A hereditary disorder in which patients develop a type of thyroid cancer (medullary thyroid carcinoma) which is accompanied by recurring cancer of the adrenal glands (pheochromocytoma). One type of this disease (MEN IIa) is also associated with hyperplasia (overgrowth) of the parathyroid gland.
Causes, incidence, and risk factors
The cause of multiple endocrine neoplasia II (MEN II) is genetic, with abnormality of a gene called RET. Multiple tumors may appear in the same person, but not necessarily at the same time. The disorder may occur at any age, and affects men and women equally. The adrenal tumor is a pheochromocytoma and the thyroid tumor is a medullary carcinoma of the thyroid . The main risk factor is a family history of MEN II.
Signs and tests
Diagnosis depends on identification of mutation of the RET gene. This can be done with a blood test. Diagnostic tests are also used to evaluate the function of each endocrine gland. A physical examination may reveal enlarged cervical lymph nodes. An examination of the thyroid may reveal a single or multiple thyroid nodules. Vital signs (temperature, pulse , rate of breathing, blood pressure ) may reveal high blood pressure , which may be sustained or episodic, rapid heart rate and elevated temperature . In MEN IIb, mucosal neuromas (benign tumors of the mucosa) may be present, as well as puffy lips and a prominent jaw. These tests help confirm the diagnosis:
adrenal biopsy showing pheochromocytoma
MIBG scintiscan showing tumor
MRI of abdomen showing adrenal mass Abdominal CT scan showing mass elevated urine metanephrine
elevated urine catecholamines
thyroid biopsy showing medullary carcinoma cells
ultrasound of the thyroid revealing nodule
thyroid scan showing cold nodule elevated calcitonin
parathyroid biopsy showing tumor or hyperplasia
radioimmune assay of parathyroid hormone showing increased level
increased serum calcium
decreased serum phosphorus
possibly increased serum alkaline phosphatase
imaging of the kidneys or ureters showing calcification or obstruction ECG possibly showing abnormalities
Treatment
Surgical removal is needed for both medullary carcinoma of the thyroid and for pheochromocytoma . Hormone replacement therapy is given after surgery. Medullary carcinoma of the thyroid must be treated with total removal of the thyroid gland and removal of surrounding lymph nodes. Family members should be screened for the RET gene mutation.
Expectations (prognosis)
Pheochromocytoma is usually benign , but the accompanying medullary carcinoma of the thyroid that characterizes this condition is a very aggressive and potentially fatal cancer. Nonetheless, early diagnosis and surgery can often lead to cure.
Complications
A complication is the metastasis of cancerous cells.
Calling your health care provider
Call your health care provide if you notice symptoms of MEN II.
Prevention
Screening of close relatives of a person with MEN II may lead to early detection.