Polyarteritis nodosa presenting as pancytopenia: case report and review of the literature.

Polyarteritis nodosa (PAN) is not commonly associated with hematologic abnormalities. We report the first case of pancytopenia as the presenting symptom of PAN. There was no associated malignancy or reactive hemophagocytic syndrome (RHS) to explain the findings. The patient, after successful treatment of PAN, subsequently developed RHS a few years later. He is the fourth reported case of RHS in a patient with PAN. In addition to describing the patient's presentation and clinical course, a systematic review of the literature was performed examining the association between hematologic conditions, including RHS, and PAN.