The impact of IgG-4-ROD on the diagnosis of orbital tumors: A retrospective analysis.

This study was to determine the prevalence of immunoglobulin G4 (IgG4)-related orbital disease (IgG4-ROD) among patients who have previously undergone biopsy and were diagnosed to have idiopathic orbital inflammatory disease (IOID) or orbital lymphoproliferative disease (OLD), namely, lymphoma and benign reactive lymphoid hyperplasia (BRLH). This is a retrospective cross-sectional study. The charts and slides of all patients who underwent biopsies and were histopathologically diagnosed to have either IOID or OLD were reviewed. Demographics, clinical features, initial histopathological diagnoses, treatment received, and final outcome were noted. Using the diagnostic criteria for diagnosis for IgG4 disease, those cases that would classify as "possible IgG4-related disease (IgG4-RD)" were reviewed, reclassified, and reassigned a diagnosis of IgG4-ROD. We reviewed 105 patients' clinical charts. Of these 105 patients, upon reviewing the histopathology, 18 (17.15%) patients were found to fit the diagnostic criteria for possible IgG4-ROD. Of these 18 patients who were now reassigned the diagnosis of IgG4-ROD, the most common previous histopathological diagnosis was found to be IOID, for eight patients (44%), then BRLH, which was noted in five patients (27.8%), followed by lymphoma, which was noted in two patients (11.1%). Previously diagnosed cases of IOID and OLD were found to fulfill the criteria for IgG4-ROD. Given the advent of recent diagnostic and histopathological techniques, all cases of suspected IOID and OLD should be screened for IgG4-ROD and all previously diagnosed cases must be closely followed up, given the systemic implication of IgG4-RD. Histopathological reassessment of previously diagnosed cases may be considered.

Orbital inflammatory pseudotumor: new advances in diagnosis, pathogenesis, and treatment.

Orbital inflammatory pseudotumor (OIP) is a benign, non-specific inflammatory disorder that commonly occurs in middle-aged adults and is usually unilateral but can occur bilaterally. Its clinical manifestations have tremendous clinical heterogeneity and vary according to the site of infiltration and the degree of lesions, including orbital pain, swelling, diplopia, proptosis, restricted eye movement, and decreased visual acuity. Clinical features, Image characteristics and pathological examinations often need to be evaluated to confirm the diagnosis. Currently, there is no systematic research on the pathogenesis of OIP, which may be related to immunity or infection. The first-line treatment is glucocorticoids. Radiotherapy, immunosuppressants, and biologics can be considered for treatment-resistant, hormone-dependent, or intolerant patients. In this review, we aim to summarize and focus on new insights into OIP, including new diagnostic criteria, pathogenesis, and discoveries in new drugs and treatment strategies. In particular, we highlight the literature and find that T cell-mediated immune responses are closely related to the pathogenesis of OIP. Further exploration of the mechanism and signaling pathway of T cells in the immune process will help to identify their therapeutic targets and carry out targeted therapy to treat refractory OIP and reduce the side effects of traditional treatments.

Inflammatory modulators and biologic agents in the treatment of idiopathic orbital inflammation.

PURPOSE OF REVIEW: To review the diagnosis and treatment of idiopathic orbital inflammation (IOI), with an emphasis on the development and use of inflammatory mediators and biologic agents. RECENT FINDINGS: Use of targeted biologic immunomodulatory therapy is becoming widespread and proving effective against many inflammatory and autoimmune conditions. Although corticosteroids remain the mainstay of care for IOI, their use is fraught with complications and side-effects, suggesting the need for novel therapies. Evidence for the successful implementation of nonsteroidal inflammatory mediators in IOI is accumulating. SUMMARY: The treatment of IOI with traditional methods, particularly corticosteroids, is often inadequate and accompanied by recurrences, medication dependence, and intolerability. Many of these issues may be avoided with the use of existing and novel pharmaceutical agents targeting specific inflammatory mediators. The literature on these agents and their use in IOI is in its infancy but shows tremendous promise in the treatment of this often-recalcitrant illness.

Idiopathic sclerosing orbital inflammation: a review of demographics, clinical presentation, imaging, pathology, treatment, and outcome.

