[A multiple myeloma case presenting with bilateral pleural involvement].

Pleural effusion is a relatively infrequent finding in multiple myeloma (MM) and malign effusions due to myelomatous effusion is seen very rarely. In this article we reported a case with bilateral myelomatous effusion. Myelomatous etiology was detected by demonstrating gammopathy in pleural fluid protein electrophoresis and demonstrating abundant number of atypical plasma cells in pleural fluid cytology. Pleural fluids due to MM are usually seen in IgA type of MM's, IgG on the surface of CD-138 positive cell was demonstrated in flow cytometric study of the pleural fluid of the reported case. In conclusion we mentioned that a patient who does not have diagnosis of MM before may present with pleural involvement, the involvement may be bilateral and flow cytometry can be used in diagnosis.