Predictive Values of Clinical Features and Multimodal Ultrasound for Central Lymph Node Metastases in Papillary Thyroid Carcinoma

Abstract

Papillary thyroid carcinoma (PTC), the predominant pathological type among thyroid malignancies, is responsible for the sharp increase in thyroid cancer. Although PTC is an indolent tumor with good prognosis, 60-70% of patients still have early cervical lymph node metastasis, typically in the central compartment. Whether there is central lymph node metastasis (CLNM) or not directly affects the formulation of preoperative surgical procedures, given that such metastases have been tied to compromised overall survival and local recurrence. However, detecting CLNM before operation can be challenging due to the limited sensitivity of preoperative approaches. Prophylactic central lymph node dissection (PCLND) in the absence of clinical evidence of CLNM poses additional surgical risks. This study aims to provide a comprehensive review of the risk factors related to CLNM in PTC patients. A key focus is on utilizing multimodal ultrasound (US) for accurate prognosis of preoperative CLNM and to highlight the distinctive role of US-based characteristics for predicting CLNM.

Keywords: central lymph node metastases; multimodal ultrasound; papillary thyroid carcinoma.

Figure 1

Locations of the thyroid. (A,B) In the coronal view, the thyroid gland is divided into the left lobe, right lobe, and isthmus (blue lines). Each lobe distribution is divided into lateral (L) and central (C) positions (yellow lines); (C,D) in the longitudinal view, the gland is divided into superior (S), middle (M), and inferior (I) positions (red lines); superficial layer, middle layer, deep layer (white lines). IJV, internal jugular vein; CA, carotid artery.

Figure 2

The blood supply of the thyroid gland.

Figure 3

Capsular contact and capsular abutment. (A,B) Capsular abutment is defined as the lack of intervening thyroid tissue between the thyroid tumor and thyroid capsule; (C,D) capsular disruption is defined as the loss of the perithyroidal hyperechogenic line at site of contact with thyroid tumor. “甲状腺”: Thyroid; “动态范围”: Dynamic range (Dym R); “余辉 中”: Persistence Medium (P Med); “分辨率”: Resolution (Res); “距离”: Dist.

Figure 4

The different types of calcifications. (A) Macrocalcifications; (B) peripheral (rim) calcifications; (C) punctate echogenic foci; (D) thyroid parenchyma microcalcification. “甲状腺”: Thyroid.