RET and Hirschsprung disease: MEN2A can also be accompanied by hyperparathyroidism, whereas MEN2B hyperparathyroidism is relatively rare and can be accompanied by clinical manifestations such as congenital megacolon, Marfan sign, and mucosal neuroma.[2,4] Studies have shown that 80% of bilateral pheochromocytomas, mainly MEN2A (42.6%), the incidence of pheochromocytoma and medullary thyroid carcinoma in MEN2A patients is generally around 40 years of age, which is similar to the onset age of this patient.