title: Eosinophilic granuloma of the sacrum treated with radiation therapy: a case report.
abstract: BACKGROUND
  Eosinophilic granulomas (EGs) of the sacrum have been reported in fewer than 10 patients. Treatment algorithms for these tumors remain poorly defined; there are no reports of treating solitary sacral EG with radiation therapy (RT).
  
  
  OBJECTIVE
  This study aimed to describe the presentation, treatment, and outcome of sacral EG in an adult patient with intractable pain and radiculopathy, treated in a novel fashion with RT.
  
  
  METHODS
  The study design was a case report from a tertiary cancer referral center.
  
  
  METHODS
  Patient records, imaging, and pathology were reviewed.
  
  
  RESULTS
  A 35-year-old man received 20 Gy of radiation to his S1 EG lesion. He subsequently developed vertebra plana of S1 causing symptomatic L5-S1 stenosis, but 15 months after RT treatment was free of pain or tumor recurrence.
  
  
  CONCLUSIONS
  Radiation therapy is an effective treatment option for sacral EG causing severe axial pain and neural impingement.
authors.affiliation: Department of Orthopaedic Surgery, Washington University, 660 S. Euclid Ave, Campus Box 8233, St. Louis, MO 63110, USA. Electronic address: dbbumpass@uams.edu.
authors.forename: David B
authors.initials: DB
authors.lastname: Bumpass
authors.affiliation: Department of Orthopaedic Surgery, Washington University, 660 S. Euclid Ave, Campus Box 8233, St. Louis, MO 63110, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Park
authors.affiliation: Department of Pathology, Washington University, 660 S. Euclid Ave, Campus Box 8118, St. Louis, MO 63110, USA.
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Hill
authors.affiliation: Department of Radiation Oncology, Washington University, 660 S. Euclid Ave, Campus Box 8224, St. Louis, MO 63110, USA.
authors.forename: Jiayi
authors.initials: J
authors.lastname: Huang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University, 660 S. Euclid Ave, Campus Box 8131, St. Louis, MO 63110, USA.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Friedman
authors.affiliation: Department of Orthopaedic Surgery, Washington University, 660 S. Euclid Ave, Campus Box 8233, St. Louis, MO 63110, USA.
authors.forename: Lukas P
authors.initials: LP
authors.lastname: Zebala
mesh_terms: D000328:Adult; D004803:Eosinophilic Granuloma / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D012447:Sacrum / Q000473:pathology*
keywords: Benign bone tumor; Eosinophilic granuloma; Langerhans cell histiocytosis; Radiation therapy; Sacrum; Spine tumor