title: Impact of tumor size on subclinical central lymph node metastasis in papillary thyroid microcarcinoma depends on age.
abstract: BACKGROUND
  The aim of this study is to evaluate whether the associations between clinicopathologic factors of papillary thyroid microcarcinoma (PTMC), especially tumor size, and subclinical central lymph node metastasis (LNM) are dependent on patient age.
  
  
  METHODS
  The medical records of 428 patients who underwent thyroid surgery for PTC measuring ≤1 cm were reviewed. All patients were clinically lymph node negative and underwent thyroidectomy with unilateral or bilateral central lymph node dissection. Univariate and multivariate analyses were performed to identify clinicopathologic factors associated with central LNM.
  
  
  RESULTS
  Central LNM was identified in 96 of 428 (22.4%) patients. Mean tumor size was significantly greater in patients with than without central LNM (0.74 ± 0.22 cm vs. 0.64 ± 0.23 cm, P = 0.001). Tumor size > 0.5 cm was significantly predictive of central LNM. Subgroup analysis according to age groups showed that tumor size was an independent predictor of subclinical central LNM only in patients aged ≥45 years.
  
  
  CONCLUSIONS
  Factors predictive of central LNM in patients with PTMC differed by age. PTMC size was an independent predictor of subclinical central LNM only in patients aged ≥45 years.
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. juyeon0910@hanmail.net.
authors.forename: Ju-Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. drjej@gnu.ac.kr.
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Jung
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. taejin6393@gmail.com.
authors.forename: Taejin
authors.initials: T
authors.lastname: Park
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. jshgnuh@naver.com.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. drjcy@hanmail.net.
authors.forename: Chi-Young
authors.initials: CY
authors.lastname: Jeong
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. drjyt@naver.com.
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Ju
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. orangejulia@naver.com.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. hongsc@nongae.gsnu.ac.kr.
authors.forename: Soon-Chan
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. kyungsk@nongae.gsnu.ac.kr.
authors.forename: Sang-Kyung
authors.initials: SK
authors.lastname: Choi
authors.affiliation: Department of Surgery, School of Medicine, Gyeongsang National University College of Medicine, 90 Chilamdong, Jinju, 660-702, Korea. haws@nongae.gsnu.ac.kr.
authors.forename: Woo-Song
authors.initials: WS
authors.lastname: Ha
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000556:secondary* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D013965:Thyroidectomy; D047368:Tumor Burden; D055815:Young Adult