Multiple endocrine neoplasia type 2B (MEN2B) is associated with the highest-risk RET mutation. Prophylactic thyroidectomy in MEN2B should be performed:
- A Within the first 6 months of life, even in the absence of elevated calcitonin ✓
- B At age 5 years when calcitonin first rises above normal
- C Only after ultrasound-confirmed thyroid nodules develop
- D Between ages 10–15 years, based on annual calcitonin monitoring
Correct answer: A. Within the first 6 months of life, even in the absence of elevated calcitonin
Explanation
MEN2B (typically caused by M918T RET mutation, the highest-risk category in ATA classification) is associated with the earliest onset and most aggressive medullary thyroid carcinoma — MTC can develop within the first year of life and can metastasise before age 1. ATA 2015 guidelines classify M918T as 'highest risk' (formerly Category D) and recommend prophylactic total thyroidectomy within the first 6 months of life, ideally in the newborn period, regardless of calcitonin level. This is the most time-critical prophylactic recommendation in surgical oncology.
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.