title: [Diagnosis and differential diagnosis of testicular epidermoid cyst with MRI].
abstract: OBJECTIVE
  To investigate the MRI characteristics and differential diagnosis of testicular epidermoid cyst.
  
  
  METHODS
  The MRI imaging features of 7 testicular epidermoid cyst cases were retrospectively analyzed and compared with that of testicular seminoma. All cases were examined by contrast-enhanced MRI scans.
  
  
  RESULTS
  The group of 7 cases of testicular epidermoid cyst MRI showed characteristic: On T₁-weighted MR images, some lesions showed low signal-based, center with spotty high signal ("target sign"). On T₂-weighted MRI, some lesions had a laminated appearance, with alternating low and high signal intensity areas ("onion skin" sign). On contrast-enhanced images, all lesions were sharply demarcated low signal intensity masses, and contrast enhancement were not seen in any of the cases.
  
  
  CONCLUSIONS
  MRI characteristics of testicular epidermoid cyst are distinctive in certain extent. It may express "target sign", "onion skin" sign, T₂ low signal intensity complete rings, and without enhancement.
authors.affiliation: Department of Radiology, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Science, Beijing 100020, China. Email: ssss197988@hotmail.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Su
authors.affiliation: Department of Radiology, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Science, Beijing 100020, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Science, Beijing 100020, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Radiology, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Science, Beijing 100020, China.
authors.forename: Renyou
authors.initials: R
authors.lastname: Zhai
mesh_terms: D003287:Contrast Media; D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D018239:Seminoma / Q000175:diagnosis*; D013733:Testicular Diseases / Q000175:diagnosis*; D013736:Testicular Neoplasms / Q000175:diagnosis*
chemical_list: D003287:Contrast Media