This handout is for multiple endocrine neoplasia type 2b (men2b). Your care team identified this based on: mucosal neuromas ("bumpy lip"/tongue/eyelid) + marfanoid habitus in a child (2015 ata wells).
Other reasons your team may use this plan: infantile chronic constipation / megacolon / feeding failure — intestinal ganglioneuromatosis (often earliest clue) (2015 ata wells); elevated calcitonin / cea or thyroid nodule = medullary thyroid carcinoma (2015 ata wells); ret m918t (codon 918) carrier or first-degree relative with men2b (2015 ata wells).
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| RET germline sequencing (codon 918 M918T) + genetic counseling | — | — | — | 2015 ATA Wells — M918T (~95% of MEN2B) defines ATA HIGHEST risk; counsel that ~50% are de novo (paternal origin) so absent family history does NOT exclude |
| cascade RET testing of first-degree relatives | — | — | — | 2015 ATA Wells — autosomal dominant; test at-risk relatives to identify carriers needing prophylactic thyroidectomy |
Plan: MEN2B sequenced pathway — phenotype/RET → pheo FIRST (α then β) → prophylactic total thyroidectomy in first year of life → metastatic MTC RET inhibitor → GI supportive → surveillance
Contact your care team if any of the following happen:
Call 911 or go to the nearest emergency room right away if you have:
Lifelong endocrine/oncology/genetics; cascade RET testing of at-risk relatives (counsel ~50% de novo); annual calcitonin/CEA/metanephrines; GI follow-up for ganglioneuromatosis; reproductive counseling (autosomal dominant, prenatal/PGT options)
Guideline: 2015 revised ATA Medullary Thyroid Carcinoma Guidelines (Wells); 2021-2025 MEN2B/RET updates (LIBRETTO-001 selpercatinib; ARROW pralsetinib)