Primary malignant lymphoma of the thyroid--a tumour of mucosa-associated lymphoid tissue: review of seventy-six cases.

Seventy-six cases of primary thyroid lymphoma have been reviewed employing the Kiel classification. These lymphomas are almost entirely of follicle centre cell origin, occur predominantly in elderly females, and are frequently associated with lymphocytic thyroiditis or Hashimoto's disease. The overall prognosis is variable, with long-term survival in a substantial number of cases following thyroidectomy and radiotherapy. Results of histological examination including immunoperoxidase studies are described. It is proposed that thyroid lymphoma represents a neoplasm of mucosa-associated lymphoid tissue (MALT), and the implications of this are discussed.