PURPOSE: To characterize clinical features, diagnostics studies, treatments, and outcomes of patients with histologically proven idiopathic sclerosing orbital inflammation (ISOI), to define optimal management for this recalcitrant disease, and to determine changes in characterization and management by comparing our results with the last significant literature review. METHODS: A search of the U.S. National Library of Medicine: National Institutes of Health's electronic database for cases and case series in the English literature of biopsy-proven ISOI published between March 1994 and September 2010 was conducted. A cross-literature review was performed to tabulate demographics, clinical findings, studies, treatments, and outcomes, which were compared with the ISOI data published by Rootman et al. (1994). RESULTS: Sixty-one cases, 71 eyes from 17 published reports, met inclusion criteria. No ethnic, sex, or comorbidity predilection was established. Patients typically presented in the fourth decade with proptosis (73%), pain (49%), and normal vision (44%). Orbital imaging and histopathology were sparsely reported. Most common treatments involved systemic corticosteroids either alone (34%) or combined with other modalities (51%). CONCLUSIONS: Characteristics of the disease remain unchanged, and best management was not determined due to inconsistent reporting methods across the literature. Collaboration with established groups (i.e., European Group On Graves Orbitopathy (EUGOGO), International Thyroid Eye Disease Society (ITEDS)) or the formation of a new group of physicians and scientists to help develop a systematic approach for future reporting and evaluation was proposed.

Single Institutional Experience on Orbital Inflammatory Pseudotumor: Diagnostic and Management Challenge.

AIMS: Orbital inflammatory pseudotumor is considered a non-neoplastic inflammatory process. The finding of clonality of B or T-cell receptors in cases pathologically diagnosed as orbital inflammatory pseudotumor has unknown clinicopathologic significance. We sought to investigate potential B and T-cell clonality and concomitant diseases in cases pathologically diagnosed as orbital inflammatory pseudotumor. METHODS: Cases diagnosed as orbital inflammatory pseudotumor at our institution were retrospectively analyzed. Hematoxylin and eosinstained slides, immunohistochemically stained slides and polymerase chain reactions on cell block material for the investigation of clonality of B and T-cell receptors were evaluated, to confirm the diagnosis and investigate the prevalence of concomitant diseases. RESULTS: A total of 13 cases showing characteristic histopathologic features of orbital inflammatory pseudotumor were identified. CD138, IgG, and IgG4 showed varying numbers of plasma cells in each case, with 5 cases (5/13, 38%) exhibiting relative increase in the presence of IgG4 plasma cells. However, no cases showed diagnostic findings of IgG4-related disease (IgG4-RD). polymerase chain reactions analysis showed clonal B-cell populations in 2 cases (2/13, 15%). No cases showed anaplastic lymphoma kinase expression by immunohistochemistry. There were no clinical reports of progression to lymphoma or development of systemic IgG4-RD in any of the patients (average follow-up of 300 days), with 38% of patients showing systemic autoimmune conditions. CONCLUSION: A small but significant percentage of typical orbital inflammatory pseudotumor on histology showed B-cell clonality on polymerase chain reactions analysis of B-cell receptors, or features suggestive, but not diagnostic of IgG4-RD. Close follow-up of these patients to identify development of lymphoma, systemic IgG4-RD, or other rheumatologic conditions may be clinically warranted.

[Idiopathic orbital inflammation syndrome in childhood--case report and literature review]. / Idiopathische orbitale Entzündung im Kindesalter--Fallbericht und Literaturreview.

BACKGROUND: Idiopathic orbital inflammation syndrome (IOIS) is a rare disease in childhood. There are only ca. 70 case reports in the scientific literature. METHOD: We present a case report and review of literature. CASE REPORT: A 6-year-old girl developed within one week beginning with a discrete, non-traumatic haemorrhage of the lower palpebra a painful proptosis, periorbital swelling, conjunctival chemosis and injection and motility restriction to lateral gaze of the right eye. MRI showed a retrobulbar and eyelid mass with enhancement and signs of haemorrhage without optic nerve involvement. A rapidly performed biopsy excluded malignancies and confirmed the diagnosis of non-specific inflammation. With high-doses of intravenous and later oral prednisolone the symptoms improved significantly. Because of an impairment under tapering of prednisolone an interim elevation of the dose was necessary, but with very slow tapering over 4.5 months the girl became symptom-free except for a minimal, non-relevant abduction deficit. There has been no recurrence in the last 1.5 years. DISCUSSION: In comparison to the clinical features of adults the rarely reported childhood cases show no relevant differences in orbital signs, frequency of bilaterality and pain, recurrence rate and success of therapy. Only iritis and papilloedema seem to be special features of childhood IOIS, these cases tend to a higher rate of recurrences. Histopathological examination is much more necessary than in adults because of the need for exclusion of rhabdomyosarcoma. Our case shows that haemorrhages can also be a sign for an IOIS.

