Abstract
Posterior reversible encephalopathy syndrome (PRES) in the postoperative period poses diagnostic and management challenges. Large pelvic soft‐tissue tumors can cause substantial blood loss, requiring massive blood transfusion (MBT). We present a case of a 46‐year‐old male who underwent excision of a large pelvic ancient schwannoma, complicated by intraoperative massive blood loss of 8 L, necessitating transfusion of 9 units of packed red blood cells. The patient subsequently developed PRES in the postoperative period, as confirmed by MRI. The diagnosis and management of rare perioperative neurological complications such as PRES remain challenging. They require a high index of suspicion, vigilant clinical evaluation, prompt neuroimaging, and coordinated multidisciplinary care to enhance patient safety and outcomes.