BackgroundEosinophilic granulomatosis with polyangiitis (EGPA) is a systemic necrotizing vasculitis mainly affecting small-sized arteries. Involvement of medium-sized vessels is very rare in EGPA. Here we present the case of a patient with EGPA who showed multiple hepatic aneurysms and distal gangrene.Case presentationA known EGPA patient visited to the emergency room (ER) with abrupt squeezing abdominal pain. She had suffered from gangrene in the fingertips of both hands for 1 year because of arterial thrombosis associated with hypereosinophilia. However, her absolute eosinophil count in the ER was 1120 cells/µL. An abdomen-pelvis CT demonstrated subcapsular hematoma in the right hepatic lobe. A celiac angiogram demonstrated multiple sized aneurysms in both hepatic lobes and some aneurysms in S7 and S8 were huge, more than 1 cm in size. The shape of the small aneurysms resembled a string of beads, as in polyarteritis nodosa. Given the clinical situation, emergency embolization was performed. Before this patient visited to the ER, she had been treated with a high dose of systemic corticosteroid, azathioprine, and cyclophosphamide. After addition of mepolizumab, the eosinophil count remained stable state with a near zero percentage of total white blood cell count.ConclusionsAneurysm and gangrene resulting from the involvement of medium-sized vessels can occur in EGPA. Destruction of vessels might occur even if eosinophil count is below 1500 cells/µL. If involvement of medium-sized arteries is suspected, thorough investigation to identify the involved organs and prompt management are needed to prevent fatal complications.