title: HBME-1 expression in hyalinizing trabecular tumours of the thyroid gland.
abstract: OBJECTIVE
  Hyalinizing trabecular tumour (HTT) is a rare thyroid neoplasm with a trabecular growth pattern, marked intratrabecular hyalinization and nuclear features of papillary thyroid carcinoma (PTC). Immunohistochemical HBME-1 expression was reported recently in PTC, but not in HTT. To clarify further the value of HBME-1 expression as a tool in differential diagnosis, we investigated the immunophenotype of HTT.
  
  
  RESULTS
  Eight HTT diagnosed from 1997 to 2012 were reviewed on H&E-stained tissue sections and analysed for HBME-1, galectin-3, CK19 and Ki67 expression by immunohistochemistry. Three of eight HTTs (37.5%) were HBME-1 positive, with staining of tumour cells as well as of intratrabecular hyaline matrix material. All cases were CK19 negative. Galectin-3 was expressed weakly in four of eight cases (50%). Five of eight cases (62.5%) showed weak-to-moderate cytoplasmic Ki67 positivity.
  
  
  CONCLUSIONS
  Immunohistochemical HBME-1 expression is present in HTT and may not serve as a reliable marker in differentiating HTT from PTC. The HBME-1 positivity of the hyaline matrix suggests that this material is partly of cytoplasmic origin.
authors.affiliation: Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Daniela
authors.initials: D
authors.lastname: Lenggenhager
authors.forename: Ewerton M
authors.initials: EM
authors.lastname: Maggio
authors.forename: Holger
authors.initials: H
authors.lastname: Moch
authors.forename: Matthias
authors.initials: M
authors.lastname: Rössle
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D006818:Hyalin / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology; D000951:Antigens, Neoplasm
chemical_list: D014408:Biomarkers, Tumor; C432845:HBME-1 antigen; D000951:Antigens, Neoplasm