Clinical signs of retroperitoneal abscess from colonic perforation. Two case reports and literature review

Retroperitoneal colonic perforation is a rare cause of retroperitoneal abscess. It presents, more frequently in frail elderly patients, with heterogeneous signs and symptoms which hamper the clinical diagnosis. Subcutaneous emphysema with pneumomediastinum and iliopsoas muscle abscess are unusual signs. Colonic retroperitoneal perforation may be consequent to diverticulitis or locally advanced colon cancer. Due to the anatomy of the retroperitoneal space and different physiopathology, diverticular perforation may present with air and pus collection; on the other hand perforated colon cancer may cause groin mass and psoas abscess. We reported 2 cases of colonic retroperitoneal perforation from diverticulitis and locally advanced colon cancer, respectively. Aim of this report is to improve differential diagnosis based on clinical signs.