Although carcinoid tumors may occur anywhere, most cases report them either in the lungs or the digestive tract (stomach, small intestine, appendix, colon, rectum). The symptoms, diagnosis, and treatment vary for both of these cases of carcinoid tumors.

Carcinoid tumors in the lungs
Carcinoid tumors in the lungs are a very slow-growing type of lung cancer. These tumors are formed in the neuroendocrine cells scattered in the lungs. People who smoke or have a family history of lung carcinoid tumors, or are suffering from multiple endocrine neoplasia type 1 (MEN1) are at high risk of getting lung carcinoid tumors.

There are two types of lung carcinoid tumors namely – typical carcinoids and atypical carcinoids. Typical carcinoids grow very slowly and don’t usually spread outside the lungs. Atypical carcinoids, on the other hand, grow quickly and can spread to the surrounding organs and tissues.

Lung carcinoid tumors are diagnosed by conducting routine lab tests or performing procedures such as – chest X-ray, CT scan, PET scan, MRI scan, MIBG scan, sputum cytology, biopsy, bronchoscopy, blood tests or urine tests.

Some of the most common symptoms of carcinoid tumors in the lungs are as follows:

• Wheezing
• Chest pain
• Breathlessness
• Diarrhea
• Large purple stretch marks in the skin
• Flushing or redness in the face and neck
• Weight gain in the upper back and midsection

Lung carcinoid tumors may be treated with surgery such as – lobectomy where a portion of the lung is removed, wedge resection wherein a small wedge-shaped portion of the lung is removed, sleeve resection wherein sections of the airways above and below the tumor is removed or lymph node dissection wherein the surrounding lymph nodes are removed. Additionally, chemotherapy or radiation therapy may also be given. Certain drugs that slow down the production of hormones in the body may also be administered to treat lung carcinoid tumors.

Carcinoid tumors in the digestive tract
A gastrointestinal carcinoid tumor forms in the lining of the digestive tract and doesn’t tend to have any signs or symptoms in the early stages. These tumors are formed from neuroendocrine cells. These cells secrete the hormones responsible for the passage of food through the stomach and intestines. People suffering from atrophic gastritis, Zollinger-Ellison syndrome or pernicious anemia are at high risk of getting gastrointestinal carcinoid tumors.

Gastrointestinal carcinoid tumors are diagnosed with the help of blood tests, urine test, MIBG scan, MRI, PET scan, endoscopy or biopsy.

Some of the most common symptoms of carcinoid tumors in the digestive tract are as follows:

• Diarrhea
• Pain in the abdomen
• Flushing or redness in the face and neck
• Vomiting and nausea
• Bowel obstruction or constipation
• Rectal pain and rectal bleeding
• Jaundice
• Changes in the color of the stools
• Heartburn
• Tiredness, bloating, and fatigue
• Unexplained weight loss

Gastrointestinal carcinoid tumors can be treated with one of the four available treatment options namely – surgery to remove the tumor, radiation therapy that uses X-rays to kill cancer cells, chemotherapy that uses specialized drugs to kill and prevent the growth of cancer cells or hormone therapy that prevents the secretion of certain hormones.