title: MR imaging findings of the uveal schwannoma.
abstract: OBJECTIVE
  Uveal schwannoma is a rare benign neoplastic proliferation of pure Schwann cells. The purpose of this study was to describe MR imaging features of uveal schwannoma.
  
  
  METHODS
  MR images in 6 female patients with uveal schwannoma confirmed by pathologic examination were retrospectively reviewed. MR imaging was performed in all 6 patients, with postcontrast T1-weighted imaging (T1WI) completed in all 6 patients and dynamic contrast-enhanced MR imaging, in 5. MR imaging findings of the tumor were evaluated with emphasis on the location, size, shape, margin, signal intensity, and pattern of enhancement.
  
  
  RESULTS
  The lesions appeared as solitary well-defined ovoid masses in the ciliochoroidal region in 5 patients and in the choroid in 1. With respect to the vitreous body, uveal schwannoma was hyperintense on T1WI spin-echo (SE) images in all 6 patients. The tumors were hypointense to the vitreous body on fast SE (FSE) T2-weighted images (T2WI) in 4 patients and isointense in 1. However, with respect to the brain, uveal schwannoma demonstrated isointensity on T1WI SE images in all 6 patients, isointensity on FSE T2WI images in 5 patients, and hyperintensity on T2WI SE images in 1. On postcontrast T1WI images, 3 patients showed markedly heterogeneous enhancement, and 3 showed markedly homogeneous enhancement.
  
  
  CONCLUSIONS
  Uveal schwannoma should be included in the differential diagnosis when an oval isointense mass relative to brain is seen in the ciliochoroidal region.
authors.affiliation: Department of Radiology, Capital Medical University, Beijing Tongren Hospital, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Xian
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Yang
authors.forename: B
authors.initials: B
authors.lastname: Li
authors.forename: F
authors.initials: F
authors.lastname: Man
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Shi
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D002829:Choroid / Q000473:pathology; D002830:Choroid Neoplasms / Q000473:pathology*; D002924:Ciliary Body / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015811:Iris Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology*; D012189:Retrospective Studies; D012583:Schwann Cells / Q000473:pathology; D014602:Uvea / Q000473:pathology; D014604:Uveal Neoplasms / Q000473:pathology*; D055815:Young Adult