Thyroid nodules are prevalent in upto 68% of randomly selected individuals in whom high resolution ultrasound is performed. The majority of nodules are benign. The use of ultrasound coupled with FNAC has dramatically reduced the number of patients who undergo surgery for nodules. The six tier Bethesda scoring system has reduced variability and increased the ability to clinicians to guide patients with thyroid nodules. There is good correlation between cytology and histopathologic outcomes. A significant proportion of patients will however fall into an indeterminate category. The availability of molecular markers enhanced with next generation sequencing technology and the expression classifier are added diagnostic aids that can help in management. However these are not available in many countries and in resource limited settings. A pragmatic approach to the diagnosis of indeterminate nodules includes utilising pre and post test probability, clinical acumen, correlation of ultrasound findings and expert opinion in some settings. Using this approach high risk patients can be appropriately chosen for surgery while relegating patients with lower risk to watchful followup.
Keywords: Atypia of undetermined significance follicular lesion of undetermined; Bethesda scoring; Thyroid Imaging Reporting and Data System; follicular neoplasm/suspicious for follicular neoplasm; indeterminate nodule; suspicious for malignancy.