Coagulopathy is an under-recognised complication of acquired HLH.

Acquired haemophagocytic lymphohistiocytosis (aHLH) is a rare and often fatal process of uncontrolled cytokine release driven by the inability of natural killer cells to eliminate infected or malignant cells. Herein, we report two cases of aHLH complicated by bleeding secondary to coagulopathy due to hypofibrinogenaemia and thrombocytopenia despite appropriate correction with blood products. These cases highlight the effect coagulopathy and thrombocytopenia can have on patient outcomes when trying to confirm and manage the underlying process driving aHLH.