Increased lipid peroxidation and impaired enzymatic antioxidant defense mechanism in thyroid tissue with multinodular goiter and papillary carcinoma.

Objectives: We aimed to evaluate the oxidant/antioxidant status of thyroid tissue in patients with multinodular goiter, papillary carcinoma and to compare with their nonpathologic tissues.

Methods: We studied 41 patients with multinodular goiter who underwent surgical treatment. The patients were divided into three groups according to clinical diagnosis. Malondialdehyde, selenium, total superoxide dismutase and glutathione peroxidase of thyroid tissue samples were determined in 14 toxic multinodular goiters, 18 non-toxic multinodular goiters, and 9 papillary carcinomas.

Result: Superoxide dismutase and glutathione peroxidase and selenium were found lower but malondialdehyde was higher in both nodule and cancerous tissues compared with those of control ones. The level of malondialdehyde in non-toxic multinodular goiters group was higher than toxic multinodular goiters group in nodule tissues.

Conclusions: It can be stated that the lipid peroxidation is increased and enzymatic free radical defense system was significantly impaired in patients with both multinodular goiters and papillary carcinomas.