Multiple endocrine neoplasia syndrome type I
Introduction
Introduction to multiple endocrine neoplasia syndrome type I Multiple endocrine neoplasia syndrome type I is characterized by a composition of parathyroid glands, islet cells, and pituitary tumors. It has been found that the MEN-I gene is on chromosome 11 and appears to act as a tumor suppressor gene. The signs and symptoms of MEN-I depend on the type of tumor involved in the patient. Islet cell tumors account for 30% to 75% of patients, of which about 40% of tumors are derived from beta cells, secrete insulin, and have fasting hypoglycemia. In about 60% of cases, islet tumors are derived from non-beta cells. A 40-year-old patient with a common non-beta cell tumor. Gastrin is the most secreted hormone in non-beta cell tumors, accompanied by refractory and complex peptic ulcers. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: kidney stones, peptic ulcer, diarrhea
Cause
Multiple endocrine neoplasia syndrome type I etiology
This disease is due to familial inheritance.
Prevention
Multiple endocrine neoplasia syndrome type I prevention
The disease has a certain hereditary nature, so early screening is very important. Because about half of the children of patients with multiple endocrine neoplasia can have this hereditary disease, screening is important for early diagnosis and treatment. Detection is usually useful. Recently, the abnormal pathogenic genes of IIA and IIB have been clarified, and the detection of abnormal genes can be used for early and more effective diagnosis and treatment.
Complication
Multiple endocrine neoplasia syndrome type I complications Complications, kidney stones, peptic ulcer, diarrhea
1, hyperparathyroidism, leading to elevated blood calcium, often cause kidney stones.
2, can secrete excessive gastrin, stimulate the stomach to secrete a large amount of gastric acid, easy to suffer from peptic ulcer disease, and ulcers are easy to hemorrhage, perforation and gastric obstruction, diarrhea and fat sputum are common, and other islet cell tumors can secrete vasoactive intestinal peptide , causing severe diarrhea and leading to dehydration.
3, can secrete prolactin, female patients have menstrual disorders, male impotence.
Symptom
Multiple endocrine neoplasia syndrome type I symptoms Common symptoms Pituitary dysfunction Fat stomach acid deficiency peptic ulcer secretory diarrhea
The signs and symptoms of MEN-I depend on the type of tumor involved in the patient. Hyperparathyroidism occurs in at least 90% of patients. Asymptomatic hypercalcemia is the most common manifestation; approximately 25% of patients have demonstrated kidney stones and renal calcification. Unlike sporadic hyperparathyroidism, diffuse hyperplasia or multiple adenomas are often found more often than single adenomas.
Islet cell tumors account for 30% to 75% of patients, of which about 40% of tumors are derived from beta cells, secrete insulin, and have fasting hypoglycemia. In about 60% of cases, islet tumors are from non- cells. <40 years old patients, cell tumors are more common; >40 years old patients, non- cell tumors are common. Gastrin is the most secreted hormone in non-beta cell tumors, accompanied by refractory and complex peptic ulcer (Zou-A syndrome). >50% of patients with MEN-I have peptic ulcer. Most patients have multiple ulcers, atypical parts, and the incidence of bleeding, perforation and obstruction is correspondingly high. Very high gastric acid secretion in these patients is accompanied by inactivation of pancreatic lipase, leading to diarrhea and fatty spasms. Although it has been previously known that MEN patients occur only from the pancreas, gastroduoma in the duodenal bulb is also reported recently. When the onset of Zoe-Eyre syndrome began to be further evaluated, approximately 20% to 60% of cases were confirmed to be MEN-I syndrome.
In other cases, non-beta cell tumors are associated with severe secretory diarrhea, causing loss of fluids and electrolytes. This combination, known as watery diarrhea, hypokalemia and gastric acid deficiency syndrome, is attributed to vasoactive intestinal peptide in some patients, although other gut hormones or secretagogues including prostaglandins may also be involved. In many patients with islet cell tumors, the level of pancreatic polypeptide is increased, which may prove useful in the diagnosis of MEN-I syndrome, but the clinical manifestations of excessive production of these hormones are not clear. Glucagon, somatostatin, chromogranin, excessive secretion of calcitonin; ectopic ACTH secretion (Cushing syndrome); GHRH hypersecretion (obvious acromegaly) is also seen in non--cell tumors In the patient.
Beta-cell and non-beta-cell tumors are usually derived from multiple centers, and multiple adenomas or diffuse islet cell proliferation are often seen. About 30% of patients with islet cell tumors are malignant with local or distant metastases, but these tumors of MEN-I syndrome have a benign process of sporadic islet cell carcinoma. The incidence of malignancy in non-beta cell tumors appears to be higher.
50% to 60% of patients with MEN-I syndrome have pituitary tumors, of which about 25% secrete growth hormone or growth hormone and prolactin, and the affected patients have acromegaly, which is clinically different from sporadic type. The report pointed out that 25% to 90% of tumors secrete prolactin, and about 3% secrete ACTH, causing Cushing's disease. Most of the rest are non-functional. Local expansion of the tumor can cause visual impairment and headache as well as hypopituitarism.
Patients with MEN-I syndrome are less likely to have thyroid and adrenal adenomas and adenomatous hyperplasia. Both are rare and functional, and they are not positive in the syndrome. Carcinoids, especially carcinoids from the embryonic foregut, have been reported in individual cases of MEN-I syndrome. Multiple subcutaneous and visceral lipomas are also visible.
Examine
Examination of multiple endocrine neoplasia type I
1. DNA restriction segment length polymorphism analysis genetic screening;
2, measuring serum calcium, intact parathyroid hormone, gastrin and prolactin;
3. Pituitary CT or MRI.
Diagnosis
Diagnosis of multiple endocrine neoplasia syndrome type I
Differential diagnosis
1. Type IIA multiple endocrine neoplasia: including rare thyroid cancer (medullary carcinoma), pheochromocytoma (mostly a benign adrenal tumor).
2, IIB multiple endocrine neoplasia syndrome: is composed of medullary thyroid carcinoma, pheochromocytoma and neuroma (neurological hyperplasia), some patients have no family history.
