Primary malignant melanoma of the breast: case report and review of the literature.

BACKGROUND

Melanoma of the breast is a rare disease and may present as a metastatic manifestation of primary cutaneous melanoma or as primary malignant melanoma of the breast (PMMB). Clinical presentations of PMMB vary and surgery is the mainstay of treatment.

CASE REPORT: We present the case of a 54-year-old woman with a primary malignant melanoma of the left breast. She was treated with mastectomy, axillary sentinel lymph node excision and primary reconstruction with a tissue expander. Final histology revealed a malignant melanoma with 10 cm in the largest diameter. Molecular characterization by DNA-sequencing showed B-RAF, N-RAS and c-kit wild types. Immunohistochemical characterization demonstrated weak expression of S100 and melan-A and strong expression of polyclonal S100. HMB45, tyrosine kinase and the cytokeratins AE1/AE3 and MNF 116 were not expressed. Lymphoma-specific markers (CD30, CD3, CD20) and sarcoma-specific markers (desmin, actin, CD34) were also negative. The tumor proliferation rate according to Mib1-staining was 90%. Staging of the abdomen, chest, head and bones showed no evidence of metastases. A dermatological examination showed no primary melanoma of the skin. Interferon-alpha was suggested as adjuvant therapy but declined by the patient. With a follow-up of 6 months, the patient is still alive with no evidence of disease.

CONCLUSION

PMMB is rare and may be successfully treated with surgical excision. Locally advanced PMMB may occur without regional and distant metastases.