Gastrointestinal stromal tumor with hemoperitoneum masquerading as appendicitis.

Gastrointestinal stromal tumor (GIST) is a rare condition with an annual worldwide incidence of 11 to 15 cases per million, with nearly 5000 cases occurring in the United States yearly. This tumor is found often when patients present with intraluminal gastrointestinal hemorrhage. Other manifestations include early satiety and unintentional weight loss. Multislice computed tomography is an appropriate modality used to diagnosis a GIST after clinical suspicion warrants such imaging. Hemoperitoneum secondary to ruptured GIST is rare. Our patient presented with classic appendicitis, but the etiology of his right lower-quadrant pain with peritonitis was found to be hemoperitoneum secondary to ruptured GIST originating from the ileum.