Nader Moeinvaziri1, Alireza Sadeghi11 Minimally Invasive Surgery Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

The retroperitoneal may be affected by variety of infectious, inflammations and tumors including benign or malignant ones. Although primary malignant tumors are the most prevalent tumors in this anatomic area, metastatic and invasive tumors rarely involve retroperitoneum. Gastrointestinal stromal tumors (GISTs) counted the most common tumors with invasion the retroperitoneum