Ramesh, MSingh, VGhuliani, RKapur, BNSingh, JShankar, S2026-06-042026-06-042010https://hdl.handle.net/20.500.14572/6371M Ramesh Resident, Dept of Paediatrics, Armed Forces Medical College, Pune, Maharashtra V Singh Resident, Dept of Paediatrics, Armed Forces Medical College, Pune, Maharashtra R Ghuliani Sr.Advisor, Dept of Paediatrics, Command Hospital, Southern Command, Pune, Maharashtra, India BN Kapur Sr. Advisor, Dept of Medicine & Oncology, Command Hospital, Southern Command, Pune, Maharashtra, India J Singh Classified Specialist, Dept of Medicine, Clinical Hematology & Oncology, Command Hospital, Southern Command, Pune, Maharashtra, India S Shankar Immunology, Reader, Dept of Medicine, Armed Forces Medical College, Pune, Maharashtra, India.Abstract: Histiocytosis Syndromes of Childhood (HSC) are a group of rare and diverse disorders characterized by aggressive proliferation or accumulation of cells of monocyte - macrophage system of bone marrow. The clinical spectrum of this syndrome is distinctly varied. The exact pathophysiology of HSC is yet to be determined; however, evidence suggests that one of the subtypes, Hemophagocytic Lymphohistiocytosis, is due to decreased Natural Killer cell activity, resulting in increased activation of other T cell subtypes and production of cytokines. We present four cases of HSC managed at our center between October 2008 & February 2010.en-USHistiocytosis Syndromes of ChildhoodLangerhan’s cell Histiocytosis (LCH)Hemophagocytic Lymphohistiocytosis (HLH)Macrophage Activation Syndrome (MAS)Article