Malignant lymphomas of the thyroid gland. Analysis of 79 patients with emphasis on histologic prognostic factors.

Prognostic factors in 79 patients with malignant lymphomas involving the thyroid gland were analyzed. These patients suffered from progressively enlarging goiter with over 6 months duration in 60% of patients. The age at operation ranged from 16 to 80 years (median, 58 years). Male to female ratio was 1:1.8. Serum tests for antithyroid antibodies were positive in 83% of the patients, who also showed histologic evidence of chronic lymphocytic thyroiditis. Histologically, 52 cases (66%) were germinal center cell tumors with follicular or follicular and diffuse pattern in 9 cases. By the Working Formulation, 5-year survival rate of immunoblastic type (IBL) (13%) was much poorer than those of intermediate (79%) and low grade cases (92%) (P less than 0.001). The cases of IBL usually had a goiter of short duration, and frequently presented as advanced disease.