Accessory spleen arising from the gastric fundus mimicking gastrointestinal stromal tumor following splenectomy: A case report.

The current case report presents an accessory spleen mimicking gastrointestinal stromal tumor (GIST) of the stomach in a patient who had undergone a splenectomy ~20 years previously. A 61-year-old male, who presented with upper abdominal discomfort lasting three months, underwent gastrointestinal endoscopy. Gastroscopy and endoscopic ultrasonography revealed a smooth, hemispherical mass of ~2 cm in diameter, with homogenous echogenicity originating from the gastric muscular layer. Abdominal contrast-enhanced computed tomography showed that the well-marginated ovoid mass was ~2.6×1.9 cm in size. The patient was diagnosed with GIST. Subsequent therapy consisted of partial gastrectomy. The pathological results indicated the mass contained splenic tissue, which confirmed it to be an accessory spleen. Changes in the postoperative platelet count were noted. The observations of this case study highlight that platelet count should be used as a routine indicator for monitoring accessory spleen arising from gastric fundus lesion.