Detection of PAX8/PPAR fusion gene by FISH Technique in follicular thyroid lesions

Abstract

The main problem established by a discovery of a thyroid nodule is to discriminate between a benign and malignant lesion. Differential diagnosis between follicular thyroid cancer (FTC) and benign follicular thyroid adenoma (FTA) is a great challenge for even an experienced pathologist and requires special effort.The purpose of the study was to detect PAX8/PPAR G gene rearrangement by fluorescent in situ hybridization (FISH) technique,the present study is the first time in Iraq used this technique to detect fusion gene in follicular thyroid lesions,follicular carcinoma (FC) follicular variant papillary of carcinoma (FVPC), follicular adenoma (FA) and follicular hyperplasia. A total of 120 paraffin block were included in the study,30 blocks were (FC),30 blocks were (FVPC). 30 blocks were (FA),30 blocks were blocks thyroid follicular hyperplasia.20 blocks endocervical epithelium.20 paraffin blocks of colonic epithelium. The clinicopathological parameters were obtained from patients’ admission case sheets and pathology reports (age,gender). The description of measures regarding fluorescent instu hybridization of PAX8/ PPAR G fusion gene there was significantly highest in follicular carcinoma,followed by follicular variant of papillary carcinoma,then follicular adenoma and lastly by follicular hyperplasia The area under the curve for all three markers was >0.8.The p-value was highly significant for all three markers (P<0.001). Cutoff values that predict malignant thyroid follicles lesion were as following: score of >1 for Galectin-3 marker,score of >2 for HBME-1 marker and number of positive cells per 50 of >13 (>26%) for PAX8 /PPAR G fusion gene marker. The sensitivities for the three markers were 100.00 %,90.00 % and 66.67 %,respectively,whereas the specificities were 88.30 %,98.33 % and 100.00 % respectively.