A diagnostic conundrum; Kimura's disease mimicking eosinophilic granulomatosis with polyangiitis.

Kimura's Disease (KD) is a benign, relapsing chronic inflammatory condition often seen in young Asian males, manifesting as recurrent swellings in skin and subcutaneous tissues especially in the head and neck region. Eosinophilic granulomatosis with polyangitis (EGPA) is a debilitating multisystem vasculitic condition which causes high morbidity due to cavitating lung lesions, neuropathy and renal impairment. Eosinophilia is common to both conditions. We, herein present a young Asian male with KD who presented with isolated recurrent nasopharyngeal mucosal swelling with eosinophilia. Biopsy of the lesion showed necrotizing vasculitis and eosinophilic granulomata mimicking EGPA. Nevertheless, he did not have any other characteristic systemic features of EGPA. Targeted evaluation through multidisciplinary approach helped secure the diagnosis of KD. KD has a wide range of presentation. The three cardinal histopathologic features in KD are eosinophilic inflammation, vascular proliferation and stromal fibrosis. However, vasculitis, granulomata and variable degree of necrosis can be present as in this case. He responded well to a course of steroids followed by Mycophenolate Mofetil. This minimized iatrogenic morbidity to the patient resulting from use of highly toxic immunomodulators which are not necessary in KD unlike in EGPA.