Cutaneous malignant epithelioid neoplasms.

In summary, cutaneous malignancies with an epithelioid appearance form a diverse group of neoplasms that may be difficult to diagnose by utilizing routine microscopy alone. Cutaneous malignancies, including malignant melanoma and metastatic carcinoma, certain benign neoplasms such as mixed tumor of the skin and angiolymphoid hyperplasia with eosinophils (epithelioid hemangioma), and infectious conditions such as bacillary (epithelioid) angiomatosis can be considered in this differential. However, through recognition of the characteristic histologic, immunocytochemical, and ultrastructural findings outlined above, definitive diagnosis of these challenging neoplasms is usually possible.