<prompt> Which of the following is commonest primary intraocular tumour in childhood isNeurofibromatosisRetinoblastomaCavernous haemangiomaMelanotic melanoma  <response>: Retinoblastoma: Ref: 280-KH, 358-K, 397-PRETINOBLASTOMA - is the most common primary intraocular malignancy of childhood. The retinoblastoma may be heritable 40 or non heritable 60 The predisposing gene RPE1 is at 13q14 Leukocoria white papillary reflex is the commonest 60 presentation Delation involving the long arm of chromosomes 22 22ql 1 are most common microdeletions identified to date, VCF Velo Cardio Facial syndrome is the most common associated syndromeTreatments1. Small tumour - no more than 4 mm diameter and 2 mm thickness without vitreous or subretinal seeds - Trans papillary thermotherapy laser or cryotherapy2. Median size tumourI Brachytherapy - is indicated for tumours of no more than 12 mm diameter and 6 mm thickness 60Co or I125II Chemotherapy - Carboplatin, vincristine, etoposide may be combined with cyclosporinIII External beam radiotherapy - should be avoided, because high risk of complications, cataract formation, radiation retinopathy and cosmetic deformity and secondary malignancy.3. Large tumours a Chemotherapy b Enucleation4. Extra ocular extension - beyond the lamina cribosa is treated with chemotherapy after enucleation Extension to the cut end of the optic nerve or extension through the sclera - chemotherapy and irradiation of the affected orbit5. Metastatic disease: - High dose chemotherapy Enucleation is the treatment of choice when the child is brought in clinical stage II or late stage I when tumour is more than 100 mm in size or when optic nerve is involved 270-KH 