title: Plaque-type syringoma: two cases misdiagnosed as microcystic adnexal carcinoma.
abstract: BACKGROUND
  Plaque-type syringoma is a rare variant of syringoma. This benign neoplasm may be easily misdiagnosed as microcystic adnexal carcinoma (MAC), potentially resulting in unnecessary surgery with disfiguring consequences.
  
  
  METHODS
  We report two cases of plaque-type syringoma that were initially diagnosed as MAC. Microscopically, these lesions were composed of nests of cuboidal cells arrayed within sclerotic collagen in the upper dermis. The deep reticular dermis was spared. No perineural involvement was observed.
  
  
  CONCLUSIONS
  Our cases are discussed in the context of histopathologic diagnosis. Detailed histopathologic findings of syringoma, as well as other considerations in the differential diagnosis, are reviewed. We also include a review of all cases of plaque-type syringoma published to date.
authors.affiliation: Department of Dermatology, University of Minnesota, Minneapolis, MN 55417, USA. suwat001@umn.edu
authors.forename: Pitiporn
authors.initials: P
authors.lastname: Suwattee
authors.forename: Matthew C
authors.initials: MC
authors.lastname: McClelland
authors.forename: Erin E
authors.initials: EE
authors.lastname: Huiras
authors.forename: Erin M
authors.initials: EM
authors.lastname: Warshaw
authors.forename: Peter K
authors.initials: PK
authors.lastname: Lee
authors.forename: Valda N
authors.initials: VN
authors.lastname: Kaye
authors.forename: Timothy H
authors.initials: TH
authors.lastname: McCalmont
authors.forename: Gloria A
authors.initials: GA
authors.lastname: Niehans
mesh_terms: D000368:Aged; D018280:Carcinoma, Skin Appendage / Q000175:diagnosis*; D003560:Cysts / Q000473:pathology*; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000175:diagnosis*; D013544:Sweat Gland Neoplasms / Q000175:diagnosis* / Q000601:surgery; D018252:Syringoma / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome