Better Understanding in the Differentiation of Thyroid Follicular Adenoma, Follicular Carcinoma, and Follicular Variant of Papillary Carcinoma: A Retrospective Study

Table 4

Diagnostic performances of USFNA and intraoperative frozen section.

(%)	FNA*	FNA^†	FS^‡
Sensitivity	87.8 (65/74)	84.2 (48/57)	80.0 (24/30)
Specificity	29.0 (36/124)	52.2 (36/69)	96.3 (77/80)
PPV	42.5 (65/153)	59.3 (48/81)	88.9 (24/27)
NPV	80.0 (36/45)	80.0 (36/45)	92.8 (77/83)
Accuracy	51.0 (101/198)	66.7 (84/126)	91.8 (101/110)

FNA: fine needle aspiration; FS: frozen section; PPV: positive predictive value; NPV: negative predictive value.
Note: raw data are in parenthesis.
*Inadequate cytology results excluded, indeterminate, suspicious for malignancy and malignant cytology results considered positive.
^†Inadequate and indeterminate cytology results excluded.
^‡46 nodules excluded due to deferred results on FS.