[Extramedullary plasmacytoma of the head and neck: a clinicopathologic, immunohistochemistry study]

To investigate the relation between histopathological feature, clinical behavior characters, immunoglobulin (Ig) secretory function and prognosis of the extramedullary plasmacytoma (EMP) of the head and neck.

12 cases of EMP in the head and neck region were studied retrospectively. The clinicopathological records from January, 1977 to December, 1996 were reviewed. Immunohistochemical (IHC) stains for detecting intracytoplasmic immunoglobulin kappa (IgG kappa) and lambda (IgG lambda) were carried out.

10 cases of the patients were male and 2 female; Their ages ranged from 32 to 67 years with an average of 57 years. The tumors were located in the nasosinus (6), nasopharynx (2), Larynx (3) and ear (1). Low-(I), intermediate (II) and high-grade (III) tumors were 3, 3 and 6 cases respectively. Two patients with EMP of nasopharynx were treated with radiotherapy, in others radiotherapy was administered after complete surgical resection. Follow-up time ranged from 10 to 76 months. IHC showed monoclonality of the plasma cell and was positive for IgG lambda (6 cases) and IgG kappa (6 cases, conferming the identical clonal origin of the plasma cells. The 5-year survival for grade I, II and III were 75.0%, 62.0% and 37.6%, 37.5% and 68.50% for IgG lambda positive and IgG kappa positive cases, respectively. There are statistically significance between them (P < 0.01).

EMP in head and neck region are rare plasma cell tumors. IHC play an important role in differential diagnosis. The combination of surgery and radiotherapy proved to be an adequate and effective treatment. The grading and IgG secretory function may be valuable for predicting the prognosis of EMP.