Search

Malignant brain tumours are one of the most relevant causes of morbidity and mortality across a wide range of individuals. Malignant glioma is the most common intra axial tumor in the adult. Many researches on this theme brought advances in the knowledge of gliomas biology and pathogenesis and to the development of new agents for targeted molecular therapy. Recent studies focused on either tumor metabolism analysis or epigenetic regulation in the pathogenesis or maintenance of brain tumors. This Review summarizes these developments analyzing molecular pathology and possible further developments for targeted therapies.

The transsphenoidal approach has specific indications in the management of craniopharyngiomas. Usually, it is best reserved for patients with preferably cystic extra-arachnoid-infradiaphragmatic tumors with small suprasellar extension. Moreover, it is definitely less traumatic than transcranial approaches and it has been proven to be feasible also in paediatric patients. When possible, radical removal of these tumours must be the goal of surgery, but this attitude, which reduces but not eliminates the risk of relapse, has to be counterbalanced by heavy morbidity and even mortality, especially in children. In this view, many neurosurgeons favour a more 'conservative' approach with subtotal removal followed by radiotherapy whose dramatic efficacy on craniopharyngiomas is well known. With these premises, a transsphenoidal approach is realistically applicable to a greater number of large cystic craniopharyngiomas if the aim is not radical removal, but is to drain them into the sphenoid sinus to relieve mass effect symptoms (cystosphenoidostomy), and delay radiotherapy and its detrimental effects on visual and pituitary function, especially in younger patients, to a more suitable time after surgery.

To examine the reliability of the diagnoses reached on multiple small fragments of cerebral glial tumors obtained via stereotactic biopsy, samples obtained from 100 consecutive glial tumors (during real or simulated biopsy) were studied by cytology and histology. In comparison to the definitive diagnosis made on the whole tumor, a correct positive diagnosis on the biopsy sample was made by histology in 96% of cases and by cytology in 93% of the cases (with 96% correct results when combining both methods). A correct identification of the tumor type and grade was achieved by histology in 82% of cases and by cytology in 80% of the cases (with 85% correct results when combining both methods). The limits of stereotactic biopsy are related to the difficulty of identifying all of the typical tumor features on tiny tissue fragments of a pleomorphic neoplasm, such as a glioma. This study demonstrates that better results may be obtained by using both cytology and histology to study multiple stereotactic biopsy samples from glial tumors.

Chronic radiofrequency stimulation of the gasserian ganglion by a percutaneous electrode is a new method for treating facial pain. The authors report their simplified technique to bring the distal end of the electrode from the cheek to the neck.

The authors report three cases in Italian children of congenital dermoid cyst at the anterior fontanelle. These are the first case reports in Europeans. Their rarity, however, is probably only apparent, since the latest reports in the literature show their wide-spread incidence. The anatomo-clinical and radiological findings and the surgical features of the three cases are described and the main pathological aspects of these cases are briefly discussed.

Four cases of large paramedian hourglass epidermoid tumors extending both in the middle and posterior cranial fossa are reported and other 16 cases from the literature are reviewed. The length of the clinical history and the triviality of neurological symptoms in spite of the size of the tumor are emphasized. CT scanning well documents the extension of these epidermoids and usually consents to differentiate them from the arachnoid cysts. The subtemporal transtentorial approach is more advisable, although a two-stage operation by subtemporal and suboccipital route can be necessary in some cases. Nevertheless the difficulties and the risk of the surgical treatment make very hard the complete removal of the tumor in most cases.

Here we characterize the intracellular effectors of the antiproliferative activity of somatostatin in glioma cell lines and post-surgical specimens. The responsiveness to somatostatin correlated with the expression of the phosphotyrosine phosphatase DEP-1/PTPeta, identified in C6 and U87MG cells, in which somatostatin inhibited cell growth. The expression of a dominant negative mutant of DEP-1/PTPeta in C6 cells abolished somatostatin effects, confirming the involvement of this phosphotyrosine phosphatase in such effects. Somatostatin treatment increased the activity of DEP-1/PTPeta and inhibited ERK1/2 activation. Conversely, basic fibroblast growth factor-dependent MEK phosphorylation was not affected, suggesting a direct effect on ERK1/2. In vitro experiments showed that PTPeta was able to interact and dephosphorylate ERK1/2 activated by basic fibroblast growth factor. Furthermore, by transfecting PTPeta in the somatostatin-unresponsive, DEP-1/PTPeta-deficient U373MG cells, the somatostatin-dependent control of cell proliferation was recovered. Finally we evaluated the requirement for DEP-1/PTPeta in somatostatin inhibition of cell proliferation in post-surgical specimens derived from different grade human gliomas. Although all of the glioma analyzed expressed somatostatin receptor mRNA, DEP-1/PTPeta expression was limited to 8 of 22 of the tumors. Culturing seven gliomas, a correlation between the expression of DEP-1/PTPeta and the somatostatin antiproliferative effects was identified. In conclusion we propose that the expression and activation of DEP-1/PTPeta is required for somatostatin inhibition of glioma proliferation.

