Acquired hemophagocytic lymphohistiocytosis: a case report

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal disease of normal but overactive histiocytes (macrophages) that commonly appears in childhood. A fever, hepatosplenomegaly, pancytopenia, lymphadenopathy, and a rash often comprise the initial presentation. Cutaneous involvement occurs in up to 65% of patients. Although the signs of central nervous system (CNS) involvement may be pronounced early, it usually develops later during the course of the disease. The pathological hallmark of this disease is the aggressive proliferation of activated macrophages and histiocytes, which phagocytose other cells, namely red blood cells, white blood cells, and platelets, leading to the clinical symptoms. Case Report: This paper presents a 4- years old girl that was admitted to the hospital because of abdominal distention .Her vital signs were normal. Physical examinations by her physician were revealed hepatosplenomegaly. She had pancytopenia, high erythrocyte sedimentation rate but tests for liver and kidney-functions were normal in primary laboratory data. The results of tests for viral hepatitis A, B, and C were negative. An abdominal ultrasonographic study confirmed the presence of hepatosplenomegaly, but no ascites was detected. Examination of a stained bone marrow aspirate (BMA) revealed dyserythropoietic change. After 2 months, she presented with intermittent fever but three blood cultures yielded no growth at 48 hours. A liver biopsy was done and it showed a picture similar to chronic persistent hepatitis. Again, she has undergone bone marrow aspiration and showed the same findings with the past BMA (dyserythropoietic change) .She was candidate for bone marrow biopsy and explorative laparotomy. During explorative laparotomy, specimens from liver (again), spleen, pancreas, and abdominal lymph nodes was obtained. There was evidence of hemophagocytosis in the spleen, marrow, lymph nodes specimens and the results of complementary laboratories were consistent with a "Hemophagocytic Lymphohistiocytosis".