Angiotropism in epidermotropic metastatic melanoma: another clue to the diagnosis

The diagnosis of epidermotropic metastatic malignant melanoma (EMMM) can be extremely challenging for both clinicians and pathologists. The diffculties include distinguishing metastatic lesions with an epidermal component from residual incompletely excised primary melanoma, and multiple primary melanomas. This has great prognostic significance as the current American Joint Committee on Cancer guidelines consider localized metastatic disease such as satellites and intransits in the nodal (N) category of N2C or stage IIIB disease. In this report, we present a case of EMMM with angiotropism. Additionally, we discuss in detail the differential diagnosis for recurrence of malignant melanoma with an epidermal component within the scar. Angiotropism may be seen in lesions of EMMM and the current literature suggests that angiotropism is highly suggestive of metastatic melanoma. The differential diagnosis of locally recurrent melanoma with an epidermal component can be extremely challenging and the presence of angiotropism may be a clue to the diagnosis of EMMM.