A 53-year-old woman was referred to our hospital for management of gastric varices that ran transversely across the greater curvature of the gastric body, detected during routine upper gastrointestinal endoscopy. CT identified a low-density calcified mass near the tail of the pancreas and the splenic hilum. Based on the results of radiographic and pathological investigations, the tumor was diagnosed as solid pseudopapillary neoplasm (SPN), and the gastric varices were considered to have developed secondary to occlusion of the splenic vein by the tumor mass. This is a rare case of SPN associated with splenic vein occlusion and left-sided extrahepatic portal hypertension.