Haemophagocytic lymphohistiocytosis as a consequence of untreated B-cell chronic lymphocytic leukaemia.

Haemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome characterised by defective cytotoxic function and hypercytokinaemia leading to macrophage expansion and haemophagocytosis. Patients often present with unexplained fevers, hepatosplenomegaly and pancytopenia, with elevation in serum ferritin and triglyceride. Acquired forms are triggered by infection, malignancy or rheumatological disorders. HLH in the setting of chronic lymphocytic leukaemia is rarely reported, however, and is usually associated with infection or as a consequence of chemotherapy. We present a case of HLH in a 64-year-old Caucasian woman with the only identified trigger being her hitherto untreated CLL.