GIST Support International - Glossary of Terms
| Definition |
| emesis | Vomiting. |
| endophytic | When applied to GIST, endophytic refers to a tumor growing into the lumen (food passageway) of the gastrointestinal tract. |
| endoscope | A small, flexible tube-like instrument, with a light on the end of it and consisting of thousands of tiny glass fibers, to allow a doctor to see into the esophagus, stomach, duodenum, and colon. An endoscope also allows a doctor to perform biopsies, take color photographs, and perform certain medical procedures that would otherwise require surgery. |
| epithelium (adjective epithelial) | The cells that line hollow organs and glands and which make up the outer surface of the body. Epithelial cells help to protect or enclose organs; some produce mucous or other secretions. Epithelial cells can be arranged in single layers or multiple layers depending on the type. |
| epitope | An epitope is a surface portion of a foreign organism (or foreign bio-molecules) that elicits an immune response. For example, an epitope may be a specific site on a bacterial or viral protein that is recognized by the immune system as a foreign substance. Antibodies manufactured by B lymphocytes or cytotoxic T cells neutralize the epitope by physically combining with it. As biological molecules such as proteins and carbohydrates can be very large, each of them may contain many unique epitopes each of which is capable of eliciting an immune response. |
| esophagus | The muscular "swallowing tube" that in adult humans is about nine inches (23 centimeters) long. It begins at the pharynx, goes down the neck between the trachea and the spinal column and behind the left bronchus where it pierces the diaphragm slightly to the left of the middle line and empties into the stomach. Also called the gullet. |
| exon | An exon is a unit of genetic instructions for constructing a protein when a new cell is formed. Exons are found within cellular DNA and the RNA used to make new cells. Relevant to GIST, different exons on chromosome 4 code the formation of specific different parts of the KIT protein and the PDGFRA protein. Mutations in these exons cause incorrect construction of the corresponding parts of the protein, leading to cancer. |
| exophytic | When applied to GIST, exophytic describes a tumor growing outward from the wall of the gastrointestinal tract toward the mesentery or abdominal cavity, not inward toward the lumen (food passageway). |
