Hobnail hemangioma occurred on the back = Hobnail hemangioma occurred on the back

다국어 초록 (Multilingual Abstract)

Hobnail hemangioma(HH) is a rare, vascular, benign solitary lesion of lymphatic origin. The typical clinical appearance is a single, annular, vascular lesion with a targetoid appearance. We report a case of 23-year-old female patient presenting with targetoid lesion on the back for 4 months. Physical examination revealed a solitary 1x1.5cm sized violaceous, slightly elevated papule surrounded 2x2.5cm sized round shaped ecchymotic ring on the back. Histopathologic findings of violaceous elevated papule revealed dilated, irregular vascular spaces in the papillary dermis. Peripheral areas showed dilated vessels with prominent plump endothelial cells with intraluminal papillary projections, showing a hobnail appearance in the papillary dermis. Deeper in the dermis, the vascular spaces were slit-shaped, angulated, and dissecting the collagen bundles. Immunohistochemical studies revealed that CD31 and D2-40 were expressed, but WT-1 was focally or weakly positive in the endothelial cells of the peripheral vessels showing a hobnail appearance. But, CD31, D2-40, and WT-1 were expressed in the endothelial cells of the central vessels. We diagnosed this case as a HH originating from a pre-existing hemangioma. Although the exact pathogenesis of HH is unknown, trauma is one of the main causes for the targetoid appearance. In our case, HH developed after trauma caused by friction from a clothing to a pre-existing hemangioma.