Case Series on hemophagocytosis in bone marrow- a key to hidden pathologies

Hemophagocytosis refers to the pathological process of histiocytes engulfing red blood cells, white blood cells, platelets, and their precursors, either in bone marrow or other parts of the reticuloendothelial system. It is one of the essential criteria for the diagnosis of a life-threatening disease called Hemophagocytic Lymphohistiocytosis. This study aimed to evaluate the clinicopathological profile of patients with hemophagocytosis in bone marrow aspirates.  A 2 ½ year retro-prospective observational study was conducted in Santosh Medical Hospital, Ghaziabad, between March 2022- August 2024. Bone marrow aspirates diagnosed as hemophagocytosis were included in the study. A complete clinical history and laboratory investigations were reviewed. Most patients who underwent bone marrow aspirations were clinically diagnosed with Pancytopenia. A minimum of 3 smears were reviewed in each bone marrow aspirate, and 500 nucleated cells were observed in each smear. A total of 10 cases were diagnosed with hemophagocytosis. One patient was suspected of HLH, and only one patient fulfilled the criteria for HLH. This case series concludes that hemophagocytosis is an essential parameter that should be reported even if one histiocytes show hemophagocytosis. It is one of the initial and important criteria in diagnosing HLH.