Malignant melanoma of the breast: controversies in the diagnosis and therapeutic management of a rare nosologic entity.

Melanoma of the breast is an infrequent entity, presenting as either primary or metastatic from extramammary solid neoplasms. Depending on the involvement of the skin, primary malignant melanoma of the breast (PMMB) can be classified as cutaneous or noncutaneous. Cutaneous PMMB accounts for <5% of all melanomas and only 0.5% of all breast cancers. Furthermore, despite the rarity of metastatic breast neoplasms, melanoma comprises a frequent source of metastases. Metastatic potential of melanoma is associated with poor prognosis, and the majority of patients present more than one metastatic foci at the time of diagnosis. Diagnostic approach for both primary and metastatic melanomas of the breast is substantiated by fine needle aspiration (FNA) cytology along with immunohistochemistry. Nevertheless, verification of a metastatic mammary melanoma requires the discovery of a primary lesion. The mainstay of treatment for primary tumors is surgery, with radical local excision and axillary lymph node dissection or, on occasion, axillary sentinel node resection, while for metastatic tumors it depends on the specificities of the melanoma. Adjuvant therapy is always implemented. The aim of this survey is to meticulously review the literature of primary and metastatic malignant melanomas of the breast and report epidemiologic and clinicopathologic data for this rare entity. Clinical features, histogenesis, morphological, and immunochemical findings are discussed, while the role of current diagnostic and therapeutic management of this uncommon entity is emphasized.