We read with interest the article on carcinoid tumor metastatic to the breast by Rubio et al1 published in the October 1998 issue of the ARCHIVES. For the benefit of the readers, we would like to update the data on tumor metastasis to the breast.
Using the MEDLINE database and other reports,2 we have reviewed 24 articles presenting data from 1855 to 1998. We found a total of 431 cases of tumor metastasis to the breast. The primary sites for metastasis were malignant melanoma (87 cases), lung (78 cases), ovary (50 cases), prostate (39 cases), kidney (24 cases), stomach (15 cases), ileum (13 cases), thyroid (12 cases), cervix (12 cases), and other (101 cases). On the basis of this review, we found an unusually high number of malignant melanoma metastases to the breast.