Detection of a stomach gastrointestinal stromal tumor in situs invertus by gallium-67 scintigraphy

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Approximately 70% of the tumors are found in the stomach, 20% to 30% are found in the small intestine, and less than 10% are found elsewhere in the gastrointestinal tract. An 80-year-old man with anemia underwent a whole-body tumor survey with Ga-67 citrate. Markedly increased uptake was observed in the right upper quadrant of the abdomen. Computed tomography (CT) showed situs invertus with a heterogeneous mass in the stomach and multiple rim-enhancing lesions in the liver. Histologic examination of an endoscopic biopsy specimen confirmed a gastrointestinal stromal tumor (GIST) of the stomach.