Diffuse epithelial pleural mesothelioma presenting as a solitary lung mass

We report the occurrence of a malignant pleural epithelial mesothelioma which presented radiographically and at surgery as a localized solitary mass, but was found microscopically to involve grossly normal pleura. Clinically diffuse mesothelioma recurred 19 months later. Localized malignant mesothelioma has been associated with the same poor prognosis as the diffuse form and, as suggested by this case, may represent an early phase of diffuse disease.