Pancreatic extragastrointestinal stromal tumor: A case report and comprehensive literature review

AIM: To provide an overview of the literature on pancreatic extragastrointestinal stromal tumors (EGISTs). METHODS: We report a case of pancreatic EGIST and review published studies on pancreatic EGIST accessed via the PubMed, MEDLINE, Google Scholar, and Google databases. The keywords used were "pancreas and GIST", "pancreas and extra GIST", "pancreas and gastrointestinal stromal tumor", and "pancreas and extragastrointestinal stromal tumor". Literature reviews and/or duplicate studies were excluded. The search included articles published in the English language between January 1, 2000 and May 15, 2014. RESULTS: From our literature survey, 30 manuscripts on pancreatic EGISTs were considered, of which 27 met the search criteria and three were excluded. The studies involved 30 patients (15 men, 15 women) with a mean age of 55.3 +/- 14.3 years (range 30-84 years). The mean age of the male patients was 50.8 +/- 13.7 years (range 30-84 years); that of the female patients was 59.9 +/- 13.3 years (range 38-81 years). Tumor dimensions were obtained for 28 cases (mean 114.4 +/- 78.6 mm; range 20-350 mm). Tumors were diagnosed incidentally in 23.3% of patients; abdominal discomfort and weight loss were the major complaints in symptomatic patients. Risk of aggressive behavior according to Fletcher criteria was determined in 25 of 30 patients (68%: high risk, 28%: intermediate risk, 4%: low risk). Histopathological examination revealed the presence of spindle cells in 96.1% of cases; CD117 and CD34 were present immunohistochemically in 96.6% and 84% of patients, respectively. The most common surgical procedures were distal pancreatectomy with splenectomy (n = 9) and pancreaticoduodenectomy (n = 7). The total follow-up period for the 28 patients ranged from 3-66 mo, during which locoregional or distant metastases were diagnosed in six patients and two patients died. CONCLUSION: Studies on EGISTs have only been published in the last decade. The lack of studies with large patient cohorts and long-term follow-up limits evidence-based commentary. In theory, each case should be assessed individually and further genetic and immunohistochemical studies are needed. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.