Immunologic and immunohistologic analysis of 27 cases with thyroid lymphomas.

Twenty-seven patients with stages I or II thyroid lymphomas were investigated immunologically. Approximately 60% of these patients had a goiter for longer than 1 year. Both the tests for serum antithyroid antibodies and histologic findings of the resected specimens showed that chronic lymphocytic (autoimmune) thyroiditis was usually present. The tumors were classified histologically as seven cases of follicular lymphomas and 20 cases of diffuse lymphomas. Immunocytologic study on suspended cells and immunohistologic study on frozen tissue sections showed that neoplastic cells in 22 of 27 cases expressed restricted immunoglobulin light chains. In remaining five cases, the neoplastic cells reacted with B-1, Leu-10, and/or Leu-14. These results indicate that thyroid lymphomas are exclusively B-cell-derived tumors.