Abstract
Aim This study aimed to demonstrate the role of Epstein-Barr Virus (EBV)
in papillary thyroid carcinomas (PTC) developing on the background of
Hashimotoʼs thyroiditis (HT).
Methods The presence of EBV in tumoral tissue, lymphocytes, and
peritumoral normal thyroid tissue was investigated using the in situ
hybridization method in paraffin blocks. The subtypes of PTC, tumor diameter,
TNM stage, multifocality, invasion of thyroid capsule, perineural invasion, and
muscular tissue invasion were identified and compared according to EBV
involvement.
Results Eighty-one patients with HT diagnosis, with 93.8% (n=76) female
and 6.2% (n=5) male, were included in the study. Papillary microcarcinoma was
the pathological diagnosis in 24.2% (n=15) of the cases. EBV was identified in
58.06% (n=36) of the tumor cells nuclei, 58.06% (n=36) in the tumor cell
cytoplasm, 16.12% (n=10) in tumor infiltrative lymphocytes, and 53.2% (n=33) in
normal parenchymal follicle epithelial cells (NPFEC). In the T2 stage, the rate
of EBV nuclear positivity in patients was significantly higher (p=0.034). The
classic variant of papillary carcinoma was accompanied by a significantly higher
rate of EBV-negative NPFEC (67.6%, p=0.049). In multifocal tumors, EBV
positivity was found to be significantly higher in lymphocytes in the
surrounding tissues (58.3%, p=0.034).
Conclusion A significant increase in EBV positivity in the surrounding
tissue lymphocytes was observed in multifocal PTC developing on a background of
HT. This suggests a possible association between HT and EBV.
Keywords
Epstein-Barr virus - thyroid papillary carcinoma - Hashimoto thyroiditis - microcarcinoma - multifocality
