Nodal plasmacytoma with significant paraproteinaemia

We present a case of primary nodal plasmacytoma in an elderly Chinese woman that was associated with significant paraproteinaemia and paraproteinuria. Clinical and laboratory features of the patient satisfied Durie's criteria for the diagnosis of multiple myeloma. The present case was unusual in two aspects. Firstly, there was no evidence of clonal plasma cell proliferation elsewhere in the body after extensive radiological investigations, repeated bone marrow examinations, and polymerase chain reaction for immunoglobulin gene rearrangement study. Secondly, the clinical behaviour was indolent despite the large amount of paraprotein production, and showed satisfactory disease control with local radiotherapy. The differential diagnoses of plasmacytosis in the lymph node are also discussed.