OBJECTIVEThe aim of this study was to evaluate the number of central cervical lymph node metastasis (CCLNM) in predicting lateral cervical lymph node metastasis (LCLNM) in patients with papillary thyroid carcinoma (PTC).

METHODSFrom January 2005 to October 2010, a total of 133 patients diagnosed as PTC underwent central and lateral cervical lymph node dissection were enrolled in this study. Quantitative analysis was performed to explore the correlation between the number of CCLNM and LCLNM.

RESULTSThe sensitivity of central cervical node metastasis to predict lateral cervical node metastasis was 84.7%(61/72), and the positive predictive value (PPV) was 66.3% (61/92). The incidence of lateral cervical LNM was correlated with the number of CCLNM (r=0.911, P=0.004). The LCLNM rates in patients with number of CCLNM <2 and ≥ 2 were 54.5% (12/22) and 70.0% (49/70), respectively, with a non-significant difference (P=0.181). The LCLNM rates in patients with number of CCLNM < 3 and ≥ 3 were 50.0% (19/38) and 77.8% (42/54), showing a significant difference (P=0.006). The LCLNM rates in patients with number of CCLNM <4 and ≥ 4 were 55.1% (27/49) and 79.1% (34/43), with a significant difference (P=0.015). The LCLNM rates in patients with number of CCLNM <5 and ≥ 5 with the LLNM rate were 57.6% (34/59) and 81.8% (27/33), showing a significant difference (P=0.019). The LCLNM rates in patients with number of CCLNM <6 and ≥ 6 were 60.0% (39/65) and 81.5% (22/27), showing a significant difference (P=0.047).

CONCLUSIONSCCLNM has a significant association with LCLNM in patients with papillary thyroid carcinoma. LCLNM is mainly observed in patients with ≥ 3 CCLNM. Therefore, the number of CLNM ≥ 3 may be a valuable predictor of lateral cervical lymph node metastasis, and lateral cervical lymph node dissection should be considered.