title: Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms.
abstract: OBJECTIVE
  To determine whether galectin-3 is a sensitive indicator of thyroid malignancy. It has been suggested as a potential marker for differentiating thyroid carcinoma from benign or non-neoplastic lesions in preoperative fine-needle aspirates (FNAs).
  
  
  METHODS
  Galectin-3 protein expression was assessed by immunohistochemistry in formalin-fixed thyroid tissues from 124 patients with histological diagnoses of papillary carcinoma (n = 38), follicular carcinoma (n = 19), follicular adenoma (n = 32) and dominant nodules of multinodular goitre (n = 35). Expression of galectin-3 was also assessed by Western blotting in 24 fresh thyroid tissues.
  
  
  RESULTS
  Galectin-3 expression was observed in the majority of carcinomas (papillary 92%; follicular 74%). However, a large proportion of follicular adenomas (72%) and multinodular goitres (57%) also expressed galectin-3. In addition, galectin-3 expression was observed in epithelial cells of normal thyroid tissue and Hashimoto's thyroiditis. Galectin-3 immunopositivity was significantly greater in papillary carcinomas than in dominant nodules or follicular adenomas (P < 0.0001, P = 0.0005, respectively). However, galectin-3 expression was no greater in follicular carcinomas than in follicular adenomas (P = 0.8735). Western blotting analysis confirmed both the specificity of the antiserum and expression of galectin-3 in multinodular goitres, follicular adenomas/carcinomas and papillary carcinomas.
  
  
  CONCLUSIONS
  The data demonstrate that galectin-3 is not a reliable immunohistochemical marker to distinguish benign from malignant thyroid follicular lesions.
authors.affiliation: School of Surgical and Reproductive Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
authors.forename: P
authors.initials: P
authors.lastname: Mehrotra
authors.forename: A
authors.initials: A
authors.lastname: Okpokam
authors.forename: R
authors.initials: R
authors.lastname: Bouhaidar
authors.forename: S J
authors.initials: SJ
authors.lastname: Johnson
authors.forename: J A
authors.initials: JA
authors.lastname: Wilson
authors.forename: B R
authors.initials: BR
authors.lastname: Davies
authors.forename: T W J
authors.initials: TW
authors.lastname: Lennard
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000473:pathology; D014408:Biomarkers, Tumor; D015153:Blotting, Western; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology; D037502:Galectin 3; D006801:Humans; D007150:Immunohistochemistry; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D037502:Galectin 3