Orbital Pseudotumor

BackgroundThe overlap of morphological feature and mean ADC value restricted clinical application of MRI in the differential diagnosis of orbital lymphoma and idiopathic orbital inflammatory pseudotumor (IOIP). In this paper, we aimed to retrospectively evaluate the combined diagnostic value of conventional magnetic resonance imaging (MRI) and whole-tumor histogram analysis of apparent diffusion coefficient (ADC) maps in the differentiation of the two lesions.MethodsIn total, 18 patients with orbital lymphoma and 22 patients with IOIP were included, who underwent both conventional MRI and diffusion weighted imaging before treatment. Conventional MRI features and histogram parameters derived from ADC maps, including mean ADC (ADCmean), median ADC (ADCmedian), skewness, kurtosis, 10th, 25th, 75th and 90th percentiles of ADC (ADC10, ADC25, ADC75, ADC90) were evaluated and compared between orbital lymphoma and IOIP. Multivariate logistic regression analysis was used to identify the most valuable variables for discriminating. Differential model was built upon the selected variables and receiver operating characteristic (ROC) analysis was also performed to determine the differential ability of the model.ResultsMultivariate logistic regression showed ADC10 (P = 0.023) and involvement of orbit preseptal space (P = 0.029) were the most promising indexes in the discrimination of orbital lymphoma and IOIP. The logistic model defined by ADC10 and involvement of orbit preseptal space was built, which achieved an AUC of 0.939, with sensitivity of 77.30% and specificity of 94.40%.ConclusionsConventional MRI feature of involvement of orbit preseptal space and ADC histogram parameter of ADC10 are valuable in differential diagnosis of orbital lymphoma and IOIP.

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.

BackgroundTo identify the prevalence of positive IgG4 immunostaining in orbital tissue among patients previously diagnosed with nongranulomatous idiopathic orbital inflammation (IOI) and to compare the clinical characteristics of patients with and without IgG4-positive cells.MethodsA retrospective review of all patients with a histopathologic diagnosis of IOI was performed. Immunohistochemical staining was performed to identify IgG-positive cells and IgG4-positive cells. Multivariate analysis was performed using likelihood ratio-test logistic regression on the differences between IgG4-related disease (IgG4-RD) and non-IgG4-RD.ResultsOf the 45 patients included, 21 patients (46.7%) had IgG4-positive cells, with 52.4% being male and a mean age of 55.9 ± 13.4 years. Bilateral ocular adnexal involvement (adjusted odds ratio [aOR] = 9.45; P = 0.016) and infraorbital nerve enlargement (aOR = 12.11; P = 0.008) were frequently found in IgG4-RD patients. Complete remission occurred in 23.8% of IgG4-RD patients and 41.7% of non-IgG4-RD patients. IgG4-RD patients had more frequent recurrent disease than non-IgG4-RD patients.ConclusionsNearly 50% of IgG4-RD patients were previously diagnosed with biopsy-proven IOI. IgG4-RD was more frequent in patients with bilateral disease and infraorbital nerve enlargement, showing the importance of tissue biopsy in these patients. Immunohistochemistry studies of all histopathology slides showing nongranulomatous IOI are highly recommended to evaluate for IgG4-RD.

RationaleAnti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare autoimmune condition that can involve various organ systems. Ocular involvement, though uncommon, may present as the initial or even sole manifestation. Orbital inflammatory pseudotumor, particularly its sclerosing subtype, can pose significant diagnostic and therapeutic challenges due to its steroid dependence and potential for recurrence.Patient concernsA 72-year-old Chinese man presented with a 6-month history of recurrent headaches. He later developed bilateral exophthalmos and progressive vision loss despite initial treatment. His past medical history included type 2 diabetes mellitus.DiagnosesThe patient initially tested positive for both p-ANCA and c-ANCA, with markedly elevated anti-myeloperoxidase and proteinase 3 antibody levels. Imaging revealed bilateral orbital masses consistent with orbital inflammatory pseudotumor, and biopsy confirmed sclerosing orbital inflammatory pseudotumor. Despite serological remission, clinical symptoms worsened during steroid tapering, suggesting steroid dependence.InterventionsThe patient was initially treated with high-dose corticosteroids and oral cyclophosphamide. Although symptoms improved transiently, relapse occurred upon tapering steroids. Rituximab (RTX; 500 mg weekly for 4 weeks) was then administered as second-line therapy.OutcomeThe patient experienced significant improvement following RTX therapy, which allowed successful steroid tapering. No further relapse occurred during short-term follow-up.LessonsThis case illustrates the limitations of cyclophosphamide-based regimens in managing steroid-dependent ANCA-associated orbital disease. RTX may be a more effective alternative in relapsing or refractory cases, particularly when ocular symptoms persist despite ANCA seronegativity. Early recognition and individualized immunosuppressive therapy are essential for preserving vision and improving outcomes in ocular ANCA-associated vasculitis.