The digestive system consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, pancreas and gall bladder. It functions to break down food particles, transport them through the digestive tract and absorb the nutrients into the bloodstream. Tumors, an abnormal growth of cells, can affect many of the organs of the digestive system and interfere with these functions. The type of digestive tumor depends upon the organ affected and the cells from which it developed.
Colorectal Tumors
Colorectal tumors develop in the large intestine or rectum and begin as a small swelling on the surface of the intestinal or rectal lining. Because most colorectal tumors develop from the cells in the lining, doctors classify them as adenocarcinomas, according to Merck Manual. As the tumor grows it invades into the wall of the intestine and can spread to nearby lymph nodes. The blood supply in the large intestinal wall flows to the liver; therefore many colorectal tumors spread, or metastasize, to the liver.
Colorectal Polyp
A colorectal polyp describes a benign, or non-cancerous, tumor that protrudes from the lining of the colon or rectum. Doctors classify polyps into two main types; adenomatous polyps and hyperplastic polyps. Adenomatous polyps may develop into colon cancer, according to MedLine Plus and the National Institutes of Health, while hyperplastic polyps rarely develop into cancer.
Esophageal Tumor
Tumors can form in the esophagus, the tube that connects the mouth to the stomach. Squamous cell carcinoma, a tumor that begins in the flat skin cells that lie just below the outer surface of the epidermis, occurs most commonly in the upper portion of the esophagus, according to the Merck Manual. Adenocarcinoma, tumors that arise from the mucosal lining of the esophagus, affects the lower portion of the esophagus. Esophageal tumors cause difficulty swallowing, chest pain and weight loss.
Pancreatic Tumor
The pancreas, a small gland located behind the stomach, produces digestive enzymes that secrete into the small intestine as well as hormones that release into the bloodstream. Exocrine tumors describe the tumors that form in the ducts leading from the pancreas to the small intestine. These tumors, classified as adenocarcinomas, account for the majority of pancreatic cancers, according to MayoClinic.com. Tumors can also form in the cells that produce the hormones, known as islet cells. Doctors classify these tumors as endocrine tumors.
Small Intestine Tumor
Many different types of tumors can affect the small intestine, including cancerous tumors and benign tumors. Although the Cleveland Clinic reports cancerous tumors are rare, they can include adenocarcina, sarcoma—tumors that arise from muscle cells, carcinoid tumors—tumors that begin in neuroendocrine cells, stromal tumors—rare tumors that start in specialized gastrointestinal cells known as interstitial cells of Cajal, and lymphoma—tumors that occur in the lymphatic cells of the immune system. Non-cancerous tumors include lipoma—tumors of the fat cells, neurofibromas—tumors of the nerve cells, fibromas—tumors of the connective tissue, and leiomyomas—tumors of the muscles cells.
