title: Papillary microcarcinoma of the thyroid: predicting factors of lateral neck node metastasis.
abstract: BACKGROUND
  Preoperative prediction of lateral lymph node metastasis (LNM) is important to prevent recurrence; however, there are few published data in predicting factors of lateral LNM before surgery. The present study investigated the factors affecting LNM in patients with papillary thyroid microcarcinoma (PTMC).
  
  
  METHODS
  A retrospective cohort study was conducted with data obtained from 671 patients with PTMC between 2004 and 2006. We reviewed the clinical, ultrasound (US), and pathology records of patients and analyzed the association between lateral LNM and clinical factors, US features of PTMC, and pathologic features.
  
  
  RESULTS
  The rate of lateral LNM was 3.7% in 671 PTMCs. We found a statistically significant association between lateral LNM and US features of PTMC (upper pole location, contact of >25% with the adjacent capsule, and presence of calcifications), and pathologic features (central LNM) in multivariate analysis (P < .05). The odds ratios of statistically significant factors were 4.7 (95% confidence interval [95% CI], 1.8-12.6), 10.8 (95% CI, 3.3-34.6), 4.8 (95% CI, 1.6-13.7), and 6.9 (95% CI, 2.4-20) at upper pole location, contact of >25% with the adjacent capsule, presence of calcifications on US, and pathologic central LNM, respectively.
  
  
  CONCLUSIONS
  In patients with PTMC, independent factors in predicting lateral LNM were US features of PTMC (upper pole location, >25% contact with the adjacent capsule, and presence of calcifications) and pathologic features (central LNM). When these US features are detected on preoperative US, lateral neck nodes should be meticulously evaluated by a multimodal approach.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Son
authors.forename: Woong Youn
authors.initials: WY
authors.lastname: Chung
authors.forename: Cheong Soo
authors.initials: CS
authors.lastname: Park
authors.forename: Kee-Hyun
authors.initials: KH
authors.lastname: Nam
mesh_terms: D000231:Adenocarcinoma, Papillary / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014463:Ultrasonography; D055815:Young Adult