Extramedullary plasmacytoma of the head and neck region: clinicopathological correlation in 25 cases

Extramedullary plasmacytomas (EMP) of head and neck are rare tumours. Between 1972 and 1993, 25 cases of EMP of head and neck were seen at our institute. The clinical and pathological features and response to treatment are presented. At initial presentation, 23 (92%) patients presented with disease confined to a single extramedullary site only and two patients had in addition clinical involvement of cervical lymph nodes. All except these two patients received radiotherapy to the primary site only as initial treatment. Initial primary control of local disease was obtained in 16 of 24 (67%) patients treated with radical intent. With salvage treatment of further radiotherapy and/or chemotherapy, local disease control was achieved in 21 of 24 (88%) patients. One patient was treated with palliative intent. Conversion to multiple myeloma was seen in two patients (8%). Pathologically, the tumours were classified into low, intermediate and high grade, which correlated closely with outcome. This classification has been used for the first time in extramedullary plasmacytomas and is based on the multiple myeloma grading criteria devised by Bartl et al (1987). Fifteen of eighteen (83%) low-grade tumours and only one of six (17%) intermediate- and high-grade tumours were locally controlled after primary radiotherapy. This is statistically significant for local control (P= 0.0019) but not for overall survival (P= 0.12). The median survival and 5-year overall survival is 68 months and 58.9% respectively. We recommend consideration of adjuvant chemotherapy in patients with higher grade disease.