Histopathologic characteristics of choroidal melanoma in eyes enucleated after iodine 125 brachytherapy in the collaborative ocular melanoma study.
OBJECTIVE
To describe the histopathologic findings in eyes with uveal melanoma that had secondary enucleation after failed brachytherapy plaque treatment.


METHODS
Histopathologic findings in eyes that had secondary enucleation after plaque radiation therapy in the Collaborative Ocular Melanoma Study (COMS) were reported on a standardized data form. The findings were compared with eyes that had primary enucleation for uveal melanoma.


RESULTS
Seventy-five eyes that had secondary enucleation were studied. Compared with primary enucleations, tumors in the irradiated eyes had lower mitotic activity, a smaller proportion of histologically intact tumor, more inflammation, more fibrosis, and more vascular damage within the tumor. In addition, compared with primary enucleations, eyes previously irradiated had a higher frequency of retinal invasion by the tumor and greater damage to the retinal vasculature, consistent with radiation retinopathy; neovascularization of the iris; and vitreous hemorrhage. Tumor growth or extrascleral extension was confirmed histopathologically in 25 of 42 eyes (60%) enucleated because of a reported failure of local control.


CONCLUSIONS
Eyes with secondary enucleation after brachytherapy differ histopathologically from eyes with primary enucleation for uveal melanoma. These histopathologic differences may be due to the effects of radiation, tissue conditions related to plaque failure, and, in some cases, tumor growth. In 40% of eyes enucleated because of suspected failure of local control, increased tumor size could not be histologically confirmed.
Avery
Robert B
RB
Division of Ophthalmology, University of New Mexico, Albuquerque, USA.
Diener-West
Marie
M
Reynolds
Sandra M
SM
Grossniklaus
Hans E
HE
Green
W Richard
WR
Albert
Daniel M
DM
D001918:Brachytherapy / Q000379:methods*; D002830:Choroid Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D015353:Eye Enucleation; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D007498:Iris / Q000098:blood supply; D008545:Melanoma / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000175:diagnosis; D011832:Radiation Injuries / Q000209:etiology / Q000473:pathology; D012160:Retina / Q000473:pathology / Q000528:radiation effects; D017211:Treatment Failure; D014823:Vitreous Hemorrhage / Q000209:etiology / Q000473:pathology
D007457:Iodine Radioisotopes