Evaluation of Gait Abnormalities in Patients with a History of Retinoblastoma

Background: The incidence of metastatic retinoblastoma (Rb) is rare, occurring in about 5% of Rb cases. This makes recognition and diagnosis of these patients challenging. The treatment outlook for metastatic Rb is less promising than that of primary malignancy. Current studies estimate 80-90% survival rates for patients having metastatic disease without central nervous system (CNS) involvement, and a mere 8% with CNS involvement. Case Information: Case #1: 6-year-old female with history of unilateral Rb that was ultimately treated with enucleation followed by chemotherapy. She presented to clinic seven weeks after completing treatment with complaint of new limp. Clinical exam was unremarkable, so no further evaluation was recommended. Symptoms progressed to include intermittent fevers and increasing low back pain. Two months after her limp began, a diagnosis of metastatic Rb with dissemination to bone was established. Case #2: 15-year-old male with history of bilateral Rb diagnosed and treated in infancy. He presented to an Emergency Department complaining of intense leg pain. Oncological workup was not recommended. Symptoms progressed to include intermittent fevers and worsening leg pain. Five months after the initial complaint, a diagnosis of metastatic Rb with dissemination to bone was established. Conclusion: The prognosis of metastatic retinoblastoma correlates highly with extent of dissemination. Therefore, early recognition and initiation of treatment is essential to enhance patient survival. These case presentations suggest that insidious onset of gait abnormalities in patients with history of Rb may be an early indicator of metastatic disease and warrants prompt evaluation.