The adrenal glands sit on top of the kidneys and are responsible for producing a variety of hormones involved in regulating crisis response, blood pressure, and general homeostasis. Most adrenal tumors are benign (non-cancerous), and elaborate no hormonal activity. However, some adrenal tumors elaborate inappropriate hormone levels that interfere with normal regulatory function, and some adrenal tumors are in fact malignant.
Adrenal tumors are so varied in type that their presentations are equally variable. Some are entirely silent and clinically insignificant; others cause a wide variety of symptoms even when very small; and others cause symptoms only when they grow to be very large.
These tumors are diagnosed by a combination of x-ray images (such as CAT scan, MRI, and ultrasound), as well as biochemical tests of the blood and urine. If the tumor is thought to represent a cancer deposit from some other primary source (eg, lung cancer), then a needle biopsy is sometimes recommended.
- The most common adrenal tumor is a benign, non-functional adenoma.
- The most common adrenal malignancies are deposits from unrelated sources, such as lung, kidney, and breast cancer.
- The most common primary malignancy of the adrenal gland is Cortical Adenocarcinoma. Primary adrenal cortical adenocarcinoma is rare (~ 1 in a million get this cancer), but may have functional features to it.
Adrenal tumors less than 3cm in size are almost never cancerous, though if they are “functional” they may still pose serious threat to life. Almost all primary cancers of the adrenal gland are over 6cm in size, though not every tumor over 6cm is a cancer. The larger the tumor, the more likely it is to represent cancer.
Of the many different kinds of adrenal tumors, three types are “functional” and are usually benign:
- Aldosterone Producing Adenoma (Conn’s Syndrome)
- Cortisol Producing Adenoma (Cushing’s Syndrome)
Pheochromocytoma is a “functional” tumor of the adrenal gland that produces adrenaline type hormones (eg, epinephrine, norephinephrine, dopamine) that are responsible for the “fight or flight” response. When you are suddenly frightened, you feel a surge in your body and your heart races – that’s a normal response to adrenaline which is produced in the adrenal glands. Pheochromocytoma tumors elaborate these compounds inappropriately and patients may feel that “fight or flight” response randomly or exaggerated. Symptoms may include rapid heart rate, pounding in the chest, headaches, facial flushing, “sense of doom”, anxiety, and / or weight loss, to name a few. Blood pressure may be very high at baseline, or episodically very high. However, some of these tumors may be seemingly silent.
While the majority of pheochromocytomas are random in their presentation, some of these tumors present in the setting of some fairly unusual syndromes: vonRecklinghausen’s, Tuberous Sclerosis, Sturge-Weber, Multiple Endocrine Neoplasia, and von Hippel-Lindau.
Aldosterone Producing Adenoma (APA) is another “functional” tumor of the adrenal gland. APA is responsible for producing Conn’s Syndrome. The hormone aldosterone is elaborated inappropriately which results in a very high blood pressure, and is often difficult to control adequately with medication. Potassium levels (an important electrolyte) may be inappropriately low. Symptoms may include: headaches, fatigue, muscle weakness, periodic paralysis, and / or frequent urination, to name a few.
Cortisol Producing Adenoma is yet another “functional” tumor of the adrenal gland, and represents one of several possibilities for the development of Cushing’s Syndrome. The steroid cortisol, which is normally important for stimulatory and regulatory function, is elaborated at inappropriately high levels. In Cushing’s syndrome, there may be weight gain, poor wound healing, new facial hair, thick streak marks on the belly, obesity of the trunk, and / or muscle wasting of the thighs, to name a few.
Primary adrenal cancers are also often “functional”. They may elaborate any or all of the hormones noted in the other three functional tumors. They may also elaborate sex hormones.