A 52-year-old man with a 1.8 cm Bethesda IV thyroid nodule undergoes molecular testing which reveals a RAS mutation (NRAS Q61R). No other suspicious features are present on ultrasound. According to current evidence, what is the most appropriate surgical management?

• A Lobectomy with isthmusectomy as initial surgery ✓
• B Total thyroidectomy as initial surgery
• C Active surveillance with serial ultrasound
• D Repeat FNA in 6 months

Explanation

RAS mutations are found in follicular-patterned lesions and carry an intermediate risk of malignancy (approximately 60-80%). They are not as strongly predictive as BRAF V600E. Current guidelines recommend diagnostic lobectomy as the initial surgical approach for Bethesda IV nodules with RAS mutation, as the lesion is more likely to be a follicular carcinoma or follicular variant PTC, and capsular/vascular invasion (which determines malignancy) can only be assessed on surgical histology.

Reference: ATA Guidelines for Management of Thyroid Nodules and Differentiated Thyroid Cancer, 2015 ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.