Congenital extraneural hemangioblastoma in a lamb

A 1-mo-old Ivesi male lamb was presented with 2 large red masses on the skin of the left ear. The tumors were removed using gentle dissection and submitted for histologic evaluation. The tumors consisted of numerous thin-walled capillaries lined by endothelial cells and nests of stromal cells. Immunohistochemically, the endothelial cells were positive for CD45, and the stromal cells were positive for neuron-specific enolase. GFAP-positive cells were occasionally present within the tumor. Endothelial and stromal cells were negative for S100, CD34, CD31, and factor VIII–related antigen. The tumor had strong gross, microscopic, and immunohistochemical similarities with human extraneural hemangioblastoma.