Multisystemic Langerhans cell histiocytosis with orbital involvement

A 3-year-old male initially presented with low grade fever and scalp rash of 2 months' duration. Patient also showed macrocephaly with bilateral proptosis since birth. Work up revealed CD1a, S100, Langerin and BRAF mutation positive results. A diagnosis of multisystemic Langerhans Cell Histiocytosis (LCH) was confirmed. Multiple punched out bony lytic lesions with geographic appearance predominantly in the frontal and parietal regions. These are classic radiographic finding for cranial vault lesions in LCH. A solitary lesion may already be suggestive. Langerhans cell histiocytosis is a rare disorder commonly affecting children with unknown etiology. It has multisystemic involvement (skin, lymph nodes, bones, central nervous system, abdominal organs especially the liver and/or spleen). The bones are commonly involved in this disease. That's why biopsy proven LCH should include a skeletal survey. Langerhans cell histiocytosis can involve any bone in the human body but mainly in the axial skeleton. Over 50% occur in the skull, ribs and pelvis.