Thyroid autoimmunity and risk of malignancy in thyroid nodules submitted to fine-needle aspiration cytology.

BACKGROUND Whether the risk of cancer is increased in patients with chronic autoimmune thyroiditis is a controversial issue. METHODS Between May 2005 and October 2012, 3777 fine-needle aspiration cytologies (FNACs) were performed on 2562 patients. Serum FT4, thyroid-stimulating hormone (TSH), anti-thyroglobulin antibody (TgAb), and anti-thyroperoxidase antibody (TPOAb) were determined. RESULTS Patients with suspicious cytology were younger and presented smaller maximum lesion diameter. In patients with TgAb positivity, suspicious cytology was detected more frequently (9.4%) than patients without TgAb (5.7%; p = .04). No significant difference was recorded between benign and suspicious cytology in the positive TPOAb rate. Risk factors for suspicious cytology were younger age (odds ratio [OR], 0.94), smaller maximum diameter (0.95), single lesion (1.85), microcalcifications (3.45), and TgAb (1.74). Mixed solid/fluid content resulted as being a protective factor (0.34). According to multivariate logistic regression analysis, age, mixed content, and microcalcification confirmed significance. CONCLUSION Thyroid nodule malignancy in patients with Hashimoto thyroiditis is not more frequent than in patients without thyroiditis.