Abstract
Objective : We aimed to evaluate the clinical significance of new categories, namely AUS/FLUS and FN/SFN, which have appeared in The Bethesda System for Reporting Thyroid Cytopathology.
Study Design : We used 1,606 thyroid fine needle aspiration cytology (FNAC) specimens obtained from patients of the Cancer Institute Hospital, Tokyo, for 3 years from 2010 to 2012. All the specimens were reviewed and classified by The Bethesda System, and the results were then compared with each histological diagnosis of the surgically removed materials.
Results : A total of 88.6% of the patients with AUS/FLUS was given a final diagnosis of malignancy after surgery. Among these malignant tumors, papillary carcinomas were predominant (71.4%), followed by follicular carcinomas, malignant lymphomas and medullary carcinomas. Among the patients with FN/SFN, the percentage of malignant tumors was 72.7%.
Conclusion : When The Bethesda System is adopted in Japan in the near future, we need to have actual knowledge of typical diseases including the histological types of each category in addition to their exceptions.
