[A case of desmoplastic malignant mesothelioma with elevated serum CYFRA 21-1]

A 70-year-old woman was admitted to our hospital for medical evaluation of a right side pleural effusion, which was pointed out at another hospital. Chest CT revealed a right pleural effusion with diffuse and irregular pleural thickening. Percutaneous pleural biopsy showed hypocellular collagenous tissue without malignant cells. Though she received antituberculosis therapy, the pleural thickening progressed and the serum CYFRA 21-1 level was elevated. Chest pain and dyspnea appeared, and she was readmitted. However, pneumonia was present as a complication, and she died. At autopsy, the right pleura was thickened and invasion of the lung and the chest wall was observed. Microscopic findings showed increased amounts of hyalinized collagen fibers forming a storiform pattern. At the tumor foci, atypical cells with distinct nucleoli were observed. Desmoplastic malignant mesothelioma, which is rarely reported in Japan, was diagnosed.