Retinoblastoma: On top of the list of leukocoria in children is retinoblastoma, the most common primary intraocular malignancy in children. The frequency varies from 1 in 14,000 to 1 in 20,000 live births. 6% of cases have a family history whereas 94% occur spontaneously. The retinoblastoma gene is located on chromosome 13 q 14 site. If a mutation occurs here, the normal suppression of the tumor is lost. To form the tumor, both gene sites have a mutation to result in lack of tumor suppression.
Clinically the patient may present with a red eye or just a white pupil. Occasionally a mass can be seen with the slit lamp. The indirect or direct ophthalmoscopy may reveal a chalky white or fleshy elevated lesion arising from the retina. Migration of tumor cells into the anterior chamber can result in a pseudohypopyon. Imaging studies often shows the extensive calcium in the tumors. Bilateral cases may have another tumor that forms in the pineal gland, which is referred to as trilateral retinoblastoma. These cases have a poor prognosis.
Chemotherapy in conjunction with laser treatment is the treatment of choice is possible. However if the tumor load is too high, enucleation is performed. The gross section (1)of the tumor reveals a chalky white mass arising from the retina. Vitreous seeding may be present. The classic histopathology is islands of blue cells in a sea of pink necrosis(1,2). Flexner-Wintersteiner rosettes consist of cuboidal cells circled around a central lumen. Fleurettes are also seen which are flower-like grouping of tumor cells which look like photoreceptors. Tumor cells may cluster around a blood vessels forming a pseudorosette. Retinoblastoma has a tendency to travel into the optic nerve. Microscopic examination of cross-sections of the specimen is needed to look for tumor cells. Systemic treatment is needed if the optic nerve margin is still positive. Back to Main