Langerhans Cell Histiocytosis of the Skull in a Burr Hole Site Covered with Hydroxyapatite Material

Background Langerhans cell histiocytosis (LCH) is a rare dendritic histiocytic disorder that affects the bones, especially the skull. Langerhans cell histiocytosis (LCH) developing in a burr hole site for chronic subdural hematoma is extremely rare. Case Description A 53-year-old man underwent a burr hole irrigation for chronic subdural hematoma, and the burr hole was covered with a burr hole button made of hydroxyapatite. Seven months after the first surgery, the connective tissue rapidly proliferated around the burr hole button, and the pathologic diagnosis was LCH. LCH recurred at 13 and 19 months after the first operation, with curettage performed each time. At 3 months after the final operation, no recurrence was identified on magnetic resonance imaging. Conclusions If there is rapid proliferation of connective tissue at an operative site where artificial material has been used, LCH should be considered.