A follow-up study on thyroid aspirates reported as atypia of undetermined significance/follicular lesion of undetermined significance and follicular neoplasm/suspicious for follicular neoplasm: A multicenter study from the Arabian Gulf region.

ABSTRACT

OBJECTIVE: This is a multicenter study which was conducted to evaluate the follow-up on thyroid aspirate cases with atypia of undetermined significance/follicular cells of undetermined significance (AUS/FLUS) and follicular neoplasm or suspicious for follicular neoplasm (FN/SFN) using the Bethesda system for reporting thyroid cytology (TBSRTC). MATERIALS AND METHODS: The archival materials of all thyroid fine-needle aspirates over a 5-year period were retrieved from 3 institutions in the Arabian Gulf Region. All cytology slides and follow-up material for cases interpreted as AUS/FLUS and FN/SFN were reviewed. The revised diagnoses and follow-up were recorded. Analysis of risk of malignancy was calculated for the 2 entities. RESULTS: A total number of 2592 thyroid fine-needle aspirates were performed, out of which AUS/FLUS was found in 115 (4.4%) while FN/SFN in 39 (1.5%). Follow-up by surgery or repeat FNA was conducted on 42 (27%) and 10 (7%) patients on these 2 categories, respectively. The risk of malignancy was found to be 29% and 45%, respectively. CONCLUSION: The risk of malignancy for AUS/FLUS and FN/SFN are 29% and 45%, respectively. This risk of malignancy in our study is on the higher range of that reported in the literature.