De Novo RB1 Germline Variant in Retinoblastoma with Two Subsequent Independent Neoplasms: Case Report and Literature Review.

Variants in the gene are associated with retinoblastoma (RB) development, and their presence in germline cells considerably increases the risk of subsequent malignant neoplasms (SMNs) in RB survivors. We report a female patient with bilateral RB who developed two SMNs in less than ten years, with a de novo pathogenic nonsense variant in [NM_000321.3:c.306T>A, p.(Cys102*)] in heterozygosity. The updated literature review of similar cases of SMN in patients with a previous diagnosis of RB reveals a wide range in both the type of subsequent malignancy and the age at which these SMNs develop. In addition, we identified only three cases with two SMNs following RB diagnosis, with at least one of these being an EWS. This case broadens the clinical and genetic landscape of RB, demonstrates the importance of a multidisciplinary approach in these patients, and highlights genetic diagnosis as a mandatory feature for management.