Histological evaluation of mixed mesodermal tumor of the ovary.

Mixed mesodermal tumor (MMT) arising from the ovary is very rare, but we recently encountered two cases of this tumor. The tumors were examined histologically using hematoxylin-eosin, alcian blue, periodic acid-Schiff (PAS), and toluidine blue staining, as well as immunohistochemical staining for S-100 protein. The two patients were postmenopausal women aged 68 and 58 years, respectively. The carcinomatous region of the mixed tumor was endometrioid carcinoma in Patient 1 and serous cystadenocarcinoma in Patient 2, while the sarcomatous region was chondrosarcoma in both patients. The chondrosarcoma tissue was positive for PAS, alcian blue, toluidine blue, and S-100 protein.