Lymphohistiocytoid mesothelioma of the pleura: a case report with cytological findings.

Lymphohistiocytoid malignant mesothelioma is an infrequent variant of sarcomatoid mesothelioma representing approximately 0.5-3.3% of malignant mesotheliomas. It has been related to asbestos exposure. The tumor is characterized by a diffuse large histiocyte-like cells proliferation mixed with an inflammatory infiltrate of lymphocytes and plasma cells. Its cytological diagnosis is difficult. We present a case of a 67-year-old female with lymphohistiocytoid mesothelioma involving the left pleura. The cytological, histological, and immunohistochemical features are discussed.