title: Posterosuperior lesion has a high risk of lateral and central nodal metastasis in solitary papillary thyroid cancer.
abstract: BACKGROUND
  Preoperative nodal assessment of papillary thyroid cancer (PTC) is very important because 60 to 70 % of all disease recurrence in the neck can occur in the lymph nodes. This study explored the association between ultrasonographic intrathyroidal location and the nodal metastasis pattern in solitary PTC.
  
  
  METHODS
  Data from 218 patients who underwent total thyroidectomy with or without neck dissection for previously untreated PTC between 2006 and 2010 were retrospectively analyzed. Only patient data for which both preoperative ultrasound findings and postoperative pathologic reports were available were included. Multifocal cases, cases with extrathyroidal extension, and distant metastasis were excluded. The association between nodal metastasis pattern and clinical or pathologic features of solitary PTCs was analyzed, as was the association between ultrasonographic intrathyroidal location and central or lateral nodal metastasis in solitary PTC.
  
  
  RESULTS
  Mass size larger than 2 cm (p < 0.001, Odds ratio (OR) 4.117) and central nodal metastasis (p < 0.001, OR 3.984) were related with lateral neck metastasis in multivariate analysis. Male sex (p = 0.001, OR 3.012) and capsular invasion (p < 0.001, OR 4.720) were related with central neck metastasis in multivariate analysis. When analyzing ultrasonographic location of intrathyroidal solitary lesion, posterosuperiorly located lesion was strongly associated with both lateral and central neck metastasis. (p < 0.001 and p = 0.002, respectively).
  
  
  CONCLUSIONS
  Posterosuperior location of intrathyroidal solitary PTC has a high risk of lateral and central nodal metastasis when compared to other locations. For such patients, careful preoperative evaluation of nodal status should be done.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Ilsong Memorial Institute of Head and Neck Cancer, Hallym University College of Medicine, Seoul, South Korea.
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Lee
authors.forename: Kyu Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Jin Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Kee Hwan
authors.initials: KH
authors.lastname: Kwon
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Yoon
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Rho
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009361:Neoplasm Invasiveness; D011184:Postoperative Period; D012189:Retrospective Studies; D012737:Sex Factors; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D047368:Tumor Burden; D014463:Ultrasonography