Pathology is the study of diseases - or more specifically, of the ways that diseases change cells, tissues, and organs. Doctors who do this kind of work are called pathologists. They work towards identifying the cells the cancer originated in, but also towards exact morphological and pathological identifications, and they also contribute to the prognostic assessment. Correct treatment always depends on the kind of cancer. Pathology therefore plays a crucial part for further treatment strategies.

Gastrointestinal stromal tumor (GIST) affects the digestive tract or nearby structures within the abdomen. The most common location is the stomach. GI stromal tumor, or GIST cancer, is a sarcoma.