title: Histiocytoid Sweet syndrome may indicate leukemia cutis: a novel application of fluorescence in situ hybridization.
abstract: BACKGROUND
  In patients with malignancy-associated Sweet syndrome, a thorough evaluation for leukemia cutis should be considered.
  
  
  OBJECTIVE
  We sought to describe the clinicopathologic characteristics of histiocytoid Sweet syndrome.
  
  
  METHODS
  We retrospectively identified patients with histiocytoid Sweet syndrome at our institution from January 1992 through December 2010. We evaluated the underlying cutaneous infiltrate using immunohistochemistry and fluorescence in situ hybridization.
  
  
  RESULTS
  We re-evaluated all 22 patients with hematologic malignancy-associated Sweet syndrome. Six patients had a monocytoid infiltrate that was consistent with histiocytoid Sweet syndrome; subsequent evaluation of these patients demonstrated cytogenetic abnormalities on prior bone-marrow biopsy specimens. Fluorescence in situ hybridization analysis was feasible in cutaneous specimens from 5 of the 6 patients and demonstrated the same cytogenetic abnormalities that were identified on prior bone-marrow biopsy specimens in 4 patients. Therefore, these 4 patients may have had a form of leukemia cutis.
  
  
  CONCLUSIONS
  This was a retrospective study.
  
  
  CONCLUSIONS
  For patients with histiocytoid Sweet syndrome, an underlying hematologic malignancy, and a monocytoid infiltrate on biopsy specimen, fluorescence in situ hybridization of the cutaneous infiltrate may be beneficial to identify cytogenetic abnormalities that may indicate leukemia cutis.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Rahul N
authors.initials: RN
authors.lastname: Chavan
authors.affiliation: Department of Dermatology, Mayo Clinic, Jacksonville, Florida.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Cappel
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota; Department of Medical Genetics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Rhett P
authors.initials: RP
authors.lastname: Ketterling
authors.affiliation: Department of Dermatology, University of Utah, and Huntsman Cancer Institute, Salt Lake City, Utah.
authors.forename: David A
authors.initials: DA
authors.lastname: Wada
authors.affiliation: College of Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Rochet
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ryan
authors.initials: R
authors.lastname: Knudson
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota. Electronic address: gibson.lawrence@mayo.edu.
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Gibson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002869:Chromosome Aberrations; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006644:Histiocytes / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D015994:Incidence; D007938:Leukemia / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D016463:Sweet Syndrome / Q000175:diagnosis* / Q000453:epidemiology
keywords: Sweet syndrome; cytogenetic abnormalities; fluorescence in situ hybridization analysis; histiocytoid Sweet syndrome; leukemia cutis; malignancy-associated Sweet syndrome