffuse or localized.

The preferred radiologic method used for assessment of pseudotumor is CT. MR imaging, however, is indicated for evaluation of the Tolosa-Hunt syndrome, which is characterized by an inflammatory infiltrate in the orbital apex and cavernous sinus leading to cranial nerve involvement with ophthalmoplegia.

The clinical and radiologic constellation of findings allows a definitive diagnosis in most cases.

LABORATORY MARKERS

GENERAL Increased SED rate
Positive ANA
Pleocytosis of CS

GROSS APPEARANCE/
CLINICAL VARIANTS CHARACTERIZATION

GENERAL

A clinical analysis of idiopathic orbital inflammatory pseudotumor.

Yan J, Wu Z, Li Y.

Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China.
Yan Ke Xue Bao 2000 Sep;16(3):208-13 Abstract quote
PURPOSE: To observe the clinical findings and response to treatment in patients with a diagnosis of idiopathic orbital inflammatory pseudotumor.

METHODS: 209 idiopathic orbital inflammatory pseudotumor cases seen between Jan 1, 1978 and Dec 31, 1999 in our hospital were evaluated retrospectively.

RESULTS: Of the 209 cases, 118 were male and 91 were female; there were 90 in the right eye, 81 left eye and 38 both eyes. Patients age ranged from 4 to 80 years (mean 44.4). Proptosis (66%), palpable mass (65%), swollen eyelid (55%), increased orbital pressure (55%) and motility restriction (48%) were the five most common presenting signs. According to radiologic and surgical findings, focal mass within orbit was the most frequent subtype (43%), followed by lacrimal inflammatory pseudotumor (32%), diffuse orbital inflammation (10%), myositis (8%). Perineuritis (2%), periscleritis (2%), acute inflammation (2%) and eyelid pseudotumor (1%) were rare clinical findings. The response to treatment (with a mean follow-up of 1.5 years) showed that the cure rate was 40% and the effective rate 97% after combined management of surgical resection, systemic steroid and local low dose radiotherapy.

CONCLUSIONS: Although recurrence of IOIP is common, the success rate of treatment for this group of patients is high.

Diagnosis and management of orbital pseudotumor.

Jacobs D, Galetta S.

Curr Opin Ophthalmol 2002 Dec;13(6):347-51 Abstract quote
Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS), may have protean clinical manifestations. Some presentations of IOIS may mimic common conditions such as orbital cellulitis and optic neuritis.

IOIS should be considered a diagnosis of exclusion, with evaluation directed toward eliminating other causes of orbital disease. Orbital magnetic resonance imaging is the single most important diagnostic test, but serologic studies are necessary to exclude a systemic cause. Biopsy is usually not performed at presentation, as the risk of producing damage to vital structures within the orbit outweighs the benefits. Patients with multiple recurrences, or those unresponsive to therapy, should have biopsy samples taken.

Corticosteroids are the mainstay of therapy and are administered for several months to ensure remission. Radiotherapy may be used in patients who fail to respond to steroids or who have a rapidly progressive course. For those patients who are refractory to both corticosteroids and radiotherapy, anecdotal reports have suggested the use of chemotherapeutic agents such as cyclophosphamide, methotrexate, and cyclosporine.

Sclerosing orbital pseudotumor: a unique clinicopathologic entity.

Weissler MC, Miller E, Fortune MA.

Division of Otolaryngology/Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill.

Ann Otol Rhinol Laryngol 1989 Jul;98(7 Pt 1):496-501 Abstract quote
A case of orbital pseudotumor is presented that histologically showed dense fibrosis invading bone and adjacent sinuses, and failed to respond to either steroids or radiation therapy.

"Orbital pseudotumor" remains a sobriquet for a variety of clinical and histopathologic entities including a monomorphous lymphocytic benign or malignant neoplasm; a polymorphous reactive inflammatory lesion; and a densely fibrosing sclerotic variant that appears to behave more aggressively, often locally invades adjacent structures, and may be related to a multifocal fibrosclerosis that also includes retroperitoneal fibrosis, Riedel's sclerosing thyroiditis, mediastinal fibrosis, and sclerosing cholangitis.

This "sclerosing orbital pseudotumor" is felt to represent a unique clinicopathologic entity, and an approach to its treatment is described.

