title: Progressive enlargement of cavity within melanoma masquerading as iris cyst.
abstract: OBJECTIVE
  To describe progressive enlargement of intralesional cavities within a mass that masqueraded clinically as an iris pigment epithelial cyst for 2 years but later proved to be a melanoma.
  
  
  METHODS
  An 81-year-old woman developed asymptomatic focal elevation of the iris, and ultrasound biomicroscopy showed a fluid-filled mass that was interpreted as an iris pigment epithelial cyst. Over a 2-year period of observation, the cavity enlarged from 0.7 to 10 mm, and the solid component enlarged from approximately 6 to 16 mm basal dimension.
  
  
  RESULTS
  On referral, visual acuity was 20/400 in the right eye and 20/25 in the left eye. The affected right eye displayed a pigmented mushroom-shaped ciliary body mass with anterior chamber invasion, distorting the pupil and occupying 40% of the anterior chamber. Ultrasound biomicroscopy and B-scan ultrasonography revealed many cavities within the 14-mm-thick mass, suggestive of ciliary body melanoma. After enucleation, histopathology disclosed multiple cavities, some with granular eosinophilic material, within a mushroom-shaped mixed-cell melanoma.
  
  
  CONCLUSIONS
  Cavitation can occur in ciliary body melanoma and can lead to misinterpretation as a cyst. Cavitary melanoma should be considered in the differential diagnosis of cystic lesions of the anterior segment.
authors.affiliation: Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Criss
authors.forename: Carol L
authors.initials: CL
authors.lastname: Shields
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Materin
authors.forename: Elias
authors.initials: E
authors.lastname: Reichel
authors.forename: Ralph C
authors.initials: RC
authors.lastname: Eagle
authors.forename: Jerry A
authors.initials: JA
authors.lastname: Shields
mesh_terms: D000369:Aged, 80 and over; D002924:Ciliary Body / Q000000981:diagnostic imaging* / Q000473:pathology*; D003560:Cysts / Q000175:diagnosis*; D003937:Diagnosis, Differential; D018450:Disease Progression; D015353:Eye Enucleation; D005260:Female; D006801:Humans; D008545:Melanoma / Q000175:diagnosis* / Q000601:surgery; D033401:Microscopy, Acoustic; D014604:Uveal Neoplasms / Q000175:diagnosis* / Q000601:surgery