Retroperitoneal Necrotizing Fasciitis Mimicking Fournier Gangrene: A Rare and Severe Diagnostic Entity

BACKGROUND Fournier gangrene is a rapidly progressive necrotizing soft tissue infection usually affecting the perineal or genital regions. Retroperitoneal involvement is rare and associated with diagnostic difficulty and high mortality. CASE REPORT A 45-year-old male patient with poorly controlled diabetes presented with perineal and lower abdominal pain, fever, tachycardia, hypotension, and scrotal swelling. Laboratory test results showed leukocytosis, elevated C-reactive protein level, and mild renal impairment. Computed tomography (CT) demonstrated necrotizing fasciitis extending from the perianal and scrotal regions into the retroperitoneum, involving the kidneys and infrahepatic region. Emergency surgery with extensive debridement and retroperitoneal drainage was performed. Wound cultures grew mixed aerobic and anaerobic organisms; blood cultures were negative. Postoperative care included broad-spectrum antibiotics, iodine-soaked gauze packing, ozonated saline irrigation, and structured education for glycemic control. The patient improved steadily, with normalization of inflammatory markers and wound healing. One-month follow-up CT confirmed resolution, and by 3 months, he achieved near-complete recovery, without complications. CONCLUSIONS This case underscores the importance of early suspicion, CT imaging, and urgent multidisciplinary management in Fournier gangrene with retroperitoneal spread. Glycemic control, infection source control, and individualized wound care were critical to the favorable outcome. This report adds to the limited literature and supports structured, patient-specific strategies for complex soft tissue infections.