VARIANTS

INTRACRANIAL EXTENSION

Idiopathic orbital inflammation with intracranial extension. Case report.

de Jesus O, Inserni JA, Gonzalez A, Colon LE.

Section of Neurosurgery, University of Puerto Rico, San Juan, U.S.A.
J Neurosurg 1996 Sep;85(3):510-3 Abstract quote
Idiopathic orbital inflammation or orbital pseudotumor with intracranial extension is a rare condition. It consists of a nonspecific infiltrate of the fatty tissue of the orbit that extends through one or more foramina into the adjacent intracranial tissue. The lesion mimics an infectious or neoplastic lesion.

The authors present a case involving the youngest patient yet reported with the broadest intracranial extension. Only 17 previous cases have been reported. The principal symptoms include decreased visual acuity and proptosis. Extension commonly develops through the superior orbital fissure into the middle cranial fossa and the cavernous sinus.

The initial treatment is a regimen of high-dose steroids, with radiotherapy given in unresponsive cases.

PEDIATRIC

Pseudotumor of the orbit in early childhood.

Stevens JL, Rychwalski PJ, Baker RS, Kielar RS.

Department of Ophthalmology, University of Kentucky, Lexington 40536-0284, USA.
J AAPOS 1998 Apr;2(2):120-3 Abstract quote
Orbital pseudotumor, also known as idiopathic orbital inflammation, is defined as a nonspecific, nonneoplastic inflammatory process of the orbit without identifiable local or systemic causes.

The disorder, first described by Birch-Hirschfield in 1905, is more prevalent in the adult population than in the pediatric population. In our study we discuss two cases of pseudotumor of the orbit in children less than 18 months old.

This report will highlight the evaluation and management of pediatric orbital pseudotumor and the importance of its inclusion in the differential diagnosis of orbital disorders in young children.

TOLOSA-HUNT SYNDROME

Idiopathic inflammatory pseudotumor of the orbit and Tolosa-Hunt syndrome--are they the same disease?

Wasmeier C, Pfadenhauer K, Rosler A.

Abteilung fur Neurologie und klinische Neurophysiologie, Zentralklinikum Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
J Neurol 2002 Sep;249(9):1237-41 Abstract quote
Unilateral periorbital pain, cranial nerve palsies and a dramatic response to corticosteroid therapy are the hallmarks of clinical presentation in Tolosa-Hunt-Syndrome (THS) and Idiopathic Pseudotumor of the Orbit (IIPO). Both are unspecific chronic granulomatous diseases of unknown origin, sharing clinical as well as paraclinical characteristics.

We observed two patients suffering from acute granulomatous IIPO, who also fulfilled the criteria of THS. Patient 1 developed leftsided infiltration of the medial ocular muscle with periorbital pain and cranial nerve palsy. After an initial response to corticosteroid therapy, contralateral relapse occurred with a THS-like infiltration of the sinus cavernosus and narrowing of the intracavernous internal carotid artery. Granulomatous infiltration of the right sinus cavernosus with secondary involvement of the ipsilateral nervus opticus and a slight exophthalmos was seen in Case 2. According to the literature, MRI and CT show identical signal intensity with different localisation: IIPO preferentially intra- and THS retroorbital.

Apart from neuroradiological findings, almost similar histopathology and clinical presentation makes it difficult to distinguish between these two syndromes. Similarities between these two syndromes have been discussed for more than 20 years.

Our two cases show their close relationship and we suggest that both diseases belong to the same pathological process.

HISTOLOGICAL TYPES CHARACTERIZATION

GENERAL Nonspecific inflammation with eosinophils and fibrosis of tissue

DIFFERENTIAL DIAGNOSIS KEY DIFFERENTIATING FEATURES

CARCINOMA, METASTATIC

Bilateral orbital metastases from breast carcinoma. A case of false pseudotumor.

Toller KK, Gigantelli JW, Spalding MJ.

Department of Pathology, University of Missouri-Columbia, USA.

Ophthalmology 1998 Oct;105(10):1897-901 Abstract quote.
OBJECTIVE: To inform clinicians of a metastatic orbital neoplasm that frequently masquerades as an orbital inflammatory syndrome and to stimulate thought regarding this neoplasm's fundamental pathobiology specific to its orbital involvement.

