[A case of diffuse peritoneal malignant mesothelioma--intraabdominal administration of cisplatin is useful for diminishing ascites].

A 59-year-old man with a history of exposure to asbestos suffered from abdominal distension and visited our hospital. Abdominal CT revealed vast ascites but there was no obvious primary lesion. Serum tumor markers and hyaluronate were within the normal range. Abdominal puncture was carried out, and cytology of ascites was negative. We suspected diffuse malignant peritoneal mesothelioma because hyaluronate in ascites rose to 10×10⁴ ng/mL. Ga-scintigraphy and FDG-PET were negative. We performed laparoscopic observation for definite diagnosis and found fine white particles at the peritoneum. The result of biopsy was malignant mesothelioma. The patient underwent intraperitoneal administration of cisplatin and his ascites was diminished. He lived for a year with no recurrence but died 23 months after diagnosis because of progression of pleural mesothelioma and liver metastases. Relapse of ascites was not found in the entire clinical course. Cisplatin administration in the peritoneal cavity is thus very effective in preventing progression of ascites.