title: The Potential Diagnostic Utility of TROP-2 in Thyroid Neoplasms.
abstract: Human trophoblast cell-surface marker (TROP-2) has been reported to be overexpressed in various human carcinomas (CAs) and suggested to be a prognostic marker for some CAs. The diagnostic utility of TROP-2 in CAs has not been explored.
  
  
  
  Immunohistochemical evaluation of TROP-2 expression on tissue microarray sections of 136 thyroid neoplasms, surgical specimens of 61 atypical thyroid follicular-patterned lesions [including 33 papillary thyroid carcinomas (PTCs), 17 atypical follicular neoplasms (AFNs), and 11 adenomatoid nodules with focal nuclear atypia (ANFNA)], and 20 benign thyroid lesions, as well as 10 cytology specimens of PTCs was performed. For comparison, immunoassay for Hector Battifora mesothelial-1 (HBME-1), galectin-3, and cytokeratin 19 was performed on the 61 atypical thyroid follicular-patterned lesions.
  
  
  
  Strong membranous staining with TROP-2 was seen in 94% (33/35) of classic PTCs and 81% (30/37) of confirmed follicular variant PTCs on tissue microarray and routine surgical sections, as well as 100% (10/10) of PTCs on cytology specimens; it was not observed in follicular adenomas (n=51) or CAs (n=37), AFNs or ANFNA (n=28), benign (n=20) or normal (n=15) thyroid tissue. In contrast, the expression of HBME-1 and galectin-3 was identified in 100% (33/33) of surgical cases of PTCs and in 57% (16/28) and 50% (14/28) of AFNs and ANFNA, respectively.
  
  
  
  Our findings demonstrate that a membranous TROP-2 staining pattern is highly specific for PTC, which may serve as a potential diagnostic marker aiding in the accurate classification of morphologically equivocal thyroid follicular-patterned lesions.
authors: Department of Laboratory Medicine, Geisinger Medical Center, Danville, PA.
authors: Haiyan
authors: H
authors: Liu
authors: Jianhui
authors: J
authors: Shi
authors: Fan
authors: F
authors: Lin
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001707:Biopsy, Needle; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D006801:Humans; D011379:Prognosis; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; C499380:TACSTD2 protein, human