Mark B. Eisenberg

Benign nonmeningeal tumors of the cavernous sinus

OBJECTIVEnResection of benign cavernous sinus tumors with minimum morbidity and mortality is increasingly more common. Although meningiomas have dominated most discussions, numerous nonmeningeal tumors also deserve attention because they are generally more amenable to radical surgical resection.nnnMETHODSnWe reviewed the records of 40 patients (19 female and 21 male patients) who were treated surgically during a 15-year period for benign, nonmeningeal tumors of the cavernous sinus. Invasive pituitary adenomas (14 cases) and trigeminal schwannomas (13 cases) comprised the majority of tumors; the remaining tumor types were hemangioma, neurofibroma, juvenile angiofibroma, dermoid tumor, giant cell tumor, chondromyxofibroma, and chondroma. Patient age ranged from 7 to 65 years (mean, 37 yr).nnnRESULTSnAll patients underwent surgery, the intent being total resection. Total resection was achieved in 33 (82.5%) of the 40 patients. Follow-up was achieved via a combination of direct patient visit or phone interview or via the referring physician. Eight patients had undergone previous surgery elsewhere, which correlated closely with complications and neurophthalmological outcomes but did not affect resectability. Postoperatively, 89.7% of the patients had either stable or improved extraocular muscle function compared with their preoperative statuses. Forty percent of the patients experienced improvement of their preoperative extraocular muscle deficits. Complications included cerebrospinal fluid leak (three cases), postoperative hemorrhage (one case), fat embolism (one case), perforator distribution infarct (one case), hydrocephalus requiring ventriculoperitoneal shunting (two cases), transient hemiparesis (one case), and diabetes insipidus (one case).nnnCONCLUSIONnWe conclude that benign nonmeningeal tumors of the cavernous sinus can be safely and radically removed and result in good long-term neuro-ophthalmological function and low morbidity and mortality. Furthermore, when compared with our previously reported results for cavernous sinus meningiomas, benign nonmeningeal tumors of the cavernous sinus carry a better chance of total removal, a lower incidence of postoperative ocular dysfunction, and a higher rate of recovery of preoperative cranial nerve deficits.

Loss of heterozygosity in the retinoblastoma tumor suppressor gene in skull base chordomas and chondrosarcomas

BACKGROUNDnThe retinoblastoma (Rb) gene is a well characterized tumor suppressor gene in which loss of heterozygosity has been implicated in a number of malignancies including osteosarcoma and breast carcinoma. Chordomas and chondrosarcomas are rare skull base neoplasms with a propensity for local recurrences, resistance to conventional radiotherapy, and a 5%-30% incidence of metastases. Except for the so called chondroid chordoma, histologic features do not correlate with the clinical behavior or growth patterns of these tumors. No study to date has investigated what role tumor suppressor genes or oncogenes play in the development and continued growth of these rare neoplasms.nnnMETHODSnIn order to evaluate the role of the retinoblastoma tumor suppressor gene in chordomas and chondrosarcomas we screened seven chordomas and two chondrosarcomas located at the skull base for loss of heterozygosity (LOH) of the Rb gene. Genomic DNA was extracted from tumor specimens as well as matched control tissue and utilizing a polymerase chain reaction technique, intron 17 and 20 were amplified from each specimen. The intron 17 product was then digested with the restriction endonuclease X ba1 followed by electrophoresis on a 1% agrose gel. The intron 20 amplified products were electrophoresed on a nondenaturing 6% polyacrylamide gel.nnnRESULTSnWe demonstrated LOH at intron 17 of the retinoblastoma gene in 2/7 chordomas and in 0/2 chondrosarcomas. The two chordomas possessing LOH were particularly aggressive tumors demonstrating extensive involvement of the skull base and rapid recurrences following radical resections.nnnCONCLUSIONSnAlterations of the Rb gene may play a role in the growth of skull base chordomas with LOH of the Rb gene serving as a marker for more aggressive tumors. This report represents the first study evaluating the Rb gene in chordomas or chondrosarcomas and is the first report of allelic loss of the Rb gene in skull base chordomas.

Management of the Vertebral Artery in Excision of Extradural Tumors of the Cervical Spine Technique and Application: 106

ABSTRACT: EXTRADURAL TUMORS OF the cervical spine may involve the vertebral artery on one or both sides, posing one of the limiting factors toward the radical resection of such neoplasms. A standard anterior approach may be inadequate for the management of such tumors. An anterolateral approach allows the dissection and mobilization of the vessel, which can then be preserved, resected, or reconstructed with a vein graft. An anterior approach can be supplemented with this for tumor resection and stabilization. This management strategy is described in 10 patients with a variety of tumors.

The Application of Modern Skull Base Techniques to Routine Neurosurgical Problems

Learning Objectives: After reading this article, the participant should be able to:Recall the philosophy behind skull base approaches.Describe the core skull base approaches.Identify the different techniques, including the cranio‐orbito‐zygomatic, petrosal, and transcondylar approaches.