Endocrine Tumor

A tumor begins when normal cells in the body become abnormal and grow uncontrollably, forming a mass. 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, meaning it can spread to and damage the body’s healthy tissues if not found early and treated.

About the endocrine system: The endocrine system is made up of cells that make hormones. Hormones are chemical substances that are made 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. For example, a component of the pancreas is made up of specialized cells clustered together in islands within the organ, called islets of Langerhans. These cells make multiple hormones, the most important being insulin, which is a substance that helps control the amount of sugar in the blood. Part of the endocrine system is the neuroendocrine system, which is made up 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.

About Endocrine Tumors: An endocrine tumor is a growth that affects the parts of the body that secrete hormones. Because an endocrine tumor starts in the cells that make hormones, the tumor itself can make hormones and cause serious illness. There are several types of endocrine tumors.

Adrenal Gland Tumor: Each person has two adrenal glands, one located on top of each of the body’s two kidneys. These glands are important to the body’s endocrine (hormonal) system. Each adrenal gland has two main parts, which function separately:

Adrenal cortex. The outer part of the adrenal gland is called the cortex. The adrenal cortex makes three hormones: cortisol, aldosterone, and dehydroepiandrosterone (DHEA). These hormones carefully control metabolism and body characteristics, such as hair growth and body shape.
Adrenal medulla. The gland’s inner part is called the medulla. The adrenal medulla makes other hormones: epinephrine, norepinephrine, and dopamine. These hormones control the body’s responses to stress, including the “fight or flight” adrenaline surge.

Types of Adrenal Gland Tumors: A tumor begins when normal cells begin to change and grow uncontrollably, forming a mass. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). An adrenal gland tumor can sometimes overproduce hormones. When it does, the tumor is called a functioning tumor. An adrenal gland tumor that does not produce hormones is called a nonfunctioning tumor. A tumor can start in an adrenal gland (called a primary adrenal tumor) or it can begin in another organ, such as the lungs, and then metastasize (spread) to the adrenal glands. The symptoms and treatment of an adrenal gland tumor depend on whether the tumor is functioning or nonfunctioning, and what hormone(s) is overproduced, and whether the tumor is a primary adrenal gland tumor or metastases from cancer of another organ. This section focuses on primary adrenal gland tumors, which include:

Adenoma: Adenoma is the most common type of adrenal gland tumor, making up 99% of all adrenal gland tumors. It is a noncancerous nonfunctioning tumor of the adrenal cortex. Also called an adrenocortical adenoma, this tumor usually does not cause symptoms, and, if it is small, often does not need treatment.

Carcinoid Tumor: 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. A tumor begins when normal cells begin to change and grow uncontrollably, forming a mass. 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 spread to and damage the body’s healthy tissues and organs. 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.

About Carcinoid Tumors: A carcinoid tumor starts in the hormone-producing cells of various organs, mostly the gastrointestinal tract (such as the stomach and intestines) and lungs, but also the pancreas, testicles (in males) or ovaries (in females). More than one carcinoid tumor can occur within the same organ. The cause of a carcinoid tumor is unknown. A carcinoid tumor is a type of neuroendocrine tumor, which means it starts in cells of the neuroendocrine system that make hormones. A carcinoid tumor can make high levels of neuropeptides and amines (hormone-like substances); however, they may not be released in large enough amounts to cause symptoms or they may be defective and not cause symptoms. A carcinoid tumor can grow slowly for many years without causing symptoms. Although a carcinoid tumor is cancerous, it is often referred to as "cancer in slow motion." Here is a general overview of where carcinoid tumors begin:

Carcinoid tumors make up only 1% of cancers of the gastrointestinal tract, but make up about 50% of all small intestine cancers. There are two subtypes of lung carcinoid tumors: typical and atypical. The difference is based on how a tumor processes and makes serotonin (5-HT, a neurotransmitter involved in behavior and depression): A typical lung carcinoid tumor has high levels serotonin and chromogranin-A in the blood, and high levels of 5-HIAA (a product of serotonin breakdown) in the urine And An atypical lung carcinoid tumor has normal levels of serotonin and chromogranin-A in the blood, and normal levels of 5-HIAA in the urine, but high levels of serotonin and 5-HTP (an amino acid) in the urine and can make 5-HTP.