Idiopathic sclerosing orbital inflammation with intranasal extension.

INTRODUCTION: To report a case of idiopathic orbital sclerosing inflammation (ISOI) with intranasal extension. MATERIAL AND METHODS: The patient presented with a 6-month history of epiphora, upper eyelid swelling, ptosis and mild orbital pain. Ophthalmologic examination, CT, MRI and biopsy with surgical debulking were performed. RESULTS: MRI revealed a homogeneously enhancing diffuse right orbital mass in the inferonasal quadrant of the orbit, which extended to the nasal cavity up to inferior nasal concha, maxillary and ethmoid sinuses. Histological analysis showed dense collagenous tissue with sparse infiltration of mixed inflammatory cells. Inmunohistochemical analysis confirmed polyclonality. The diagnosis of idiopathic sclerosing orbital inflammation was made and 80 mg/day of oral prednisolone was prescribed. At last follow up, one year later, there was no clinical evidence of recurrent orbital disease. CONCLUSION: ISOI can present with extraorbital extension. Corticosteroids are a reasonable first-line treatment, until the pathogenesis is better understood.

Treatment of recalcitrant orbital inflammatory syndrome with plasmapheresis therapy.

Refractory idiopathic orbital inflammation (IOI) represents a management challenge due to its significant proportion of treatment failures. Currently, there are no established guidelines for recalcitrant IOI and majority of immunosuppressive agents have resulted in variable outcomes. Advancements of plasmapheresis therapy can play a significant role in ophthalmological diseases. This treatment has shown to produce a satisfactory therapeutic response in immune-mediated neurological conditions. In this case report, we share our successful experience with the use of plasmapheresis therapy in a patient with recalcitrant IOI.

[Management of orbital inflammatory disorders in internal medicine: New findings resulting from a retrospective study of 31 consecutive patients]. / Prise en charge des orbitopathies inflammatoires en médecine interne : nouvelles données issues de l'étude d'une série de 31 patients consécutifs.

PURPOSE: To describe a case series of patients investigated in internal medicine for orbital inflammation (OI) since the individualization of the clinical entity of the IgG4-related orbital disease (IgG4 ROD). PATIENTS AND METHODS: Thirty four patients were consecutively referred by a specialized center where orbital biopsy was performed when the lesion was surgically accessible. Fourteen patients were excluded in case of missing data or lymphoma, periocular xanthogranuloma or Graves' orbitopathy. Patients with systemic or auto-immune disease according to the international criteria, or presenting with idiopathic orbital inflammation syndrome (IOIS), were included. Knowing the histological similarities between IOIS and IgG4 ROD, immunohistochemical assessment of plasma cells for IgG4 positivity was performed for every patient with available biopsy. Clinical and biological characteristics, treatment and response to treatment of included patients are reported. RESULTS: Among 22 included patients, 10 presented with orbital manifestation of a systemic or autoimmune disease including 2 sarcoidosis (9%) and 8 (36%) cases of non specific OI which were reclassified in IgG4 ROD. Finally, IOIS of various clinicopathological presentation was diagnosed for 12 patients including 10 with histological documentation. Whereas relapse and resistance were not found to be related to IgG4 positivity (50% in both IOIS and IgG4 ROD groups), another treatment in addition to corticosteroids was more often necessary in IgG4 ROD patients (50%) than in IOIS patients (25%). CONCLUSION: After ruling out auto-immune orbital diseases, especially IgG4 ROD, IOIS should be discussed. Factors conditioning the corticosteroid response are yet to be determined.

Enfermedad inflamatoria orbitaria idiopática. Presentación de un caso / Idiopathic orbital inflammatory disease. Case presentation

