[Targetoid hemosiderotic hemangioma].

Introduction: Targetoid hemosiderotic hemangioma (THH) is a new vascular disorder, rarely reported. The lesion presents as violaceous papule surrounded by an ecchymotic ring usually measuring less than 1 cm in diameter. Epithelioid endothelial cells with a hobnail appearance, vascular papillary projections and hemosiderin deposits are the histological hallmarks of this entity.
Observation: We report a case fulfilling these criteria. Particular morphologic features were the presence of a very prominent lymphocytic infiltrate, with numerous intraluminal lymphocytes closely associated with the neoplastic endothelial cells, scarcity of siderophages, rought of retiform pattern, predilection of newly formed vessels for muscles of hair erection and eccrine ducts.
Discussion: Having regard to these worrisome histologic features the differential diagnosis between THH, Kaposi's sarcoma and newly recognized entities such as lymphangioendothelioma and retiform hemangioendothelioma is discussed.