From a Suspicious Cystic Pineal Gland to Pineoblastoma in a Patient with Familial Unilateral Retinoblastoma

Patients with hereditary retinoblastoma (Rb) have an increased risk of developing pineoblastoma.1 Unfortunately, most patients with concurrent pineoblastoma do not survive; Kivelä2 has shown that only patients who were diagnosed by screening and had a tumor smaller than 15 mm had a chance of survival. However, not all pineal lesions found with screening at the time of retinoblastoma diagnosis are pineoblastomas. Pineal cysts are a relatively common finding in the general population. In children up to 5 years of age the prevalence of pineal cysts diagnosed with magnetic resonance imaging (MRI) is 2.0%.3 Potentially, about 50% of pineoblastomas can be found at baseline screening and another 25% during the first year after Rb diagnosis.2 Therefore, baseline screening of the brain in newly diagnosed retinoblastoma is currently advised in imaging guidelines.4 In a recent study Rodjan and colleagues5 showed that the majority of pineoblastomas in Rb patients had a cystic appearance. Consequently baseline brain imaging with extended follow-up of pineal cysts might help early detection of pineoblastoma. We present a rare case of unilateral familial retinoblastoma and a suspicious cystic pineal gland on brain MR imaging that progressed into a pineoblastoma.