Glycosaminoglycans in malignant diffuse mesothelioma.

Abstract

Because of frequently encountered diagnostic difficulty due to a morphologic similarity between diffuse pleural mesothelioma and peripheral pulmonary adenocarcinoma, glycosaminoglycans (GAG) of human malignant diffuse mesothelioma were histochemically stained and chemically quantitated, and were compared with GAG of papillary adenocarcinoma of the lung. In all seven patients, the diagnosis of diffuse mesothelioma was confirmed morphologically by such findings as abundant bushy microvilli on cell surface and intermediate filaments in cytoplasm. The total GAG in mesothelioma obtained from fresh materials (5 cases) was significantly increased over that in pleural connective tissue (P less than 0.01) and lung adenocarcinoma (P less than 0.02). Two dimensional electrophoretic separation of GAG of mesothelioma and lung cancer showed hyaluronic acid, heparan sulfate, heparin, dermatan sulfate and chondroitin sulfate; among them, the two predominant fractions were hyaluronic acid and chondroitin sulfate. In the quantitative analysis, the hyaluronic acid content of mesothelioma averaged 57% of the total GAG, but that of lung adenocarcinoma, 38%. The results suggest that chemical analysis of GAG may be useful as supplementary diagnostic procedure to morphologic examination in the differentiation of diffuse mesothelioma from papillary adenocarcinoma of the lung.