RESUMEN El pseudotumor orbitario es la tercera causa de oftalmoplejía dolorosa; constituye un desafío diagnóstico pues obliga a descartar enfermedades de etiología muy diversa que lo provocan. Se presenta el caso de una paciente femenina, de color de piel blanca, de procedencia urbana, ama de casa, fumadora, que no practica ejercicios ni lleva dieta, con antecedentes de hipertensión arterial y artritis reumatoidea, que acudió al Servicio de Oftalmología por presentar síntomas inflamatorios anexiales: edema palpebral, quemosis conjuntival, vasos conjuntivales dilatados, que se acompañaban de proptosis, oftalmoplejía dolorosa con diplopía y de una masa tumoral palpable a nivel de la porción supero-externa de la órbita. Se ingresó y se le realizaron estudios imagenológicos e histológicos, que solo aportaron signos inflamatorios y una pansinusitis. Se concluyó como un pseudotumor orbitario en su forma aguda de aparición, asociada a la artritis reumatoidea, cuyo diagnóstico se realizó por exclusión sobre la base de los resultados negativos de los estudios imagenológicos y de la biopsia. Llevó tratamiento con antibióticos parenterales y altas dosis de esteroides orales con regresión del cuadro y mejoría clínica. Se decidió la presentación del caso porque en la provincia no existen reportes sobre esta entidad, y por el énfasis en cómo llegar al diagnóstico y su correcto manejo, evitando con ello secuelas en el órgano visual.

ABSTRACT Orbital pseudotumor is the third cause of painful ophthalmoplegia; it constitutes a diagnostic challenge as it forces us to rule out diseases of very diverse etiology that cause it. A female patient, of white skin color, of urban origin, housewife, smoker, who does not practice exercises or is not on a diet, with a history of high blood pressure and rheumatoid arthritis, who attended the Ophthalmology service for presenting Adnexal inflammatory symptoms: eyelid edema, conjunctival chemosis, dilated conjunctival vessels, which were accompanied by proptosis, painful ophthalmoplegia with diplopia and a palpable tumor mass at the level of the superior-external portion of the orbit was presented. She was admitted and imaging and histological studies were performed, which only revealed inflammatory signs and pansinusitis. It was concluded as an orbital pseudotumor in its acute onset form, associated with rheumatoid arthritis, the diagnosis of which was made by exclusion on the basis of the negative results of imaging studies and biopsy. She was treated with parenteral antibiotics and high doses of oral steroids with regression of the symptoms and clinical improvement. The presentation of the case was decided because in the province there are no reports on this entity, and because of the emphasis on how to reach the diagnosis and its correct management, thereby avoiding effects in the visual organ.

[Clinical presentation, differential diagnosis and treatment of lacrimal gland tumours]. / A könnymirigydaganatok klinikai tünetei, diagnosztikája és kezelése.

PURPOSE: We describe the tumours occurring in the lacrimal gland fossa region, the important symptoms and the principles of the therapy. METHODS: We surveyed the patients observed and operated at the National Institute of Neurosurgery, Budapest, Hungary. RESULTS: Space-occupying lesions of lacrimal gland fossa are: 1. Epithelial lacrimal gland tumours, which may be benign or malignant (benign pleomorphic adenoma, malignant pleomorphic adenocarcinoma, adenoid cystic carcinoma, other carcinomas). 2. Lymphoproliferative tumours (lymphoma, leukaemia, Hodgkin's disease, lymphosarcoma, plasmocytoma). 3. Pseudotumours (chronic inflammation, granuloma, sarcoidosis, reactive lymphoid hyperplasia). 4. Other tumours (dermoid cyst, haemangioma, neurinoma, haemangiopericytoma, metastatic tumour). In our Institute, 42% of the tumours of the lacrimal fossa was epithelial, 50% was lymphoid or pseudotumour, and 8% other tumours. Of the 59 primary epithelial tumours 62.7% was benign and 37.3% was malignant. The differential diagnosis and management are based on the clinical presentations, imaging studies and histological examination. CONCLUSIONS: Pleomorphic adenomas of the lacrimal gland should be diagnosed on radiological and clinical evidence, and biopsy avoided to prevent the recurrences and malignant transformation. The prognosis of pleomorphic adenomas depends on the early diagnosis and radical surgical excision of the lesion. In cases of suspected malignant epithelial tumours, lymphomas and pseudotumours, biopsy is indicated for the choice of appropriate treatment.

Good response to surgical treatment and mycophenolate in woman with inflammatory pseudotunor secondary to ANCA positive vasculitis.

We present the case of a young woman with ANCA positive vasculitis and infammatory pseudotumor as a granulomatous manifestation, who had a good response to surgical removal and mycophenolate mofetil.

IgG4-related disease in idiopathic sclerosing orbital inflammation.

