Delayed diagnosis of MEN2B in children with this distinctive syndrome leads to metastatic thyroid cancer at presentation.

Delayed diagnosis of MEN2B in children with this distinctive syndrome leads to metastatic thyroid cancer at presentation.

MEN2B is a genetic syndrome caused by the RET p.M918T mutation requiring prophylactic thyroidectomy within the first year of life. This single-center study of 6 children with sporadic MEN2B found that despite exhibiting the complete, distinctive phenotype (marfanoid habitus, mucosal neuromas, alacrima, GI symptoms), all were diagnosed late.

66.7% already had cervical lymph node metastases at presentation. After surgery (median follow-up 2.8 years), only 1 patient achieved biochemical remission. Delayed diagnosis directly compromised prognosis in all cases.

The study highlights urgent need for better awareness among pediatric specialists and efficient multidisciplinary recognition pathways.

Key Findings

• All 6 MEN2B children exhibited complete classic phenotype but were diagnosed late
• 66.7% had lymph node metastases at presentation
• Only 1 patient (T2N0M0) achieved biochemical remission after surgery
• All cases had de novo p.M918T RET mutation
• Delayed diagnosis severely compromises prognosis in an otherwise preventable cancer situation

Implications

Pediatricians, ophthalmologists, gastroenterologists, and orthopedic surgeons should be aware of the MEN2B phenotype to enable timely genetic diagnosis and prophylactic thyroidectomy before medullary thyroid carcinoma develops. Multidisciplinary referral pathways are critical.

Caveats

Small case series (n=6); single-center; abstract-only. Educational/clinical awareness value. Short median follow-up (2.8 years). Results represent the consequence of diagnostic delay, not a research finding about a new treatment or biomarker.

Source: European journal of pediatrics — 2026-04-10