J.-C. Marchal

Le xanthoastrocytome pléomorphe. À propos de cinq observations

Resume Objectifs de l’etude Les auteurs presentent une serie de 5 xanthoastrocytomes pleomorphes et analysent les aspects diagnostiques, histologiques et therapeutiques de cette tumeur rare qui affecte surtout l’enfant et l’adulte jeune. Methodes Il s’agit d’un travail retrospectif a partir de cinq patients (trois de sexe masculin et deux de sexe feminin), recenses entre 1985 et 1996. Resultats L’epilepsie est le signe clinique le plus souvent retrouve. La tumeur se situe au niveau temporo-parietal dans deux cas, parietal dans un cas, frontal dans un cas et au niveau de l’hypothalamus et du troisieme ventricule dans un dernier cas. A notre connaissance, nous decrivons le premier cas de xanthoastrocytome pleomorphe localise dans la region de l’hypothalamus/troisieme ventricule. Tous les patients ont ete operes : l’exerese a ete totale pour deux patients, subtotale pour deux autres et partielle dans un cas. Quatre patients ont beneficie d’une radiotherapie adjuvante (deux recidives et transformation maligne et deux diagnostics errones) (dose moyenne d’irradiation encephalique : 44,75 Gy). Deux patients ont ete traites par chimiotherapie adjuvante. Un patient a ete perdu de vue. Deux patients ont presente au moins une recidive. Deux patients sont decedes d’une transformation anaplasique de la tumeur. Deux patients sont actuellement en survie sans recidive a 12 et 16 ans du diagnostic avec une excellente qualite de vie (Glasgow Outcome Scale = I). Conclusion La chirurgie represente le traitement de choix de cette tumeur rare. Le pronostic reste tres favorable (en l’absence de transformation anaplasique), mais une surveillance clinique et iconographique sur le long terme reste indispensable.BACKGROUND AND PURPOSE We present a review of five patients who developed pleomorphic xanthoastrocytomas, presenting the clinical features, pathology findings and therapeutic approach of these rare tumours which almost always occur in children and young adults. METHODS This paper is a retrospective study of five patients (three males and two females), treated from 1985 to 1996. RESULTS Seizure was the most frequent symptom. The tumor was located in the temporal or temporo-parietal lobe in two patients, in the parietal lobe in one, the frontal in one and in hypothalamus and third ventricle in the final patient. To our knowledge, no case of pleomorphic xanthoastrocytoma located in the area of hypothalamus/third ventricle has been reported in the literature. All patients underwent surgery which was complete for two patients, subtotal for two others and partial for one. Four were given post-operative cerebral radiation therapy (two recurrences and malignant transformation and two erroneous diagnoses) (mean dose: 44.75 Gy), for two patients surgery was followed by chemotherapy. One patient was lost for follow-up. Two patients presented at least one tumor recurrence. Two died from malignant transformation. Two patients are alive without recurrence at 12 and 16 years from diagnosis with excellent quality-of-life (Glasgow Outcome Scale=I). CONCLUSION Surgery is the gold standard treatment. Prognosis is very good (except for malignant transformation), so that a close long-term clinical and radiological follow-up is mandatory.

Les astrocytomes pilocytiques du diencéphale de l’enfant: À propos de sept observations

BACKGROUND AND PURPOSE Pilocytic astrocytoma (PA) is a WHO grade I tumor of the central nervous system mostly arising in children and young adults. Management of diencephalic PA is a difficult challenge. Surgical treatment has to cope with both the difficulties of deep location and eloquent area tumors. MATERIALS AND METHODS We retrospectively reviewed seven pediatric cases (female: 4, male: 3) of diencephalic PA. Opto-chiasmatic tumors were excluded from the series. Mean age at diagnosis was 108 months (9 years) (range: 4 month-18 years), median age was 111 months. Median follow-up for the series was 125 months. Tumor locations were as followed: right thalamus: 2, both thalami: 1, hypothalamus: 3, and right basal ganglia: 1. At the onset, the first symptom was mostly raised intracranial pressure. The delay in diagnosis ranged from 48 hours up to 6 years. TREATMENT a shunting procedure was performed in 3 patients, a direct surgical approach in 5 patients (gross total removal: 2; partial removal: 3) and one patient had only a biopsy. Three children were re-operated. Three patients were treated by radiationtherapy (RT) after surgery. Chemotherapy was delivered for 4 children. RESULTS The overall survival rate was 71.4 months (almost 6 years) (range: 3-184 months). Median survival rate was 42 months (3.5 years). Three children died, two by tumor progression and one death related to late side-effects of RT. Four patients have a good quality of life with GOS I (n = 3) or II (n = 1). We observed tumor regression in two patients at 1 and 17 years after the beginning of treatment. Correct diagnosis was only made for two cases at the initial pathological examination. CONCLUSION The course of diencephalic PA is still unpredictable. The tumor can be controlled by a partial surgical removal, and a residual tumor can sometimes decrease in size after surgery. Gross total removal of these tumors, although difficult, may be performed. With cranial navigation systems, the risk is low. Pathological diagnosis is sometimes difficult to assess.

