PaPillary thyroid carcinoma (Ptc) is the most common thyroid malignancy. Although it is generally indolent, several clinicopathological factors predicting a poorer prognosis in PTC patients have been identified. Among them, extrathyroid extension is prominent. Several studies demonstrated that PTC patients with extrathyroid extension show a significantly poorer prognosis than those without extrathyroid extension, and they were therefore classified as being at high risk [1][2][3][4][5].The recurrent laryngeal nerve (RN) is one of the most common organs to which PTC extends. The RN can be preserved when carcinoma extension is partial and the preoperative vocal cord function is normal [6]. However, RN resection is required when it is completely involved with the carcinoma and/or vocal cord paralysis is preoperatively detected. When the RN is resected, permanent vocal cord paralysis causing Prognosis and prognostic factors of patients with papillary thyroid carcinoma requiring resection of recurrent laryngeal nerve due to carcinoma extension Yasuhiro Ito, Minoru Kihara, Yuuki Takamura, Kaoru Kobayashi, Akihiro Miya and Akira Miyauchi Department of Surgery, Kuma Hospital, Kobe 650-0011, Japan abstract. The recurrent laryngeal nerve (RN) is one of the most common organs to which papillary thyroid carcinoma (PTC) extends. However, the prognosis and prognostic factors for patients with PTC extending to the RN remain unclear. In this study, we investigated this issue in 298 patients who underwent initial and locally curative surgery for PTC requiring RN resection due to carcinoma extension. Preoperative vocal cord paralysis was detected in 179 patients (60.1%), and directly linked to significant extension to other organs, large tumor size, and advanced age. However, it did not have a significant prognostic impact on uni-or multivariate analyses. On multivariate analysis, independent prognostic factors were large node metastasis and advanced age for lymph node recurrence, significant extension to other organs for distant recurrence, and significant extension to other organs, large node metastasis, extranodal tumor extension, and advanced age for carcinoma death, respectively. Most prognostic factors identified in the entire series of patients also had a strong prognostic impact on the subset of patients requiring RN resection, together with significant extension to other organs. Preoperative vocal cord paralysis reflected the aggressive characteristic of PTC to some extent, but did not have a significant prognostic value.Key words: Papillary thyroid carcinoma, Prognosis, Recurrent laryngeal nerve hoarseness and aspiration occurs, but recovery in phonation is expected if nerve reconstruction is performed by end-to-end anastomosis with other nerves such as the ansa cervicalis [7][8][9].We previously showed that PTC extending only to the RN showed a better prognosis than that extending to other posterior organs such as the trachea and esophagus [1]. Furthermore, more recently, we proposed that T4a in the UICC TNM classificat...