The adrenal glands, also known as the suprarenal glands, are small hormone-producing organs located just above each kidney. The adrenal glands produce several hormones, including adrenalin, cortisol and aldosterone. Adrenal gland enlargement is most commonly detected with diagnostic imaging tests, such as a CT scan. Different types of noncancerous and cancerous tumors account for most cases of adrenal gland enlargement.
Benign Adrenal Tumors
Different types of benign, or noncancerous, adrenal tumors prove a frequent cause of enlargement of the gland. Adrenal adenomas remain the most common type of benign adrenal tumors, representing over 50 percent of adrenal masses. Uncommon benign adrenal tumors include adrenal cysts and lipomas, or fat-derived tumors. Some adrenal adenomas produce hormones, including cortisol and aldosterone. Excessive aldosterone production from an adrenal adenoma commonly causes high blood pressure, muscle weakness, increased urination and thirst. Cortisol-producing adrenal tumors often cause fat redistribution, with increased fat in the trunk and decreased fat deposits in the arms and legs. Other signs and symptoms of increased cortisol production include high blood pressure, muscle weakness and wasting, easy bruising and an elevated blood sugar.
Adrenocortical carcinoma is a rare form of cancer arising from the outer region of the adrenal gland. These tumors may produce aldosterone or cortisol, causing signs and symptoms that mimic a benign adrenal adenoma. Surgical removal of the affected adrenal gland remains the definitive treatment for early-stage adrenocortical carcinoma. Chemotherapy and radiation therapy may be used for more advanced disease.
A pheochromocytoma is an adrenal tumor arising from the adrenalin-producing cells of the gland. More than 90 percent of adrenal pheochromocytomas are benign. On average, these tumors measure approximately 2 to 2.5 inches across but can grow much larger. Although most pheochromocytomas arise sporadically, they can occur in association with certain genetic conditions, including familial multiple endocrine neoplasia syndromes, von Hippel-Lindau disease and neurofibromatosis. Excessive adrenalin production associated with a pheochromocytoma causes characteristic signs and symptoms, including high blood pressure, headaches, a rapid heart rate, nervousness, anxiety, excessive sweating, chest pain, nausea and vomiting.
Cancers in other body organs can spread, or metastasize, to the adrenal glands. This condition, known as adrenal metastasis, accounts for approximately 30 percent of adrenal tumors found incidentally. Cancers that frequently metastasize to the adrenal glands include lung, kidney, breast, liver and colorectal cancer.