Metastasis from breast carcinoma to a tamoxifen-related endometrial polyp

Background. Metastasis of extragenital neoplasms to an endometrial polyp is rare and until now, only 6 cases of such involvement has been described. Case. A 58-year-old woman, who had been diagnosed 4 years ago with infiltrating ductal breast carcinoma and treated with surgery and tamoxifen therapy, was admitted to the gynecology clinic because of endometrial thickening observed during a routine abdominal ultrasonographic examination. A total hysterectomy with bilateral salpingo-oophorectomy was performed. Pathological examination of the specimen showed a large polyp which microscopically showed clusters of cells with signet ring morphology within the polyp stroma. The positivity of tumor cells for GCDFP-15 supported the diagnosis of metastatic breast carcinoma to endometrial polyp. Conclusion. Metastatic breast carcinoma should be considered in the differential diagnosis of carcinomas with signet ring cell morphology involving uterus. (c) 2005 Elsevier Inc. All rights reserved.