Case Presentation: An 80-year-old male with past medical history of angiosarcoma of the scalp status-post resection, presented for a right lung biopsy for an incidental pulmonary nodule. However, a CT chest performed prior to the procedure revealed a new hydropneumothorax. The patient reported symptoms of a productive cough with intermittent hemoptysis, along with an unintentional 30-pound weight loss over three years. He denied fever, chills, or night sweats. Laboratory evaluation revealed a hemoglobin of 9.7 g/dL, normal white cell count, eosinophilia of 11.4%, erythrocyte sedimentation rate (ESR) of 48 mm/hr, C-reactive protein (CRP) of 6 mg/L, and negative procalcitonin. A chest tube was placed, and a lung biopsy was performed. Pleural fluid analysis revealed an exudative effusion with 85% eosinophils. Cytology and gram stain were negative. The patient underwent a robotic-assisted diagnostic wedge resection with lysis of adhesions. Pathology demonstrated diffuse interstitial chronic inflammation with eosinophilic infiltration. Stains for mycobacteria and fungi were negative. Serum IgE was elevated at 1100 IU/mL, while parasitic serologies, ANA, and ANCA were negative. Final histopathology revealed intra-alveolar hemorrhage, non-caseating granulomas, and a prominent eosinophilic infiltrate raising high suspicion for EGPA. Given peripheral eosinophilia and extravascular eosinophil-predominant inflammation, the patient met the 2022 ACR/EULAR classification criteria for EGPA.
Discussion: EGPA is a multisystem disease with varying severity. It differs from GPA in that it is characterized by eosinophilia along with the characteristic necrotizing granulomatous inflammation seen in GPA [3]. Although pathogenesis of EGPA is not fully understood, it involves eosinophilic-mediated and ANCA-mediated processes with significant roles for both innate and adaptive immunity [4]. It typically presents in three phases: 1) Allergic rhinitis/adult-onset asthma. 2) Peripheral eosinophilia. 3) Vasculitis with organ damage [5]. However, it can present atypically as well. While ANCA-positive EGPA presents with renal involvement, ANCA-negative EGPA usually presents with cardiac and pulmonary infiltration. Clinically, 30% to 50% of patients with EGPA are ANCA positive, with MPO-ANCA accounting for 70% of the cases [6]. Based on EULAR, clinical criteria include obstructive airway disease (+3), nasal polyps (+3), mononeuritis multiplex (+1). Laboratory and biopsy criteria include blood eosinophil count >1 x10^9/liter (+5), extravascular eosinophilic-predominant inflammation on biopsy (+2), positive c-ANCA or anti-PR3 antibody (-3), and hematuria (-1). A score of greater than 6 is diagnostic of EGPA [7]. Our patient had a score of at least 7 based on blood eosinophilic count and lung biopsy findings of eosinophilic-predominant inflammation, thus confirming the diagnosis of EGPA. The patient would have benefited from high-dose steroids given his latest pathology report showed that he was in vasculitic stage. However, before the diagnosis was confirmed, the patient’s condition acutely deteriorated with him requiring intubation and the family chose to go for comfort measures.
Conclusions: This case underscores the diagnostic challenges of EGPA, a rare and often elusive condition that can lead to life-threatening complications if not promptly identified. Thus, a greater clinical awareness among hospitalists for vasculitides is crucial to achieving earlier diagnosis and better outcomes.