Statut de méthylation du promoteur du gène Rarb dans les tumeurs cérébrales gliales de bas et de haut grade: Comparaison avec le tissu sain

Resume Le recepteur aux acides retinoiques beta (RARs) est un recepteur nucleaire frequemment deregule en pathologie tumorale. Une etude immuno-histochimique a ete conduite pour etudier le niveau d’expression de ce recepteur dans les noyaux des cellules tumorales gliales (gliomes de bas et de haut grade) ainsi qu’une etude du statut de methylation du promoteur du gene codant ce recepteur sur les memes echantillons tumoraux. Une comparaison avec le tissu sain a ete effectuee. Quarante-huit tumeurs ont ete etudiees (15 glioblastomes, 20 oligodendrogliomes de grade III et 13 oligodendrogliomes de grade II). On retrouve une diminution constante de l’expression de RARs par comparaison avec le tissu sain, quel que soit le grade histologique de la tumeur, suggerant une deregulation de l’expression du gene codant RARs. La methylation du promoteur du gene codant RARs est, par contre, un evenement rare (12,5 % des cas), sauf pour les oligodendrogliomes de grade III (20 %), et n’est donc pas un evenement majeur dans l’origine de cette deregulation. D’autres causes de deregulation de RARs devraient etre recherchees comme la perte d’heterozygotie en 3p24, l’etude de l’ARNm et des interactions de RARs avec d’autres recepteurs aux retinoides.Retinoic acid receptor beta (RARbeta) is a nuclear receptor often deregulated in tumors. An immunohistochemical study was conducted to examine the level of expression of this receptor in the nucleus of glial cell tumors (low and high grade glioma) as well as a study of the methylation status of the gene promoter coding this receptor on the same tumor samples. A comparison with normal tissue was done each time. 48 tumors were eligible for the study (15 glioblastomas, 20 grade III oligodendrogliomas and 13 grade II oligodendrogliomas). A constant decrease of RARbeta expression was found by comparison with normal tissue whatever the histological grade of the tumor, suggesting a deregulation of RARbeta gene expression. Methylation of RARbeta promoter gene was a rare event (12.5% of all cases), except for grade III oligodendrogliomas (20%), and is thus not a major event of this gene deregulation. Other reasons of this deregulation of RARbeta should be studied, such as loss of 3p24 heterozygoty, mRNA studies and RARbeta interactions with other retinoid receptors.

Hémorragies sous-arachnoïdiennes par rupture anévrismale. Chirurgie ou embolisation ?☆

Traditionally the aneurysms of the circle of Willis have been an indication for neurosurgery. New technologies of endovascular treatment with electrically detachable coils resulted in a different therapeutical concept since four years. A series including 140 patients has been treated in our institution from 1 January 1992 to 31 December 1994, 94 of them presenting with a subarachnoid haemorrhage.Out of these 140 patients, 84 were treated with surgery, 51 with the endovascular technique, five with surgery after incomplete or unsuccessfull endovascular treatment. Surgery was indicated in patients presenting early after bleeding, devoid of vasospasm, with a favourable Hunt and Hess grading and in aneurysms located in the anterior part of the circle of Willis. Endovascular treatment was indicated in patients admitted with delay, with severe vasospasm, a poor Hunt and Hess grading and in all aneurysms of the vertebrobasilar arterial network. Age was of less importance in comparison to the status of the vessels for selection of the method of treatment. Giant aneurysms are difficult to treat as surgery is faced with the size of the aneurysm itself and endovascular technique with the width of the aneurysmal neck.