Malignant fibrosarcomatous mesothelioma and benign pleural fibroma (localized fibrous mesothelioma) in tissue culture:A comparison of the in Vitropattern of growth in relation to the cell of origin

Abstract

Two cases of fibrous mesothelioma are presented. The first is a malignant tumor containing bundles of spindle-shaped cells with a dense reticulin network and nests of epithelial-like cells. The second is a benign tumor made up of spindle-shaped cells arranged in bundles with abundant reticulin and collagen fibers. Tissue culture in the first case revealed plagues similar to those formed by epithelial tumors. The second case had a fibroblastic pattern with single isolated spindle-shaped cells. These findings confirmed the mesothelial nature of fibrosarcomatous mesothelioma and supported the view that the so-called localized fibrous mesotheliomas could be fibroblastic neoplasms derived from the submesothelial connective tissue.