Low-grade astrocytoma of the tectal region as an unusual cause of knee pain: case report.

A 12-year-old boy was investigated for knee pain and contractures, and was found to have an intraspinal tumor of a lumbar nerve root and a tumor in the tectal region, both low-grade astrocytomas. We postulated that the tectal region astrocytoma metastasized to the lumbar intraspinal region. After surgery, the child underwent focal irradiation to the posterior fossa supplemented by craniospinal irradiation and a boost dose to the region of the lumbar spinal tumor. A low-grade astrocytoma rarely presents as spinal metastasis. This case may represent the first of a primary tectal low-grade astrocytoma manifesting as a symptomatic spinal mass.