AIMS: To investigate the frequency of IgG4-related disease (IgG4-RD) among patients previously diagnosed with idiopathic sclerosing orbital inflammation (ISOI), and to compare the clinical features and treatment outcomes of patients with ISOI associated with IgG4-RD and those without IgG4. METHODS: Retrospective clinicopathological series of 24 patients with ISOI diagnosed between June 2001 and June 2010. Biopsy specimens were immunostained for IgG-expressing and IgG4-expressing cells. Clinical data of patients with IgG4-RD and ISOI unrelated to IgG4 were obtained from patient records. RESULTS: Of 24 patients, 11 patients (45.8%) were identified with IgG4-RD. 10 patients (10/11, 90.9%) presented with bilateral lacrimal gland enlargement, and seven of those also had submadibular gland enlargement. One patient (1/11, 9.1%) presented with a superior orbital mass. All patients were successfully treated with steroids and/or radiotherapy or had an indolent clinical course. 13 patients (54.2%) were identified with ISOI unrelated to IgG4. Eight patients (8/13, 61.5%) showed unilateral orbital involvement, and nine patients (9/13, 69.2%) had orbital lesions not involving the lacrimal glands. Treatment modalities for ISOI unrelated to IgG4 were varied and less effective: eight patients (61.5%) relapsed following initial treatment with steroids or radiation, and additional therapies were required to enter remission. CONCLUSIONS: IgG4-RD may be identified frequently in patients with ISOI, and distinguishing features may be bilateral lacrimal gland enlargement with associated submandibular gland enlargement. Patients with IgG4-RD may have better treatment outcomes with less aggressive treatment modalities than those with ISOI unrelated to IgG4. An additional workup for IgG4-RD should be considered in all histopathological biopsy specimens suspicious of ISOI.

Idiopathic orbital inflammation: distribution, clinical features, and treatment outcome.

OBJECTIVE: To evaluate the distribution and clinical as well as treatment outcome characteristics of idiopathic orbital inflammation with the aim of delineating a more systematic approach to diagnosis and treatment. METHODS: A 10-year retrospective review of patients with idiopathic orbital inflammation treated at one institution. RESULTS: Ninety eyes in 65 patients (22 men and 43 women) were studied. Diagnoses were isolated dacryoadenitis (n = 21), isolated myositis (n = 19), concurrent dacryoadenitis and myositis (n = 5), orbital apex syndrome (n = 6), and idiopathic inflammation involving the preseptal region, supraorbital region, sclera, Tenon capsule, orbital fat, or optic nerve (n = 14). The mean age at presentation was 45 years. Pain and periorbital swelling were the most common clinical features and were observed in 45 (69%) and 49 (75%) patients, respectively. Seventeen patients (26%) had bilateral involvement. Biopsy was performed in 19 patients (29%) with atypical presentations or who failed to respond to the initial therapy. Patients were treated with steroids alone (n = 45), steroids and subsequent radiation therapy (n = 8), steroids and nonsteroidal anti-inflammatory agents (n = 6), nonsteroidal anti-inflammatory agents alone in mild cases (n = 2), and, rarely, radiation therapy without steroids (n = 1) or surgical debulking alone (n = 1). Of 65 patients, 41 (63%) represented treatment successes, with complete symptom relief at the time of the last follow-up, and 24 (37%) represented treatment failures, with partial or no relief of symptoms. Treatment failures were often characterized by recurrence of inflammation after a period of quiescence (58%) and unremitting, recalcitrant inflammation (38%); 1 patient ultimately required an exenteration. CONCLUSION: Systemic steroid with a slow taper has been the established first-line treatment for idiopathic orbital inflammation, but refractory cases accounted for a significant portion of treatment failures in our study, reflecting the need for a more systematic approach to the study of this multifaceted disease and for therapeutic alternatives to systemic steroids.

Echographic findings in benign reactive lymphoid hyperplasia of the choroid.

BACKGROUND: Benign reactive lymphoid hyperplasia is an uncommon uveal tumor. Misdiagnosis may lead to unnecessary enucleations. Clinical evaluation alone is usually not sufficient to diagnose this tumor. OBJECTIVE: To evaluate the utility of standardized echography in the recognition of this disease. METHODS: Retrospective review of the medical and echographic records of 6 patients with choroidal involvement of benign reactive lymphoid hyperplasia. RESULTS: Extraocular episcleral lymphoid nodules were present in 5 of the 6 patients and were usually seen as a late manifestation of the disease. Two patients had repeated echography after treatment of the tumor and showed marked regression of the episcleral nodules. CONCLUSIONS: A combination of clinical and echographic findings can assist in the accurate diagnosis of this rare uveal tumor. The presence of episcleral nodules on standardized echography supports the diagnosis.

