Commonly associated with RET gene.
Associated with pheochromocytomas and medullary carcinomas of the thyroid.
MEN2B associated MCT presents in individuals younger than 20 years.
MEN type 2B ois also associated with thyroid and adrenal medulla tumors, but is found in patients with marfanoid features.
MEN2B effects 8-15% of all MEN2 patients.
MEN2B has a hereditary predisposition to MTC and pheochromocytoma, but not to hyperparathyroidism.
MEN2B patients have mucosal neuromas of the lips tongue and intestinal ganglioneuromas.
MEN2B patients also have disorders such as chronic constipation and megacolon, abnormalities in the upper to lower body ratio, skeletal deformities such as kyphoscoliosis, lordosis, joint laxity, Marfanoid habitus, everted eyelids and myelinated corneal nerves (O’Riordain DS et al).
Individuals are disproportionately tall and thin resembling Marfan’s habitus.
Patients will frequently have pectus excavatum full nodular lips, and eyelid eversion.