Islet Cell Tumor: Function of the pancreas: The pancreas is a pear-shaped gland located in the abdomen between the stomach and the spine. It is about six inches in length and is composed of two major components:

The exocrine component, made up of ducts and acini (small sacs on the end of the ducts), produces enzymes (specialized proteins) that are released into the small intestine to help the body digest and break down food, particularly fats.

The endocrine component of the pancreas is made up of specialized cells clustered together in islands within the organ, called islets of Langerhans. These cells make specific hormones, specifically insulin, the substance that helps control the amount of sugar in the blood.

Types of pancreatic cancer: Cancer begins when normal cells begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). The most common type of pancreatic cancer is called ductal adenocarcinoma, or simply, adenocarcinoma. This type of pancreatic cancer begins in the exocrine component. Learn more aboutadenocarcinoma of the pancreas. Much less commonly, tumors can begin in the islets of Langerhans, the endocrine component. An islet cell tumor can also be called a pancreatic islet cell tumor, pancreatic endocrine tumor, Islet of Langerhans tumor, or neuroendocrine tumor. The rest of this section focuses on islet cell tumors.

Subtypes of islet cell tumors: An islet cell tumor can be either benign or cancerous. Also, an islet cell tumor may be classified as either functioning or nonfunctioning. The term functioning means that the tumor cells produce hormones that cause specific symptoms, while a nonfunctioning islet cell tumor does not produce hormones. There are five major classifications of functioning islet cell tumors, based on the hormone the cells normally make. However, some tumors can make two or more of these hormones at the same time:

Gastrinoma. A gastrinoma is an islet cell tumor that makes a lot of gastrin, a hormone that causes too much acid in the stomach. This causes a condition called Zollinger-Ellison syndrome.

Insulinoma. This type of tumor makes too much insulin, causing hypoglycemia (low blood sugar). An insulinoma is more likely to be noncancerous; only 10% become cancerous.

Glucagonoma. A glucagonoma is an islet cell tumor that makes too much of the hormone glucagon. Unlike an insulinoma, a glucagonoma causes hyperglycemia, a condition where there is too much sugar in the blood.

VIPoma. A VIPoma starts in cells in the pancreas that make vasoactive intestinal peptide (VIP), a hormone that helps move water in the intestines. Too much VIP can cause chronic, watery diarrhea, which causes a condition called Verner-Morrison syndrome.

Somatostatinoma. A somatostatinoma usually develops in the head of the pancreas. A somatostatinoma may make somatostatin, a hormone that stops the secretion of several other hormones (such as growth hormone, insulin, and gastrin).There is one major classification of nonfunctioning islet cell tumors:

Nonfunctioning tumors. Nonfunctioning tumors make up the majority of islet cell tumors. They produce none of the symptoms or syndromes described above. As a result, they are usually diagnosed at more advanced stages of disease.

Neuroendocrine Tumor, The endocrine system consists of cells that make 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. A tumor begins when normal cells begin to change and grow uncontrollably, forming a mass. 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 spread to and damage the body’s healthy tissues and organs. 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.

About Neuroendocrine Tumors: A neuroendocrine tumor begins in the hormone-producing cells of the body’s neuroendocrine system, which is made up 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 (such as the stomach and intestines), 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.

Types of Neuroendocrine Tumors: There are many types of neuroendocrine tumors. This section will focus on three specific types: pheochromocytoma, Merkel cell cancer, and neuroendocrine carcinoma. Learn more about other types of cancer that begin in hormone-producing cells, including endocrine tumors, carcinoid tumors,thymoma, thyroid Cancer, and 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). Pheochromocytoma most often occurs 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 increase 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 people with pheochromocytoma have a tumor on only one adrenal gland, 10% have tumors on both glands, and 10% have a tumor 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 starts from hormone-producing cells just beneath the skin and in the hair follicles, and it is found 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.