Malignant extra-gastrointestinal stromal tumor of the pancreas:Report of two cases and review of the literature

Gastrointestinal stromal tumors(GISTs)are mesenchymal tumors that arise from the gastrointestinal tract.In rare cases,these tumors are found in intra-abdominal sites unrelated to the gastrointestinal tract,such as the mesentery,omentum and retroperitoneum.However,pancreatic extra-gastrointestinal stromal tumors are extremely rare,with only 14 previous cases reported.A 61-year-old man with no clinical symptoms had a routine check-up,during which an abdominal mass located in the pancreas tail was detected.Abdominal surgery was performed with resection of the pancreas tail and the spleen,and he was diagnosed with lowrisk GISTs.Another 60-year-old man with no clinical symptoms underwent Computed tomography which revealed a well-demarcated tumor,6 cm in diameter,in the head of the pancreas.He was diagnosed with pancreatic GISTs.Here,we describe two rare cases of pancreatic GISTs and review the cases previously reported in the literature.

Extra-gastrointestinal Stromal Tumor :Clinical Characteristics,Diagnosis, Treatment, and Prognosis

Objective:To explore the clinicopathological characteristics,treatment and prognosis of extrogastrointestinal stromal tumor(EGIST).Methods:In our study,Clinicopathological data of EGISTs from January 2010 to October 2014were systematically investigated.Pathology results were rechecked.Patients also were followed Up.Prognostic factors were evaluated using Cox proportional hazard models and univariate and multivariate with Log-rank test.Results:An amount of EGISTs cases were selected due to inclusion criteria,including 28males and 26Females,with age from 18 To78 years(median,58).Patients were follwed up.12cases were dead.The 1-,3-,5-year survival rates were 91%,75%,66%.Patients undergoing R0 resection had a better 5-year overall survival rate than those undergoing R1 resection(75%vs46%,P<0.05).For patients with high risk of recurrence after surgery,the 5-year overall survival rate was 62%and 40%respectively(P<0.05).Conclusions:Tumor size,mitotic count and tumor rupture affect the prognosis of patients after resection of primary EGISTs independently.Adjuvant imatinib can effectively improve the prognosis of the patients with high risk of recurrence,and the survival rate of patients after surgery.Surgical resection is the main treatment of EGIST,and R0 resection helps to prolong the survival time.