[A case of malignant peritoneal mesothelioma with a good response to treatment].

A rare case of malignant peritoneal mesothelioma in a 49-year-old Japanese woman is presented. The tumor was limited to the peritoneum, and was cytologically and histologically identified as being composed of two components, epithelial and non-epithelial forms. The transition in her CA-125 level suggested that this tumor had good prospects of developing into a malignant mesothelioma. The good prognosis of the patient is considered to be attributed to detecting this tumor in its early stage and to aggressive chemotherapy.