Clinical and ultrasonographic characteristics of breast metastases from extramammary malignancies.

Breast metastases from extramammary malignancies are uncommon, constituting about 2 per cent of all breast tumors. Breast metastasis may be confused with primary benign or malignant neoplasm of the breast. An accurate diagnosis of breast metastasis is important because the treatment and outcome of primary and secondary malignancies of the breast are completely different. The clinical features of 15 patients with breast metastases from extramammary malignancies, excluding lymphoma, between 1982 and 2001 were retrospectively reviewed. There were 2 male and 13 female patients, with ages ranging from 16 to 73 years (median, 48 years). Primary tumors in the 15 cases were 3 hepatocellular carcinomas, 2 gastric carcinomas, 2 malignant melanomas, 1 colon carcinoma, 1 lung adenocarcinoma, 1 ovarian carcinoma, 1 uterine leiomyosarcoma, 1 nasopharyngeal carcinoma, 1 esophageal squamous carcinoma, 1 embryonal rhabodomyosarcoma, and 1 cervical carcinoma. Bilateral breast involvement was observed in two patients. A solitary lesion was evident in 13 patients, with 6 in the right breast and 7 in the left. The interval between diagnosis of primary cancer and the discovery of breast metastasis ranged from 0 to 144 months (median, 12 months). The follow-up period of the primary tumor ranged from 7 months to 156 months (median, 17 months). Breast metastases were associated with disseminated metastatic disease in 14 of the 15 patients. Fourteen of the patients died within a year of breast metastasis diagnosis; median survival was 4 months. Breast metastases from extramammary malignancy are infrequent. Virtually any malignancy can metastasize to the breast. Breast metastasis usually indicates disseminated metastatic disease and a poor prognosis.