Inflammatory orbital pseudotumor with extension beyond the orbit.

PURPOSE: To summarize the clinical profile and response to treatment of 4 biopsy-proven cases of inflammatory orbital pseudotumor extending beyond the orbit. DESIGN: Retrospective observational case series. METHODS: Four patients' charts were retrospectively reviewed. There were three men with extraorbital extension (two intracranial; one maxillary antrum) and one woman with intracranial disease that extended into the orbit. The men were 40, 41, and 60 years old; the woman was 73 years old. RESULTS: Two men with orbital myositis and mild discomfort, initially treated with corticosteroids, had asymptomatic intracranial disease 9 and 12 months after initial presentation. A third man had extension into the maxillary antrum after initial symptoms of painless diplopia. The woman had intraorbital disease with minimal discomfort (dacryoadenitis and myositis) 5 years after presenting with intracranial disease in the Meckel cave that subsequently became bilateral. Histopathologic examination in all cases showed nonspecific inflammation without evidence of vasculitis or granulomas. CONCLUSIONS: Unlike typical cases of nonspecific orbital inflammation, two of these four cases did not have pain as a prominent feature. Neuroimaging was essential in diagnosing asymptomatic extraorbital disease. Surgery has a prominent role in confirming this diagnosis, primarily by helping to rule out other diseases, such as those with granulomatous inflammation or vasculitis. Additional therapy was usually not required postoperatively.

Orbital pseudotumor as a presenting sign of temporal arteritis.

Both unilateral proptosis (2 cases) and radiological evidence of orbital inflammatory pseudotumor in the absence of exophthalmos (1 case) have been separately described as presenting signs of temporal arteritis. We report a patient presenting with bilateral exophthalmos associated with CT and MRI signs of orbital inflammation, who had biopsy-proven temporal arteritis. Our case is unique in view of the association of the above clinical and radiological features, and the bilateral involvement of orbital tissues.

Prevalent use of complementary and alternative medicine by patients with inflammatory eye disease.

AIM: To study complementary and alternative medicine (CAM) use in patients who suffer from inflammatory eye disease. METHODS: Current and previous use of CAM was determined by face-to-face interviews of consecutive patients attending a university-based tertiary-referral inflammatory eye disease clinic during a 3-month period. Additional sociodemographic and clinical information was obtained by review of clinical records. RESULTS: Of the 89 eligible patients who were interviewed, 37 (42%) reported using CAM for the specific purpose of improving their eye condition. Most commonly used CAM included vitamin preparations (n = 13), herbal medicines (n = 10), prayer (n = 15) and acupuncture (n = 9). Multiple forms of CAM were used by one third of patients. Female gender (p = 0.05), a higher rating of occupational prestige (p = 0.05) and the diagnosis of uveitis rather than another form of inflammatory eye disease (p = 0.04) were significantly associated with reporting of current or past use of CAM. Most patients who used CAM considered that these therapies were benefiting their ocular condition, and few adverse events were reported. Sixteen percent of patients cited physician resources as a source for therapeutic information about CAM. CONCLUSIONS: Use of CAM is common among patients with inflammatory eye diseases. Because CAM may influence the course of disease, cause adverse effects, and interact with conventional immunosuppressive treatment, physicians should routinely question patients with these diagnoses regarding the use of such therapies.

Diagnostic dilemmas in orbital inflammatory disease.

Orbital inflammatory disease (OID) broadly describes a variety of pathologic processes and clinical presentations. OID may be idiopathic or may be secondary to a systemic inflammatory disease, retained foreign body, or infectious disease. OID includes the spectrum of bacterial or fungal infections, diffuse inflammation of multiple tissues (e.g., sclerosing orbititis or diffuse anterior OID), and preferential involvement of specific orbital structures (e.g., orbital myositis or optic perineuritis). Mimics of OID include congenital orbital mass lesions or orbital neoplastic disease such as lymphoma or rhabdomyosarcoma. The ultimate diagnosis and treatment plan relies on a careful history and detailed clinical examination followed by the judicious use of ancillary diagnostic testing and a comprehensive treatment plan. The purpose of this review is to provide an overview of the spectrum of diseases known as OID, with emphasis on specific diagnostic challenges in the evaluation and management of patients with idiopathic OID.