Primary pulmonary lymphoma. Report of a case diagnosed by fine needle aspiration cytology.

A case of primary pulmonary lymphoma, small lymphocytic type, with plasmacytoid differentiation (lymphoplasmacytic lymphoma) and IgM gammopathy, was diagnosed by fine needle aspiration of the lung. It was further substantiated by pleural fluid cytology, biochemical and immunologic parameters, and the clinical picture. This case is documented for its rarity along with a review of literature on the diagnosis of low grade small lymphocytic lymphomas.