非糖尿病患者における敗血症性ショックを呈した気腫性腎盂腎炎：稀な症例報告

Emphysematous pyelonephritis is a rare and fulminant necrotizing infection of the kidney characterized by gas formation within the renal parenchyma and surrounding tissues. It is traditionally associated with diabetes mellitus and carries significant morbidity and mortality if diagnosis and management are delayed. Occurrence in non-diabetic patients is uncommon and may pose diagnostic challenges due to a lower index of clinical suspicion. We report the case of a 56-year-old non-diabetic man who presented with an acute onset of left flank pain, high-grade fever, and systemic toxicity. Clinical examination revealed features of sepsis, and laboratory investigations demonstrated leukocytosis, markedly elevated inflammatory markers, and acute kidney injury, with normal glycemic indices. Imaging studies played a pivotal role in diagnosis, with plain radiography and ultrasonography suggesting intrarenal gas, and contrast-enhanced computed tomography confirming extensive gas within the renal parenchyma and perinephric space, consistent with emphysematous pyelonephritis. Despite aggressive resuscitation and broad-spectrum intravenous antibiotics, the severity of renal involvement and hemodynamic instability necessitated emergency nephrectomy. The patient had a complicated but ultimately favorable postoperative course with recovery of renal function and resolution of sepsis. This case emphasizes that emphysematous pyelonephritis can occur in the absence of diabetes mellitus and may follow an aggressive clinical course. Early recognition, prompt cross-sectional imaging, and individualized management guided by disease severity are crucial to improving outcomes. Clinicians should maintain a high degree of suspicion for emphysematous pyelonephritis in patients presenting with severe upper urinary tract infection and sepsis, regardless of diabetic status.