Prevalence and significance of lymphocyte infiltration in papillary carcinoma of the thyroid gland

OBJECTIVE: We have investigated the prevalence, signification and prognostic value of lymphocytic infiltration associated to differentiated thyroid carcinoma in our series of differentiated carcinoma of the thyroid. METHODS: We studied the presence of lymphocytic infiltration in 223 patients effected of differentiated thyroid carcinoma, 138 of them were papillary carcinoma. The diagnostic was made with optic microscopy and we studied antithyroid antibodies in these patients. In survival analysis we studied all the variables of the patients and the event used as end point was death due to thyroid carcinoma, summarized in Kaplan-Meir curve and Cox method. RESULTS: We found eight patients with differentiated thyroid carcinoma, six with papillary carcinoma, and lymphocytic thyroiditis and in three cases, antithyroid antibodies were present at low levels. We did not found any difference between the two groups and the survival rate was similar. CONCLUSIONS: These data support that in our series the prevalence of lymphocytic infiltration was low and probably without prognostic signification.