We report the pathology and outcome of secondary skull base tumors in patients previously
treated with external beam radiation for retinoblastoma (Rb). Rb patients are at increased
risk of second head and neck primary malignancies due to early radiation exposure
during treatment and loss of RB1 protein in genetic carriers. An institutional database was reviewed for patients
with retinoblastoma who had previously received radiation therapy and subsequently
developed skull base tumors. Seventeen patients met the selection criteria. The median
age of Rb diagnosis was 12 months. Thirteen cases underwent enucleation in addition
to radiation therapy as part of initial Rb treatment. A median of 19 years elapsed
between the diagnosis of Rb and diagnosis of skull base malignancy. The most common
tumors were osteogenic sarcoma (39%) and leiomyosarcoma (22%). Eleven (71%) patients
received postoperative chemotherapy, and 7 (41%) received postoperative radiotherapy.
Three (24%) patients underwent salvage surgery for recurrent disease. Five-year survival
was 68%, and 10-year survival was 51% by Kaplan-Meier analysis. Secondary malignancy
in Rb patients is a well-defined event. The use of surgery with appropriate adjuvant
therapy was associated with a 51% 10-year survival in this study population.
Skull base neoplasms - retinoblastoma - neoplasms - second primary - radiotherapy
