Malignant mesothelioma: a review of 35 cases with diagnosis and prognosis.

Twenty-five men and 10 women with malignant mesothelioma seen at the Austin Hospital between 1965 and 1978 were reviewed. The patients ranged in age from 34 to 79 yr. Prognosis was poor but was somewhat better for patients with epithelioid tumours than for patients with fibrous mesotheliomas and biphasic tumours. A history of occupational exposure to asbestos was obtained in the majority of patients, the latent period being from 18 to 52 yr. Ten patients had no history of asbestos exposure. The pathological diagnosis was established on tissue obtained at open biopsy in 22 cases and at post mortem in 11. Needle biopsy provided a diagnosis in only 2 cases. Cytology suggested a diagnosis of mesothelioma in 1 case. Gross pathology in general conformed with a diffuse confluent-nodular serosal tumor. A right sided preponderance was found in pleural tumours, and metastases were found rather more frequently than is usually reported. Histological features were distinctive in the majority of cases provided that sufficient material was examined. Recognition of coexisting patterns was often more helpful in making the diagnosis than any one single feature. Histochemical reactions are useful in distinguishing mesothelioma from mucin-secreting adenocarcinoma. In a majority of cases the histology and histochemistry were not characteristic and the diagnosis depended on the clinical features and the absence of another primary source of tumour.