Clinicopathological and ultrasound characteristics of extranodal extension in metastatic papillary thyroid carcinoma patients

Abstract

Objective: To explore clinicopathological and ultrasound characteristics of extranodal extension in metastatic papillary thyroid carcinoma patients. Methods: 176 patients with papillary thyroid carcinoma who were diagnosed in Tianjin Medical University Cancer Institute and Hospital between March 2011 and March 2016 were identified and recruited in the study. Among the 176 patients, 59 patients were diagnosed with regional lymph nodes metastasis accompanied with extranodal extension (extranodal extension positive group), 117 patients were regional lymph nodes metastasis without extranodal extension (extranodal extension negative group). The clinicopathological and ultrasound characteristics between extranodal extension positive group and extranodal extension negative group were also discussed in this article. Results: 59 patients were diagnosed with regional lymph nodes metastasis accompanied with extranodal extension (extranodal extension positive group). Single lymph node region of extranodal extension was identified in 40 patients, while 19 patients were confirmed with more than 2 regions of extranodal extension. The most frequent extranodal extension were detected in region Ⅵ lymph nodes(32 cases), following by Ⅲ(25 cases), Ⅳ(16 cases), Ⅱ(11 cases). In the aspect of ultrasound characteristics, metastatic papillary thyroid carcinoma with extranodal extension showed a higher incidence of node matting[13.6%(8/59) vs 3.4%(4/117), P=0.022], micro-calcification[66.1%(39/59) vs 46.2%(54/117), P=0.016], cystic[28.8%(17/59) vs 12.8%(15/117), P=0.013], aspect ratio(L/S)<2[88.1%(52/59) vs 75.2%(88/117), P=0.032] and larger diameter(1.95±1.01 cm vs 1.63±0.94 cm, P=0.028). Logistic multivariate analysis demonstrated that node matting (P=0.025) and cystic (P=0.026) were independent risk factors for extranodal extension. Conclusion: Node matting, micro-calcification, cystic, aspect(L/T)>2 and larger diameter were associated with extranodal extension in metastatic papillary thyroid carcinoma patients, especially node matting and cystic, which might help topre-operative ultrasound diagnosis of extranodal extension.