A giant jejunal gastrointestinal stromal tumor misconceived as pancreatic cystic neoplasm: A case report

INTRODUCTION: Gastrointestinal stromal tumors (GISTs), although not common in gastrointestinal (GI) tumors, constitute the most frequent mesenchymal tumors of the GI tract. This report describes a patient with a large sporadic GIST at proximal jejunum that mimicked the pancreatic cystic neoplasm. CASE PRESENTATION: We report a 59-year-old female patient with unexplained weight loss and palpable left upper quadrant abdominal mass for 6 months. Computed tomography (CT) scan demonstrated a heterogeneously mass measuring 10 cm in a maximal diameter at pancreatic body and tail. Laparotomy was done, and the tumor was found at proximal jejunum closed to the ligament of Treitz, so en bloc resection of the tumor was done. The pathological and immunohistochemical study confirmed GISTs. DISCUSSION: Although most GISTs are originated from the intestine, they frequently arise from the stomach, the duodenum and rarely from the jejunum. And jejunal GISTs are usually asymptomatic. The misdiagnosis as mucinous cystadenoma of this case might be due to the proximity of the tumor to the body and tail of pancreas, and compressing the adjacent organ due to its large size. CONCLUSION: GISTs are most frequently small and arising from the stomach. GISTs are rarely present as a large tumor of the jejunum, and particularly mimicked a pancreatic tumor.