Objective: To investigate the potential risk factors for occult lateral cervical lymph node metastasis (LNM) to levels Ⅲ and Ⅳ in patients with papillary thyroid carcinoma (PTC) and the necessity of super-selective lateral lymph node dissection for patients harboring these metastases. Methods: This prospective study included PTC patients who were operated by the same surgeon in the Department of Head and Neck Surgery of Cancer Hospital, Chinese Academy of Medical Sciences from October 2015 through October 2019. Preoperative ultrasound and enhanced Computer Tomography (CT) did not denote suspected enlarged lymph nodes in the lateral neck. All patients underwent lymph node dissection in levels Ⅲ and Ⅳ on the basis of original thyroid collar incision after LNM to level Ⅵ was confirmed by preoperative fine needlebiopsy or intraoperative frozen pathology. Results: Of all 143 patients, 74 (51.7%) had occult LNM in levels Ⅲ and Ⅳ confirmed by postoperative pathology. The average number of metastasized lymph nodes in levels Ⅲ and Ⅳ was 2.64±1.80, and that in level Ⅵ was 3.77±3.27. There was a significant linear positive correlation between the number of metastasized lymph nodes in level Ⅵ and that in levels Ⅲ and Ⅳ (r=0.341, P<0.001). That the metastasized lymph nodes in level Ⅵ equals three was the best predictor of occult lateral LNM to levels Ⅲ and Ⅳ. Univariate analysis showed that age <55 years, tumor size ≥2.0 cm, number of metastasized lymph nodes in level Ⅵ ≥3, and percentage of metastasized lymph nodes in the total number of dissected lymph nodes in level Ⅵ >50% were associated with occult LNM in levels Ⅲ and Ⅳ (P<0.05). Multivariate analysis showed that number of metastasized lymph nodes in level Ⅵ≥3 was an independent risk factor for occult LNM in levels Ⅲ and Ⅳ (P=0.006). Conclusions: Age, tumor size and LNM in level Ⅵ were associated with occult lateral LNM in PTC patients. Lymph node dissection in levels Ⅲ and Ⅳ could be considered for selective patients, since it will help to avoid secondary operation for residual tumor or recurrence resulted from insufficient treatment without increasing the incidence of complications or affecting patients' appearances.
目的： 探讨甲状腺乳头状癌(PTC)患者发生侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移的危险因素和侧颈淋巴结隐匿性转移患者的超择区性颈淋巴结清扫方法。 方法： 2015年10月至2019年10月在中国医学科学院肿瘤医院就诊的143例PTC患者，经术前穿刺细胞学检查或术中冰冻病理学检查证实Ⅵ区淋巴结转移，而术前颈部超声及增强CT检查未提示存在侧颈可疑肿大淋巴结，头颈外科同一位主诊医师行手术治疗，在原有甲状腺领式切口的基础上直接完成侧颈Ⅲ、Ⅳ区淋巴结清扫。 结果： 143例患者中，74例(51.7%)患者术后病理证实存在Ⅲ、Ⅳ区淋巴结隐匿性转移。侧颈Ⅲ、Ⅳ区淋巴结转移数为(2.64±1.80)枚，Ⅵ区淋巴结转移数为(3.77±3.27)枚，二者呈正相关(r＝0.341，P<0.001)。Ⅵ区淋巴结转移数为3枚时预测侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移最佳。单因素分析显示，患者年龄<55岁、术前超声肿瘤长径≥2.0 cm、Ⅵ区淋巴结转移数≥3枚及Ⅵ区淋巴结转移数占Ⅵ区清扫淋巴结总数百分比>50%与侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移有关(均P<0.05)。多因素logistic回归分析显示，Ⅵ区淋巴结转移数≥3枚为侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移的独立危险因素(P＝0.006)。 结论： 患者年龄、肿瘤大小及Ⅵ区淋巴结转移与PTC患者侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移有关，对经筛选可能出现侧颈Ⅲ、Ⅳ区淋巴结隐匿性转移的患者可考虑行Ⅲ、Ⅳ区淋巴结清扫，能在不增加并发症发生率、不影响美观的同时，减少因治疗不足导致的肿瘤残留和肿瘤复发，避免二次手术。.
Keywords: Lymph node metastasis; Papillary thyroid carcinoma; Super-selective lateral lymph node dissection; Thyroid cancer.