Prospective Study of Bethesda Categories III and IV Thyroid Nodules: Outcomes and Predictive Value of BRAF

introductionAtypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has emerged as the most controversial category because of its heterogeneity and inconsistent reporting. There is a definite paucity in data available from the Indian subcontinent about the outcome of nodules carrying Bethesda category III or Bethesda category IV diagnoses. AIMS AND

objectivesThe primary objective of our study was to determine the malignancy rate in Bethesda categories III and IV nodules. The secondary objectives were to determine predictive value of BRAF MATERIALS AND

methodsThis prospective study included 176 consecutive nodules of Bethesda categories III and IV, diagnosed over a period of 2 years from August 2015 to August 2017. A part of the fine needle aspirate was used to perform the BRAFV600E mutation analysis. The malignancy risk associated with these Fine needle aspiration Cytology categories were discussed with the patients. Those with Bethesda category IV diagnosis was advised surgery, whereas those with Bethesda category III were given the options of close follow-up with repeat FNA in 3 months or immediate surgery.

resultsIn our prospective study, there were 176 consecutive samples of categories III (140/79.5%) and IV (36/20.5%). Seventy-five (53.6%) category III nodules and 29 (80.6%) category IV nodules underwent immediate surgical excision. Fifty-five consecutive indeterminate cytology nodules were subjected for BRAF

conclusionMalignancy rate in Category III at our center was much higher than that described by ATA and by other studies published from centers around the world, including the only two studies from India. In view of the strikingly high malignancy rate in these indeterminate nodules, strong consideration to surgery should be given to patients with FNA results suggesting these two categories. BRAFV600E mutation analysis in FNA specimen has limited utility in improving the preoperative diagnostic rate for malignancy.