Some manifestations may be seen in early childhood. Prominent physical features include full lips, thickened eyelids, high arched palate and a marfanoid habitus. Medullary carcinoma of the thyroid is almost always present and can be the cause of death in relatively young individuals. Metastases are usually to the regional lymph nodes or to liver, lungs, or bone. Pheochromocytomas and megacolon secondary to gastrointestinal neuromas are commonly seen. The esophagus sometimes lacks normal motility for the same reason. Neuromas often lead to thickening of the lips and tongue and can also appear as pedunculated nodules on these structures. Cafe-au-lait spots and increased pigmentation of the hands, feet, and circumoral areas are frequently present. Many patients have dysmorphic features suggestive of Marfan syndrome including a typical habitus, pectus excavatum, scoliosis, and pes cavus. Proximal myopathy and peripheral neuropathy are sometimes seen.
Another form of multiple endocrine neoplasia, called MEN2A, differs in the absence of mucosal neuromas and the marfanoid habitus. MEN2A patients are more likely to have parathyroid hyperplasia.