Hemophagocytic lymphohistiocytosis: a rare cause of pancytopenia.

A 36-year-old man with fever and pancytopenia due to Hemophagocytic Lymphohistiocytosis is reported. The patient was started on the HLH-94 based treatment. Two weeks after the initiation of therapy the patient's pancytopenia had resolved and he was discharged to complete treatment as an outpatient. The initial clinical presentation, diagnostic criteria, pathophysiology and treatment will be discussed.