Intraoperative pathologic evaluation of central compartment lymph nodes in patients undergoing lobectomy for unilateral papillary thyroid carcinoma.

BACKGROUND/OBJECTIVE: Although papillary thyroid carcinoma (PTC) has an excellent prognosis, it can cause central lymph node metastasis (CLNM) which can increase local recurrence. Intraoperative pathologic evaluation (IOPE) can provide evidence regarding CLNM and help surgeons determine the appropriate surgical approach. The aim of this study was to evaluate the efficacy of IOPE and to determine risk factors associated with CLNM in unilateral PTC without preoperative clinical evidence of CLNM.

METHODS: Medical charts of 227 patients who had unilateral PTC without clinical lymph node metastasis preoperatively were reviewed retrospectively. They were scheduled for thyroid lobectomy and prophylactic central lymphadenectomy (CND) from January 1, 2017 to December 31, 2017.

RESULTS: Total follow-up period was 47.6 ± 10.6 months. CLNM was identified in 57 (25.1%) patients during IOPE and in 72 (31.7%) patients during final pathological analysis. The sensitivity and specificity of IOPE were 76.4% and 98.7%, respectively. IOPE through central lymph node dissection was safely performed with low complications (vocal cord palsy, 5.7%; hypoparathyroidism, 22.8%). Age < 55 years, echogenic foci on preoperative ultrasonography, and extrathyroidal extension at final pathological report were significantly associated with an increased risk of CLNM (p = 0.006, p < 0.001, and p < 0.001, respectively). In terms of oncological outcomes, there was no significant difference between the true negative and false negative results in IOPE.

CONCLUSION: IOPE can safely provide accurate information for determining disease status and surgical extent. Further long-term studies are needed to evaluate clinical benefits of IOPE.