[Three cases of primary pulmonary plasmacytoma].

Extramedullary plasmacytoma is a plasma cell malignancy that most commonly occurs in the upper respiratory tract. Plasmocytoma located in the lung is an unusual finding, and in such cases the disease may be confined to the lung and regional lymph nodes or may be disseminated. When only located in the lower respiratory tract (primary pulmonary plasmacytoma), diagnosis is difficult and is usually based on the excised tissue. We present 3 cases, 2 of which were particularly unusual in that diagnosis was confirmed by bronchial biopsy. Other important findings included the detection of paraprotein in the blood and urine of 2 of the patients, and follow-ups over 10 and 15 years without recurrence of the disease in 2 of the cases.