A 16-year-old female developed sarcoma in the anterior skull base approximately 15 years after irradiation for bilateral retinoblastoma.
At the age of 1.5 years, the right eye of this patient was enucleated and she received 6300 rails through two portals for retinoblastoma. When she was three years old, her left eye was enucleated because of retinobalstoma, and cobalt 60 was implanted in her left orbit.
The patient remained disease-free for 15 years until a mass developed on the right side of her nose. Computed tomography scans demonstrated a tumor involving the ethmoidal sinuses, nasal cavities and epipharyngeal space. She underwent anterior craniofacial resection through a frontal craniotomy and complete rhinotomy. The tumor was removed totally and diagnosed histopathologically as sarcoma.
The association between bilateral retinoblastoma and the development of secondary, nonocular tumors has been emphasized in recent years. This association is thought to occur as a consequence of irradiation therapy. Recently, molecular genetic techniques have made great progress and the retinoblastoma gene (RB) has been isolated as a human tumor suppressor gene. Secondary tumors have been shown to lose RB function. Patients with bilateral retinoblastoma always have an abnormal gene.
After irradiation treatment for bilateral retinoblastoma, it is advisable to pay attention to the possibility of a secondary malignant tumor which can be radiation-induced and hereditary.
