Management of Thyroid Nodules with Atypical Cytology on Fine-Needle Aspiration with Ultra Sonogram

Objective: Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) are indeterminate lesions with malignancy incidence of 5-15%. We evaluate the role of thyroid ultrasound in predicting malignancy in Bethesda type III nodules, and thus suggest management guidelines in these nodules.

Method: Patient with Bethesda type III nodules were subjected to high resolution ultrasonography of neck. The features analysed while performing US examination are size, site, echogenicity (solid, cystic), margins (circumscribed, micro lobular, irregular), calcification (micro, macro or egg shell) and shape of the lesion. On the basis of ultrasound these nodules were categorized into probably benign or suspicious of malignancy. All these patients were subjected to surgery and final histopathological report were compared with ultrasonography features.

Results: The positive predictive value of ultrasonogram in predicting malignancy in Bethesda type-III nodules is 84.2%, while specificity of ultrasonogram is 90.9% and sensitivity in predicting malignancy is 80%.

Conclusion: When the USG features are suggestive of benign lesion then a repeat USG guided FNAC may be considered and when the USG features are suggestive of malignant lesion then a repeat FNA is unnecessary and a definitive surgery should be considered.