Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Langerhans cell histiocytosis (LCH) is a pediatric disease that is characterized by idiopathic proliferation of Langerhans cells. LCH is classified into single or multisystemic disease, according to the sites of involvement. The disease is most commonly seen in the frontal and parietal skull. The classic CT imaging findings include a very well-defined osteolytic defect with beveled edges in the calvarium (arrows in A and B), without marginal sclerosis, and soft tissue mass that enhances homogeneously after iodinated contrast administration (arrow in C).