Diffuse pulmonary amyloidosis with monoclonal IgG-kappa gammopathy

A 62-year-old female with diffuse pulmonary amyloidosis developed abnormal radiographic findings while under observation for hyperimmunoglobulinemia over a ten-year period. Serum immunoglobulin G (IgG) was elevated (4,620 mg/dl), and associated with monoclonal gammopathy (M protein) of the kappa type, but no evident abnormalities were apparent in bone marrow. Chest radiograph and computed tomography showed a diffuse reticulonodular shadow in the bilateral lung. Thoracoscopic lung biopsy specimen revealed depositions of amyloid in the bronchus and pulmonary vessel. We emphasize that diffuse pulmonary amyloidosis should be considered a possible diagnosis in the presence of monoclonal immunoglobulin.