Petrous bone Langerhans cell histiocytosis treated with radiosurgery.

Langerhans cell histiocytosis (LCH) is a rare disease that may show as a solitary or multifocal lesion of bone, soft tissue or viscera. Involvement of the temporal bone has been described in 15-61% of patients with LCH, usually in association with multisystemic involvement. We report the case of a 30-year-old man presenting with vertigo and fluctuating hearing loss caused by monosystemic LCH of the left petrous bone. The patient was treated with radiosurgery (covering dose 10 Gy at 85% isodose, maximum dose 11.76 Gy). Two years after treatment, no evidence of recurrent disease was found in the CT scan or MRI. We discuss the treatment of temporal bone LCH, traditionally based on surgery, low-dose radiation therapy and intralesional steroids. To our knowledge, this is the first reported case of LCH of the petrous bone successfully treated with radiosurgery. This approach may be interesting in cases of LCH located on nonaccessible areas of the temporal bone.