Prevalence and Diagnostic Assessment of Thyroid Nodules in a Rural District Hospital: Bethesda Classification and FNAB Correlations

Objective: Thyroid nodules are a common clinical finding, with diagnostic strategies guided by ultrasonographic features and fine-needle aspiration biopsy (FNAB) interpreted via the Bethesda system. This study aimed to evaluate the prevalence, clinical characteristics, and cytological classification of thyroid nodules in a rural district hospital.Materials and Methods: This retrospective cross-sectional study included 1,400 adult patients who underwent thyroid ultrasonography and laboratory testing between January 2018 and October 2024 at Alaca State Hospital. Nodules ≥1 cm or with suspicious ultrasound features were biopsied, and cytological results were reported according to the Bethesda System.Results: Thyroid nodules were detected in 33.5% of patients, with a higher prevalence in females (p < 0.001) and euthyroid individuals (39.98%). FNAB was performed in 144 patients, with most results classified as Bethesda II (68.06%). Bethesda III and IV comprised 9.72% and 2.78%, respectively, while categories V–VI accounted for 2.08%. Patients with nodules were older (median: 54 vs. 45 years, p < 0.001) and had lower median TSH levels (1.48 vs. 2.26, p < 0.001). ROC analysis indicated age as a modest predictor of nodule presence across thyroid states.Conclusion: Thyroid nodules are prevalent in rural populations, particularly among older, euthyroid women. Most nodules are benign, but cytological assessment remains essential for malignancy risk stratification. Age, TSH, and gender may inform diagnostic prioritization in resource-limited settings.