Biological differential diagnosis of follicular thyroid tumor and Hürthle cell tumor on the basis of telomere length and hTERT expression.

Background The most difficult thyroid tumors to diagnose by histology are follicular carcinomas (FTCs) and Hurthle cell carcinomas (HCCs). Telomere alteration and human telomerase reverse transcriptase (hTERT) expression have been observed in most human cancers and are known to be a feature of malignancy. The purpose of this study was to clarify whether hTERT protein expression and telomere alteration could be applicable biological markers for distinguishing FTC from HCC.