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. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.