Hemophagocytic Iymphohistiocytosis (HLH) is a rare disorder with an estimated incidence of 1/50,000 - 1/100,000 population. Patients uniformly present with regular fever, a bi- or trilineage cytopenia and rapidly result in deaths due to fulminant multi-organ failure unless arrested with appropriate treatment. At Cho Ray hospital during 2 years 2010-2011, have total of 6 cases with HLH diagnosed. The median age was 51 years with a male: female ratio of 1:1. The most common symptoms were seen as follows
fever (100 percent), a bi- or trilineage cytopenia on CBC (83.3 percent), hemophagocytic evidence on bone marrow aspiration (66.6 percent). The presumed cause of all 6 cases was secondary to infections. After 14 days with modified HLH-04 guidelines, there was a good consequence of 4 cases (66.6 percent) alive and discharged from hospital.