[A case of desmoplastic malignant mesothelioma]

A 43-year-old man was admitted to Nara Medical University Hospital because of right-sided chest pain. Computed tomographic examination revealed a right pleural effusion and diffuse pleural thickening. Malignant mesothelioma was diagnosed from the results of a percutaneous pleural biopsy, and the patient then underwent right pleuro-pneumonectomy. The resected specimen was examined by light and electron microscopy, which revealed scattered sarcoma-like malignant cells with some epithelial differentiation, in abundant extracellular collagen with storiform derangement. Therefore, desmoplastic malignant mesothelioma (mixed type) was diagnosed. This is a rare histological subgroup of malignant mesotheliomas. The patient died 2 months after the operation, due to multiple and rapidly growing metastases. After lung tissue was dissolved, ferruginous (asbestos) bodies were counted, and the results were consistent with occupational exposure to asbestos (413 asbestos bodies per 5 g of lung tissue).