Uterine carcinosarcoma with heterologous chondrosarcomatous differentiation and bone formation – A rare case report

Uterine carcinosarcomas are rare tumors that make up fewer than 5% of all uterine malignancies. These tumours are dedifferentiated carcinomas that originate from a single malignant clone and contain both carcinomatous (Epithelial) and sarcomatous (Mesenchymal) features, which were formerly known as malignant mixed Müllerian tumours (MMMT). We present here a case of 77 years old female patient with a polypoidal endometrial neoplasm. The patient underwent Extra-fascial Hysterectomy with Bilateral salpingo-oophorectomy. On histopathological examination it showed features of carcinosarcoma with tumor cells composed predominantly of sheets of dyscohesive tumor cells, focally exhibiting severe pleomorphism with bizarre nuclei, areas of myxoid change with chondrosarcomatous differentiation and heterologous bone formation with focal areas showing serous carcinoma. The patient develop malignant pleural effusion and succumbed to the disease on follow up. This case report reiterates the poor prognosis associated with the disease and highlights the importance of extensive sampling in case of polypoidal tumors to prevent misdiagnosis especially when the tumor is mesenchymal predominant which can help to start early treatment.