A case of virus associated hemophagocytic syndrome and malignant histiocytosis: sometimes a difficult distinction.

The differential diagnosis among hemophagocytic syndromes and particularly between the virus-associated hemophagocytic syndrome (VAHS) and the malignant histiocytosis (HM) is quite easy in typical cases. Difficulties of interpretation may sometimes ensue when viral-bacteriologic work-ups indicative of VAHS are negative and/or morphologic histiocytic aberrations indicative of HM are missing. The authors present a case of hemophagocytic syndrome with the latter characteristics and discuss the differential diagnosis.