Epithelioid hemangioma of the temporal artery clinically mimicking temporal arteritis

A rare case of epithelioid hemangioma (angiolymphoid hyperplasia with eosin ophilia) arising in the right temporal artery of a 68-year-old Japanese wom an was investigated. The patient had been treated with corticosteroids (Pre donine 5 mg/day p.o.) for 4 years for idiopathic thrombocytopenic purpura. Headaches in the right temporal region with repeated high fevers first appe ared 1 year prior to the biopsy of a nodule at the artery. The clinical dia gnosis was temporal arteritis (giant cell arteritis). The specimen consiste d of a short segment of the superior arterial branch having a sheetlike pro liferation of the epithelioid endothelial cells in the lumen, which was alm ost occluded, focal rupture of the media, and marked proliferation of the c apillaries (neovascularization) radiating out from the media to the adventi tia. There were scattered foci of inflammatory cell infiltration composed m ainly of small lymphocytes in the adventitia, but there were no histologica l changes suggestive of giant cell arteritis. The lesion was thus character ized by the proliferation of epithelioid endothelial cells in the lumen of the artery, and neovascularization between the media and adventitia. The hi stological features were very close to epithelioid hemangioma except for th e absence of an eosinophilic reaction. The long-term administration of cort icosteroids may have suppressed it. The authors believe this is the first c ase of epithelioid hemangioma arising from the temporal artery without a hi story of trauma. It showed some unique features both clinically and histopa thologically, which contributed to the study of the yet not clearly classif ied Vascular proliferative lesion, epithelioid hemangioma.