Background: Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is a heterogeneous that cannot be definitively diagnosed as benign, malignancy-suspect, or malignant. The estimated risk of AUS/FLUS malignancy is reported 5% to 15% according to the Bethesda System (BS). This study was conducted to evaluate the ability of mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) to predict the malignant potential of nodules diagnosed as AUS/FLUS.
Materials and Methods: We retrospectively analyzed 101 patients for whom thyroid fine needle aspiration biopsy (FNAB) analysis indicated AUS/FLUS and who underwent surgery between 2011 and 2015. Demographic, laboratory, and histopathological data were obtained from a database. The patients were categorized into two groups: malignant or benign and comparisons between groups were performed.
Results: The mean age was 49.01±11.59 (2080) years, the mean TSH level was 2.04±2.09 μIU/ml. (0.0111.87), the mean FT4 level was 0.98±0.43 pg/ml (0.543.96), and the mean FT3 level was 3.71±0.80 pg /ml, (2.157.46). Of the 101 patients, 26 (25.7%) had solitary nodules and 75 (74.3%) had multinodulary goiter. The malignancy rate (cytological atypia) was 33.7%, and there were no differences between the two groups in terms of age, gender, or TSH or FT4 levels. Median preoperative red cell distribution width (RDW) level was 13.4 inthe benign group, while it was 14.4 in patients with malignancy, demonstrating a significant correlation (P=0.034) Both MPV and NLR were elevated in malignant nodules.
Conclusions: The malignancy risk of AUS/FLUS evident upon thyroid FNAB was higher than anticipated by the BS. MPV, NLR and RDW are useful for estimating the malignancy risks of these diseases.