Progressive enlargement of cavity within melanoma masquerading as iris cyst.
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.
Criss
Jonathan S
JS
Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Shields
Carol L
CL
Materin
Miguel A
MA
Reichel
Elias
E
Eagle
Ralph C
RC
Shields
Jerry A
JA
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