title: Cutaneous metaplastic synovial cyst: unusual presentation with "a bag of worms".
abstract: BACKGROUND
  Cutaneous metaplastic synovial cyst (CMSC) is a rare cystic tumor that is unfamiliar to most dermatologists. A traumatic history usually precedes its onset. CMSC is often misdiagnosed as suture granuloma clinically. A correct diagnosis requires histopathologic examination to reveal its characteristic features, that is, a cystic tumor line by synovium-like structure.
  
  
  OBJECTIVE
  To describe a case of CMSC encountered during dermatologic surgery practice. We present an unusual case with elongated projections.
  
  
  METHODS
  A case report and literature review are presented.
  
  
  CONCLUSIONS
  The differential diagnosis of tender cutaneous cysts should include CMSC. Projections from the cyst wall may attain significant size and give the intraoperative impression of a "bag of worms."
authors.affiliation: Department of Dermatology, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Lin
authors.forename: Tsen-Fang
authors.initials: TF
authors.lastname: Tsai
mesh_terms: D005260:Female; D006801:Humans; D008875:Middle Aged; D012871:Skin Diseases / Q000473:pathology* / Q000601:surgery; D013581:Synovial Cyst / Q000473:pathology* / Q000601:surgery