Meningeal melanocytoma. Report of a case and a historical comparison.

Meningeal melanocytomas are rare tumors of the central nervous system that are found almost exclusively in the posterior fossa and spinal cord and whose natural history is poorly defined. In this report, the authors review the clinical presentation, radiological appearance, operative findings, and histological features in two cases of meningeal melanocytoma: one cranial and one spinal. Two women, aged 21 and 30 years, were admitted to the hospital 60 years apart: the first because of progressive paraplegia and the second because of slowly progressive hearing loss. The first patient had an extradural tumor that was treated by laminectomy, subtotal resection, and postoperative radiotherapy in 1936. Her symptoms recurred 16 years later and she underwent reoperation of the residual tumor, which was found to have an intradural component. The authors' patient, who presented 60 years later, underwent plain and enhanced computerized tomography and magnetic resonance imaging that demonstrated a large posterior fossa lesion indicative of either an acoustic neuroma or a meningioma. She underwent posterior fossa decompression but only partial excision of the tumor could be accomplished because vigorous bleeding limited the extent of the resection. Surgery was followed by radiotherapy. The residual tumor enlarged despite these measures and required repeated resection 6 months later. At the second operation the tumor was much less vascular, perhaps reflecting the effects of radiotherapy, and was removed almost entirely. The patient died 6 months later from an anticoagulant-related cerebellar hemorrhage. In both cases the lesions were jet black, and histological examination revealed melanin-containing hypercellular tumors with rare mitotic figures. Meningeal melanocytomas are being diagnosed with increased frequency in parallel with improvements in neuroimaging and clarification of histological features. Clinical presentation of patients with these tumors typically occurs in their fifth decade and women are affected twice as often as men. The posterior fossa lesions can mimic acoustic neuromas and meningiomas in location and radiological appearance; however, the internal auditory canal is normal. In the spine, meningeal melanocytomas present with the clinical features of myeloradiculopathy. Diagnosis is made intraoperatively from the gross, jet-black appearance of the tumor and from histological examination. Vascularity, size, and location may render complete resection unfeasible. Because of the tumor's propensity to recur, radiotherapy has been recommended but its role remains to be elucidated.

Intracranial metrizamide following myelography.

Twenty patients were studied by cranial computed tomography within 24 hours of myelography with metrizamide (Amipaque) to determine the intracranial manifestations of the use of this nonionic water soluble contrast medium. The findings ranged from relative hypodensity of the white matter due to ventricular opacification and gray matter penetration of metrizamide, to apparent trans-ependymal migration of the contrast agent resulting in what we have termed "pseudohydrocephalus." Trans-ependymal migration in normal humans has not been previously described. We were unable to establish precise radiologic correlates with the neurologic complications which some of the patients developed.

Pulmonary embolism during operation.

A case of intra-operative pulmonary embolism is reported. Though this is evidently a rare occurrence, the diagnosis should be seriously considered when unexplained hypoxia occurs during operation. Appropriate investigation and treatment can then be initiated promptly.

Familial lumbar spinal stenosis with acute disc herniations. Case reports of four brothers.

The case histories are reported of four brothers with lumbosciatic syndrome due to acute disc herniations, and associated spinal stenosis. Hereditary factors, although not hitherto reported, may be implicated for these spinal lesions, as the parents had also undergone spinal operations previously.

Lumbo-sacral radiculopathy induced by radiation.

Two patients had lumbo-sacral radiculopathy following radiation treatment of cancer. Twenty previously reported cases were similar. The clinical picture is one of progressive motor and sensory loss in the legs, usually appearing within a year after radiation, but sometimes delayed up to several years. Experimental studies quoted indicate greater vulnerability of peripheral nerves to ionizing radiation than has been previously recognized. Lumbo-sacral radiculopathy is readily produced in the experimental animal (rat) and affords an experimental model closely resembling the human cases reported.

Decadron in the treatment of cerebral abscess. An experimental study.

Forty rabbits were inoculated with Streptococcus pyogenes or Staphylococcus aureus to produce cerebral abscesses. One-third of the rabbits received no treatment and served as controls. One-third received dexamethasone (Decadron) plus an appropriate antibiotic. One-third received only the appropriate antibiotic in the same dosage. The animals were sacrificed 10 days after inoculation and the brains examined. In the control group, an abscess at the stage of granulation tissue encapsulation containing the inoculated organisms was found. The surrounding brain showed a marked inflammatory response. In the Decadron plus antibiotic group, necrotic lesions were found containing the inoculated organisms and surrounded by relatively normal brain. In the group treated with antibiotic alone, healed glial scars were found in relatively normal brain. Our findings are discussed with reference to the medical literature regarding the influence of glucocorticoids on the inflammatory response and the efficacy of antibiotics when this response is suppressed.