Plaque-type syringoma: two cases misdiagnosed as microcystic adnexal carcinoma.
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.
Suwattee
Pitiporn
P
Department of Dermatology, University of Minnesota, Minneapolis, MN 55417, USA. suwat001@umn.edu
McClelland
Matthew C
MC
Huiras
Erin E
EE
Warshaw
Erin M
EM
Lee
Peter K
PK
Kaye
Valda N
VN
McCalmont
Timothy H
TH
Niehans
Gloria A
GA
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