Center for Head and Neck Surgery, Kusatsu General Hospital , Kusatsu, Japan .
Thyroid. 2015 Jan;25(1):107-11. doi: 10.1089/thy.2014.0152.
Although rare, invasion by papillary thyroid carcinoma (PTC) of the upper aerodigestive tract significantly affects patients' prognosis and quality of life. Within the central compartment, the recurrent laryngeal nerve (RLN) is most frequently invaded by lymph node metastases (LNM). However, such an invasion has not been described in the literature, although reports on RLN invasion by primary tumors have been published. The present study aimed to characterize LNM with RLN invasion in patients with PTC.
The participants of this retrospective investigation were selected from 629 PTC patients who received initial surgical treatment at our institution between January 1981 and December 2012. They included 38 (6%) patients with 40 cases of RLN invasion by LNM (LNM invasion group) and 112 (17.8%) patients with 117 cases of RLN invasion by the primary tumor (primary invasion group).
In the LNM invasion group, 70% of the RLN invasion cases occurred on the right side, whereas those in the primary invasion group were almost equally distributed. RLN invasion caused vocal cord paralysis, affecting 13 nerves (32.5%) in the LNM invasion group and 68 nerves (58%) in the primary invasion group. Significant differences in laterality and preoperative vocal cord paralysis were observed between the two groups. In the LNM invasion group, the longest diameter of metastatic lymph nodes (mean±standard deviation) of patients with RLN paralysis was 21±8 mm, whereas it was significantly different at 14±7 mm in those without RLN paralysis.
Our results indicate that most patients with RLN invasion by LNM did not experience preoperative vocal cord paralysis. LNM invasion of the RLN (70%) more often occurred on the right side as expected given the complexity and three-dimensional anatomy of the RLN in the right paratracheal region compared to the left. RLN invasion by LNM should be considered if preoperative paratracheal nodal disease, especially when bulky, is noted in the right paratracheal region.
尽管罕见，但甲状腺乳头状癌（PTC）侵犯上呼吸道会显著影响患者的预后和生活质量。在中央区，喉返神经（RLN）最常被淋巴结转移（LNM）侵犯。然而，尽管已有原发性肿瘤侵犯 RLN 的报道，但文献中尚未描述这种侵犯。本研究旨在描述 PTC 患者中伴有 RLN 侵犯的 LNM 特征。
本回顾性研究的参与者选自 1981 年 1 月至 2012 年 12 月期间在我院接受初始手术治疗的 629 例 PTC 患者，包括 38 例（6%）患者的 40 例 RLN 受 LNM 侵犯（LNM 侵犯组）和 112 例（17.8%）患者的 117 例 RLN 受原发性肿瘤侵犯（原发性侵犯组）。
在 LNM 侵犯组中，70%的 RLN 侵犯发生在右侧，而原发性侵犯组的 RLN 侵犯几乎均匀分布。RLN 侵犯导致声带麻痹，LNM 侵犯组中影响了 13 根神经（32.5%），原发性侵犯组中影响了 68 根神经（58%）。两组间侧别和术前声带麻痹存在显著差异。在 LNM 侵犯组中，RLN 麻痹患者的转移性淋巴结最长直径（平均值±标准差）为 21±8mm，而无 RLN 麻痹患者的最长直径为 14±7mm，差异具有统计学意义。
我们的结果表明，大多数 RLN 受 LNM 侵犯的患者术前未出现声带麻痹。考虑到 RLN 在右侧气管旁区的复杂性和三维解剖结构，右侧 RLN 比左侧更常发生 LNM 侵犯（70%）。如果术前发现右侧气管旁区的淋巴结疾病，特别是肿大的淋巴结，应考虑 RLN 受 LNM 侵犯。
