The diagnostic accuracy of the immunochemical markers in the pre-operative evaluation of follicular thyroid lesions

Abstract

Aim of the study was to consider the diagnostic accuracy of galectine-3 (GAL3) in the pre-operative cytological evaluation of follicular lesions. We retrospectively evaluated 100 patients suffering from thyroid nodular disease submitted to thyroidectomy from 2006 to 2007 in our Institution. Before surgery all patients underwent fine needle aspiration biopsy. The immunocytochemical analysis was performed on fine needle aspiration specimens using species-specific monoclonal antibodies and a biotin-free detection system. Based on preoperative cytological reports, 40 patients had pre-operative malignant results, and 60 patients (46 females and 14 males) showed follicular lesions. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of GAL3 was evaluated. Chi-square test was used to compare frequencies of GAL3 expression between the different hystopathological groups. GAL3 proved to have 55% sensitivity, 100% specificity, 70% negative predictive value, and 78% diagnostic accuracy. The GAL3 expression in neoplastic and benign lesions was significantly different (GAL3+ in 16 out of 29 neoplastic lesions, GAL3+ 0 out of 31 benign lesions, p<0.01). Even comparing the GAL3 positivity between the follicular adenomas (0 GAL3+ out of 20) and the group of follicular carcinomas (5 GAL3+ out of 6), we found a statistically significant difference (p<0.01). Based on the data from our experience, the patients with a cytological diagnosis of GAL3 positive follicular neoformation should be referred for surgery without any further immunocytological testing.