it should be noted that FNAC cannot differentiate between benign and malignant follicular neoplasms.differentiation between follicular adenoma and follicular carcinoma is only possible after thyroid lobectomy.[2,3] In addition, a study of FNAC showed that 68% of the cases diagnosed by FNAC as follicular neoplasm turned out to be the follicular type of papillary carcinoma, indicting a considerable overlap between benign and malignant neoplasms.[4] Incidental findings of thyroid nodules have increased exponen¬tially in recent years, mostly due to the widespread application of high-resolution ultrasound (US) to the thyroid [5].Several in¬ternational scientific societies have established clinic-radiolog¬ical guidelines for the diagnosis and the management of thy¬roid nodules [2,3]. The American College of Radiology identifies 5 radiological risk levels and recommends US-guided fine-nee¬dle aspiration cytology (US-FNAC) of high-suspicion nodules if 10 mm or larger, and of nodules with a low risk for malignan¬cy only if larger than 25 mm [2]. According to the European Thyroid Association Guidelines (EU-TIRADS), nodules with no high-risk features (oval-shaped, isoechoic/hyperechoic with smooth margins) should be considered at low risk and FNA performed only if greater than 20 mm, while high-risk nodules greater than 10 mm should undergo FNAC, with possible FNAC also in 5-10 mm nodules if highly suspicious [3].
Thyroid gland diseases are the second most common endocrine disease following diabetes mellitus(1). Thyroid nodules are common disorders with a prevalence ranged from 4 to 7% in adult population, 5%-30% are malignant [1].Fine-needle aspiration cytology (FNAC) is an easy, cost-effective test for cancer diagnosis, and its use has markedly decreased the number of unnecessary thyroid surgeries(2).