Medical expert of the article
New publications
Type IIB multiple endocrine neoplastic syndrome
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Multiple endocrine neoplastic syndrome, IIB type (MEN IIB, MEN type II syndrome, neuroma mucosa syndrome, multiple endocrine adenomatosis) is characterized by multiple mucous neuromas, medullary thyroid carcinomas, pheochromocytomas and often Marfan syndrome. The clinical picture depends on the affected glandular elements. Diagnosis and treatment are similar to the diagnosis and treatment of MEN MA syndrome.
About 50% of cases are more often sporadic than related, although the cause of sporadic syndrome MEN IIB is not clear. The incidence among men is two times higher than among women. Hyperparathyroidism occurs in cases of MEN-IIB syndrome. As a result of genetic studies, mutations in the receptor tyrosine kinase of oncogenes were detected.
Symptoms of MEN type IIB
Symptoms and signs reflect glandular pathologies. About 50% of patients have complete syndrome of the neuroma mucosa, pheochromocytoma and medullary thyroid carcinoma. Less than 10% have only neurinomas and pheochromocytomas, while the remaining patients have neuromas and medullary thyroid carcinomas without pheochromocytoma.
Often, mucosal neuromas are an early sign of the disease, and they occur in the majority or in all patients. Neuromas appear in the form of small shiny cones on the lips, tongue, cheeks and mucous membrane. On the eyelids, conjunctiva and the cornea may also appear neuroma. A characteristic feature are thickened eyelids and diffusely hypertrophied lips. Pathologies of the gastrointestinal tract associated with motor disorders (constipation, diarrhea, and sometimes megacolon) are characteristic and arise as a result of diffuse-intestinal ganglioniorematosis. Patients may have Marfan syndrome; skeletal anomalies of the spine (lordosis, kyphosis, scoliosis), a hollow foot and equinovarus deformation of the foot are common signs of the disease.
Medullary carcinoma of the thyroid gland and pheochromocytoma resemble the corresponding pathologies of the MEN IIA type syndrome, both bilateral and multicenter. However, medullary thyroid carcinoma tends to be particularly aggressive in the MENE type II syndrome and can affect young children.
Although neuroma, facial features and gastrointestinal disturbances are observed at an early age, the syndrome can not be recognized until the medullary carcinoma of the thyroid gland or pheochromocytoma becomes more apparent in later life.
Diagnostics of ME IIB type
The MEN IIB syndrome is expected in patients with the family history of MEN II B, pheochromocytoma, multiple mucous neuromas or medullary thyroid carcinoma. Genetic testing has high accuracy and is done in the 1st degree of kinship and any relatives with symptoms of the disease.
The pheochromocytoma can be clinically suspected and confirmed by measuring the level of free plasma metanephrin and fractionated urinary catecholamines. A laboratory test can be conducted for medullary thyroid carcinoma. MRI or CT scan is used to search for pheochromocytoma and medullary thyroid carcinoma.
[6]
Who to contact?
Treatment of ME IIB type
Affected patients should have a general thyroidectomy immediately after diagnosis. Pheochromocytoma, if any, should be removed before thyroidectomy. In case of gene transfer, preventive thyroidectomy is recommended in infancy or early childhood.