Fig 1. Pre-operative 3-dimensional CT reconstruction. The mass (black arrow) abuts the celiac axis and encases the left gastric artery (white arrow). A 48-YEAR-OLD MAN underwent upper endoscopy for epigastric pain and nausea. Because of endoscopic findings of gastritis and positive biopsy for Helicobacter pylori, he was started on standard triple drug therapy, but failed to respond. His symptoms became more severe and he reported a 10-pound weight loss. Abdominal computed tomography (CT) and magnetic resonance imaging revealed a 3 3 4 cm mass in the gastrohepatic omentum abuting the celiac axis and encasing the left gastric artery (Fig 1). A pre-operative biochemical workup was normal. During exploratory laparotomy, a 5 3 8 cm mass was found to involve the left gastric artery and the celiac axis. Therefore, celiac axis resection was needed to accomplish complete tumor removal (Figs 2 and 3). To test the sufficiency of the collateral blood supply to the liver, a clamp was applied to the common hepatic artery proximal to gastroduodenal artery and proper hepatic artery pulse was verified by Doppler. The tumor was completely mobilized and resected en bloc with the celiac axis. The patient had an uneventful postoperative course with slight elevation of aspartate and alanine aminotransferase levels. Pathologic examination of the specimen demonstrated a mass arranged in solid sheets with myxoid changes and plexiform patterns containing spindle cells with uniform nuclei and ill-defined cytoplasmatic borders. There was no necrosis or lymphovascular invasion. Operative margins were clear of tumor. Immunoperoxidase stains demonstrated positivity for C-kit (CD117), CD34, S-100, and actin. Immunostaining for desmin was negative. The pathologic diagnosis was consistent with extragastrointestinal stromal