Retinoblastoma in the adolescent. Unusual clinical and histopathology findings

A 17-year- old male with 2years history of an intraocular mass and progressive visual loss of the left eye. Spontaneous sclera rupture occurred during enucleation. Microscopic evaluation with H-E, PAS and immunohistochemistry (NSE, GAFP, SYN, CD99) revealed a small blue round cell malignant neoplasm with extensive necrosis and apoptosis. The optic nerve, ciliary body, choroid, anterior chamber, and sclera were infiltrated. SYN was positive and CD99 was negative in neoplastic cells, consistent with a poorly differentiated retinoblastoma.

Retinoblastoma is the most frequent primary intraocular malignant tumour in childhood, but occasionally older patients can be affected. Immunohistochemistry is mandatory in poorly differentiated retinoblastomas.