DESIGN: Interventional case report and literature review.

PARTICIPANTS: A 47-year-old woman with an acquired, bilateral, diffusely infiltrative orbital process is described.

INTERVENTION: The clinical and radiographic features of the patient's orbital process are reported. The review of two prior fine-needle aspiration biopsy specimens failed to reveal a diagnosis. Histopathologic examination of an open surgical biopsy specimen included standard light microscopy of frozen and formaldehyde-fixed, paraffin-embedded tissue.

RESULTS: Characteristics light microscopy findings suggested the diagnosis of metastatic lobular carcinoma of the breast. The patient refused all therapeutic intervention and died 9 months after orbitotomy.

CONCLUSION: The presentation of breast carcinoma metastatic to the orbit as a bilateral infiltrative process is far more common than appreciated previously. Its rate of bilateral orbital involvement is 20%, whereas this rate for other adult neoplasms is much lower. The authors report an additional case, review the clinical features of previous case reports and series, and discuss aspects of the metastatic process. Breast carcinoma must be included in the differential diagnosis of infiltrative orbital processes encountered in adult female patients. When "orbital pseudotumor" is detected in an adult female patient, a thorough medical history must be obtained and physical examination performed. If a possible primary breast carcinoma is indicated, one must be wary of metastatic disease, and a histologic orbital diagnosis is warranted. The frequency of orbital metastasis and bilateral orbital involvement of this neoplasm reinforces the possibility for organ-specific metastases.

WEGENER'S GRANULOMATOSIS

Elevated anti-neutrophil cytoplasmic antibody titer in a patient with atypical orbital pseudotumor.

Yamashita K, Kobayashi S, Kondo M, Ishikura H, Shibuya Y, Hayasaka S.

Third Department of Internal Medicine, Shimane Medical University, Japan.
Ophthalmologica 1995;209(3):172-5 Abstract quote
We recently examined a patient with ophthalmic manifestations of Wegener's granulomatosis in whom antineutrophil cytoplasmic antibody (cANCA) titers provided helpful diagnostic information. A 40-year-old man who had suffered from bilateral exophthalmos for 9 months was diagnosed initially as having idiopathic inflammatory pseudotumor.

The patient exhibited purulent nasal discharge and microhematuria. A histopathologic study revealed vasculitis. His ANCA titer for cANCA was found to be evaluated, and our patient was subsequently diagnosed as having Wegener's granulomatosis. His ocular symptoms resolved and did not recur after treatment with corticosteroid in combination with cyclophosphamide.

We believe that cANCA levels should be investigated in patients with orbital pseudotumor as a possible sign of Wegener's granulomatosis.

PROGNOSIS CHARACTERIZATION

Orbital pseudotumor. Fine-needle aspiration biopsy and response to therapy.

Char DH, Miller T.

Department of Ophthalmology, University of California, San Francisco 94143.
Ophthalmology 1993 Nov;100(11):1702-10 Abstract quote
PURPOSE: To determine the diagnostic accuracy of fine-needle aspiration biopsy and study the natural history and therapeutic response of a group of patients with orbital pseudotumor.

METHODS: Retrospective review of patients seen by one ocular oncologist for diagnosis and management of presumed orbital pseudotumor.

RESULTS: Thirty-eight patients had fine-needle aspiration biopsy under computed tomographic (CT) guidance. No false-positive results were observed. In 10% of fine-needle aspiration biopsies, negative results were observed. In all patients in this series, lymphomas could be differentiated from pseudotumors. Flow cytometry or Southern blot analysis could be performed on these cytopathologic specimens and was useful in selected cases. Eighty-one patients were followed after various forms of treatment. Essentially complete remissions were observed in 49 of 81 patients. High-dose oral corticosteroids were effective in approximately 31% of patients. A poor steroid response was observed in patients with mass lesions and those with fibrotic disease. Surgical resection was effective in 76% of patients; most of these had relatively discrete mass lesions. Radiation was effective in approximately 64% of patients. Radiation was more effective in nonfibrotic lesions and in patients with erythema. This type of treatment was less effective in fibrotic lesions and in patients who had a longer interval between diagnosis and therapy.

