Causes of leukocoria and imaging of retinoblastoma

• MC, highly malignant intraocular tumor of childhood.

• Equal sex predeliction

• Most frequent intraocular malignancy in children: retinoblastoma.

• Mean age at diagnosis: 18 months.

• B/L cases: 25–30%.

• Autosomal Dominant

• Familial -usually bilateral.

• Clinical features-Leukocoria 60% ,Squint 20%,Glaucoma ,vision loss

  Imaging modalities

• USG:

  • heterogenous retinal mass with calcifications necrotic components and increased vascularity

  • Varying size.

  • Infiltration.

• CT:

  • Suitable for calcification.

  • Detection of local extension.

  • Orbital/intracranial extension.

  • Lesion with high attenuation.

  • Bilateral/ unilateral findings noted.

• MRI:

  • Useful for post-therapy assessment.

  • More detail of optic nerve and intracranial spread.

• Types of RB

  • Endophytic type.-Anterior tumor growth into the vitreous cavity.

  • Exophytic type.-Into the sub retinal space with secondary retinal detachment

  • Diffuse-Growth along the retina as a placoid mass

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Differentials

Causes of leukocoria include:

• Retinoblastoma.

• Congenital cataract.

• Persistent fetal vasculature (PHPV/PFV).

• Retinal detachment.

• Coats disease.

• Retinopathy of prematurity.

• Chorioretinal coloboma.

• Vitreous hemorrhage.

• Endophthalmitis / severe intraocular infection.

• Toxocariasis and other inflammatory scars.

• Ocular toxoplasmosis or chorioretinal scars.

• Advanced familial exudative vitreoretinopathy.

• Medulloepithelioma and other rare intraocular tumors.