Metastatic breast carcinoma manifesting as postmenopausal uterine bleeding in a patient on tamoxifen therapy.

A rare case of breast carcinoma metastasizing to the endometrial and endocervical mucosa during tamoxifen treatment is presented. Routine histologic evaluation has been supplemented by immunohistochemical staining for intermediate filaments. Although the association of tamoxifen therapy for breast carcinoma with the development of endometrial carcinoma is well known, this is, to the best of our knowledge, the first report of metastatic breast carcinoma to the uterus of a patient on tamoxifen therapy.