title: Lymph node metastases in clinically N0 patients with papillary thyroid microcarcinomas - a single institution experience.
abstract: OBJECTIVE
  To register the frequency of central and lateral lymph node metastases (LNMs) from papillary thyroid microcarcinomas (PTMCs), and to assess whether sentinel lymph node (SLN) biopsy of the lateral compartment is an accurate technique to select patients with true positive but clinically negative lymph nodes for one-time selective lateral neck dissection (sLND). The correlation between tumor characteristics (size, multifocality, bilaterality, capsular invasion) and LNMs was analyzed.
  
  
  METHODS
  During a 10-year-period (2004-2013), 111 clinically N0 patients with PTMCs had total thyroidectomy, central neck dissection and SLN biopsy of the lateral neck compartment in our institution. SLN mapping was performed by subcapsular injection of 0.2 to 0.5ml of 1% methylene blue dye. If SLNs were positive on frozen section, one-time sLND was done.
  
  
  RESULTS
  Forty per cent of PTMCs were multicentric. LNMs were detected in 25% of the patients and isolated central LNMs were found in 18% of the patients. Lateral LMNs were present in 7% of the patients, of which 4% were isolated, skip LNMs. All these patients had therapeutic sLND. Specificity and sensitivity of SLN biopsy were 100% and 57%, positive and negative predictive values were 100% and 97%, respectively. Method's accuracy was 97%.
  
  
  CONCLUSIONS
  SLN biopsy of the lateral neck compartment is more precise than physical examination and ultrasonography for detection of lateral LNMs in clinically N0 patients with PTMCs. Intraoperative assessment of lateral lymph nodes (SLNs) provides one-time therapeutic dissection for patients with occult LNMs at initial operation, reducing the need for additional operations. This method provides appropriate disease staging and optimizes treatment.
authors.affiliation: Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, Serbia.
authors.forename: Merima
authors.initials: M
authors.lastname: Goran
authors.forename: Tatjana
authors.initials: T
authors.lastname: Pekmezovic
authors.forename: Ivan
authors.initials: I
authors.lastname: Markovic
authors.forename: Nada
authors.initials: N
authors.lastname: Santrac
authors.forename: Marko
authors.initials: M
authors.lastname: Buta
authors.forename: Dusica
authors.initials: D
authors.lastname: Gavrilovic
authors.forename: Nikola
authors.initials: N
authors.lastname: Besic
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Igor
authors.initials: I
authors.lastname: Djurisic
authors.forename: Gordana
authors.initials: G
authors.lastname: Pupic
authors.forename: Radan
authors.initials: R
authors.lastname: Dzodic
mesh_terms: D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D021701:Sentinel Lymph Node Biopsy; D013964:Thyroid Neoplasms / Q000473:pathology*