Retinoblastoma

Excerpt

Retinoblastoma is an uncommon type of malignancy occurring in 1 per 18000 childbirths, but it is the most commonly encountered primary intraocular malignancy of childhood and accounts for 3% cases of all childhood cancers. It is also the second most prevalent intraocular malignant tumor after uveal melanoma. In specialized care centers, survival rates are up to 95% with retention of vision in most cases, but it is lower in developing countries. Retinoblastoma is composed of retinoblasts (basophilic cells with hyperchromatic nuclei and scanty cytoplasm). Mostly retinoblastomas are undifferentiated, but different degrees of differentiation are present owing to the formation of structures known as rosettes. The tumor can be endophytic (in vitreous) and seeding of tumor cells throughout the eye, or it can be exophytic (in subretinal space), or it can demonstrate a mixed presentation. Optic nerve invasion can occur with the spread of tumor in subarachnoid space and into the brain. Metastatic spread occurs in regional lymph nodes, liver, lungs, bones, and brain.