Diffuse Infiltrating Retinoblastoma
- Retinoblastoma (RB) is a malignant tumor of the embryonic neural retina that usually affects children under 5 years (about 98% of the cases).
- The most typical symptoms at presentation are leukocoria and strabismus. However, in some cases, especially in older children, there may be atypical signs, such as visual disturbance, uveitis, endophthalmitis, anterior chamber and vitreous hemorrhages, orbital inflammation, hyphema, heterochromia, secondary glaucoma, and proptosis.
- Key Diagnostic Features:
- Diffuse infiltrating retinoblastomas represents 1.4% of all RBs. This form usually presents unilaterally in boys (male:female rate of 1.8:1.0) at a more advanced age (around 6 years old). There are some special clinical and imaging characteristics: while pseudohypopyon is relatively commom in this form (59% of the cases), leukokoria is rare (24% versus 63% in the classic form), and calcifications are usually absent in this form of the disease.
- DDx:
- Coats disease
- Rx: Because of this RB subtype is usually unilateral, has extensive retinal infiltration, and has a high frequency of vitreous dissemination, enucleation is the treatment of choice. Adjuvant chemotherapy depends on histopathologic risk factors. This RB subtype has a better prognosis than typical RB, despite the frequently delayed diagnosis.
