Abstract
Purpose: :
To evaluate the clinical, histopathologic and genetic features of retinoblastoma (RB) in children over age 5 years.
Methods: :
Of 90 consecutive patients with RB who presented to the Retina Service at the Massachusetts Eye and Ear Infirmary, 6 patients (6.7%) had initial diagnosis after age 5 years. 4 had active tumors (4.4% of all cases) and 2 had inactive tumors (retinoma). Genetic testing for RB1 mutations was performed on constitutional and tumor DNA in 2 cases.
Results: :
There were 2 boys and 2 girls, all unilateral with no family history, ranging in age from 6 to 11 years (mean 8 years). 3 (2 girls, 1 boy) with unilateral decrease in vision (1 symptomatic, 2 by vision screen), total retinal detachment (RD) with vascular dilatation and telangiectasia were referred with diagnosis of Coats disease. 2 had RD in contact with the lens and third had tumor spherules in the vitreous. White plaques or tumors with dilated vessels that dive or arise from them were seen. Ultrasound (US) and CT done in 2 cases showed tumor with calcium (Ca). The fourth patient, referred with intractable uveitis (vitritis, hypopyon, negative work–up, unresponsive to prednisone and cyclosporin A) had white iris nodules but no retinal mass. US and CT showed no mass or Ca. Vitreous biopsy was positive for RB. All patients underwent enucleation. Histologic examination of Coats–like eyes showed both discreet tumors and areas of retinal infiltration. 1 case (11 year–old) had extrascleral extension and received chemotherapy and orbital proton radiotherapy (PRT). The uveitis–like case had diffuse infiltration of the retina and a retinoma at the edge. He received orbital PRT. RB1 analysis showed homozygous non–sense mutation in codon 251 in exon 8 in the tumor but not in the blood of 1 patient. No mutation was found in the other patient. No recurrence was seen in follow–up of 24 to 66 months.
Conclusions: :
RB can present in older children mimicking Coats disease and uveitis resulting in delayed or misdiagnosis. Retinal infiltration appears to be a component, and additional genetic analysis is needed to determine if this subset of RB is genetically different from that in younger children.
Keywords: retinoblastoma • tumors • pathology: human