Definition: Angiocarcinoma, also known as cancer in its early stages, is a type of tumor that grows slowly from just one cell to multiple cells spread throughout your body. Angiocarcinomas occur when abnormal tissue or cells are grown and develop into a tumor, often causing severe pain and discomfort. They can be found in any part of the body, but most commonly in the stomach, pancreas, lung, liver, colon, uterus, and cervix (uterus).