Breast Metastasis From Cutaneous Melanoma: Beyond the Infiltrating Ductal Carcinoma

Breast metastases of extramammary origin are an extremely rare entity. Solid organ metastases to the breast include malignant melanoma, epithelial carcinoma (adenocarcinoma and squamous cell carcinoma of the lung and gastrointestinal tract), and sarcoma. A breast neoplasm can be caused by a primary tumor, in-transit metastasis, breast metastasis, and skin metastasis. A 42-year-old female patient presented with a hyperpigmented lesion on the first finger of her left hand. An incisional biopsy was carried out, reporting pigmented epithelioid melanoma. Amputation of the finger was performed, as well as an axillary sentinel lymph node excision. Later during the treatment and follow-up by medical oncology, a breast tumor was located, followed by a protocol and the approach of possible differential diagnoses. Finally, it was characterized as metastatic cutaneous melanoma. The therapeutic approach regarding the possible origin of the metastatic neoplastic character of breast tumors culminated in this case in the palliative treatment with immunotherapy of cutaneous malignant melanoma. The diagnosis of breast metastases from cutaneous malignant melanoma is a real challenge, so an extensive history and high clinical suspicion are crucial in order to provide adequate treatment, despite the gloomy prognosis.