Background: Optimal surgical intervention is straightforward when a fine-needle aspiration (FNA) is diagnostic for papillary thyroid cancer (PTC). However, if there are characteristics of an aspirate suspicious for PTC but not meeting criteria for diagnosis of PTC, the management is less clear.
Methods: Of the 1,051 patients who underwent thyroid surgery at the University of Wisconsin between May 24, 1994, and October 21, 2004, 102 had preoperative FNA cytology that was diagnostic or suspicious for PTC. Within the subgroups of diagnostic for PTC and suspicious for PTC, we evaluated the accuracy of FNA, the utility of frozen section (FS), and the predictive value of demographic and pathologic variables.
Results: When diagnostic for PTC, FNA was 97% accurate and FS did not alter management. However, if an FNA was interpreted as suspicious for PTC, there was a 57% (17/30) likelihood of PTC on permanent histology. In this subgroup, FS led to the optimal operative procedure in 96% (25/26) of cases. With the exception of size greater than 4 cm, demographic and pathologic variables did not predict malignancy or increase the likelihood of an FNA being diagnostic for PTC.
Conclusion: Intraoperative FS is a useful diagnostic tool when an FNA is suspicious for PTC.