CONCLUSIONS: Fine-needle aspiration biopsy is useful in evaluating patients with presumed orbital pseudotumor. There is a high success rate in many patients with orbital pseudotumor, although patients with diffuse fibrotic disease have a poor prognosis.

TREATMENT CHARACTERIZATION

GENERAL

CORTICOSTEROIDS

.

Are systemic corticosteroids useful in the management of orbital pseudotumors?

Mombaerts I, Schlingemann RO, Goldschmeding R, Koornneef L.

Department of Ophthalmology, University of Amsterdam, The Netherlands.

Ophthalmology 1996 Mar;103(3):521-8 Abstract quote
PURPOSE: Systemic corticosteroids are the established primary treatment for orbital pseudotumors, but patients with recurrent and refractory pseudotumors commonly are observed. In this retrospective study, the authors aimed to assess the value of corticosteroids in the management of orbital pseudotumor.

METHODS: The clinical notes, computed tomography scans, and histologic specimens of patients with orbital pseudotumor seen at the Orbital Center, Amsterdam, between 1976 and 1994 were analyzed with particular regard to the clinical and visual outcome. The patients were categorized according to the anatomic location of the pseudotumor within the orbit. Patients with pseudotumors restricted to the lacrimal gland or an extraocular muscle were excluded.

RESULTS: The authors studied 32 patients with orbital pseudotumor, 20 of whom had histopathologic confirmation. Twenty-seven of these 32 patients received systemic corticosteroids as an initial treatment. Of these 27 patients, 21 (78%) showed an initial response and 10 (37%) obtained a cure. After the initial response, 11 (52%) of the 21 patients recurred. Optic nerve involvement was present in 13 (41%) of the 32 patients, and all except 1 patient recovered with corticotherapy. The mean follow-up of therapy was 4.3 years (range, 5.3 months-21.5 years).

CONCLUSION: The authors found a moderate response, a high recurrence, and a low cure rate in patients treated with corticosteroids for orbital pseudotumor, and they therefore challenge the value of corticosteroids in both diagnosing and treating this condition. However, in patients with pseudotumor-induced optic neuropathy, corticosteroids remain of value.

RADIOTHERAPY

Radiotherapy for idiopathic inflammatory orbital pseudotumor. Indications and results.

Sergott RC, Glaser JS, Charyulu K

Arch Ophthalmol 1981 May;99(5):853-6 Abstract quote
Supervoltage radiotherapy was used in 21 orbits of 19 patients with idiopathic inflammatory orbital pseudotumor. Seventeen orbits (15 patients) were initially treated with systemic corticosteroids, but recurrence of orbital inflammation during dosage tapering was the most frequent indication for radiotherapy.

Fifteen orbits (14 patients) responded favorably, as judged by reduced proptosis, decreased lid edema and conjunctival injection, improved ocular motility, and increased visual acuity. Six orbits (five patients) did not improve with radiotherapy. Patients who were successfully treated with radiotherapy have been free of recurrence for a mean follow-up period of 25.05 months; these patients have not required further corticosteroid treatment or additional radiotherapy.

Low-dose (1,000 to 2,000 rad) supervoltage radiotherapy seems to have a definite role in the management of idiopathic orbital pseudotumor in the following instances: (1) when corticosteroids fail or systemic complications are unacceptable (2) when signs and symptoms recur during decreasing corticosteroid dosage, and (3) when systemic corticosteroids are medically contraindicated.

Henry JB. Clinical Diagnosis and Management by Laboratory Methods. Twentieth Edition. WB Saunders. 2001.
Rosai J. Ackerman's Surgical Pathology. Eight Edition. Mosby 1996.
Sternberg S. Diagnostic Surgical Pathology. Third Edition. Lipincott Williams and Wilkins 1999.
Robbins Pathologic Basis of Disease. Sixth Edition. WB Saunders 1999.
DeMay RM. The Art and Science of Cytopathology. Volume 1 and 2. ASCP Press. 1996.
Weedon D. Weedon's Skin Pathology Second Edition. Churchill Livingstone. 2002
Fitzpatrick's Dermatology in General Medicine. 5th Edition. McGraw-Hill. 1999.
Weiss SW and Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors. Fourth Edition. Mosby 2001.

