A 66-year-old man diagnosed with IgA nephropathy, currently undergoing hemodialysis, presented at the emergency department with new-onset right abdominal pain and fever. Twenty years prior, he had received his first kidney transplant in the right iliac region at another medical center, followed by a second kidney transplant in the left iliac region four years ago. Upon admission to the emergency department, the patient exhibited a febrile state and arterial hypotension. The complementary study revealed several significant clinical findings, including anemia (Hb 8.5g/dL), thrombocytopenia (59000/mm³), an elevated C-reactive protein level (85mg/L), a procalcitonin level of 215ng/mL, and a serum lactate concentration of 4.2mmol/L. An immediate abdominal computed tomography scan was performed, revealing a substantial retroperitoneal mass measuring approximately 12x10x10 cm. This mass was located between the right iliac region and the patient's native right kidney, enclosed within a pseudocapsule that contained a voluminous collection, where there was a suspicion of the presence of a foreign body. The medical team promptly initiated broad-spectrum antibiotic therapy and intravenous fluids. Notwithstanding these interventions, the patient developed septic shock and urgent surgical exploration was decided. In the operating room, a large encapsulated soft mass was identified. An attempt was made to separate it, resulting in the release of fetid, purulent, and hemorrhagic contents; within this material was a large compress, which was extracted. He was transferred to the intensive care unit, where his condition continued to deteriorate, marked by worsening shock and multiple organ dysfunctions. Despite medical interventions the shock remained refractory, and the patient was taken back to the operating room for urgent surgical exploration to control the sources of bleeding. Hemorrhage was identified on the surgical drape, and packing was performed with compresses to manage the bleeding. Unfortunately, despite all medical interventions, the patient died on the same day.