Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms.
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.
Mehrotra
P
P
School of Surgical and Reproductive Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
Okpokam
A
A
Bouhaidar
R
R
Johnson
S J
SJ
Wilson
J A
JA
Davies
B R
BR
Lennard
T W J
TW
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
D014408:Biomarkers, Tumor; D037502:Galectin 3