Utilizing medical thoracoscopy for the diagnosis of myelomatous pleural effusion: 2 case reports.

Multiple myeloma (MM) is characterized by neoplastic proliferation of monoclonal antibody producing plasma cells. In clinical practice, pleural effusion is seen in up to 6% of MM patients, with many causative factors. Nevertheless, true myelomatous pleural effusion, defined as infiltration of the pleura by myeloma cells, is very rare. In this case report, we present two patients with biopsy proven myelomatous pleural effusion. The first patient developed myelomatous pleural effusion as initial presentation while the second patient's pleural effusion occurred during disease relapse. In both cases, prompt diagnosis via medical thoracoscopy (MT) followed by early commencement of myeloma specific chemotherapy led to clinical, biochemical, and radiological resolution and therefore were crucial steps in the management of myelomatous pleural effusion.