PECAM1 and melanoma: The tumour cells are highly heterogeneous, epithelial-like and eosinophilic with obvious nucleoli and abundant cytoplasm, and many cells are mitotic.[6, 7, 9] However, since sarcomas have epithelial-like features, they are often misdiagnosed as poorly differentiated cancer or melanoma, and thus, immunohistochemistry, such as CD31, CD34, F VIII factor, and CD117 staining,[2, 10] is needed to confirm the diagnosis.