Thyroid nodule evaluation: US-FNA and on-site cytology assessment

摘要

Thyroid nodules are a very common endocrine problem, with an estimated 4% of the population having a palpable nodule and more than 50% having a nodule detectable by ultrasound (US). In each of the major clinical guidelines on the management of thyroid nodules (1-3), US is highlighted as a critical tool in selecting nodules requiring fine needle aspiration (FNA). In addition to using US to assess thyroid nodule characteristics, parathyroid abnormalities, and lymph nodes, US-guided FNA has essentially replaced the use of palpation FNA. US-guided FNA reduces the inadequacy rate of cytology samples when compared to palpation FNA (4). In addition, the sensitivity and specificity of the FNA procedure are improved when FNA is combined with US (5). With US guidance, specific areas of the lesion, such as calcifications or the vascular solid mural component of a cyst can be targeted with precision.