Somatostatin (SST) controls the proliferation of a variety of cell types. Its effects are mediated by five G protein-coupled receptors (SSTR1-SSTR5), variably expressed in normal and cancer tissues. SST inhibition of cell proliferation can be exploited by both direct and indirect mechanisms: the main direct pathway involves the modulation of phosphotyrosine phosphatase (PTP) activity. Here we show that SST cytostatic activity is mediated by the activation of a receptor-like PTP, named PTPeta. The role of this PTP in the antiproliferative activity of SST in five glioma cell lines (C6, U87MG, U373MG, DBTRG05MG, and CAS1) and in four postsurgical human glioblastoma specimens, has been studied. SST inhibited growth only in C6 and U87MG that express PTPeta. In C6 cells, SST antiproliferative effects were reverted by pretreatment with pertussis toxin and vanadate, indicating the involvement of G proteins and PTPs. The role of PTPeta in the SST inhibitory effects was demonstrated by testing the PTPeta activity: it was increased by SST treatment and paralleled by inhibition of ERK1/2 activation. Since basic fibroblast growth factor-dependent MEK phosphorylation was not affected by SST, we propose a direct effect of SST-activated PTPeta on ERK1/2 phosphorylation. Finally, the SSTR mRNAs were identified in all of the 36 gliomas analyzed, whereas PTPeta expression was found in 33% of cases. Culturing four gliomas, a precise correlation between the expression of PTPeta and the SST antiproliferative effects was identified. In conclusion, in glioma cells, SST antiproliferative activity requires the expression and activation of PTPeta, which directly dephosphorylates ERK1/2.

Background Hemangiomas are benign vascular tumors. Because less than 1% of all hemangiomas are intramuscular, only 8 cases of temporal muscle hemangioma have been described to date. This is a case study of a 13-year-old girl who was referred to our institution because of a soft swelling located in the left temple that has enlarged progressively since birth. Methods CT scan, angiography and MRI showed a tumor mass lying in the temporal muscle, with homogeneous contrast enhancement. No tumor blush or feeding arteries were detected. At surgical exploration, the tumor appeared to be well demarcated. It was totally excised, sparing the surrounding temporal muscle, which did not present any sign of infiltration. Histopathologic examination showed the lesion to be a cavernous hemangioma. Results The cosmetic result was excellent, and MRI after 1 month and 2 years showed complete absence of the lesion and no evidence of recurrence. Conclusions Although this type of tumor may be treated by various methods surgical excision yields the best results in the short and the long term. The surrounding tissue is spared as much as possible when no signs of infiltration are noted at operation, especially when involving small and functionally important muscles, as in our case. HEAD & NECK 1996;18:197–200 © 1996 John Wiley & Sons, Inc.

The effects of a chronic treatment with octreotide were evaluated in 19 patients affected with functionless pituitary adenomas. Octreotide caused a significant decrease of GH and IGF-I levels in all the patients and no significant change in thyroid, adrenal and gonadal function. In contrast, during the therapy, the glucose response to an oral glucose tolerance test considerably increased and was delayed, while the insulin response decreased and was delayed. Serum alpha-subunit (alpha-SU) was above normal in 10 of 16 patients in which this evaluation was performed: octreotide caused a significant decrease (p < 0.01) of alpha-SU levels in 6 of these 10 patients. Octreotide did not induce any significant change in visual fields except in 1 patient, who had a great improvement of visual perimetry and a decrease of alpha-SU levels but unmodified CT scan features. In our series of patients, octreotide was ineffective in reducing tumor mass. The efficacy of octreotide might rely on the presence of somatostatin receptors on adenoma-cell membranes. Therefore patients with functionless adenomas to be treated with octreotide might be identified with pituitary scintiscan using the recently available labeled 111In-octreotide.

Even though the main problems of transsphenoidal surgery are encountered during the intra- and suprasellar portions of the operation, proper reconstruction of the sella turcica plays an important role in the overall results, greatly influencing the final outcome. Improper measures may bring about a complicated postoperative course, whereas a wise and precise method allows one to control any surgical condition, preventing the more dangerous consequences of the transsphenoidal approach (i.e., empty sella, cerebrospinal fluid leakage, hemorrhage, infection, etc.). The authors review the different methods of sellar plugging and, on the basis of their own experience, indicate the most suitable one for each of the more usual situations. A good result is achievable if only natural materials are used and one avoids synthetic prostheses. Extradural packing is the technique of choice whenever a hermetic closure and a particularly effective intrasellar plug are required.

End to side microsurgical anastomoses between vessels of small calibre require interruption of blood flow of about 25-40 min. In terminal vascular beds this time may be incompatible with the cellular survival. The authors refer their experience in rats with a partly original experimental technique requiring less time of clamping the receiving vessel (about 3-4 min), as the main part of the anastomosis is performed between the wall of the donor vessel and the adventitia of the receiving vessel, without interruption of blood flow in this latter. Histological examinations, performed 21 days later, reveal a patency rate of 60%.

Four cases of benign intrasellar cysts are reported. Three of these were treated surgically. Their origin and typical clinical features are discussed, in particular the altered pituitary function and visual disturbances. Computerized tomography has many advantages over traditional neuroradiological tools in reaching a diagnosis. The indication for active treatment and the surgical techniques and the methods used in the prevention of complications are outlined.

Surgery of the intervertebral disc, despite its relative simplicity, has a high failure rate at the functional level. There is often severe residual pain which is a real problem because it is so difficult to treat either the symptom or its cause. We report the results of 122 procedures in 100 patients, some of whom had multiple lesions, using a technique (already described in a preliminary paper) consisting of an interlaminar approach modified to provide greater preservations of neural, bony and joint structures. The results were very good, both soon after operation and at later follow-up (between six months and five years). There were no cases of recurrence or pseudo-recurrence, one case of contralateral recurrence (cured by further operation) and a very low incidence of residual backache. These results confirm that, provided the patients have been well selected so that not every patient with lumbar backache is operated on but only those with proven disc lesions, operation does fundamentally influence the quality of the results.