Syndrome of multiple endocrine neoplasia

Syndrome of multiple endocrine neoplasias of the 1st type is transmitted by an autosomal dominant type of inheritance with high manifestation of the mutant gene. The set of components of the syndrome changes not only between families within the same family, several members of which have the syndrome of multiple endocrine neoplasias of type 1.In most cases, there is a combination of two endocrine tumors.

The most common component of the syndrome of multiple endocrine neoplasias of type 1 is usually hyperparathyroidism - an increased function of the thyroid gland( 97% of patients), followed by gland tumors( 80%) and pituitary tumors( 54%).At the time of detection, all 3 components of the syndrome of multiple endocrine neoplasias of type 1 occur only in 1/3 of all cases.

Primary hyperparathyroidism in the syndrome of multiple endocrine neoplasias of the 1st type does not differ in its manifestations from sporadic( accidentally arisen) forms. The peculiarity is a high frequency of exacerbations of the disease after the almost complete removal of parathyroid glands. Detection of parathyroid gland proliferation is the reason for examination for the syndrome of multiple endocrine neoplasias of the 1st or 2nd type. The share of the syndrome of multiple endocrine neoplasias accounts for 10-15% of all cases of hyperparathyroidism.

Among tumors in the syndrome of multiple endocrine neoplasias of type 1, most often gastric tumors( 25-60% of all stomach tumors are detected in this syndrome) and pancreas. Significantly less common tumors of the endocrine system.

All family members of a sick person of the first and second degree of relationship between the ages of 15 and 65 are subject to a family examination of the syndrome of multiple endocrine neoplasias of type 1 with an interval of once every two years.

Syndrome of multiple endocrine neoplasias of the 2nd type. Sipple's syndrome is the most frequent and well-studied variant of syndromes of multiple endocrine neoplasias. The development of the syndrome of multiple endocrine neoplasms of type 2 is associated with mutations of a gene that is located on chromosome X. The prediction for syndrome of multiple endocrine neoplasias of type 2 is significantly worse than in other variants of this syndrome, because it is determined by such severe diseases as thyroid cancergland and pheochromocytoma( adrenal tumor).

Medullary( C-cellular) thyroid cancer is a tumor of thyroid cells, the main product of which is the hormone calcitonin. There is this pathology in 5-12% of cases of malignant tumors of the thyroid gland.

There are 3 forms of medullary thyroid cancer:

1) sporadic form;

2) family form;

3) medullary thyroid cancer in the syndrome of multiple endocrine neoplasias of type 2.

The sporadic form of medullary thyroid cancer is found on average at 45 years, whereas the family form and medullary thyroid carcinoma in the syndrome of multiple endocrine neoplasias of the 2nd type are 15-20 years old. Medullary thyroid cancer, as a rule, is characterized by slow growth. Manifestations of medullary thyroid cancer are either absent altogether, or( in 1/3 of cases) in later stages are manifested by diarrhea and / or carcinoid syndrome. Very rarely, medullary thyroid cancer produces adrenocorticotropic hormone, which leads to the development of Cushing's syndrome( ACTH's ectopic syndrome).Most often, the medullary thyroid carcinoma is revealed during examination of the nodular goiter. When an ultrasound reveals a characteristic node. At the time of diagnosis, 40% of cases already have metastases in the cervical lymph nodes, often bilateral. In the future, metastasis occurs by transferring cancer cells to lymphatic organs in the organs of the upper mediastinum, and with the blood flow cancer cells enter the lungs, liver, bones. According to different data, 5-year survival varies from 48 to 78% of all cases of this disease. The family form of medullary thyroid cancer is most favorable in this respect, followed by medullary thyroid cancer within the framework of the syndrome of multiple endocrine neoplasias of type 2, then sporadic form.

Pheochromocytoma( adrenal gland tumor) is detected in half of people with the syndrome under consideration, more often after the appearance of the first signs of medullary thyroid cancer. Typically, the tumor is bilateral( 70% of cases).

Gorlin syndrome is represented by the same tumors as Sipple's syndrome. The difference is in the more rare development of primary hyperparathyroidism.

Principal differences of this syndrome are:

1) pathology of the musculoskeletal system( marfanoid appearance, curvature of the spine and thorax, horse foot, dislocations of the hip heads, long fingers);

2) tumors( neurinomas) of the mucous membranes, visible on the lips, cheeks, tongue, but can affect the entire gastrointestinal tract. Neurinomas are white-pink painless nodules 1-3 mm in size. The appearance of a person is also characteristic: an elongated face with a jaw protruding forward, a considerable thickening of the lips, giving a "Negroid" appearance.

The average age of a person with this disease when diagnosed is 20 years.

Relatives of persons who have pheochromocytoma and signs of hyperparathyroidism have the greatest potential risk, and in this situation, after a genetic examination, the question of prophylactic removal of the thyroid gland is posed. If there are no signs of pheochromocytoma in a person and signs of hyperparathyroidism, there is no need to examine relatives.

Treatment of in the syndrome of multiple endocrine neoplasias of type 2 begins with the removal of pheochromocytoma( adrenal tumor).With any variant of medullary thyroid cancer, removal of the gland with removal of the cervical lymph nodes and fatty tissue is necessary. With non-surgically performed operations( high levels of the hormone calcitonin are preserved) and octreotide and chemotherapy( doxorubicin, vindestine, cisplatin) are prescribed in inoperable cases. With a radically performed operation, a lifelong observation is necessary for the endocrinologist.

Mixed forms of the syndrome of multiple endocrine neoplasias are characterized by a combination of signs of various syndromes from this group( "cross syndrome").Thus, family cases of the combination of pheochromocytoma with tumors of the pituitary gland are described. Frequently additional components of mixed syndromes of multiple endocrine neoplasias are functionally inactive endocrine tumors of the gastrointestinal tract and pancreas, as well as carcinoid tumors. The method of treatment in such cases is determined strictly individually.