Carcinoid tumors in the breast

Background Carcinoid tumors in the breast are rare. Most represent metastases from other primary sites, but commonly are mistaken for primary breast lesions. Methods A literature search of the English language found 59 cases of carcinoid tumors in the breast, 21 (36%) of which were metastases. Results We present an additional 3 cases of carcinoid tumors metastatic to the breast and discuss the clinical, radiologic, and pathologic manifestations. Conclusions It is important to differentiate between primary breast carcinoid tumor and metastatic disease to the breast because of differences in treatment. All palpable breast masses and mammographically detected lesions should undergo a biopsy examination. In those patients with a known history of carcinoid tumor, pertinent clinical history, and previous surgical specimens should be reviewed to avoid an unnecessary mastectomy. If there is no history of a prior carcinoid tumor, a thorough work-up to look for an occult primary tumor elsewhere should be performed.