Melanoma Metastasis to the Breast Masquerading as Fibroadenoma

Background: Although primary malignant breast lesions are common, tumor metastasis to the breast is rare. Melanoma metastasis to the breast occurs even more rarely. Case: In the present case report, we describe an adolescent girl with malignant melanoma metastasis to the breast masquerading as fibroadenoma, in which it was impossible to perform differential diagnosis based only on the physical examination and ultrasonographic evaluation. The definitive diagnosis both of the primary and of the metastatic lesion was reached by immunohistochemistry, which revealed positivity to Mart-1 antibody. Conclusion: Melanoma metastasizing to the breast is occasionally indistinguishable from a benign lesion at ultrasonographic evaluation. Emphasis should be made on the importance of a correct diagnosis prior to therapeutic management.