In this case report, we presented a 68 year- old man whom was accepted to our intensive care unit and treated as Crimean-Congo Hemorrhagic Fever due to his clinical features. Patient died at the eighth hour of the treatment due to severe hemorrhagic diathesis and multiorgan deficiency. The patient received a postmortem Chronic Lymphocytic Leukaemia (CLL) diagnosis after assessment of the peripheral blood smear. Crimean-Congo Hemorrhagic Fever test was also negative. We state that in populations dwelling in regions where Crimean-Congo Hemorrhagic Fever is endemic, late- stage presentations of undiagnosed patients with Chronic Lymphocytic Leukaemia might complicate diagnostic work-up as for Crimean-Congo Hemorrhagic Fever.
Keywords: Crimean-Congo hemorrhagic fever, chronic lymphocytic leukemia, differential diagnosis