Environmental malignant mesothelioma in southern Anatolia: A study of fifty cases

Malignant mesothelioma is a highly aggressive tumor of the serous membranes , which in humans results from exposure to asbestos and asbestiform fibers. Although occupational malignant mesothelioma is still the most common form of this lesion, naturally contaminated soil can play an important role in the development of environmental malignant mesothelioma in some parts of th e world. Fifty cases of malignant mesothelioma (MM) from southern Turkey wi th no occupational history of asbestos exposure were reviewed regarding pat hologic and clinical features. A case of hyaline fibrous plaque of the pleu ra was also included in this series. Histologically the cases were classifi ed as epithelial (36 cases); sarcomatous (7 cases); and biphasic (7 cases). One of the sarcomatous cases was desmoplastic. Ultrastructural examination of the tumor tissue in three cases revealed long-surface microvilli in epi thelia cells. Intersititial cells of the lung in one case showed electron-d ense asbestos fibers in the cytoplasm. Mineralogical analyses of the lung t issue in three cases of MM and the case of pleural plaque showed high amoun ts of asbestos fibers most consistent with tremolite and actinolite. The cl inical and pathologic features of our cases support that the environmental inhalation of asbestos is still a major health problem in some parts of Tur key.