Endocrine tumors are growths that appear on the glands that produce hormones. There are several types of endocrine tumors, from benign growths to malignant cancers as well as tumors that produce hormones and those that do not. Endocrine tumors can appear on the pancreas, adrenal gland, thyroid and pituitary gland.
Several types of endocrine tumors can appear on the adrenal glands. The most common adrenal gland tumor is an adenoma, which is non-cancerous and does not result in increased hormone production. Typically, people who have an adenoma on one of the adrenal glands do not even know it is there, as it usually produces no symptoms. Most people with an adrenal adenoma will not need treatment.
More severe endocrine tumors can form on the adrenal glands, including adrenocortical carcinoma and pheochromocytoma. Both of these cancers are extremely rare. Only about two people per million may develop adrenocortical carcinoma. If a person has the carcinoma, her body may produce extra cortisol, testosterone or other hormones. A key symptom of adrenocortical carcinoma is a fatty lump on the neck. Women with the cancer also may take on male characteristics, as the level of testosterone in their bodies increases.
Symptoms of pheochromocytoma include a fast heartbeat, an increase in blood pressure, and weight loss. The cancer forms in the chromaffin cells, which release adrenaline. The cancer can cause the body to release too much adrenaline after physical exertion or injury, which can cause death. In most cases, the effective way to treat the tumor is to take out the adrenal glands. Once the glands are removed, a patient will have to take medication to make up for the loss of hormones.
Endocrine tumors can also develop on the pituitary gland. Most pituitary tumors are benign and are small enough not to cause symptoms or disturbances. Large tumors, those bigger than 3/4 of inch (about 1.9 cm) can put pressure on the gland, which can lead to headaches, weight loss or gain, vision problems, and signs of hormone deficiency. Some types of pituitary tumors cause excess production of the cortisol hormone, which leads to a condition known as Cushing's syndrome.
There is also a wide variety of pancreatic endocrine tumors, which can disrupt the hormone production of the pancreas. An insulinoma is a tumor that causes faintness, weakness, hunger and trembling when a person's blood sugar dips, usually after they have not eaten for several hours. A gastrinoma tumor causes the pancreas to produce too much gastrin, a hormone that can lead to stomach ulcers. Almost all endocrine tumors on the pancreas are rare and treatable.