Abstract
Retroperitoneal tumors, either benign or malignant, usually cause problems both for an accurate diagnosis and for therapeutic approach, due to their reduce incidence, late presentation and anatomical location, in the neighborhood of vital structures from the retroperitoneal space. Materials and methods: Aim of study was to search correlations between, gender, age, and histo-pathological type of retroperitoneal tumors, as well as their impact upon renal function. Results: Sarcomas represented about 30% of retroperitoneal tumors. The most frequent benign retroperitoneal tumors included: neurogenic tumors, paragangliomas, renal angiomyolipomas and benign retroperitoneal lipomas. Renal function was altered in about 55% of the patients, and postsurgical mortality was 8.73%.