Metastases to the Breast from Extramammary Neoplasms

Abstract

Metastatic deposits to the breast from extramammary neoplasms are rare. Clinically and radiologically, metastatic neoplasms may mimic primary benign and malignant neoplasms of the breast. A correct diagnosis of metastasis to the breast is of considerable importance since the treatment of primary and secondary malignancies of the breast is different. Six cases of metastatic neoplasms in the breast were diagnosed by fine needle aspiration biopsy (FNAB). The cases included poorly differentiated squamous carcinoma of the cervix, endometrial adenocarcinoma, gastric signet-ring cell carcinoma, small cell carcinoma of the lung, large cell carcinoma of the lung and plasma cell myeloma. Four of the patients were female and two male. Four had a previously diagnosed extramammary malignancy, but in two cases the breast mass was the first manifestation of cancer. A correct cytologic diagnosis was made in all six cases. FNAB can distinguish metastatic deposits from primary breast tumors even when this is the first presentation of an extramammary neoplasm. A good knowledge of cytomorphology and histomorphology, together with clinical correlation and comparison with previous cytologic/histologic material, will prevent an incorrect diagnosis.