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.

The endocrine system consists of cells that produce hormones. Hormones are chemical substances that are formed in the body and carried in the bloodstream to have a specific regulatory effect on the activity of other organs or cells in the body. An endocrine tumor is a growth that affects the parts of the body that secrete hormones. Because an endocrine tumor arises from cells that produce hormones, the tumor itself can produce hormones and cause serious illness.

A neuroendocrine tumor originates from the hormone-producing cells of the body’s neuroendocrine system, which consists of cells that are a cross between traditional endocrine cells (or hormone-producing cells) and nerve cells. Neuroendocrine cells are found throughout the body in organs, such as the lungs and gastrointestinal tract, and perform specific functions, such as regulating the air and blood flow through the lungs and controlling the speed at which food is moved through the gastrointestinal tract.

There are many types of neuroendocrine tumors. This section will focus on three specific types: pheochromocytoma, Merkel cell cancer, and neuroendocrine carcinoma. For information on other types of cancers that occur in hormone-producing cells, read the Cancer.Net Guide to Endocrine Tumor, Cancer.Net Guide to Carcinoid Tumor,Cancer.Net Guide to Thymoma, Cancer.Net Guide to Thyroid Cancer, and Cancer.Net Guide to Islet Cell Tumors.

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.

Statistics

An estimated 800 people in the United States are diagnosed with pheochromocytoma each year. The overall five-year relative survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) of people with pheochromocytoma is less than 50%.

More than 400 people in the United States are diagnosed with Merkel cell cancer each year. The survival rate of patients with Merkel cell cancer is about 75%.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with neuroendocrine tumor. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Source: National Cancer Institute

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