Uterine carcinosarcoma showing immature teratoid-like differentiation.

A carcinosarcoma is a rare form of cancer characterised by the presence of both carcinomatous and sarcomatous components. Here, we present our experience with an extremely rare case of an uterine carcinosarcoma with immature teratoid-like differentiation. The patient was a woman in her 60s. She was referred for the evaluation of a uterine tumour. She underwent total abdominal hysterectomy with bilateral adnexectomy and received postoperative treatment with paclitaxel and carboplatin. On microscopic examination, the tumour had a heterogeneous appearance with a combination of carcinomatous and sarcomatous elements, and teratoid features. The tumour included immature squamous epithelial cells and immature epithelial glands, and focal atypical fused glands, which are consistent with endometrioid carcinoma, were identified in the endometrium. Pathological differentiation from extrarenal Wilms' tumour and teratocarcinosarcoma was challenging. The final pathological diagnosis was uterine carcinosarcoma with immature teratoid-like differentiation. At 14 months after the surgery, the patient has not experienced recurrence.