A patient with MEN2A syndrome is found to have an RET proto-oncogene mutation in codon 634. Prophylactic thyroidectomy should be performed at what age according to risk-stratified guidelines?

• A By age 6 months (ATA Highest Risk category D mutation)
• B By age 10 years (ATA Moderate Risk category B)
• C When calcitonin level rises above normal
• D By age 5 years (ATA High Risk category C) ✓

Explanation

Codon 634 mutations are classified as ATA High Risk (category C) and carry a high penetrance for medullary thyroid carcinoma, often before age 5. Prophylactic total thyroidectomy is recommended by age 5 years (or earlier if calcitonin is elevated or ultrasound shows nodularity). ATA Highest Risk (category D, codon 918) mutations in MEN2B mandate thyroidectomy within the first 6 months of life. Moderate risk (category B) mutations permit a more watchful approach with calcitonin monitoring.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.