Koebner phenomenon on skin graft donor site in cutaneous angiosarcoma.

An 81-year-old woman developed a necrotic plaque and a surrounding purple-red, irregularly shaped macule on her scalp. The diagnosis of angiosarcoma was confirmed histologically. A wide surgical excision was made followed by a split-thickness skin graft from her right buttock. Nine months later, she noticed a dark purple-red lesion on the donor site which grew rapidly into a large mass. Histological examination revealed irregular clefts and vascular channels lined by atypical endothelial cells. Lung metastasis and pneumothorax were also noted. The secondary tumor appeared to represent Koebner phenomenon in a patient with angiosarcoma of the scalp.