Definition

May 22nd, 2008 by admin

Adrenocortical carcinoma is a malignant growth that originates in the cortex, or the outer portion, of one of the two adrenal glands.

Description

There are two adrenal glands in the body. Each one is paired with a kidney. The adrenal gland rests atop the kidney, on the side of the kidney that is nearest to the head.

An adrenal gland has two parts. The inner part (medulla) produces hormones such as epinephrine (adrenaline) that increases the heart rate. The cortex, or outer part, is made up of layers of epithelial cells, the cells that form coverings for the surfaces of the body. The cortex produces cortical hormones that are essential to well-being, or homeostasis.

The hormones produced by the cortex include glucocorticoids, mineralocorticoids, and sex hormones. Among the many hormones the cortex makes, three— aldosterone, cortisol and adrenal sex hormones—are very important. Aldosterone helps regulate salt and water content in the body. Cortisol helps keep sugars, fats and proteins in balance. Adrenal sex hormones influence sex organ development and sex drive (libido).

Adrenocortical carcinoma is a cancer that originates in the cortex of the adrenal gland. When a tumor grows in the adrenal cortex, it interferes with the production of hormones. Consequently, the effects of adrenocortical carcinoma can be severe and are almost always a threat to life.

There are two types of adrenocortical carcinoma. In one type, a tumor functions—that is, it makes hormones. In the other type, the tumor does not function. If the tumor functions, it acts like the cells in the cortex from which it grew and thus, produces hormones. But since it grows large, it produces extra amounts of hormones and the body is thrown far out of balance in any one of a number of ways.

When a tumor functions

How excess hormones cause the symptoms they produce is complex because more than one hormone from the adrenal cortex can be involved in producing a single symptom. For example, both aldosterone and cortisol, when present in extra quantities, may contribute to the increase in blood pressure (hypertension) many patients experience. Extra amounts of adrenal sex hormones can cause children to begin to display the sexual characteristics (hair growth, genital maturation) of adults. And adults with extra amounts of sex hormones often begin to display the sexual characteristics of the opposite sex. A woman may grow excess facial hair. A man may begin to develop fatty tissue in his breasts. Large quantities of adrenal sex hormones coursing through the body disrupt what would be a normal loop of feedback from the pituitary area of the brain. The pituitary is geared to send information, via a stimulating hormone, to the adrenal cortex, to prompt the tissue to manufacture adrenal sex hormone. When there is an extra amount of adrenal sex hormone in the body, the pituitary stops sending instructions to the adrenal cortex, as well as to other organs that produce the hormones responsible for male features. Thus, a man can begin to look like a woman because he does not have enough male hormones. A woman can begin to look like a man because she has too much adrenal sex hormone.

When a tumor does not function

If the tumor does not function, it just grows large, and may go unnoticed for a long time. Sometimes a tumor that does not function is called dormant. Often, the tumor that does not function first gets attention when it grows large enough to push against the body wall or an organ and cause pain; or when it has spread (metastasized) to another organ.

The adrenocortical carcinoma that does not function has a high likelihood of metastasizing before it is discovered. The two most common sites for metastases are the lungs and liver. Thus, even a non-functioning tumor may cause serious complications.

Demographics

Adrenocortical carcinoma is rare. Fewer than two in one million people, and perhaps as few as one in four million people, are diagnosed in a year. Two age groups are most likely to be diagnosed: those between zero and ten years of age, and those between 40 and 50 years.

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