Primary pleural mesothelioma.

In this series of nine patients with primary pleural mesothelioma, three patients, all women, had "localized benign" tumors located in the left chest, although one had a recurrence on the right. Five patients all male, had the "diffuse malignant" type, and one woman had "multiple discrete" pleural tumors. Classification on the basis of gross appearance is useful clinically and prognostically, as reflected by the relatively benign behavior of localized pleural mesothelioma in contrast to the relentless lethal nature of the diffuse type. Although seven patients had pleural effusion, cytologic studies were of little help in establishing the diagnosis and all underwent thoracotomy. None of these patients had hypoglycemia or evidence of asbestosis, although three patients had a history of previous asbestos exposure.