Objective: To study histopathological findings of enucleated eyes with retinoblastoma.
Methods: Twenty-eight cases of retinoblastoma treated by enucleation at the Federal University of São Paulo from December 2000 to October 2002 were histopathologically reviewed. Clinical data included age, gender, race, unilateral or bilateral involvement and previous treatment. The histopathological review evaluated the presence of iris and/or angle neovascularization, tumor differentiation and optic nerve and choroidal invasion according to Khelfaoui's classification.
Results: Of 27 patients, 13 (48.5%) were boys and 14 (59.3%) were girls, 16 were white, 6 were black and 5 were asiatic, age ranging from 2 to 96 months (mean, 22.7 months). 13 cases were bilateral and 14 cases were unilateral. All tumors were histologically characterized by a proliferation of small cells with high nuclear-to-cytoplasmic ratios and 20 (71.4%) of them were well differentiated. Choroidal involvement was observed in 18 (64.2%) cases (degree II, III) and optic nerve invasion in 8 (28.5%) cases (degree III, IV, V).
Conclusion: Neovascularization, necrosis and calcification were the most commonly observed feature. The invasion into the optic nerve and choroid, which are the two most important predictors of patient outcome were found in 28.5% and 64.2% of the cases, respectively.