Ki–67 Cell Proliferation Labeling Index in Familial and Sporadic Unilateral Retinoblastoma

Abstract

Abstract: : Purpose: To report on the cell proliferation indices as measured by the Ki–67 antigen in two enucleated unilateral retinoblatoma eyes. Methods: One unilateral familial (mother with unilateral disease – patient 1) and one unilateral sporadic retinoblastoma (patient 2) patients were submitted to enucleatin only. The tumor cell proliferation rate was assessed by the Ki–67 antigen labeling index (stained cells/100cells) in five tumor fields. Results: Patient 1 was 23 months old and the tumor was exophitic with associated iris neovascularization; patient 2 was 6 years old and the tumor was endophitic with coarse vitreous seeds. Both enucleated eyes presented tumor invasion of the choriocapillaris and of the optic nerve up to the lamina cribosa. Positive cell index varied from 75 to 90 in patient 1 (MD±SD: 79.5± 6.61) and in patient 2 from 38 to 60 (MD±SD: 46.6±8.20). The eye of patient 1 eye showed 45.8% more Ki–67 positive cells than the eye of patient 2. Conclusions: The familial retinoblastoma, besides the earlier age presentation, showed 45.8% more Ki–67 positive cells than the same stage sporadic one.

Keywords: retinoblastoma • proliferation • microscopy: light/fluorescence/immunohistochemistry