Comparison of high-risk histopathological features in eyes with primary or secondary enucleation for retinoblastoma

To compare high-risk histopathology of eyes with primary versus secondary enucleation from patients with retinoblastoma.

A retrospective histopathology review identified 207 eyes enucleated from 202 patients between March 1997 and August 2013. Our review considered high-risk histopathological features to include extraocular disease or invasion of the anterior chamber, iris, ciliary body, choroid (massive), postlaminar optic nerve or sclera.

Most eyes (144, 70%) were primarily enucleated; 63 (30%) were secondarily enucleated after neoadjuvant therapy. The primary enucleation group had more advanced disease (Reese-Ellsworth group V: 95% vs 59%; International Classification Group D/E: 97% vs 59%; p<0.001). The incidence of high-risk histopathology features was similar between groups (32% vs 21%, n=59; p=0.132). The type of prior therapy was not associated with high-risk histopathology features. Time to enucleation was longer for secondarily enucleated eyes with high-risk features. Choroid and postlaminar optic nerve invasion were more frequent in eyes primarily enucleated (p<0.001). Forty-six of the 59 (78%) patients with high-risk features received adjuvant chemotherapy and/or external beam radiation therapy. Three patients who received primary enucleation and adjuvant therapy died of metastatic recurrence.

Despite the more favourable classification of eyes treated with neoadjuvant therapy, the risk of high-risk histopathology features at enucleation was comparable with eyes undergoing primary enucleation. Delayed enucleation was associated with these features, and the majority of patients required further adjuvant therapy. Caution must be exercised in treating recalcitrant intraocular retinoblastoma to promptly pursue definitive enucleation in an effort to minimise further treatment exposures and metastases.