title: Clinical findings and molecular diagnosis of retinoblastoma in older children.
abstract: BACKGROUND
  Retinoblastoma (RB) is the most common primary childhood intraocular malignancy and usually presents before the age of 4 years. RB in late childhood is rare and may pose a diagnostic challenge to clinicians.
  
  
  METHODS
  Patients over the age of 4 years with RB were identified retrospectively. Clinical data, histological findings, and molecular genetic diagnoses were obtained.
  
  
  RESULTS
  Two cases of late onset RB were identified. Case 1 was a 10-year-old boy who presented with floaters, and was found to have a unilateral exudative retinal detachment and RB on clinical examination. Genetic testing showed a novel homozygous mutation in exon 20 of the RB1 gene in the tumor sample, c.2027_2034dup, resulting in p.Ile679X. No mutation was found in the DNA obtained from the peripheral blood sample. Case 2 was a 6-year-old boy who presented with loss of vision and pain in the left eye. RB was diagnosed on clinical examination with exudative retinal detachment. Genetic testing showed no mutation in the RB1 gene, but complete methylation of the RB1 promoter region.
  
  
  CONCLUSIONS
  RB can rarely present in late childhood. Clinicians should consider RB as a diagnosis when faced with a patient with unexplained exudative retinal detachment.
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland.
authors.forename: Leo H N
authors.initials: LH
authors.lastname: Sheck
authors.forename: Yvonne S P
authors.initials: YS
authors.lastname: Ng
authors.forename: Mike
authors.initials: M
authors.lastname: Watson
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Vincent
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D002648:Child; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005091:Exons / Q000235:genetics; D016161:Genes, Retinoblastoma; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D025202:Molecular Diagnostic Techniques; D009154:Mutation; D016133:Polymerase Chain Reaction; D012163:Retinal Detachment / Q000175:diagnosis; D019572:Retinal Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D012175:Retinoblastoma / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000235:genetics*; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D014792:Visual Acuity
chemical_list: D000970:Antineoplastic Agents; D016160:Retinoblastoma Protein