Myelomatous pleural effusion and extensive extraskeletal soft tissue involvement: a rare presentation of clonal plasma cell disorders

A 65-year-old woman presented with a history of progressive dyspnoea, left pleuritic pain, loss of weight and appetite. Previous history was significant for pulmonary tuberculosis diagnosed 10 years before. Physical examination revealed a left supraclavicular soft tissue mass with absent breath sounds over the left hemithorax. Investigations revealed hypercalcemia with albumin:globulin reversal. The bone marrow biopsy was consistent with the diagnosis of multiple myeloma (IgG). Pleural fluid analysis revealed an exudative effusion; cytology showed mature plasma cells and plasmablasts. Serum electrophoresis revealed an M band in the gamma region. Biopsy of the supraclavicular mass revealed plasma cells which were CD 138+ with Kappa light chain restriction. She was initiated on chemotherapy and is currently doing well. Myelomatous pleural effusion is a rare presentation of multiple myeloma.