Secondary Hemophagocytic Lymphohistiocytosis Mimicking Sepsis in Adults: A Case Series

Background: Hemophagocytic lymphohistiocytosis is a life-threatening hyperinflammatory syndrome that can mimic sepsis in adults, delaying diagnosis and treatment. Methods: We reviewed three adult patients admitted to a high-complexity referral hospital in Colombia, all initially managed as sepsis, analyzing clinical findings, laboratory results, bone marrow studies, diagnostic approach, and outcomes. Results: All patients had persistent fever, cytopenias, organomegaly, hyperferritinemia, and hypertriglyceridemia, with ongoing inflammation despite appropriate antimicrobial therapy. Bone marrow examination showed hemophagocytosis in all cases. One case was associated with acute myeloid leukemia and had a poor outcome, while two infection-related cases, triggered by disseminated histoplasmosis and visceral leishmaniasis, improved with targeted therapy and supportive care. Conclusions: Persistent inflammation, cytopenias, and markedly elevated ferritin despite standard sepsis treatment should prompt early consideration of hemophagocytic lymphohistiocytosis and investigation of the underlying trigger.