Management of Atypia of Undetermined Significant Thyroid Nodule

Abstract

Thyroid nodules are one of frequent clinical problem with prevalence of 5% palpable nodules. Results of atypia of undetermined significance (AUS) can be found with risk of 5-15% malignancy rates. Management of AUS is still challenging and complex including observation until surgical approach. We present two cases of nodule thyroid. The 1st case of 44-year-old female with nodule of left thyroid lobe for 1 year. Ultrasonography (USG) examination showed TIRADS 4 at left lobe yet the Fine needle aspiration (FNA) resulted as AUS. The 2 nd case was 44-year-old male with nodule at left thyroid lobe for 3 years. USG showed TIRADS 5 of left lobe and TIRADS 4 of right lobe meanwhile FNA resulted as AUS. Left hemithyroidectomy was performed for the 1 st patient and histopathology examinations showed as struma adenomatous with focus of thyroid papillary carcinoma with follicular variant. Completion thyroidectomy then performed 2 months after the first procedure. Observation was chosen for the 2 nd case. Patient has been asymptomatic with close thyroid function and USG follow up. Hemithyroidectomy was performed 6 months afterwards since the mass getting bigger, and histopathology showed papillary carcinoma thus proceed with total thyroidectomy. Management of AUS is still debatable. It can present as heterogeneous lesions with different sub classifications according to cytomorphologic and molecular findings. Considerations of clinical risk stratification, USG findings and FNAB should be combined altogether for the best management and treatment outcome.