Digestive disorders

III/4.3: Course

Due to its aspecific symptoms, it is recognized lately, 6 months after the appearance of the symptoms. In 20% of patients with the tumor there is already a systemic propagation at the detection. All GISTs can be considered as potentially malignant, even tumors detected by chance may metastasize at the time of their recognition. 2/3 of GIST cases are malignant; those occurring in the esophagus are almost always benign.

It metastasizes most frequently into the liver (54%) and on the peritoneum. The liver is affected via a hematogenous spread, and peritoneal propagation occurs through a local spread. In 32% of patients with hepatic metastases a peritoneal propagation is also present. Metastases which develop in the liver are multiple, affect both lobes and have a large size. In 31% there is peritoneal involvement with no hepatic metastases. Lymphogenous, pulmonary  (usually in case of a rectal localization) and bone metastases are uncharacteristic.