A35-18 Overlapping Shadows: Navigating the Complexities of Sarcoidosis and Eosinophilic Granulomatosis With Polyangitiis in an Elderly Patient With Eosinophilic Granulomatous Lung Disease

Abstract Introduction Sarcoidosis is a multisystem inflammatory disease characterized by non-necrotizing granulomas, affecting the lungs and intrathoracic lymph nodes. EGPA is a necrotizing vasculitis marked by asthma, peripheral eosinophilia, and eosinophil-rich granulomatous inflammation. We present a rare case of an older woman with features of both sarcoidosis and EGPA overlap. Case Presentation A 93-year-old woman, a non-smoker, presented with a chronic cough persisting for four years. CT chest revealed an irregular, lobulated mass in the periphery of the right upper lobe, suspicious for malignancy, along with multiple enlarged mediastinal lymph nodes. A PET-CT scan demonstrated FDG uptake in the right upper lobe nodule and hypermetabolic activity in the right supraclavicular, mediastinal, and bilateral hilar lymph nodes. Bronchoscopy with EBUS revealed enlarged subcarinal, right paratracheal, and right hilar lymph nodes. Transbronchial needle aspiration biopsies of these lymph nodes demonstrated non-necrotizing granulomas, consistent with sarcoidosis. Over time, the patient developed cough, dyspnea, chest tightness, and relief with albuterol. These features suggested airway involvement of sarcoidosis or asthma overlap. She was initiated on inhaled corticosteroid/long-acting beta-agonist (ICS/LABA) therapy, resulting in symptomatic improvement. The patient later experienced a transient ischemic attack with transient right arm numbness, right eye blurring, and dizziness. She had recurrent asthma exacerbations. Workup included normal spirometry. Laboratory data revealed marked peripheral eosinophilia (absolute eosinophil count 2,910 cells/μL) and elevated IgE level (284 IU/mL), suggestive of Type 2 (T2) inflammation. Given her constellation of asthma-like symptoms, eosinophilia, neuropathic symptoms, and a pulmonary nodule, the differential diagnosis was broadened to include eosinophilic granulomatosis with polyangiitis (EGPA). P-ANCA and C-ANCA were negative, while atypical ANCA was indeterminate. Strongyloides, Echinococcus, and Toxocara serologies were negative, ruling out parasitic etiologies. Given persistent respiratory symptoms and peripheral eosinophilia >1,000/μL, the patient was initiated on oral prednisone 20 mg daily, planned for a 6-month course with gradual tapering. Mepolizumab (anti-IL-5 therapy) was initiated, targeting her hypereosinophilic/asthma-EGPA overlap phenotype. The patient demonstrated sustained clinical improvement after initiation of these medications. Discussion The non-necrotizing granulomas on lymph node biopsy supported sarcoidosis, though the presence of eosinophilia and asthma-like features, and peripheral neuropathy suggested a possible EGPA. The case highlights diagnostic complexity of differentiating Sarcoidosis and EGPA- when there are overlapping clinical and radiographic data. This also the therapeutic challenge of managing elderly patients with eosinophilic inflammation and granulomatous disease, where individualized therapy combining ICS/LABA, corticosteroids, and biologic agents can lead to significant clinical improvement. This abstract is funded by: none