MicroRNA as a Diagnostic Tool in Fine-Needle Aspiration Biopsy

Thyroid cancer accounts for 1.5 % of all malignancies in the U.S., and it is the most common endocrine malignancy. Detection of thyroid cancer mostly relies on evaluation of thyroid nodules, which are very common but only 5%–7% harbor malignancy. Fine-needle aspiration biopsy (FNAB) is currently the most important tool for the evaluation of thyroid nodules; however, it is limited in that it provides only a cytology assessment of the aspirated cells, and inde-terminate diagnoses are present in up to 30 % of FNAB re-sults. This limitation can be overcome by the molecular analysis of FNAB, and more specifically with the use of mi-croRNAs (miRs). miRs constitute a class of endogenous small noncoding RNA fragments that regulate gene expression, and in vitr