Gastrointestinal stromal tumors (GISTs) are subepithelial neoplasms most often located in the stomach (60%-70% of cases) and proximal small intestine (20%-30% of cases), but they can occur at any portion of the alimentary tract including the omentum, mesentery, and peritoneum. GISTs most commonly occur in middle-aged and older individuals, although there are pediatric forms associated with syndromes such as the Carney triad, Carney-Stratakis syndrome, and neurofibromatosis type 1.

Clinical manifestations include nonspecific symptoms such as early satiety and bloating. Often, GISTs are discovered on imaging performed for another purpose. GISTs may remain asymptomatic unless they ulcerate, bleed, or grow large enough to cause mechanical obstruction. Sites of metastases include the liver and peritoneum; lymph node metastases are not common.

Related topic: Extra-gastrointestinal stromal tumor