Hemophagocytosis on bone marrow aspirate cytology: Single center experience in North Himalayan region of India

BACKGROUND: The differentiation of hemophagocytic lymphohistiocytosis (HLH) with other causes of hemophagocytosis is essential as HLH is life-threatening condition and requires definite clinical and biochemical criteria for its diagnosis. AIM: The present study was conducted to study hemophagocytosis on bone marrow aspirates and to observe if there is any difference on bone marrow examination between HLH and non HLH cases showing hemophagocytosis. MATERIALS AND METHODS: The study reviewed all the cases of bone marrow aspirate for evidence of hemophagocytosis in which at least three smears and 500 nucleated cells were observed for every case. The cases were provisionally diagnosed as HLH according to the proposed HLH diagnostic criteria, 2009. RESULTS: A total of 80 cases showed hemophagocytosis in the present study with infections followed by HLH being the most common cause. Pancytopenia and erythroid hyperplasis were common hematological presentation. Moderate to severe hemophagocytosis was observed in HLH cases while mild grade in non HLH cases. CONCLUSION: The study concludes that hemophagocytosis even if observed in single cell should always be documented in the bone marrow reports. It may be the only indicator of subtle infection in the marrow. Pancytopenia and higher grade of hemophagocytosis on bone marrow examination may be helpful in establishing an early differentiation of HLH and non HLH cases.