Multifocal Langerhans cell histiocytosis in an adult with a pathological fracture of the mandible and spontaneous malunion: A case report.

Langerhans cell histiocytosis (LCH) is rare in the adult population and even rarer with jaw involvement. The current study presents the case of a 39-year-old male who complained of recurrent pain, swelling of the gingiva and an occasional pus-like discharge in the right mandible for one year. The patient was previously prescribed antibiotics, but this did not resolve the problem. An initial panoramic radiograph showed an osteolytic lesion and bone fracture in the right mandible. Eight months later, a new radiograph showed the spontaneous malunion of the fractured mandible. The patient was eventually diagnosed with Langerhans cell histiocytosis by histopathology and immunohistochemistry. Further lesions were found in the ribs and ilium by nuclear bone scanning. The patient was subsequently treated with systemic chemotherapy, and the lesions are currently effectively being controlled. This study is the first to show that spontaneous intralesional bone regeneration may lead to reunification of the mandible fracture caused by LCH in an adult.