Background: Fine-needle aspiration (FNA) is widely used as a diagnostic tool to assess thyroid nodules. This study correlates FNA cytology results with surgical pathologic findings.
Methods: All thyroidectomies performed between 1994 and 2004 were reviewed, identifying 242 patients. Data were obtained for FNA diagnosis, demographics, findings on ultrasound, and histologic findings.
Results: Among 89 patients with a carcinoma on FNA, 89% of cases were verified on final histopathology. Of 78 patients with "follicular lesion" on FNA, only 36% of cases were verified to be malignant at surgery. Only 13% of the 75 cases diagnosed as benign, mostly colloid nodules, on FNA were found to have a carcinoma on histopathology.
Conclusion: A cytologic diagnosis of papillary carcinoma has a highly predictive of thyroid cancer. When dealing with follicular lesions the predictive value of FNA drops considerably. However, we found a 13% false positive result to occur in FNA declared benign lesions.