Post-irradiation polyradiculopathy mimics leptomeningeal tumor on MRI.

Three patients with a remote history of Hodgkin's disease treated with total or subtotal lymphoid radiation 17 to 24 years earlier developed lumbosacral polyradiculopathy associated with nodular meningeal enhancement of the conus medullaris and cauda equina on MRI. None had evidence of recurrent Hodgkin's disease or second malignancy, and the MRI findings may be sequelae of radiation therapy.