Diagnostic criteria of ultrasonographic examination for lateral node metastasis of papillary thyroid carcinoma

Abstract

Conclusion: Considering the incidence of metastasis from papillary thyroid carcinoma (PTC) with respect to the lateral cervical regions and limited detection on preoperative ultrasonography (US), level II to IV dissection may be essential when lateral node metastasis (LNM) is detected on preoperative US. Objectives: LNM is frequent in patients with PTC. However, a consensus regarding its preoperative diagnosis and the indication/extent of lateral node dissection (LND) has not been reached. We prepared criteria for diagnosing LNM from PTC using US. Furthermore, we investigated the usefulness and limits of US and appropriate extent of dissection. Patients and methods: We conducted a retrospective study in 70 patients with PTC (80 sides) in whom LNM was detected preoperatively, and level II to V LND was performed. We compared the results of the preoperative diagnosis of LNM using US in accordance with the criteria with those of histopathological diagnosis after LND. Results: Diagnostic criteria for LNM were a minor axis of 6 mm or more and a minor/major axis ratio of 0.5 or more. Histopathologically, metastasis was detected in 467 lymph nodes. Of these, 199 (43%) were detected on US, and met the diagnostic criteria.

• Papillary thyroid carcinoma
• ultrasonography
• lateral node metastasis
• diagnostic criteria