Unsuspected multiples myeloma presenting as bilateral pleural effusion - a cytological diagnosis

Multiple Myeloma presenting as a pleural effusion is extremely rare. It is usually a late complication and is associated with a poor prognosis.

A 40-year-old male presented with dyspnea and fever of six months duration. Clinical diagnosis of pulmonary tuberculosis was considered. X-ray chest showed bilateral pleural effusion. Pleural cytology revealed numerous plasma cells, some of which were binucleated and atypical. Cytological differential diagnosis included: Myelomatous effusion and Non-Hodgkin's Lymphoma deposit (Immunoblastic type). Bone marrow biopsy, serum protein electrophoresis and bone scan confirmed the diagnosis of multiple myeloma (Plasmablastic type).

Myelomatous pleural effusion as an initial presentation although extremely rare, should always be considered in presence of atypical plasma cells irrespective of age.