GIST (3 of 3)

Note the submucosal tumor mass with the classic features of central umbilication and ulceration. GISTs are typically diagnosed as solitary lesions, although in rare cases, multiple lesions can be found. These tumors can grow intraluminally or extraluminally toward adjacent structures. When the growth pattern is extraluminal, patients can harbor the disease symptom free for an extended period and present with very large exogastric masses. Distant metastases tend to appear late in the course of the disease in most cases. In contrast to other soft tissue tumors, the common metastatic sites of GISTs are the liver and peritoneum. Lymph node involvement is rare, occurring in only 0-8% of cases.