Uterine malignant mixed müllerian tumor after adjuvant tamoxifen treatment for breast cancer

Background:  Uterine malignant mixed müllerian tumor, also known as carcinosarcoma, is a biphasic tumor of the female genital tract and demonstrates both malignant epithelial (carcinoma) and mesenchymal (sarcoma) components. We present 2 cases of uterine malignant mixed müllerian tumor after adjuvant tamoxifen treatment for breast cancer and review current literature.
Cases: Our patients presented with a complaint of abnormal uterine bleeding. They had history of breast cancer stage ΙΙb treated with modified radical mastectomy, before 51 and 78 months respectively. They also had history of tamoxifen treatment 20 mg daily for 7 and 73 months respectively. They underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and total omentectomy. The histopathology revealed uterine malignant mixed müllerian tumor. Postoperatively, they receive adjuvant chemotherapy and radiotherapy. One of our patients, died 26 months after initial surgery for uterine MMMT.
Conclusion: Uterine MMMT is a rare, highly aggressive and rapidly progressing tumor associated with a poor prognosis. Postmenopausal patients, with prolonged adjuvant TAM treatment for breast cancer, are at increased risk for the development of uterine MMMT.