Langerhans Cell Histiocytosis
- Langerhans cell histiocytosis is an idiopathic reticuloendothelial proliferative disorder involving the Langerhans cell, an immature dendritic cell of bone marrow origin. It describes a spectrum of disease ranging from isolated eosinophilic granuloma to disseminated Letterer-Siwe disease.
- Disease can occur at any age but most frequently develops in children less than 4 years old.
- Orbital LCH frequently occurs in the supratemporal frontal bone as stem cell precursors of Langerhans cells are located in hematopoetic bone marrow in the frontal bone. As the frontal sinus develops, the marrow space is crowded into the lateral orbital roof.
- Orbital LCH may include significant juxtaneural or intracranial extension.
- Children with evidence for orbital LCH should undergo work-up for more generalized disease.
