A case of eosinophilic angiocentric fibrosis with possible lung involvement

SESSION TITLE: Not all Lung Problems Start Within the Lungs SESSION TYPE: Case Reports PRESENTED ON: 10/10/2023 08:30 am - 09:30 am INTRODUCTION: IgG4 related disease is a systemic fibroinflammatory disease, characterized by various organ involvement. In 2011, eosinophilic angiocentric fibrosis (EAF) was included as a subgroup of IgG4 related disease. Here, we present a case of EAF with possible pulmonary involvement. CASE PRESENTATION: A 55-year-old woman with history of pyoderma gangrenosum, recurrent sinusitis, and 30 pack year smoking history, presented to the hospital with progressively worsening right eye swelling and diplopia of three months' duration. Exam was notable for right eye proptosis. A computed tomography (CT) scan of the orbits revealed a large mass along the medial aspect of the right orbit, infiltrating the extraocular muscles and optic nerve, and extensive right side pansinusitis. She underwent surgical resection of the mass, the biopsy revealing various evolutionary stages of a fibroinflammatory process characterized by perivascular inflammatory infiltrate composed of lymphocytes, plasma cells, and eosinophils. There was a predominant pattern-dense angiocentric fibrosis characterized by an onion skin whorled appearance. IgG4 immunostaining showed 31 IgG4 positive cells/HPF, features most consistent with eosinophilic angiocentric fibrosis. Further laboratory workup revealed an ESR of 65 mm/hr, ANA of 1:320, C-ANCA titer of 1:80, IgG level of 1586 mg/dL, and IgG4 level of 67.1 mg/dL. She was started on corticosteroids and Rituximab for treatment of EAF. Chest CT revealed an infiltrative soft tissue encasing the right upper lobe bronchus with significant bronchial narrowing, measuring 4.7 x 1.7 cm. Bronchoscopy with endobronchial ultrasound confirmed the narrowing of the right upper lobe takeoff due to extrinsic compression. Though the biopsies were nondiagnostic, they did show acute inflammatory cells and multinucleated histocytes. Patient was discharged home on prednisone taper and continued Rituximab. DISCUSSION: Eosinophilic angiocentric fibrosis (EAF) is a subgroup of IgG4 related diseases, characterized by tumefactive lesions involving the orbit and upper respiratory tract. EAF was first included in the spectrum of IgG4 related diseases, after numerous cases of EAF fulfilled a histologic diagnostic criterion for IgG4 related disease. However, limited cases are reported in literature describing pulmonary involvement. Of those described, pulmonary EAF may present with dyspnea and have peribronchial involvement on imaging. Although not histopathologically proven, our patient had known EAF involving the orbit and sinonasal tract, along with typical radiographic findings suggestive of pulmonary EAF. The case aims to highlight the varied presentations of IgG4 related diseases and provides further insight to the rare subgroup of EAF. CONCLUSIONS: Pulmonary eosinophilic angiocentric fibrosis is an extremely rare presentation of EAF and IgG4 related disease typically presenting with peribronchial infiltrates. REFERENCE #1: Deshpande V, Khosroshahi A, Nielsen GP, Hamilos DL, Stone JH. Eosinophilic angiocentric fibrosis is a form of IgG4-related systemic disease. Am J Surg Pathol. 2011 May;35(5):701-6. doi: 10.1097/PAS.0b013e318213889e. PMID: 21502911. REFERENCE #2: Stone JH, Zen Y, Deshpande V. IgG4-related disease. N Engl J Med. 2012 Feb 9;366(6):539-51. doi: 10.1056/NEJMra1104650. PMID: 22316447 REFERENCE #3: Deshpande, V., Zen, Y., Chan, J. et al. Consensus statement on the pathology of IgG4-related disease. Mod Pathol 25, 1181–1192 (2012). https://doi.org/10.1038/modpathol.2012.72 DISCLOSURES: No relevant relationships by Elie Fares No relevant relationships by Vani Mulkareddy No relevant relationships by michael scharf