Commonly Used Terms

Basic Principles of Disease
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Commonly Used Terms
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Internet Links

Last Updated 3/14/2003

GROSS APPEARANCE/ CLINICAL VARIANTS	CHARACTERIZATION
GENERAL
A clinical analysis of idiopathic orbital inflammatory pseudotumor. Yan J, Wu Z, Li Y. Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China.	Yan Ke Xue Bao 2000 Sep;16(3):208-13 Abstract quote PURPOSE: To observe the clinical findings and response to treatment in patients with a diagnosis of idiopathic orbital inflammatory pseudotumor. METHODS: 209 idiopathic orbital inflammatory pseudotumor cases seen between Jan 1, 1978 and Dec 31, 1999 in our hospital were evaluated retrospectively. RESULTS: Of the 209 cases, 118 were male and 91 were female; there were 90 in the right eye, 81 left eye and 38 both eyes. Patients age ranged from 4 to 80 years (mean 44.4). Proptosis (66%), palpable mass (65%), swollen eyelid (55%), increased orbital pressure (55%) and motility restriction (48%) were the five most common presenting signs. According to radiologic and surgical findings, focal mass within orbit was the most frequent subtype (43%), followed by lacrimal inflammatory pseudotumor (32%), diffuse orbital inflammation (10%), myositis (8%). Perineuritis (2%), periscleritis (2%), acute inflammation (2%) and eyelid pseudotumor (1%) were rare clinical findings. The response to treatment (with a mean follow-up of 1.5 years) showed that the cure rate was 40% and the effective rate 97% after combined management of surgical resection, systemic steroid and local low dose radiotherapy. CONCLUSIONS: Although recurrence of IOIP is common, the success rate of treatment for this group of patients is high.
Diagnosis and management of orbital pseudotumor. Jacobs D, Galetta S.	Curr Opin Ophthalmol 2002 Dec;13(6):347-51 Abstract quote Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS), may have protean clinical manifestations. Some presentations of IOIS may mimic common conditions such as orbital cellulitis and optic neuritis. IOIS should be considered a diagnosis of exclusion, with evaluation directed toward eliminating other causes of orbital disease. Orbital magnetic resonance imaging is the single most important diagnostic test, but serologic studies are necessary to exclude a systemic cause. Biopsy is usually not performed at presentation, as the risk of producing damage to vital structures within the orbit outweighs the benefits. Patients with multiple recurrences, or those unresponsive to therapy, should have biopsy samples taken. Corticosteroids are the mainstay of therapy and are administered for several months to ensure remission. Radiotherapy may be used in patients who fail to respond to steroids or who have a rapidly progressive course. For those patients who are refractory to both corticosteroids and radiotherapy, anecdotal reports have suggested the use of chemotherapeutic agents such as cyclophosphamide, methotrexate, and cyclosporine.
Sclerosing orbital pseudotumor: a unique clinicopathologic entity. Weissler MC, Miller E, Fortune MA. Division of Otolaryngology/Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill.	Ann Otol Rhinol Laryngol 1989 Jul;98(7 Pt 1):496-501 Abstract quote A case of orbital pseudotumor is presented that histologically showed dense fibrosis invading bone and adjacent sinuses, and failed to respond to either steroids or radiation therapy. "Orbital pseudotumor" remains a sobriquet for a variety of clinical and histopathologic entities including a monomorphous lymphocytic benign or malignant neoplasm; a polymorphous reactive inflammatory lesion; and a densely fibrosing sclerotic variant that appears to behave more aggressively, often locally invades adjacent structures, and may be related to a multifocal fibrosclerosis that also includes retroperitoneal fibrosis, Riedel's sclerosing thyroiditis, mediastinal fibrosis, and sclerosing cholangitis. This "sclerosing orbital pseudotumor" is felt to represent a unique clinicopathologic entity, and an approach to its treatment is described.
