title: Adult-onset systemic Langerhans cell histiocytosis mimicking inflammatory bowel disease: the value of skin biopsy and review of cases of Langerhans cell histiocytosis with cutaneous involvement seen at the Mayo Clinic.
abstract: BACKGROUND
  Langerhans cell histiocytosis (LCH) is frequently known to involve multiple organ systems. However, gastrointestinal involvement by LCH is rare.
  
  
  METHODS
  We describe a 68-year-old woman with a 3-year history of intermittent diarrhea initially diagnosed as inflammatory bowel disease. She was subsequently found to have systemic LCH with involvement of the gastrointestinal tract, lungs, liver, and skin after skin biopsy was performed. A retrospective review of patients with cutaneous involvement of LCH seen at the Mayo Clinic over the past 15 years was conducted. The presence of systemic disease as well as specific organ system involvement was reviewed.
  
  
  RESULTS
  Twenty-four patients with cutaneous LCH were identified. Besides our case, one other patient with both gastrointestinal and cutaneous involvement was identified. This patient died at six months of age. No other adult-onset cases were identified.
  
  
  CONCLUSIONS
  Gastrointestinal involvement with LCH is rare, can be easily misdiagnosed, and likely portends a poor prognosis. In patients with ill-defined systemic symptoms, cutaneous exam and biopsy have the potential to diagnose systemic disease.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Joshua O
authors.initials: JO
authors.lastname: Podjasek
authors.forename: Conor G
authors.initials: CG
authors.lastname: Loftus
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Carilyn N
authors.initials: CN
authors.lastname: Wieland
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000554:Ambulatory Care Facilities; D001706:Biopsy; D003937:Diagnosis, Differential; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007223:Infant; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology*; D055815:Young Adult