OVERVIEW
Multiple endocrine neoplasia (MEN) is a group of dominantly inherited disorders with a strong familial predisposition to multiple endocrine gland tumors that produce a variety of hormones or hormone-like substances that are identical to the glands in which they are found, resulting in an extremely complex and variable endocrine syndrome. MEN2 is characterized by the coexistence of medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism, while MEN2B patients may also have mucosal neuromas and equine-like forms.
Etiology
The etiology of this syndrome is unknown, with a significant familial predisposition to autosomal dominant inheritance. It is mostly autosomal dominant. It should be caused by mutation of RET proto-oncogene.
Symptoms
MEN2 is characterized by the coexistence of medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism; MEN2B patients may also have mucosal neuroma and equine-like body.
1. Hyperparathyroidism (hyperplasia or adenoma)
May manifest as hypercalcemia.
2. Pheochromocytoma accounts for 50% of cases, mostly familial
Mostly located in adrenal glands, often bilateral, malignancy is rare. Clinical manifestations are the same as those of sporadic pheochromocytoma, manifesting as persistent or paroxysmal hypertension, headache, palpitation, profuse sweating, change of color, cold extremities, chest tightness and other symptoms.
3. Medullary carcinoma of thyroid gland
Medullary carcinoma of the thyroid is the most common manifestation, which is a tumor originated from C cells of the thyroid. Clinically, in addition to goiter, it can also secrete calcitonin and many kinds of heterologous hormones (ACTH, VIP, 5-HT, etc.), which may cause many clinical syndromes: skin flushing, diarrhea, peptic ulcer, hypertension, but serum calcium is not low or even high; blood calcitonin is measured to be elevated.
The main symptoms of this syndrome are medullary thyroid carcinoma and pheochromocytoma, and any of the first clinical signs should be examined for the possible presence of MEN.
4. Multiple mucosal neuromas
It occurs in oral mucosa, tongue, lips, eyelids and gastrointestinal tract, etc. It manifests as thick and uneven lips, thickened and uneven surface of tongue, diffuse or nodular eyelid ectropion, and gastrointestinal mucosal neuroma manifests as diarrhea or constipation.
5. Horse-like square body type
Long and thin body, long and narrow face, elongated limbs, lax joints, subluxation or subluxation, scoliosis or retroconvexity of the spine, chicken chest, funnel chest, dilatation of the ascending aorta, subluxation of the crystalline lens, high myopia.
Examination
Urinary catecholamines, blood glucose, blood norepinephrine, epinephrine and calcitonin may be significantly elevated, and blood electrolytes, T3, T4, aldosterone, cortisol and glucagon must be routinely checked. Determination of blood hormone concentrations such as growth hormone, calcitonin, parathyroid hormone, blood glucose 5-hydroxyamine, etc., to facilitate the early diagnosis of the signs of the disease. For imaging, CT and MRI of the lesion should be performed.
Diagnosis
Diagnosis can be made by combining the etiology, clinical manifestations, family history and laboratory tests.
Treatment
The principle of treatment is to take appropriate measures for the main endocrine gland hyperplasia. Tumors can be surgically removed or treated with radiotherapy or chemotherapy.