Metastasis predictors for neck sublevel IIb in papillary thyroid carcinoma

Objective To investigate possible metastasis predictors for neck sublevel IIb in papillary thyroid carcinoma (PTC) with lateral neck metastasis and to determine the reliability of preoperative ultrasound-guided fine-needle aspiration biopsy (FNAB) as a method of detecting positive lymph nodes in sublevel IIa in comparison with the finding of definitive pathohistological analysis. Design Prospective study with patients with proven lateral neck metastases from PTC at the time of initial diagnosis. All patients had total thyroidectomy, central neck dissection (level VI) and selective neck dissection (levels II-V). Potential predictive factors for the occurrence of metastasis in sublevel IIb were analysed. Sensitivity and specificity tests were used to determine the reliability of preoperative ultrasound-guided FNAB. Patients were monitored for recurrence for at least ten years. Setting Single-centre study. Participants Study included 53 patients with proven lateral neck metastases from PTC at the time of initial diagnosis. Results Predictive factors for the occurrence of metastasis in sublevel IIb that have reached statistical significance are positive sublevel IIa, number of positive lymph nodes and positive levels IIa + III + IV + V. None of the patients who fulfilled predefined criterion for minimum 10-year follow-up had local recurrence in operated lateral levels. Conclusion Highest clinical significance has positivity of sublevel IIa. Therefore, it is necessary to prove or exclude metastasis in sublevel IIa, preoperatively or intraoperatively, to decide whether to include sublevel IIb in dissection. Preoperative ultrasound-guided FNAB is a reliable method for the detection of positive lymph nodes in sublevel IIa in comparison with the definitive histopathological analysis.