Abstract
Background: Thyroid nodules are common endocrine disorders. Most nodules are benign, with only 5% to 15% being malignant. Fine needle aspiration (FNA) is a primary diagnostic method, but recent studies have raised concerns about its diagnostic reliability. This study aimed to evaluate FNA performance on thyroid nodules with pathology results as the gold standard.
Study design: A cross-sectional study.
Methods: This study analyzed patients from an endocrine clinic in Hamadan city who underwent thyroidectomy during a 10-year period. Demographics, clinical, FNA results and pathological outcomes data were collected. Statistical analysis was conducted using Stata software, with the significance level at 0.05.
Results: The study included 700 patients, predominantly female (86.2%), with a mean age of 42.5 years. FNA results indicated 4.8% nondiagnostic (n = 43), 43.4% benign (n = 304), 6.1% Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance (n = 42), 13.2% follicular neoplasm (n = 92), 22.8% suspicious for malignancy (n = 160), and 9.7% malignant nodules (n = 68). Pathology revealed 56.9% (n = 398) malignant nodules, predominantly papillary carcinoma. Significant factors associated with malignancy included younger age, male sex, history of thyroid cancer in a first-degree relative, and the presence of neck adenopathy. FNA showed a sensitivity of 72.43% (95% CI 67.58%, 76.93%) and a specificity of 89.64% (95% CI 85.46%, 92.95%), with an accuracy of 79.85% (95% CI 76.55%, 82.87%).
Conclusion: While FNA is a valuable diagnostic tool for thyroid nodules, its sensitivity varies, necessitating close follow-up for patients with negative results.