Trilateral retinoblastoma: clinical and radiologic progression.

OBJECTIVE: The purpose of this study was to assess the clinical and radiologic features of tumor progression in children with trilateral retinoblastoma.
MATERIALS AND METHODS: Clinical records of eight children with trilateral retinoblastoma were reviewed for the patient's age at the time of diagnosis of the ocular tumor, time interval from diagnosis of ocular retinoblastoma to discovery of the intracranial tumor, time interval from diagnosis of retinoblastoma to death, and time interval from diagnosis of the intracranial tumor to death. CT or MRI studies were reviewed for the appearance of the primary intracranial neoplasm, intracranial metastases, and spinal metastases.
RESULTS: The mean age of the patients at diagnosis of bilateral retinoblastoma was 4.5 months, and the mean age at diagnosis of the intracranial midline tumor was 26 months. The mean interval from the time of diagnosis of retinoblastoma to discovery of the intracranial tumor was 21.5 months. Two children had spinal leptomeningeal metastases at the time of discovery of the midline intracranial mass although no intracranial metastases were seen on imaging. In the other children, intracranial and spinal leptomeningeal metastases frequently developed within months of the diagnosis of retinoblastoma despite lack of progression in the midline intracranial lesion. Six children died of leptomeningeal spread of tumor. The mean interval from diagnosis of the ocular tumor to death was 46 months and from diagnosis of the intracranial tumor to death was 17 months. One child developed metastatic retinoblastoma in the ulna 10 years after the diagnosis of the intracranial tumor.
CONCLUSION: Children typically died of leptomeningeal tumor dissemination despite lack of progression in the midline intracranial mass. Effective treatment of trilateral retinoblastoma may require close evaluation of these children for leptomeningeal dissemination.