EXTRAMEDULLARY PLASMACYTOMA IN THE HEAD AND NECK: REPORT OF 10 CASES

Ten cases of extramedullary plasmacytoma (EMP) in the head and neck were studied. There were 6 males and 4 females, the ages ranging from 30 to 72 years. Except one located in the thyroid, most tumors appeared in the upper respiratory tract and oral cavity: 6 in the nasal cavity, paranasalsinus and nasopharynx; 1 in the tonsil and pharynx; 1 in the root of the tongue and cervical lymph node; and 1 in the lingula gingiva. The tumors originating in the nasal cavity, paranasalsinus and nasopharynx usually appeared polypoid with a smooth surface, dark red in color. In microscopy, they consisted of the tumorous plasma cells. According to the ratio of the mature plasma cells to atypical ones, the tumors fell into two histologic groups: well-differentiated (4 cases)and poor-differentiated (6 cases). Diverse histologic patterns might be found in different sections of the same tumor. Follow-ups of 6 cases showed a high radio-sensititivity and little correlation between the histologic feature and prognosis of the disease. The differentiation between EMP and plasma cell granuloma was discussed. Coexistance of EMP of the thyroid and Hashimoto’s struma in one of our cases might probably be referred to a cause-and-effect relationship bewteen these two diseases.