Eosinophilic angiocentric fibrosis (EAF) is a rare, slowly progressive fibrosing condition with a predilection for the upper respiratory tract, particularly the nasal cavity. Patients often present with nonspecific nasal symptoms and may experience rare ocular manifestations such as epiphora, diplopia, and proptosis. We report a case of a 39-year-old male who presented with sudden-onset vision loss, ptosis in right eye and diplopia, which was found to be associated with recurrent EAF leading to compressive optic neuropathy. Despite initial management with intravenous steroids, the patient showed no improvement and was subsequently treated with rituximab. This case highlights the importance of considering EAF in the differential diagnosis of orbital masses and emphasizes the role of immunosuppression in managing recurrent cases.

Eosinophilic Angiocentric Fibrosis (EAF) is a rare inflammatory condition affecting the upper respiratory and sinonasal tracts. This study aims to elaborate on the clinical and pathological features of a patient with extensive, rare EAF involving the sinonasal tract, subglottic region, and orbit. A fifty-five-year-old female patient with a known case of bronchial asthma, hypothyroidism, and IgG-4-related necrotizing blepharitis presented to our clinic with a 14-year history of bilateral nasal obstruction and post-nasal drip despite medical and surgical intervention. Rhinoscopy revealed fibrosis and adhesion of the nasal cavity and nasopharynx, along with grade I subglottic stenosis. Functional endoscopic sinus surgery was performed to relieve her symptoms and obtain a specimen confirming the diagnosis of EAF. Given the wide variety of differential diagnoses for bilateral nasal obstruction, imaging and histopathological evaluation are necessary to diagnose EAF. The characteristic onion-skin pattern reflecting the perivascular eosinophil-rich inflammatory infiltrate with subsequent concentric fibrosis is the gold standard in diagnosing these patients. Despite advancements in clinical practice, a clear management guideline for patients with EAF has not yet been established. In our paper, we pool our management approach with the literature.

Eosinophilic angiocentric fibrosis (EAF) is a rare, tumefactive inflammatory process of the sinonasal and upper respiratory tract and orbit. Numerous histologic mimickers of EAF occur in these locations. A comprehensive literature review focused on EAF and its histologic mimickers was performed. This manuscript serves as an overview of the histopathological characteristics of EAF and its histologic mimickers, including granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), sinonasal inflammatory polyps, epithelioid hemangioma, invasive fungal rhinosinusitis, Langerhans cell histiocytosis, rhinoscleroma, inflammatory myofibroblastic tumor, and fibromatosis. A correct diagnosis of EAF can be reached by identifying the classic histopathologic features of prominent eosinophilia, lymphoplasmacytic inflammation, and concentric perivascular fibrosis. Additionally, as EAF sometimes lies on the spectrum of IgG4-related disease, immunohistochemistry and serologic studies can be used to aid in diagnosis.

Introduction: Immunoglobulin G4 (IgG4) related disease is a localized or multisystem chronic inflammatory disease with characteristic pathological features. Several consensus criteria are available to aid in the diagnosis and its management. These criteria are highly specific, owing to their dependency on major histopathological criteria and laboratory investigations to diagnose IgG4-related diseases (IgG4-RD). We evaluated the lesions diagnosed as IgG4-RDs with histopathological scoring criteria based on histopathology, immunohistochemistry, and serology in the screening of IgG4-RDs. Materials and methods: The lesions diagnosed as IgG4-RD during the study period were evaluated using the histopathological scoring criteria which include storiform fibrosis, obliterative phlebitis, plasmacytic infiltrates, and lymphoid follicles. Immunohistochemistry with IgG4 was performed on all these lesions. Results: There were twelve patients with IgG4-RD involving the retroperitoneum, pancreas, lymph node, and nasal sinuses. Lesions involving the retroperitoneum showed all the characteristic histopathological findings of IgG4-RD. Storiform fibrosis and obliterative vasculitis were seen in 67% and 58% of the lesions respectively. Two patients (17%) lacked both storiform fibrosis and obliterative phlebitis. Additionally, lymphoid follicles were present in 58%, perineural infiltration in 33%, and tissue eosinophilia in 58% of individuals. Two patients with eosinophilic angiocentric fibrosis and a single patient with IgG4-RD associated with retroperitoneal mucinous cystadenoma were identified. Conclusion: IgG4-RD is a group of rare diseases that needs a multidisciplinary team approach for diagnosis. In our study, we report a rare association of IgG4-RD and retroperitoneal mucinous cystadenoma as well as rare lesions of IgG4-related eosinophilic angiocentric fibrosis. Clinicopathological and radiological correlation is crucial in the accurate diagnosis of IgG4-RD and to avoid overdiagnosis.