Mesothelioma lymphohistiocytoid

Henderson DW, Attwood HD, Constance TJ, et al. 1988. Lymphohistiocytoid mesothelioma A rare lymphomatoid variant of predominantly sarcomatoid mesothelioma. Ultrastruct Pathol 12 367-384. 

Thymomas may occur in the pleura and can be confused with mesothelioma. These neoplasms may be confused with a sarcomatoid mesothelioma with a heavy lymphoid infiltrate or with a lymphohistiocytoid mesothelioma. None of the cases presented by Moran and coworkers showed radiographic evidence of a mediastinal tumor, however 6 cases showed histologic features of a mixed (lymphocyte-epithelial) thymoma. The neoplastic thymic epithelial cells express keratin and CD5. 

Lymphohistiocytoid mesothelioma is a rare form of sarcomatoid mesothelioma that was initially histologically diagnosed as a lymphoma. Lymphohistiocytoid mesothelioma is composed of large, mostly round cells admixed with numerous inflammatory cells (Fig. 12.66). This neoplasm can be misdiagnosed as a large cell lymphocytic lymphoma. The neoplastic cells characteristically express low molecular weight keratin, high molecular... 

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