Multiple endocrine neoplasia type 2B (MEN2B) is a genetic rare disease in which one or more of the endocrine glands are overactive and form a tumor (neoplasia). Calcitonin is the hormone that is overproduced and can be tested by a simple blood test.

 

Common tumors that may be associated with MEN2B include medullary thyroid carcinoma (MTC) and tumors of the adrenal glands called pheochromocytomas. Other features of MEN2B can include having bumps on the lips, eyelids and tongue. The eyelids may often appear to be thickened. Another feature is having really high arches in the feet. People with MEN2B typically have a body type with long arms, legs, and fingers. They may also have joints that are very loose (hyperextensible).  They may also lack tear ducts in the eyes.  Ophthalmologists have found prominent corneal nerves upon examination. Gastrointestinal issues may appear at birth or have a later onset with constipation, belly bloat or diarrhea.

 

The disease can be inherited or be a spontaneous mutation. A diagnosis of MEN2B is suspected when a person has a family history of medullary thyroid cancer, pheochromocytoma, or physical findings suggestive of MEN2B. The diagnosis can be confirmed with genetic testing.