“…Links among auto-immune disease, chronic antigenic stimulation, and PTL have been demonstrated, and Hashimoto's thyroiditis represents the major risk factor (1,12,14) especially in a delay of 20-30 years after initial diagnosis (5,7,10,12) . Commonly, Hashimoto's thyroiditis is considering as a causal factor of primary thyroid MALT lymphoma, which itself may evolve into aggressive lymphoma (6,12,14,15) , by activating B-cells to secrete antibodies, conducting to hyperplasia or malignant transformation of lymphoid tissue (4) . Concerning our patients, we didn't notice any antecedent of Hashimot's thyroiditis, but we suggest a pre-existing chronic thyroiditis within 3 patients having a biologic hypothyroidism.…”