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.