Neuroradiologic Imaging Findings in Histiocytosis Syndromes in Children and Young Adults

There are 2 major subtypes of histiocytosis syndrome in children and adults, classified according to their cellular basis: disorders of varied biologic behavior (dendritic cell‐related or macrophage-related) and malignant disorders (monocyte-related, dendritic cell‐related histiocytic sarcoma, or macrophage-related histiocytic sarcoma). While some neuroradiologic manifestations of histiocytosis syndromes are more closely linked to the underlying pathophysiology, others are less well-defined and remain within a broader differential diagnostic consideration. The underlying epidemiology, pathophysiology, and known radiologic manifestations are reviewed to aid the neuroradiologist in considering the diagnosis of histiocytosis in the appropriate clinical setting.