Overview

A tumor occurs when cells in the body become abnormal and multiply without control or order, forming a growth of tissue. A tumor can be benign or malignant. A benign tumor is not cancerous and usually can be removed without it causing much harm. A malignant tumor is cancerous and can be harmful if not found early and treated. It can invade and damage the body’s healthy tissues and organs.

Pheochromocytoma

Pheochromocytoma is a cancer of the chromaffin cells (the cells in the body that release the hormone adrenaline during times of stress). Most cases of pheochromocytoma occur in the adrenal medulla, the area inside the adrenal glands. Each person has two adrenal glands, one located on top of each kidney. This type of tumor increases the production of the hormones adrenaline and noradrenaline, which raise blood pressure and heart rate. Pheochromocytoma can be life-threatening because the tumor may release large amounts of adrenaline into the bloodstream after injury. Eighty percent (80%) of pheochromocytoma cases are found on only one adrenal gland, 10% are found on both glands, and 10% are found outside of the adrenal glands.

Merkel cell cancer

Merkel cell cancer, also called neuroendocrine carcinoma of the skin or trabular cancer, is a highly aggressive, rare cancer. It arises from hormone-producing cells just beneath the skin and in the hair follicles, and it occurs in the head and neck region.

Neuroendocrine carcinoma

Approximately 60% of neuroendocrine tumors are not able to be described as a specific type of cancer other than neuroendocrine carcinoma. Neuroendocrine carcinoma can be found in a number of places in the body, including the lungs, brain, and gastrointestinal tract.

The following factors can raise a person's risk of developing a neuroendocrine tumor:
Age. Pheochromocytoma is most common between the ages of 40 and 60. Merkel cell cancer is most common in people after the age of 70.
Gender. Men are more likely to develop pheochromocytoma than women, by a three to two ratio. Men are also more likely to develop Merkel cell cancer than women.
Race/ethnicity. White people are most likely to develop Merkel cell cancer; however, there have been reported cases in black people and Polynesians.
Family history. Ten percent of pheochromocytoma cases are linked to hereditary causes. Multiple endocrine neoplasia type 1 (MEN1) is a hereditary condition that increases the risk of developing a tumor of three glands: pituitary, parathyroid, and pancreas.

Symptoms

People with a neuroendocrine tumor may experience the following symptoms. Sometimes, people with a neuroendocrine tumor do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer. If you are concerned about a symptom on this list, please talk to your doctor.

Pheochromocytoma:

• Hypertension (high blood pressure)
• Anxiety attacks
• Fever
• Headaches
• Sweating
• Nausea
• Vomiting
  

Treatment

The treatment of a neuroendocrine tumor depends on the size and location of the cancer, whether the cancer has spread, and the person's overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan.

Surgery
Surgery is the main treatment for both pheochromocytoma and Merkel cell cancer. A surgical oncologist is a doctor who specializes in treating cancer using surgery. The tumor will be removed along with a small amount of healthy tissue around the tumor, called the margin. In pheochromocytoma, laparoscopic surgery may be performed. Laparoscopic surgery is a minimally invasive type of surgery that uses three or four small incisions where a laparoscope (a thin, lighted tube) attached to a video camera is inserted through one opening to guide the surgery. Surgical instruments are inserted through the other openings to perform the surgery. Learn more about cancer surgery.

Radiation therapy
Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy, or brachytherapy.
Side effects from radiation therapy may include fatigue, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished. Learn more about radiation therapy.

Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Some people may receive chemotherapy in their doctor's office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time. There are many clinical trials underway to study new drugs for neuroendocrine tumors.