Rare Presentation of a Gastrointestinal Stromal Tumor Encapsulating the Spleen: A Case Report

Gastrointestinal stromal tumors (GISTs) are rare tumors of the digestive tract, often found incidentally on imaging. Although these tumors possess malignant potential, splenic encapsulation has not yet been described in the literature. A 74-year-old male fell and suffered blunt abdominal trauma followed by a 20-pound weight loss, early satiety, and left-sided abdominal pain. Computed tomography (CT) imaging showed splenomegaly with gastric compression. At the time of surgery, it was felt that this was a neoplastic process. He underwent a subsequent splenectomy and en bloc wedge gastrectomy. Further analysis revealed a GIST, of gastric origin, encapsulating the spleen and invading the diaphragm. Specimen stained strongly positive for the cluster of differentiation (CD) 117 mutation. Following recovery from the operation, the patient was started on Imatinib (Gleevec) therapy and will continue treatment for five years. Splenic metastasis and contiguous spread are rare sequelae of GISTs. While these tumors hold the potential for metastasis, the primary locations are the liver and peritoneum. This case illustrates the importance of considering malignancy as a possible underlying etiology when presented with an apparent splenic hematoma and abdominal pain. Since this patient possessed the CD117 mutation, Imatinib is an appropriate therapeutic choice in addition to surgical resection of the neoplasm.