Primary endobronchial plasmacytoma involving local lymph nodes and presenting with rare immunoglobulin G lambda monoclonal gammopathy.

Extramedullary plasmacytoma occurring as a primary pulmonary lesion is rare. The present report describes a 42-year-old Chinese man diagnosed with primary pulmonary plasmacytoma following left lower lobectomy. Of note, an extremely rare immunoglobulin G lambda paraprotein was documented in the patient's serum by immunofixation electrophoresis. The patient has been well, showing no local recurrence or multifocal disease during a 15-month follow-up.