Pediatric eosinophilic granulomatosis with polyangiitis presenting as a mediastinal mass in a 6-year-old boy.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a small vessel vasculitis characterized by asthma, eosinophilia, and small vessel necrotizing granulomatosis with annual incidence of 0.5-4.2 cases per million. EGPA is uncommon in childhood and only a handful of pediatric cases have been reported in the literature making it difficult to diagnose. EGPA in the pediatric population presenting with mediastinal mass is extremely rare. Here, we present a rare case of pediatric EGPA with unique presentation i.e. mediastinal lymphadenopathy in a 6-year-old boy who presented with recurrent episodes of cough and shortness of breath. On further evaluation, patient was found to have mediastinal lymphadenopathy and the diagnosis of pediatric EGPA was confirmed by histopathology of the mass. High dose steroid was started at 1mg/kg/day and then gradually tapered to maintenance dose and weaned off after remission. Diagnosis of EGPA in pediatric population is challenging and requires careful differentiation under mimicking conditions. Though uncommon, EGPA can cause mediastinal lymphadenopathy and should be considered a differential diagnosis.