Diagnosis of gastric subepithelial mass as an accessory spleen using fusion of spleen SPECT and CT images.

More than 10% of the healthy population has one or more accessory spleens. An accessory spleen can be mistaken for a gastric subepithelial mass, and may not be differentiated by CT or endoscopic ultrasonography (EUS). A gastric subepithelial mass was detected on routine endoscopy in a 52-year-old man with a history of splenectomy 10 years previously for trauma. Subsequent EUS and CT located the subepithelial mass on the fourth layer of the stomach fundus. A definitive diagnosis was obtained by performing technetium-99m (99m Tc-)-labeled denatured red blood cell (RBC) scintigraphy. Fusion images were obtained by combining the digital CT and SPECT images on a computer workstation. Here, we report the use of spleen SPECT and CT fusion images to diagnose a case of accessory spleen mimicking a gastric subepithelial mass, thereby avoiding the need for an invasive procedure.