Radiothérapie stéréotaxique des méningiomes intracrâniens

Radiotherapy of benign intracranial tumours

We present the updated recommendations of the French Society for Radiation Oncology on benign intracranial tumours. Most of them are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumours. Some grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumours are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumour, or a local relapse. Indications have to be discussed at a multidisciplinary panel, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumours, are commonly realized, to avoid as much a possible the occurrence of late side effects.

Intraventricular microcystic meningioma in a child: a case report

BACKGROUND

Microcystic meningiomas are extra axial masses that are extremely rare in the pediatric population. Intraventricular meningiomas are also rarely seen. CASE PRESENTATION: This case reports an 18-year-old boy who had an intraventricular mass on magnetic resonance imaging at the age of 12 years and had shown growth at a 6-year follow-up after subtotal resection. The mass was removed by total resection and pathological examination indicated microcystic meningioma.

CONCLUSION

The present case is the first pediatric intraventricular microcystic meningioma in the literature. We believe that this unique case presented with its radiological, pathological and clinical features will contribute to the literature.

Pediatric bypasses for aneurysms and skull base tumors: short- and long-term outcomes

OBJECT

Cerebral bypass is a useful microsurgical technique for the treatment of unclippable aneurysms and invasive skull base tumors. The authors present the largest reported series of cerebrovascular bypasses in the pediatric population. They describe the short- and long-term clinical and radiographic outcomes of extracranial-intracranial and local bypasses performed for complex cerebral aneurysms and recurrent, invasive, and malignant skull base tumors in pediatric patients.

METHODS

A consecutive series of 17 pediatric patients who underwent revascularization were analyzed retrospectively for indications, graft patency, and neurological outcomes.

RESULTS

The mean age was 12 years (median 11 years, range 4-17 years), and there were 7 boys (41%) and 10 girls (59%). A total of 18 bypasses were performed in 17 patients and included 10 aneurysm cases (55.5%) and 8 tumor cases (45%). Of these 18 bypasses, there were 11 (61.1%) extracranial-intracranial bypasses (10 saphenous vein grafts [90%] and 1 radial artery graft [10%]), 1 side-to-side anastomosis (5.5%), 2 intracranial reimplants (11.1%), and 4 interposition bypass grafts (22.2%; 2 radial artery grafts, 1 saphenous vein graft, and 1 lingual artery graft). The mean clinical follow-up was 40.5 months (median 24 months, range 3-197 months). The mean radiographic follow-up was 40 months (median 15 months, range 9-197 months). Eighty-two percent of patients (14 of 17) achieved a modified Rankin Scale score between 0 and 2; however, 2 patients died of disease progression during long-term follow-up. The short-term (0- to 3-month) graft patency rate was 100%. Two patients had graft stenosis (11.7%) and underwent graft revisions. Two patients (11.1%) with giant middle cerebral artery aneurysms (> 25 mm) had strokes postoperatively but recovered without a persistent neurological deficit. One patient observed for 197 months showed a stable dysplastic change at the end of the graft. The long-term graft patency was 100% with a mean follow-up of 40 months. There were 2 deaths in the cohort during follow-up; both patients died of malignant tumors (osteogenic sarcoma and chondrosarcoma).

CONCLUSIONS

The authors conclude that in properly selected cases, bypasses can be safely performed in patients with aneurysms and skull base tumors. The bypasses remained patent over long periods of time despite the growth of the patients.

Pediatric microcystic meningioma: a clinical, histological, and radiographic case-based review

BACKGROUND

Microcystic meningioma (MM) is a World Health Organization grade I tumor that is rare in the pediatric population. Meningiomas account for approximately 2-4 % of all childhood central nervous system (CNS) tumors compared to approximately 20 % of all adult CNS tumors. The authors present one of the few confirmed cases of microcystic meningioma in a child and discuss the characteristic radiographic appearance and histological findings.

HISTORY

We report the case of an 11-year-old boy who presented with first-time seizure and imaging consistent with brain tumor. There was significant vasogenic edema within the entire right hemisphere, disproportionate to the size of the falcine-based tumor. Histopathological analysis revealed the microcystic subtype of meningioma.

DISCUSSION

We review the radiographic characteristics, histopathological findings, and reported pediatric cases of MM in conjunction with our case.

CONCLUSION

MM has distinct radiographic characteristics (variable enhancement, lack of a dural tail, and disproportionate vasogenic edema) that can be misinterpreted in the pediatric population, suggesting a more aggressive tumor.