OVERVIEW
Overview of Multiple Endocrine Neoplasia
Multiple endocrine neoplasia (MEN) type 2 is a genetic disorder in which patients have tumors or hyperplasia of two or more endocrine glands at the same time or in succession. It can be divided into two subtypes, MEN2A (Sipple syndrome) and MEN2B, both of which are autosomal dominant. MEN2A is the most common.
Whether medical insurance
Yes
Department
Endocrinology
Clinical Symptoms
Both MEN2A and MEN2B have medullary thyroid carcinoma and pheochromocytoma.There are also two variants in MEN2A; in MEN2B there are multiple mucosal neuromas and equine body types.
Hazards
Fatalities and disabilities are high, especially in MEN2B.
Examination
Blood and urine catecholamine assay, methoxy epinephrine assay, blood calcitonin basal level test, serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone assay, calcium gluconate assay, pentagastrin co-stimulation test, ultrasound, CT, MRI, thyroid puncture biopsy, and molecular genetics test.
Diagnosis
Diagnosis can be made based on the different clinical characteristics of each subtype of MEN2, combined with laboratory tests and ultrasound, CT, MRI, etc.
Treatment principle
The main treatment is radical surgery, including total thyroidectomy and central lymph node dissection. For those who have metastases that cannot be cured, palliative surgery is performed. If necessary, radiotherapy will be performed.
Curative
Treatment can relieve symptoms in those without metastases and improve prognosis in those with metastases.
Dietary advice
Iodine-deficient individuals season with iodized salt and eat iodine-rich foods. Discontinue goiter-causing foods.
Important reminders
MEN2 family members should undergo early genetic testing. Since the outgrowth rate of RET gene mutation carriers is almost 100 percent, early diagnosis and early treatment are possible.
Etiology
Epidemiology
The incidence of MEN2 is 1-10/100,000, and MEN2A develops in adolescence.
Etiology
MEN2 is associated with specific mutations in the RET gene.
Symptoms and Diagnosis
Typical symptoms
1. Medullary carcinoma of thyroid: multifocal. Thyroid enlargement or nodules, skin flushing, peptic ulcer, diarrhea, hypertension, etc. Patients with extensive metastasis may have diarrhea. Patients with extensive metastasis may present with diarrhea.2. Pheochromocytoma: mostly benign, often involving bilateral adrenal glands, occurring only within the adrenal glands, not outside the adrenal medulla. Clinical manifestations include intermittent headache, palpitation, nervousness and excessive sweating.3. Hyperparathyroidism (hyperplasia or adenoma): often asymptomatic, with hypercalcemia in late stage or enlarged parathyroid glands due to resection of medullary carcinoma of thyroid.4. Mucosal neurinomas: occurring in the oral mucosa, tongue, lips, eyes, face, cornea, skin, and gastrointestinal tract mucosa, and manifested as hypertrophy of the lips, broad nose, lid ectropion and multiple neurinomas.5. .Equine body type: long and thin, elongated limbs, emaciation, reduction of muscle and subcutaneous fat, spider-like hands and feet or bowed feet, toe ectropion deformity, chicken chest or funnel chest.
Diagnostic basis
1. Medical history and family history MEN2A onset age is usually 30-40 years old, MEN2A can be onset after 5 years old or as early as 1 year old. Definitive gene carriers may develop the disease as late as 70 years of age.2. Physical examination observes the presence of thyroid masses, enlarged cervical lymph nodes, and lesions on the lips, tongue, oral mucosa, eyes, face, body shape, and skin.3. Laboratory tests include blood and urinary catecholamine measurements, methoxy adrenaline measurements, basal levels of calcitonin, serum calcium, phosphorus, alkaline phosphatase, and parathyroid hormone, calcium gluconate test, pentagastrin test, and parathyroid hormone test. Calcium gluconate test, pentagastrin co-stimulation test, etc. 4. Pathological examination is the gold standard for the diagnosis of malignant tumors. 5. Molecular genetics examination is not only helpful for diagnosis, but also can detect the carriers of mutated genes. 6.
Treatment
Treatment guidelines
The main treatment is radical surgery, including total thyroidectomy and central lymph node dissection. For those with metastases that cannot be cured, palliative surgery is performed. If necessary, radiotherapy is performed.
Drug treatment
(1) Application of adriamycin, vincristine, cyclophosphamide, dacarbazine combined with chemotherapy can be used as palliative treatment. (2) Thyroid hormone replacement therapy is given after total thyroidectomy. (3) Tyrosine kinase inhibitors can inhibit the phosphorylation of RET proto-oncogene, and some of them may show signs of tumor regression.
Radiotherapy
In patients with extensive local metastatic lesions in the neck, external radiation is feasible to prevent local recurrence or reduce the size of the tumor, which is not curative.
Surgery
Medullary thyroid carcinoma in MEN2 should be surgically removed as early as possible. For mutation gene carriers, prophylactic thyroidectomy is necessary even if there is no clinical manifestation at present. For those with concomitant pheochromocytoma, surgery for pheochromocytoma should be performed before surgery for medullary thyroid carcinoma. There is no effective treatment for multiple neuromas, plastic surgery is feasible for facial lesions, and surgical treatment for gastrointestinal lesions depends on the functional impairment. Early hyperparathyroidism is often asymptomatic and biochemical abnormalities can be routinely explored during thyroid surgery. Frozen sections should be made if there is any suspicion, and surgical resection should be performed if hyperplasia or adenoma is confirmed.
Prognosis
Early diagnosis and aggressive treatment can improve the condition and symptoms. Total thyroidectomy with lymph node dissection and adrenalectomy with preservation of the adrenal cortex remain the fundamental cure for the disease.
Nursing care
Daily care
1. After the operation, take the flat lying position, take the semi-sitting position after the anesthesia is awake and the blood pressure is stable, and keep the head and neck comfortable. Use hands to fix the neck when changing the lying position, getting up or coughing.2. 6 hours after the operation, the patient can eat a small amount of warm liquid food.3. Observe the patient to eat and drink water without aspiration and choking.4. Take medication according to the doctor’s instruction, observe the efficacy of the medication and the adverse reaction.5. Adhere to the follow up visit, review the thyroid function, and detect and treat the hypothyroidism in the early stage.6.
Dietary management
For those with iodine deficiency, season with iodized salt and eat iodine-rich food. Stop eating goiter-causing foods.
Other Precautions
Patients may develop various postoperative complications after surgery. Patients should be closely observed for postoperative recovery.