Autopsy‐Confirmed CMV Adrenalitis With Bilateral Adrenal Hemorrhage Following Presumed Critical Illness–Related Corticosteroid Insufficiency During Prolonged ICU Stay: A Case Report

Background In critically ill patients, critical illness–related corticosteroid insufficiency (CIRCI) is an important cause of vasopressor‐refractory shock. However, distinguishing relative or functional CIRCI from structural adrenal insufficiency—such as that caused by hemorrhagic adrenal necrosis—can be challenging because their clinical presentations often overlap despite fundamentally different pathophysiological mechanisms. Cytomegalovirus (CMV) adrenalitis with hemorrhagic adrenal necrosis is rare, potentially fatal, and may be overlooked. Case Presentation A 70‐year‐old man with ischemic cardiomyopathy and diabetic nephropathy–related chronic kidney disease, without known immunodeficiency, was admitted for acute decompensated right‐sided heart failure. He required intensive care and continuous renal replacement therapy for refractory right‐sided heart failure and renal failure. During his ICU stay, he experienced two episodes of vasopressor‐refractory shock. Although the random serum cortisol level was not unequivocally low, hydrocortisone was administered for clinically presumed CIRCI, resulting in transient hemodynamic improvement. After tapering and discontinuation of hydrocortisone, shock recurred and progressed despite treatment for presumed septic shock, and the patient died. Autopsy revealed extensive bilateral hemorrhagic adrenal necrosis. Microscopic examination demonstrated characteristic “owl′s eye” intranuclear inclusions and positive CMV immunohistochemistry, consistent with CMV adrenalitis causing acute structural adrenal failure. Conclusion Even in critically ill patients without apparent baseline immunodeficiency, secondary immunosuppression due to prolonged ICU care may facilitate CMV reactivation, leading to fatal adrenal insufficiency. This case highlights the importance of distinguishing presumed CIRCI from evolving structural adrenal failure and of considering CMV adrenalitis in prolonged ICU patients with recurrent shock.