Cutaneous epithelioid angiosarcoma: A potential diagnostic trap for cytopathologists

Angiosarcoma in FNA smears: diagnostic accuracy, morphology, immunocytochemistry and differential diagnoses

“…The differential diagnosis of epithelioid angiosarcoma includes adenoma, carcinoma, melanoma, high‐grade lymphoma, epithelioid sarcoma and all epithelioid variants of various sarcomas 13–15 . When a pleural mass is aspirated or cells are present in pleural effusion, mesothelioma must also be considered 4 .…”

“…Some authors have stated that melanin and nuclear inclusions in melanomas are helpful features in differentiating melanoma from angiosarcoma 5,6 . However, other authors have noted that nuclear inclusions can also be present in angiosarcomas 15 and that melanin cannot always be differentiated from haemosiderin 16 . Immunopositivity for S‐100 protein, HMB45 and melan A together with negativity for endothelial markers in melanomas is definitively more helpful.…”

Macrophage‐rich epithelioid angiosarcoma mimicking malignant melanoma

“…Finally, there have been documented cases showing weak positivity for cytokeratins in cutaneous epithelioid angiosarcoma. These findings underscore the necessity for additional staining for endothelial markers 4,5 , 7,10 , 11 …”

“…Unfortunately, undifferentiated or high‐grade epithelioid angiosarcomas usually are negative for Factor VIII‐RA. In some cases, weakly positive or focal staining may be detected in more differentiated areas of high‐grade angiosarcoma 7,10–12 . CD‐31 is an endothelial marker that is more helpful as it usually stains positive in classical cutaneous epithelioid angiosarcoma 3,4 , 8,10 …”

“…Nonetheless, as mentioned above, there have been rare cases of S‐100 protein positive cutaneous angiosarcomas. Therefore, it is wise to incorporate other melanoma markers such as HMB‐45 or MART‐1/Melan‐A 3,4 , 10,13 …”