VARIANTS
INTRACRANIAL EXTENSION
Idiopathic orbital inflammation with intracranial extension. Case report. de Jesus O, Inserni JA, Gonzalez A, Colon LE. Section of Neurosurgery, University of Puerto Rico, San Juan, U.S.A.	J Neurosurg 1996 Sep;85(3):510-3 Abstract quote Idiopathic orbital inflammation or orbital pseudotumor with intracranial extension is a rare condition. It consists of a nonspecific infiltrate of the fatty tissue of the orbit that extends through one or more foramina into the adjacent intracranial tissue. The lesion mimics an infectious or neoplastic lesion. The authors present a case involving the youngest patient yet reported with the broadest intracranial extension. Only 17 previous cases have been reported. The principal symptoms include decreased visual acuity and proptosis. Extension commonly develops through the superior orbital fissure into the middle cranial fossa and the cavernous sinus. The initial treatment is a regimen of high-dose steroids, with radiotherapy given in unresponsive cases.
PEDIATRIC
Pseudotumor of the orbit in early childhood. Stevens JL, Rychwalski PJ, Baker RS, Kielar RS. Department of Ophthalmology, University of Kentucky, Lexington 40536-0284, USA.	J AAPOS 1998 Apr;2(2):120-3 Abstract quote Orbital pseudotumor, also known as idiopathic orbital inflammation, is defined as a nonspecific, nonneoplastic inflammatory process of the orbit without identifiable local or systemic causes. The disorder, first described by Birch-Hirschfield in 1905, is more prevalent in the adult population than in the pediatric population. In our study we discuss two cases of pseudotumor of the orbit in children less than 18 months old. This report will highlight the evaluation and management of pediatric orbital pseudotumor and the importance of its inclusion in the differential diagnosis of orbital disorders in young children.
TOLOSA-HUNT SYNDROME
Idiopathic inflammatory pseudotumor of the orbit and Tolosa-Hunt syndrome--are they the same disease? Wasmeier C, Pfadenhauer K, Rosler A. Abteilung fur Neurologie und klinische Neurophysiologie, Zentralklinikum Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.	J Neurol 2002 Sep;249(9):1237-41 Abstract quote Unilateral periorbital pain, cranial nerve palsies and a dramatic response to corticosteroid therapy are the hallmarks of clinical presentation in Tolosa-Hunt-Syndrome (THS) and Idiopathic Pseudotumor of the Orbit (IIPO). Both are unspecific chronic granulomatous diseases of unknown origin, sharing clinical as well as paraclinical characteristics. We observed two patients suffering from acute granulomatous IIPO, who also fulfilled the criteria of THS. Patient 1 developed leftsided infiltration of the medial ocular muscle with periorbital pain and cranial nerve palsy. After an initial response to corticosteroid therapy, contralateral relapse occurred with a THS-like infiltration of the sinus cavernosus and narrowing of the intracavernous internal carotid artery. Granulomatous infiltration of the right sinus cavernosus with secondary involvement of the ipsilateral nervus opticus and a slight exophthalmos was seen in Case 2. According to the literature, MRI and CT show identical signal intensity with different localisation: IIPO preferentially intra- and THS retroorbital. Apart from neuroradiological findings, almost similar histopathology and clinical presentation makes it difficult to distinguish between these two syndromes. Similarities between these two syndromes have been discussed for more than 20 years. Our two cases show their close relationship and we suggest that both diseases belong to the same pathological process.

