title: Classic papillary thyroid carcinoma with tall cell features and tall cell variant have similar clinicopathologic features.
abstract: BACKGROUND
  The tall cell variant of papillary thyroid carcinoma (TCVPTC) is more aggressive than classic papillary thyroid carcinoma (PTC), but the percentage of tall cells needed to diagnose TCVPTC remains controversial. In addition, little is known about the clinicopathologic features of classic PTC with tall cell features (TCF).
  
  
  METHODS
  We retrospectively selected and reviewed the clinicopathologic features and presence of the BRAF mutation in 203 cases of classic PTC, 149 cases of classic PTC with TCF, and 95 cases of TCVPTCs, which were defined as PTCs having <10%, 10-50%, and ≥50% tall cells, respectively.
  
  
  RESULTS
  TCVPTCs and classic PTCs with TCF did not vary significantly in clinicopathologic characteristics such as pathologic (p) T stage, extrathyroidal extension, pN stage, lateral lymph node metastasis, or BRAF mutations; however, these features differed significantly in TCVPTCs and classic PTCs with TCF in comparison to classic PTCs. Similar results were obtained in a subanalysis of patients with microcarcinomas (≤1.0 cm in size).
  
  
  CONCLUSIONS
  Classic PTCs with TCF showed a similar BRAF mutation rate and clinicopathologic features to TCVPTCs, but more aggressive characteristics than classic PTCs.
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Oh
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Young Sub
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Uiju
authors.initials: U
authors.lastname: Cho
authors.affiliation: Department of Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Ja Seong
authors.initials: JS
authors.lastname: Bae
authors.affiliation: Department of Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Sohee
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Dong Jun
authors.initials: DJ
authors.lastname: Lim
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Gyeong Sin
authors.initials: GS
authors.lastname: Park
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Chan Kwon
authors.initials: CK
authors.lastname: Jung
keywords: Classification; Histologic types; Tall cell features; Thyroid neoplasms