Abstract: Langerhans cell histiocytosis (LCH), an abnormal proliferative and infiltrative disorder of Langerhans cells, usually involves skeleton, skin, pituitary and can also affect liver, spleen, blood system, lungs, lymph nodes, and central nervous system. LCH is rare in adults. It lacks a recognized therapeutic regimen, and therapies of LCH mainly include surgery, topical injections of steroids, chemotherapy, radiotherapy, and combined therapy. Herein, we report an adult patient with oral single system (SS)-LCH with multifocal bone lesions involving the maxilla and mandible treated with local small-dose radiotherapy. We discuss the therapeutic regimen selection of oral single system LCH combined with multifocal bone lesions, with the help of its diagnosis, treatment experience and previous literature reports.

Key words: Langerhans cell histiocytosis, adult, oral cavity, therapy, radiotherapy, multifocal