title: Spontaneous regression of Langerhans cell histiocytosis: a case report.
abstract: BACKGROUND
  Spontaneous regression of Langerhans cell histiocytosis (LCH) has been reported in skin, bone, and pulmonary lesions. However, such phenomena in the central nervous system (CNS) have not been described previously.
  
  
  METHODS
  A case of LCH in the CNS with spontaneous regression is reported. A 2-year-old boy presented with general convulsion followed by frequent vomiting and diabetes insipidus. Magnetic resonance imaging (MRI) scan revealed numerous multifocal nodules predominantly in the left frontal lobe. The patient underwent surgery to remove part of the frontal lesion. Subsequent to surgery, residual lesions showed regression without any additional treatment, and clinical symptoms also subsided. The multiple lesions disappeared completely and did not relapse during 5-year observation.
  
  
  CONCLUSIONS
  Surgical resection and/or adjuvant therapy such as radiation and chemotherapy has been performed for the treatment of LCH in the CNS. However, there may be a subgroup of patients with multifocal brain LCH that regress spontaneously. Further clinical study is required to establish the natural course and prognostic factors of this disease.
authors.affiliation: Department of Neurosurgery, Hiroshima City Asa Hospital, and HiroshimaUniversity, 1-2-3 Kasumi, Minami-ku, Hiroshima City, Hiroshima 734-8551, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Shuichi
authors.initials: S
authors.lastname: Oki
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D002675:Child, Preschool; D005500:Follow-Up Studies; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012075:Remission, Spontaneous; D013997:Time Factors