甲状腺乳头状癌颈部淋巴结转移特点及清扫策略

背景与目的：目前，在甲状腺癌颈淋巴结清扫方面存有较大分歧。该研究总结甲状腺乳头状癌淋巴结转移的特点，为择区淋巴结清扫提供理论依据。方法：回顾性分析2006年7月—2014年8月收治的462例甲状腺乳头状癌患者病历资料，分析其淋巴结转移规律及其影响因素，评判cN0标准的准确性。结果：全组患者均行患侧中央区(Ⅵ区)淋巴结清扫，320例行侧颈区淋巴结清扫术(Ⅱ～Ⅴ区)或择区淋巴结清扫(Ⅱ～Ⅳ区中的部分或全部)，90例行对侧中央区淋巴结活检。73.2%(338/462)符合cN0标准，病理证实其中有184例淋巴结转移，cN0标准误诊率达60.9%。颈部淋巴结总转移率为65.4%(302/462)，侧颈区淋巴结转移率为42.6%(197/462)，“跳跃转移”率为13.1%(42/320)，对侧中央区淋巴结转移率为50%(45/90)。男性、肿瘤累及腺叶上1/3、肿瘤T3或T4、多中心病灶是淋巴结转移的危险因素。肿瘤累及腺叶上1/3是喉前淋巴结转移及“跳跃转移”的危险因素。喉前淋巴结转移及中央区淋巴结2个以上转移者侧颈区淋巴结转移率显著增加(分别为85.7%和83.3%， P＜0.05)。结论：现行cN0标准不能作为确定淋巴结清扫范围的依据；甲状腺乳头状癌易发生淋巴结转移，其中Ⅵ区淋巴结转移率最高，依次为Ⅲ区、Ⅱ区、Ⅳ区、Ⅴ区；初次手术应常规清扫患侧中央区淋巴结，建议将Ⅵ区淋巴结送冰冻病理；当喉前淋巴结有转移或Ⅵ区2个以上淋巴结转移时，或肿瘤累及腺叶上1/3者，有必要行侧颈区(或择区)淋巴结清扫；对侧中央区淋巴结转移率较高，需予以重视；中央区淋巴结再分亚区具有重要意义，应深入研究。

Characteristics related to lymph node metastasis and strategy of lymph node dissection in papillary thyroid carcinoma

Background and purpose:For treatment of papillary thyroid carcinoma (PTC), there is substantial divergence of opinion in neck dissection currently. In this study, we aimed to provide theoretical basis for selective neck dissection through summarizing the characteristics of cervical lymph node metastasis (LNM) in PTC.Methods:From Jul. 2006 to Aug. 2014, 462 patients with PTC at our hospital were retrospectively analyzed. We analyzed the characteristics and predictive factors of cervical LNM and evaluated the accuracy of cN0 standard.Results:All patients received ipsilateral central cervical lymph node dissection (LevelⅥ). 320 patients underwent lateral cervical lymph node dissection (LevelⅡ-Ⅴ) or elective lymph node dissection (some or all of LevelⅡ-Ⅳ). 90 patients received contralateral central cervical lymph node biopsy. 73.2% (338/462) were cN0 patients, but among those 184 patients were pathologically conifrmed with LNM. The misdiagnosis rate of cN0 standards was 60.9%. The cervical LNM rate was 65.4% (302/462) in total. The lateral compartment LNM rate was 42.6% (197/462). 13.1% (42/320) patients had skip lateral cervical LNM leaping central compartment, whereas 50% (45/90) with contralateral levelⅥ metastasis. Male, tumor involving upper 1/3 gland, tumors T3 or T4, and multicentricity were all predictive factors of LNM. Patients with tumor involving upper 1/3 gland prone to prelaryngeal lymph node (PLN) metastasis and “skip metastasis”. Lateral compartment LNM increased signiifcantly when PLN(+) and≥2 central lymph nodes metastasis (85.7% and 83.3%, respectively,P<0.05).Conclusion:Existing cN0 standard is not a suitable criteria for determining the margin of lymph node dissection. PTC is prone to lymph node metastasis, and levelⅥ is most likely to be involved, thenⅢ,Ⅱ,Ⅳ,Ⅴ. Ipsilateral central lymph nodes should be routinely dissected and intraoperative frozen examination is suggested in initial surgery. If patients had PLN metastasis, or≥2 central lymph nodes metastasis, or tumor involving upper 1/3 gland, lateral cervical lymph node dissection (or elective lymph node dissection) is necessary. Attention should be paid to contralateral levelⅥ for it has high metastasis rate. Subdivision of central compartment is of great signiifcance and needs thorough research.