Myelomatous Pleural Effusion with Elevated ADA Activity / 대한내과학회지

Multiple myeloma is a plasma cell neoplasm mainly involving the bone marrow and skeletal system. Myelomatous pleural effusion is rare, accounting for less than 1%. In cases with high adenosine deaminase (ADA) activity, with lymphocytic exudate in the pleural fluid, tuberculous pleural effusion should be differentiated first. We report herein a rare case of a unilateral pleural effusion in a patient who was undergoing chemotherapy for multiple myeloma, with an ADA level of > 100 IU/L and lymphocytic exudate in the pleural fluid. An acid fast bacillus stain and polymerase chain reaction test for tuberculosis were negative. Consequently, the patient was diagnosed with myelomatous pleural effusion with elevated ADA activity.