Poorly differentiated endometrial sarcoma with clear cell features - Case report

A case of poorly differentiated endometrial sarcoma with clear cell features in a 46-year-old female is presented. A 9 x 8 x 6 cm, transmural, white solid tumor in the uterine fundic wall was characterized histologically by infiltrative growth and a solid arrangement of tumor cells with clear cytoplasm. The tumor showed vascular invasion, moderate to severe cellular atypia, mitotic activity of 20 per 10 high-power fields and necrosis. It was immunohistochemically positive for vimentin and negative for CAM5.2, epithelial membrane antigen, desmin, alpha-smooth muscle actin, muscle actin, estrogen and progesterone receptors. Electron microscopy showed that the clear cytoplasm was attributed to the presence of numerous dilated mitochondria and lipid droplets. Flow cytometry showed a diploid phenotype. Pathologists should be aware of the existence of this type of endometrial sarcoma with clear cells and should not confuse it with other neoplasma showing clear cell features.