Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 55 1 2017 02 05 74 76 EN Nitin Agarwal Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. Mohammad Shazib Faridi Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. Pradeep Saini Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. Navneet Kaur Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. Arun Gupta Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, India. 2015 10 21 2015 10 21 Necrotizing soft tissue infections (NSTIs) are polymicrobial infections with high morbidity and mortality. We report a case of retroperitoneal NSTI in an immunocompetent young male, with clinical symptoms and signs mimicking acute pancreatitis (pseudo-Cullen’s and pseudo-Grey-Turner’s signs. The initiating lesion was a pustule which progressed and mimics acute pancreatitis. CT scan showed features of retroperitoneal NSTI. After extensive debridement and antibiotics, the patient improved. NSTI of the retroperitoneum is rare. The absence of external clinical signs and anatomical barriers make the disease difficult to manage. https://acta.tums.ac.ir/index.php/acta/article/view/5025 https://acta.tums.ac.ir/index.php/acta/article/download/5025/4692