Epidemiology
Disease Associations
Pathogenesis
Laboratory/Radiologic/Other Diagnostic Testing
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Differential Diagnosis
Prognosis
Treatment
Commonly Used Terms
Internet Links

EPIDEMIOLOGY	CHARACTERIZATION
SYNONYMS	Sclerosing orbitis I diopathic orbital inflammatory syndrome (IOIS)
INCIDENCE/PREVALENCE	Rare
AGE	Adults
SEX	About equal

LABORATORY/RADIOLOGIC/ OTHER TESTS	CHARACTERIZATION
RADIOLOGIC
Pseudotumor of the orbit. Clinical, pathologic, and radiologic evaluation. Weber AL, Romo LV, Sabates NR. Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA.	Radiol Clin North Am 1999 Jan;37(1):151-68 Abstract quote Pseudotumor, Graves' disease, and lymphoproliferative disease are the most common ophthalmologic disease entities requiring evaluation by CT and MR imaging. A history of acute onset, pain, swelling, proptosis, and response to steroids are the classical findings. The radiologic findings are categorized according to location into dacryoadenitis, myositis, and sclerouveitis, with and without associated infiltrations. The inflammatory infiltrate, which is composed of polymorphic leukocytes, lymphocytes, and plasma cells interspersed with a variable amount of fibrovascular tissue, may be diffuse or localized. The preferred radiologic method used for assessment of pseudotumor is CT. MR imaging, however, is indicated for evaluation of the Tolosa-Hunt syndrome, which is characterized by an inflammatory infiltrate in the orbital apex and cavernous sinus leading to cranial nerve involvement with ophthalmoplegia. The clinical and radiologic constellation of findings allows a definitive diagnosis in most cases.
LABORATORY MARKERS
GENERAL	Increased SED rate Positive ANA Pleocytosis of CS

HISTOLOGICAL TYPES	CHARACTERIZATION
GENERAL	Nonspecific inflammation with eosinophils and fibrosis of tissue

DIFFERENTIAL DIAGNOSIS	KEY DIFFERENTIATING FEATURES
CARCINOMA, METASTATIC
Bilateral orbital metastases from breast carcinoma. A case of false pseudotumor. Toller KK, Gigantelli JW, Spalding MJ. Department of Pathology, University of Missouri-Columbia, USA.	Ophthalmology 1998 Oct;105(10):1897-901 Abstract quote. OBJECTIVE: To inform clinicians of a metastatic orbital neoplasm that frequently masquerades as an orbital inflammatory syndrome and to stimulate thought regarding this neoplasm's fundamental pathobiology specific to its orbital involvement. DESIGN: Interventional case report and literature review. PARTICIPANTS: A 47-year-old woman with an acquired, bilateral, diffusely infiltrative orbital process is described. INTERVENTION: The clinical and radiographic features of the patient's orbital process are reported. The review of two prior fine-needle aspiration biopsy specimens failed to reveal a diagnosis. Histopathologic examination of an open surgical biopsy specimen included standard light microscopy of frozen and formaldehyde-fixed, paraffin-embedded tissue. RESULTS: Characteristics light microscopy findings suggested the diagnosis of metastatic lobular carcinoma of the breast. The patient refused all therapeutic intervention and died 9 months after orbitotomy. CONCLUSION: The presentation of breast carcinoma metastatic to the orbit as a bilateral infiltrative process is far more common than appreciated previously. Its rate of bilateral orbital involvement is 20%, whereas this rate for other adult neoplasms is much lower. The authors report an additional case, review the clinical features of previous case reports and series, and discuss aspects of the metastatic process. Breast carcinoma must be included in the differential diagnosis of infiltrative orbital processes encountered in adult female patients. When "orbital pseudotumor" is detected in an adult female patient, a thorough medical history must be obtained and physical examination performed. If a possible primary breast carcinoma is indicated, one must be wary of metastatic disease, and a histologic orbital diagnosis is warranted. The frequency of orbital metastasis and bilateral orbital involvement of this neoplasm reinforces the possibility for organ-specific metastases.
WEGENER'S GRANULOMATOSIS
Elevated anti-neutrophil cytoplasmic antibody titer in a patient with atypical orbital pseudotumor. Yamashita K, Kobayashi S, Kondo M, Ishikura H, Shibuya Y, Hayasaka S. Third Department of Internal Medicine, Shimane Medical University, Japan.	Ophthalmologica 1995;209(3):172-5 Abstract quote We recently examined a patient with ophthalmic manifestations of Wegener's granulomatosis in whom antineutrophil cytoplasmic antibody (cANCA) titers provided helpful diagnostic information. A 40-year-old man who had suffered from bilateral exophthalmos for 9 months was diagnosed initially as having idiopathic inflammatory pseudotumor. The patient exhibited purulent nasal discharge and microhematuria. A histopathologic study revealed vasculitis. His ANCA titer for cANCA was found to be evaluated, and our patient was subsequently diagnosed as having Wegener's granulomatosis. His ocular symptoms resolved and did not recur after treatment with corticosteroid in combination with cyclophosphamide. We believe that cANCA levels should be investigated in patients with orbital pseudotumor as a possible sign of Wegener's granulomatosis.