Histopathologic Risk Factors of Retinoblastoma: A Retrospective Study of 104 Enucleated Eyes

Purpose: to introduce a novel classification system for the extent of choroid invasion and to analyze the incidence of histopathologic risk factors (hrfs) in the patients with retinoblastoma in chinamethods: the clinical data of 104 enucleated eyes diagnosed with retinoblastoma were retrospectively reviewed, and the pathological re-examination of the enucleated eyes was conducted.results: overall, the hrfs were present in 53% of the 104 eyes. for choroid infiltration, type 1 was observed in 38 eyes as isolated, sporadic tumor cells, or suspected tumor cells with no obvious choroid thickening; type 2 in 26 eyes, as localized nest-like or nidulant tumor cells without obvious choroid thickening; and type 3 in 25 eyes, as lumpish, massive or dense invasion with or without obvious choroid thickening. the mean follow-up period was 27.6 months (median, 24.9; range, 8.3-65.7). during the course of the study, four patients died of recurrence or metastasis. statistically significant differences between the proportional mortality ratios were observed in choroidal infiltration of type 3 (p=0.003), invasion of postlamina (p=0.033), sclera (p=0.003), and optic nerve resection line (p=0.005) cases. based on univariate and multivariate analysis, leukocoria was negatively correlated with hrfs (p=0.001, or=0.21; p=0.010, or=0.25).conclusion: clinically, the novel classification system for the extent of choroid invasion could function as a practical definition for choroid infiltration, and the hrfs are present in a significant proportion of patients enucleated for retinoblastoma in china.