Matrix metalloproteinases (MMP) play a role in a wide range of tumorigenesis, including early carcinogenesis events, tumor growth and tumor invasion and metastasis. Given that the ability of tumor cells to infiltrate and disseminate widely is what makes the tumors malignant, a role of MMP in cell migration during this invasive and metastatic process is important. There are two types of cancer cell migration: single cell locomotion and cohort migration (cell movement en mass keeping cell-cell contact, which is frequently seen in better differentiated carcinomas). Cell surface localization and activation of MMP is essential for cells to migrate, through rearrangement of extracellular matrix (ECM) to suit cell migration. Certain MMP, such as gelatinases and membrane -type 1 MMP, have special mechanisms to localize at leading edges in both types of cell migration. Moreover, in cohort migration, expression of these MMP is regulated via cell-cell contact within migrating cell sheets and confined to the foremost pathfinder cells of the migrating cell sheets. New roles of cell surface MMP, such as cleavage of cell surface receptors or cofactors involved in cell-ECM interactions during cell migration, are also discussed.

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EMMPRIN (extracellular matrix metalloproteinase inducer), also called CD147, basigin or M6 in the human, is a member of the immunoglobulin superfamily that is present on the surface of tumor cells and stimulates adjacent fibroblasts to produce matrix metalloproteinases (MMPs). In our study, we investigated expression of EMMPRIN in human normal brain and gliomas, since mouse basigin and chicken HT7, the species homologues of human EMMPRIN, are associated with neuronal interactions and normal blood‐brain barrier function, respectively. EMMPRIN expression was detected in all samples of non‐neoplastic brain and glioma tissues examined. However, expression levels of EMMPRIN mRNA and protein were significantly higher in gliomas than in non‐neoplastic brain. Moreover, levels of mRNA expression and immunohistochemical staining correlated with tumor progression in gliomas: They were highest in the most malignant form of glioma, glioblastoma multiforme, followed by anaplastic astrocytoma and then low‐grade astrocytoma. Also, immunolocalization revealed quite different distributions in non‐neoplastic brain and glioma: EMMPRIN was demonstrated only in vascular endothelium in non‐neoplastic regions of the brain, whereas it was present in tumor cells but not in proliferating blood vessels in malignant gliomas. These data indicate that an MMP inducer molecule EMMPRIN is differently expressed in human normal brain and gliomas and could be associated with astrocytoma progression. Possible mechanisms whereby glioma cell EMMPRIN could influence tumor progression will be discussed. Int. J. Cancer 88:21–27, 2000. © 2000 Wiley‐Liss, Inc.

Complex tumors OF the glomus jugulare present a surgical challenge because of their difficult location, extreme vascularity, and involvement with multiple cranial nerves. Modern microneurosurgical and cranial base techniques have enabled safe total removal of these complicated tumors. We describe a one-stage transjugular posterior infratemporal fossa approach for radical resection of glomus jugulare tumors located around the jugular foramen, the lower clivus, and the high cervical region from an anterolateral direction. This approach is a combination of transmastoid, suprajugular, transjugular, extreme lateral infrajugular transcondylar transtubercular, and high cervical approaches. Total exposure of the jugular foramen can be achieved, and multidirectional approaches can be performed, including infralabyrinthine/suprajugular, retrosigmoid/transcondylar/infrajugular, and transjugular exposures. Exposure of the vertical C7 segment of the infratemporal internal carotid artery and the lower clivus can be performed without permanent rerouting of the facial nerve. The details of this approach are described and illustrated in a stepwise fashion, and the microsurgical anatomy is reviewed.

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BACKGROUND AND PURPOSE:The stiffness of intracranial tumors affects the outcome of tumor removal. We evaluated the stiffness of 4 common intracranial tumors by using MR elastography and tested whether MR elastography had the potential to discriminate firm tumors preoperatively.

