Primary Angiomatoid Melanomas in Dogs

Melanocyte-derived tumours are common in humans and animals and their spontaneous occurrence in dogs and the clinicopathological progression in malignant presentations is comparable with humans. Melanomas are a heterogeneous group of malignant neoplasms and several subtypes have been classified, including angiomatoid melanoma, of which only five cases have been reported in humans but none in animals. We now document cases of primary angiomatoid melanoma in the skin and oral cavity of two dogs. Neoplastic cells resembling endothelial cells that lined large blood vessels in the tumours were immunonegative for CD34 but intensely positive for SOX10.