Breast carcinoma metastatic to endometrial polyp.

An elderly woman presented with an enlarged uterus without uterine bleeding. The hysterectomy specimen contained a large, solitary intrauterine mass. Microscopic examination revealed metastatic poorly differentiated adenocarcinoma infiltrating an endometrial polyp. This metastatic tumor appeared histologically identical to the patient's ductal carcinoma of the breast removed by modified radical mastectomy 6 years earlier. An extrapelvic primary carcinoma metastatic to tan endometrial polyp is a very rare event but should be included in the differential diagnosis of endometrial carcinomas.