Abstract
BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hyperinflammatory syndrome marked by excessive immune activation. It can be triggered by various factors, including infections, malignancies, and autoimmune diseases, making the diagnosis challenging due to its overlap with other severe conditions. CASE REPORTS: We discuss two intensive care unit (ICU) cases illustrating the diverse manifestations of HLH and the critical importance of early recognition and treatment. The first case involves natural killer-cell leukaemia, and the second, a suspected viral trigger. Both highlight the necessity of a multidisciplinary approach in diagnosis and management, emphasizing the complexity of HLH in ICU settings. CONCLUSIONS: High mortality rates, particularly in malignancy-associated HLH, underscore the importance of tailored treatment strategies based on the underlying aetiology. LEARNING POINTS: Hemophagocytic lymphohistiocytosis (HLH) in adults can arise from a variety of triggers, including infections and malignancies, each influencing disease progression and prognosis differently. Recognizing these underlying aetiologies is crucial for tailoring management strategies and anticipating clinical outcomes.Due to its life-threatening nature, HLH requires prompt diagnosis and a coordinated, multidisciplinary approach. Early intervention, incorporating immunosuppressive therapies and supportive care, is essential to improve patient outcomes, particularly in intensive care unit settings where disease severity is often pronounced.Utilizing diagnostic tools such as the HScore and HLH-2004 criteria can facilitate early identification of HLH in critically ill patients with unexplained inflammatory symptoms. These tools, along with a high index of suspicion, help distinguish HLH from other hyperinflammatory conditions, enabling timely and appropriate therapeutic interventions.