Rare case of trilateral retinoblastoma with spinal canal drop metastasis detected with fluorine-18 fluorodeoxyglucose positronemission tomography/computed tomography imaging
A 10-year-old boy presented with a right eye proptosis and leukocoria. He underwent magnetic resonance imaging (MRI) which showed right orbital mass lesion infiltrating optic nerve, and diagnosis of retinoblastoma was made. He was referred for fluorodeoxyglucose (FDG) PET/CT to find out the extent of the disease. Whole body contrast enhanced PET/CT [] showed abnormal FDG-uptake within right orbital mass lesion [] and suprasellar region [], sagittal fused-PET/CT showing enhancing lesion in the cervical spinal canal level [, arrows]. He was diagnosed as a case of TRb with spinal drop metastasis. He underwent chemotherapy and craniospinal irradiation.