Ultrasound-guided core-needle biopsy in thyroid nodules. A study of 676 consecutive cases with surgical correlation

Objectives To analyze the diagnostic accuracy of ultrasound-guided core-needle biopsy (CNB) of thyroid nodules. Methods Of 3517 CNBs performed using an 18G spring-loaded device in one institution, we retrospectively reviewed 676 nodules in 629 consecutive patients who underwent surgery. CNB and pathological examination were compared. CNB diagnosis was standardized in four categories: insufficient (I), benign (B), follicular lesion (FOL), and malignant (M). Main outcome measures were predictive positive values (PPV), false positives (FP), and false negatives (FN). Results CNB showed a low rate of insufficient and FOL diagnoses (5.8 % and 4.5 %). On surgery, there were eight FNs in 374 benign CNBs and three FPs in 148 malignant CNBs. The 154 nodules classified as FOL in CNB included, at surgery, 122 neoplasms; 28 of them malignant. PPV for malignancy of a malignant CNB was 98 %, and for a CNB diagnosis of FOL 18.2 %. Sensitivity for malignancy if CNB of FOL and M are considered positive was 95.6. Only one major complication was observed. Conclusions CNB is reliable, safe, and accurate to evaluate thyroid nodules and can be an alternative technique to FNA. It has low rate of non-diagnostic and undetermined cases, with high sensitivity and PPV. Key Points • Thyroid core-needle biopsy (CNB) has high sensitivity and PPV. • Pitfalls of CNB are rare. • Pitfalls are due to cystic cancer, histological heterogeneity, and mistakes in analysis. • CNB is a reliable, safe, and accurate method to approach thyroid nodules. • CNB can be used primarily or after insufficient or indeterminate FNA.