Accuracy of ultrasound-guided fine-needle aspiration cytology for diagnosis of carcinoma in patients with multinodular goiter

BACKGROUND: Fine-needle aspiration (FNA) is a useful method for evaluating multinodular goiter; however, its role is still controversial. The aim of this study was to assess the utility of ultrasound-guided thyroid FNA in detecting malignancy in patients with multinodular goiter in Oman. MATERIALS AND METHODS: This was a retrospective study where all patients with multinodular goiter seen at the Sultan Qaboos University Hospital endocrinology clinic in Oman in 2005 were evaluated. The thyroid FNA results were grouped into either malignancy (positive result) or others (negative result). They were compared to those of final histopathological examination in order to calculate the value of the test in diagnosing malignancy. Analyses were evaluated using descriptive statistics. RESULTS: A total of 272 patients were included in the study. The mean age was 39΁13 years with an age range from 5 to 85 years. The majority of the patients were females (n=236; 87%). The results of thyroid FNA revealed that 6% (n=15) of the patients had malignancies while histopathological results showed that the proportion of subjects with malignancies was 18% (n=49). Out of the 15 cases identified to have malignances by thyroid FNA, only 53% (n=8) of the subjects were confirmed to have malignancy by biopsy. Overall, the results of the tests were poor, revealing a sensitivity of 16%, specificity of 97% and a diagnostic accuracy of 82%, with a positive predictive value of 53% and a negative predictive value of 84%. CONCLUSION: Thyroid FNA is not a useful test in differentiating multinodular goiter from malignancy, as more than 80% of the malignancies go unnoticed.