Adrenal Conditions

Most cases of this condition are caused by benign tumors of the adrenal, which overproduce aldosterone leading to high blood pressure and loss of the mineral potassium, which, if severe, can cause muscle weakness and kidney problems. About a third of cases are caused by overfunction (hyperplasia) rather than a tumor of these cells.
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All adrenal cortical hormones are produced by a series of biochemical steps. Each step requires an enzyme to act as a catalyst to make the process proceed. Adrenal hyperplasia refers to a number of genetic deficiency states in which one of these enzymes is either missing or significantly reduced. This leads to a reduction in the production of that enzyme and a “build-up” of the chemicals before that enzyme step. These chemicals are then “shunted” through other pathways, much like traffic detouring a roadblock. The products of these detour pathways are then produced in excess. Depending on which enzyme is decreased, there is then a pattern of an excess of certain adrenal hormones with a deficiency of others.

Although these disorders are genetic, some are apparent at birth, while others do not appear until later in development, usually around the time of puberty.

The most common of these, called 21 hydroxylase deficiency, may be present at birth with “ambiguous genitalia” in females because of an excess of adrenal androgens, whereas male genitalia are normal. In both genders, some varieties of this disorder include a reduction in mineralocorticoids, which results in low blood pressure, low body sodium and excess potassium. In older children, there can be accelerated growth rate, but a shorter growing period, leading to short stature. In girls, signs of excess androgens, including acne, facial hair, deepening of the voice, and increased muscle mass, are present. If the disorder is not apparent during childhood, signs are often present around the time of puberty, including absent or irregular menstrual periods and signs of androgen excess.

A more rare form of adrenal hyperplaisia is caused by deficiency of the enzyme11 hydroxylase enzyme, which leads to increased androgens and excess mineralocorticoid activity that causes high blood pressure and loss of potassium.

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This is a tumor of the adrenal medulla, which overproduces adrenaline and noradrenaline leading to high blood pressure which may be continuous or intermittent. There may be fast heartbeat with palpitations, weight loss, sweats, blanching or flushing, headache and chest pain. Although fewer than 0.1% of all people with high blood pressure harbor this tumor, under certain circumstances, testing is important to rule out this disorder, since it can cause fatalities because of “crisis” consisting of severe hypertension and heart arrhythmia. Pheochromocytomas occur more frequently in people with rare hereditary disorders, including multiple endocrine neoplaisia type 2 (MEN 2), VonHippel Lindau disease and Neurofibromatosis. Genetic testing is available for these disorders and for family members of affected patients.
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Insufficiency of the hormones of the adrenal gland may occur as a result of disease in the adrenal gland itself (primary adrenal insufficiency) or as a result of failure of the pituitary gland to adequately stimulate the production of adrenal hormones (secondary adrenal insufficiency).

In both cases, inadequate cortisol is produced, leading to weakness, fatigue, vague abdominal pain, sometimes with nausea and vomiting, low blood pressure, dizziness and sometimes fainting. People with inadequate cortisol fail to respond well to physical stress such as injury, anaesthesia, surgery or other medical illnesses and can develop “adrenal crisis” in these situations. This is characterized by profound weakness, low blood pressure, dehydration, shock and, ultimately, death if untreated.

If the adrenal gland itself is diseased, there is also failure to produce aldosterone, which makes the low blood pressure even worse and results in loss of sodium and water and accumulation of excess potassium. In primary adrenal insufficiency, there may be excess pigmentation of the skin, particularly in areas of skin creases, as well as in the gums and inside lining of the mouth. When the disorder is due to pituitary failure, mineralocorticoid deficiency and pigmentation do not occur.

The most common cause of primary adrenal failure is an attack by the immune system on the cells of the adrenal cortex (autoimmune disease) and this disorder is seen more frequently in people with other autoimmune diseases, including chronic thyroiditis, type 1 diabetes, hypoparathyroidism, pernicious anemia, myasthenia gravis and systemic lupus erythematosis (SLE). Adrenal failure may also occur as a result of infection of the adrenal gland with tuberculosis, mycobacterium avarium intracellulare (MAI), fungi such as histoplasmosis, and viruses, including cytomegalovirus (CMV). It occurs more commonly in patients with HIV, as a result of either the virus itself or the “opportunistic infections” listed above which occur in this population.

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What if a tumor is found on my adrenal gland on a CAT scan?
Tests of the blood and sometimes urine should be performed to see if the tumor is oversecreting any of the adrenal hormones. Specialized CAT scans and MRIs often yield clues about whether a tumor is benign or malignant. Remember that fewer than 10% of adrenal tumors over-secrete hormones, and less than 1/1000 are cancerous. The rest may be safely observed.

Adrenal tumors may be either benign or malignant, functional (hormone-secreting) or non-functional (not hormone-secretory). Malignant tumors compise less than 0.1% of all adrenal tumors and may secrete cortisol, androgens, mineralocorticoids or more than one type of hormone or no hormones at all. Benign tumors secrete only one type of hormone, with cortisol being more common than catecholamines or aldosterone (least common).

Most adrenal tumors are non-functional. In fact, as many as 8-10% of us have adrenal nodules, which are seen on imaging studies done for other reasons or found at autopsy. If an adrenal nodule is found, it is very important to make sure that it is not a pheochromocytoma because of the serious, even fatal, consequences of not treating this rare type of tumor. Pheochromocytomas make up only 3% of all incidentally found tumors, while Cushing’s syndrome tumors (cortisol-producing) account for 7% and aldosterone-secreting tumors about 0.5%. The rest are non-secretory. Small non-secretory tumors do not require treatment, whereas tumors should be removed to make sure they are not malignant.

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