title: Thyroid carcinoma showing thymus-like elements: a clinicopathologic, immunohistochemical, ultrastructural, and molecular analysis.
abstract: OBJECTIVE
  To investigate the clinicopathologic, immunophenotypic, ultrastructural, and molecular features of thyroid carcinoma showing thymus-like elements (CASTLE).
  
  
  METHODS
  We retrospectively analyzed the clinicopathologic data of 10 patients with CASTLE and described the immunophenotypic and ultrastructural features of these tumors. The expression of Epstein-Barr virus-encoded RNA and the gene status of EGFR, C-KIT, and HER-2 were also assessed by molecular techniques.
  
  
  RESULTS
  The tumor cells were positive for CD5, CD117, p63, HMWK, EGFR, GLUT-1, Pax8, E-cadherin, bcl-2, and p53 in all cases and for CA-IX, CEA, p16, HER-2, and neuroendocrine markers in some cases. Ultrastructural examination indicated that the tumor cells contained large quantities of tonofilament with abundant intercellular desmosomes, including intracytoplasmic neuroendocrine granules in one case. EGFR gene amplification in two patients and polyploidy of chromosome 7 in one patient were identified by fluorescence in situ hybridization. Sequencing analysis revealed that a synonymous mutation, Q787Q 2363 (G→A), occurred on exon 20 of the EGFR gene in three patients.
  
  
  CONCLUSIONS
  GLUT-1 can be used as a novel biomarker for CASTLE, and combined detection of GLUT-1 with CD5 and CD117 aids in the diagnosis of this tumor. Aberrant expression of Bcl-2, p53, p16, E-cadherin, EGFR, C-KIT, and HER-2 may play important roles in the development of CASTLE.
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Yan-fen
authors.initials: YF
authors.lastname: Wang
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Pathology, Drum Tower Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Xiang-shan
authors.initials: XS
authors.lastname: Fan
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Rao
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Qiu-yuan
authors.initials: QY
authors.lastname: Xia
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Shi
authors.affiliation: From the Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China zhouxj3456@126.com.
authors.forename: Xiao-jun
authors.initials: XJ
authors.lastname: Zhou
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D051272:Glucose Transporter Type 1 / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D012189:Retrospective Studies; D013950:Thymus Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000648:ultrastructure*
chemical_list: D014408:Biomarkers, Tumor; D051272:Glucose Transporter Type 1; C495677:SLC2A1 protein, human
keywords: Carcinoma showing thymus-like elements; EGFR gene amplification; GLUT-1; Gene mutation; Immunophenotype; Thyroid neoplasm; Ultrastructure