Thyroid Fine-Needle Aspiration Practice in the Philippines

ABSTRACT

Fine-needle aspiration (FNA) is a well accepted initial approach in the management of thyroid lesions. It has come a long way since its introduction for nearly a century ago. In the Philippines, FNA of the thyroid was first introduced 30 years ago and has been utilized until now as a mainstay in the diagnosis of thyroid malignancy. The procedure is performed by pathologists, endocrinologists, surgeons, and radiologists. Most pathologists report the cytodiagnosis using a combination of the aspiration biopsy cytology method that closely resembles the histopathologic diagnosis of thyroid disorders and the six-tier nomenclature of The Bethesda System for Reporting Thyroid Cytopathology. Local endocrinologists and surgeons follow the guidelines of the 2015 American Thyroid Association in the management of thyroid disorders. There is still a paucity of local research studies but available data deal with cytohistologic correlations, sensitivity, specificity, and accuracy rates as well as usefulness of ultrasound-guided FNA. Cytohistologic correlations have a wide range of sensitivity from 30.7% to 73% and specificity from 83% to 100%. The low sensitivity can be attributed to poor tissue sampling since a majority of the thyroid FNA is done by palpation only. The reliability can be improved if FNA is guided by ultrasound as attested in both international and local studies. Overall, FNA of the thyroid has enabled the diagnosis of thyroid disorders with an accuracy of 72.8% to 87.2% and it correlates well with histopathology.