George S. Davidson

Meningeal tumors of childhood

Meningeal tumors occurring in a pediatric hospital over a period of 18 years were studied. The incidence of meningeal sarcomas was much lower than has been previously reported. A histologic subtype of meningiomas was found which has not previously been described. In these “sclerosing” tumors only a small portion of the lesion contained viable cells, most of which bore little resemblance to conventional meningothelial cells. The bulk of the lesions consisted of whorling collagen bundles produced by the tumor. All cases in which there was tumor invasion of the brain fell into this category. The prognosis for the sclerosing meningiomas was similar to conventional meningiomas, casting doubt on the value of brain invasion as a marker of malignancy in childhood meningiomas. The recognition of this histologic type may aid diagnosis, guide surgical management, and possibly make postoperative radiotherapy unnecessary.

Transependymal Benign Dorsally Exophytic Brain Stem Gliomas in Childhood: Diagnosis and Treatment Recommendations

Sixteen children with dorsally exophytic transependymal benign brain stem gliomas were treated at the Hospital for Sick Children, Toronto, between 1949 and 1985. The diagnosis of these benign brain stem gliomas was based on neuroradiographic and operative observations. Five children were diagnosed in the pre-computed tomography (CT) era using ventriculography and pneumoencephalography, and 11 children were diagnosed using CT with and without contrast enhancement. Histological diagnosis was obtained in all 16 cases. In 1980, we first described this distinct group of benign brain stem gliomas, which accounted for 8% (total, 121 cases) of all brain stem gliomas diagnosed at our institution. However, with the use of high resolution CT in recent years, earlier and better definition of this particular type of brain stem tumor can be made. During the 10 years (1976 to 1985) in which CT has been used for preoperative evaluation in our institution, we have treated 49 patients with primary brain stem tumors. Eleven of these cases (22%) fell into the category of dorsally exophytic transependymal benign brain stem tumors. These tumors characteristically protrude into and largely fill the 4th ventricle, breaking through the overlying ependyma and frequently extending into the cisterna magna. On CT, they are isodense and enhance brightly with contrast agent. Clinically, these patients have a longer history of symptoms in comparison with patients with the more malignant, intrinsic types of brain stem tumor. All of our patients were treated by subtotal resection. Radiotherapy was utilized in 7 of the 16 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Amyloid destructive spondyloarthropathy causing cord compression: related to chronic renal failure and dialysis.

Destructive spondyloarthropathy is a recently recognized disease that has not been reported in the neurosurgical literature. It is associated with spinal amyloid deposition in long-term renal failure and dialysis, and it occurs increasingly as the number of dialysis patients and their survival times increase. Clinically, there is a multisegmental and often rapidly progressive radiculomyelopathy that may require emergency stabilization. The radiological features are disc space narrowing with erosion of vertebral end plates and subarticular cysts. The pathological features include deposition of amyloid, which stains with Congo Red and antibodies to beta-2-microglobulin. We present two cases with clinical, radiological, and pathological features and a review of the literature.

Intracranial arterial occlusion associated with high-activity iodine-125 brachytherapy for glioblastoma.

SummaryWe describe two patients who developed devastating strokes due to intracranial arterial occlusion 15 weeks and 97 weeks following high dose stereotactic iodine-125 brachytherapy for glioblastoma multiforme. In both cases the occlusion was within the implant volume at points receiving 110–281 Gy and there was no other evidence of significant atherosclerosis in the patients. We therefore conclude that these complications were a direct result of the brachytherapy. The phenomenon of radiation-induced occlusion of large cerebral arteries is reviewed.

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.