An adrenal adenoma is a benign, or non-cancerous, tumor of the adrenal gland, located just above the kidney. Some such adenomas, called non-functioning adrenal adenomas, do not secrete hormones, but others do. Depending upon the type of hormone secreted by the adenoma, the tumor can cause different medical problems in the patient.
Adrenal adenomas tend to have a genetic basis and usually only appear in adults. One's risk of developing one increases with age, and about 6% of patients over 60 have an adrenal adenoma. There is currently no known prevention for these growths. Most are discovered through computed-tomography (CT) or magnetic-resonance imaging (MRI) scanning of the abdomen for unrelated reasons.
If an adrenal adenoma releases cortisol, the patient can develop Cushing's Syndrome, also known as hypercorticism or hyperadrenocorticism. Cushing's Syndrome is characterized by excess cortisol in the blood, and symptoms include excessive sweating, rapid weight gain, thinning of the skin and mucous membranes, and facial hair growth. Patients with Cushing's Syndrome characteristically gain weight in the torso and face, but not in the limbs, and develop pads of fat along the back of the neck and the collar bone, a symptom called buffalo hump. Cushing's Syndrome can also cause various skin disorders, heart disease, diabetes mellitus, high blood pressure, gastrointestinal disorders, impaired wound healing, and osteoporosis. Psychological problems including insomnia, loss of libido, depression, anxiety, and psychosis can also result.
If an adrenal adenoma releases aldosterone, the patient can suffer from Conn's Syndrome, or primary aldosteronism. Conn's Syndome causes sodium retention and hypocalcaemia, or low calcium levels. Symptoms can include high blood pressure, muscle cramps and weakness, and headache. Finally, an adrenal adenoma may secrete androgens, leading to hyperandrogenism. Hyperandrogenism can cause excessive body hair growth, loss of hair growth on the scalp, a deepened voice, acne, obesity, infertility, and increased muscle mass. In women, it can also cause the uterus or breasts to shrink.
If an adrenal adenoma is functioning, or releasing hormones of any kind, the resulting symptoms can be treated through surgical removal of the adenoma, or adrenalectomy. Usually, the adenoma is small enough to be removed through laparoscopy, in which the tumor is extracted through very small incisions. Eighty percent of adrenal adenomas are non-functioning, and do not cause any harm to the patient.