A dvAnces in microsurgical techniques and cranial base approaches have allowed access to areas of the brain once considered inaccessible. Despite these advances, however, the microsurgical resection of jugular foramen schwannomas continues to pose a formidable challenge. Fewer than 200 cases of schwannomas arising from the jugular foramen have been reported in the literature, a testament to the rarity of this tumor. 25,29,41,53,59,65,71,74 Experience has shown that the traditional suboccipital and transmastoid approaches do not provide adequate exposure of these lesions. Understanding and utilizing advanced skull base surgery techniques and concepts is essential for adequate resection of these tumors with CN preservation. We review the senior author's experience (T.F.) in the management of 53 jugular foramen schwannomas and propose a modified grading scheme to guide operative planning for these tumors. MethodsWe retrospectively reviewed all cases of jugular foramen schwannomas treated by the senior author Object. Due to the proximity and involvement of critical neurovascular structures, the resection of jugular foramen schwannomas can pose a formidable challenge. The authors review their experience in the microsurgical management of jugular foramen schwannomas and propose a modified grading scale to guide surgical management.Methods. All jugular foramen schwannoma cases treated by the senior author (T.F.) between 1980 and 2004 were retrospectively reviewed. The average age at presentation, surgical approach, tumor characteristics, cranial nerve (CN) deficits, and tumor recurrence rates were assessed. The authors present the following modified grading scale: Type A, intradural tumors; Type B, dumbbell-shaped tumors; and Type C, triple dumbbell tumors with a high cervical extension.Results. The authors treated jugular foramen tumors in 129 patients during the study period. Of these, 53 patients (41%) had jugular foramen schwannomas. The mean patient age was 52 years (range 14-74 years); there were 12 male and 41 female patients. The mean follow-up period was 8.4 years. Patients presented most commonly with deficits of the vagus nerve, followed by vestibular/cochlear nerve and glossopharyngeal nerve deficits. Gross-total resection of the tumor was achieved in 48 patients (90.5%). New postoperative paresis in a previously normal CN was not seen; however, worsening of preoperative CN deficits was frequently noted. The highest incidence occurred with the glossopharyngeal and vagus nerves (30%), with 26% of the deficits being permanent. There were no deaths related to surgery in this series. Three patients (5.7%) experienced tumor recurrence.Conclusions. The microsurgical resection of jugular foramen schwannomas carries a risk of worsening preoperative CN deficits; however, these are often transient. Based on their experience, the authors have formulated a grading scale that predicts the optimal surgical approach to these lesions. Considerable technical training and microneuroanatomical knowledge of the region is requi...

Postoperative visual outcome is a major concern in transsphenoidal surgery (TSS). Intraoperative visual evoked potential (VEP) monitoring has been reported to have little usefulness in predicting postoperative visual outcome. To re-evaluate its usefulness, we adapted a high-power light-stimulating device with electroretinography (ERG) to ascertain retinal light stimulation. Intraoperative VEP monitoring was conducted in TSSs in 33 consecutive patients with sellar and parasellar tumors under total venous anesthesia. The detectability rates of N75, P100, and N135 were 94.0%, 85.0%, and 79.0%, respectively. The mean latencies and amplitudes of N75, P100, and N135 were 76.8 ± 6.4 msec and 4.6 ± 1.8 μV, 98.0 ± 8.6 msec and 5.0 ± 3.4 μV, and 122.1 ± 16.3 msec and 5.7 ± 2.8 μV, respectively. The amplitude was defined as the voltage difference from N75 to P100 or P100 to N135. The criterion for amplitude changes was defined as a > 50% increase or 50% decrease in amplitude compared to the control level. The surgeon was immediately alerted when the VEP changed beyond these thresholds, and the surgical manipulations were stopped until the VEP recovered. Among the 28 cases with evaluable VEP recordings, the VEP amplitudes were stable in 23 cases and transiently decreased in 4 cases. In these 4 cases, no postoperative vision deterioration was observed. One patient, whose VEP amplitude decreased without subsequent recovery, developed vision deterioration. Intraoperative VEP monitoring with ERG to ascertain retinal light stimulation by the new stimulus device was reliable and feasible in preserving visual function in patients undergoing TSS.