Prediction of Malignancy in Thyroid Nodules; A Retrospective Comparative Study

Aim: This study assessed the potential of malignancy in patients presenting with clinically solitary thyroid nodules and compared the histopathology of excised samples and sonographic characteristics and fine-needle aspiration cytology results. Participants Methods: This retrospective study was conducted over three years on data from 140 patients attended general surgery outpatient departments at Al-Sader Teaching Hospital and a private clinic with different complaints of solitary thyroid nodules. The collected data included initial diagnoses according to the results of clinical assessment, ultrasound evaluation, fine-needle aspiration cytology, and histopathological examination. Findings: As confirmed by histopathological examination, the prevalence of malignancy in clinical solitary thyroid nodules was 9.29% with male patients affected more than females (15% vs. 8.33%). Clinical assessment was a poor predictor for malignancy, as it was associated with a low sensitivity rate (69.23%), which means high false negative results, despite its high specificity rate (92.91%). According to the ultrasound examination, most malignancies were found in solid and mixed nodules (85% and 15%, respectively) with a significant association between the nature of nodules and malignancy potential. Fine-needle aspiration cytology was the most sensitive and specific investigation of thyroid nodules, it combined both high sensitivity and specificity for diagnosing malignant thyroid nodules (90.91% and 97.65%) respectively. Positive and negative predictive values were 79.83% and 99.06% respectively with an overall agreement of 97.02%. Conclusion: Fine-needle aspiration cytology is a minimally invasive diagnostic tool for the early detection of malignancy among patients with solitary thyroid nodules, which combines high degrees of both specificity and sensitivity with a high accuracy rate of 97.02% comparable to histological examination.