In MEN2A syndrome, medullary thyroid carcinoma (MTC) is associated with RET proto-oncogene mutations. Prophylactic thyroidectomy timing depends on the codon mutation category. In codon 634 mutation (ATA risk category C), what is the recommended timing for prophylactic thyroidectomy?

• A At birth
• B Before age 10 years
• C When calcitonin levels become elevated
• D Before age 5 years ✓

Explanation

ATA risk category C (including codon 634, one of the highest-risk mutations in MEN2A) recommends prophylactic thyroidectomy before age 5 years, as MTC can develop and metastasize early in these children. ATA category D (codon 918, MEN2B) requires thyroidectomy within the first 6 months of life. Category A mutations (lower risk) can be monitored until calcitonin rises. Early surgery is curative and prevents metastatic disease.

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.