Diffuse anterior retinoblastoma: A review

Diffuse anterior retinoblastoma is a rare variant of diffuse infiltrating retinoblastoma which occurs in up to 1-2% of cases of retinoblastoma. In diffuse anterior retinoblastoma there is a small focus of tumor in the peripheral retina from which free tumor cells enter the aqueous humor and implant on the ciliary body, iris, lens and trabecular meshwork. Patients most commonly present with pseudouveitis, pseudohypopyon and increased intraocular pressure. The differential diagnosis is broad and all of the reported cases relied upon aspirates from the aqueous humor in order to make the diagnosis prior to proceeding with treatment. Treatment involves enucleation and, depending upon the extent of the tumor, may require systemic chemotherapy or external beam radiation. This review summarizes the 7 previously reported cases of diffuse anterior retinoblastoma, discusses pathologic features, and addresses the challenges of early diagnosis and future directions.