RESUMO
Cyst-like cavities in uveal melanoma occur rarely and can simulate a benign intraocular cystic lesion resulting in delayed diagnosis and inappropriate management. Herein, we describe a 66-year-old Caucasian female who presented with a "cystic" ciliary body mass in the right eye oculus dexter [OD]. Slit lamp examination OD showed anterior bulging of the iris temporally from an underlying pigmented ciliary body mass and transillumination disclosed slight shadow from the tumor. Ultrasound biomicroscopy [UBM] revealed multiple cyst-like cavities within a tumor, lined by "thick walls" of at least 200 microm and occupying 80% of the tumor volume. A clinical diagnosis of multi-cavitary ciliary body melanoma was suspected and partial lamellar sclero iridocyclectomy was performed. Histopathology confirmed the diagnosis of low-grade spindle melanoma of the ciliary body with multiple empty and fluid filled cyst-like cavities without epithelial lining. UBM is an important diagnostic tool in the differentiation of "thick walled" cavitary melanoma from "thin walled" benign pigment epithelial cyst