What is Histiocytic Disorder?
introduction Classification Pathophysiology Reference Further reading Histiocytic disorders are a group of disorders that arise from the overproduction of histiocytic white blood cells called histiocytes. ‘Histiocytosis’, meaning ’tissue cell’, is a general concept for a disease exemplified by myeloid cells, i.e. mononuclear phagocytes, which share histological features with macrophages or dendritic cells. Image Credit: Babul Hosen/Shutterstock Classification Histiocytic disorders were initially classified by the histologic features of the pathological cells as compared to their putative physiological counterparts. There are competing systems for classifying histiocytosis. According to the World Health Organization (WHO), they can be divided into three categories as proposed in the 1999 classification: Langerhans cell histiocytosis: may be localized and asymptomatic, as in isolated bone lesions, or may involve multiple organs and systems. LCH mainly affects children < 10 years.