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.