Respective roles of Pik3ca mutations and cyproterone acetate impregnation in mouse meningioma tumorigenesis.

Despite their rarity, PIK3CA mutations in meningiomas have raised interest as potentially targetable, ubiquitous mutations owing to their presence in sporadic benign and malignant tumors but also in hormone-related cases. Using new genetically engineered mouse models, we here demonstrate that Pik3ca mutations in postnatal meningeal cells are sufficient to promote meningioma formation but also tumor progression in mice. Conversely, hormone impregnation, whether alone or in association with Pik3ca and Nf2 mutations, fails to induce meningioma tumorigenesis while promoting breast tumor formation. We then confirm in vitro the effect of Pik3ca mutations but not hormone impregnation on the proliferation of primary cultures of mouse meningeal cells. Finally, we show by exome analysis of breast tumors and meninges that hormone impregnation promotes breast tumor formation without additional somatic oncogenic mutation but is associated with an increased mutational burden on Pik3ca-mutant background. Taken together, these results tend to suggest a prominent role of Pik3ca mutations over hormone impregnation in meningioma tumorigenesis, the exact effect of the latter is still to be discovered.

Decompensation of a Thoracic Meningioma Below the Operated Level: A Dramatic and Unexpected Complication.

BACKGROUND: Paraplegia after lumbar spinal surgery has been previously described. It was generally provoked by a missed thoracic compression because of degenerative processes, arachnoid cyst, and spinal cord tumor such as meningioma. We describe here a case of a patient with neurofibromatosis type 2 (NF-2) with multiple spinal meningiomas that developed postoperative paraplegia because of decompensation of spinal cord compression below and far from the operated level. CASE DESCRIPTION: A 54-year-old woman with NF-2 was followed-up for multiple spinal meningiomas (C7-T1, T6-7, T9-10 levels). Surgery for the symptomatic and larger lesion (C7-T1) was scheduled. Postoperatively, the patient was found to have paraplegia with sensor anesthesia below the level of the T6 vertebra. An urgent spinal magnetic resonance imaging (MRI) scan was performed revealing the absence of complication at the operated level (C7-T1) but the appearance of a marked intramedullary hyperintensity at the T6-7 level. An urgent T6-7 laminectomy and removal of the meningioma was performed. The postoperative phase was marked by a poor recuperation. Spinal MRI scan at 3 months clearly showed a severely injured spinal cord at the T6-7 level consistent with the neurologic status of the patient. CONCLUSIONS: We report here the first case of acute neurologic deterioration after decompensation of a spinal cord compression below the operated level in spinal intradural surgery. Neurosurgeons must be aware of this possible complication when treating patients with multiple spinal meningiomas.

Transsphenoidal resection for pituitary adenoma in elderly versus younger patients: a systematic review and meta-analysis.

INTRODUCTION: Pituitary adenomas (PA) are common intracranial tumors. In the context of the aging of the population, the question is whether postsurgical outcomes are comparable to the younger ones. The primary objective of the present study was to review published resection and recurrence rates after transsphenoidal resection. The secondary aim was to evaluate visual improvement and complication rates. METHODS: The authors searched PubMed and Medline databases, of published English series, with no time frame limit, evaluating outcomes of transsphenoidal resection in populations aged more or less than 65, 70, and 80 years. We performed a systematic review and meta-analysis. RESULTS: Median overall resection rates for younger population was 70.7% (range 54-76.8) and for elderly one was 65.7% (range 16.6-78.2) (two-sample t test, p = 0.35). The only statistically significant difference for gross total resection rates (GTR) favored patients aged less than 80 (p = 0.01). There was no statistically significant difference among recurrence rates. There was a statistically significant difference for visual improvement favoring patients aged more than 80 (p = 0.03). For the age groups of less versus more than 70, there was a statistically significant difference for overall complication rate favoring younger groups (p < 0.05). CONCLUSION: Present data shows GTR rates favoring younger patients. Recurrence rates remain similar over the mean follow-up period. Moreover, visual improvement favors patients aged more than 80. Overall complication rates favor patients younger than 70, which might be also related to additional comorbidities, frequently present in seniors. Transsphenoidal surgery is safe and effective even for older patients.

Microsurgical resection of a radicular hemangioblastoma with subarachnoid hemorrhage: how I do it.

BACKGROUND: Hemangioblastomas (HBL) are benign tumors occurring sporadically or associated with Von Hippel-Lindau syndrome (VHL). METHOD: We present the pre-, per-, and postoperative course of a rare case with radicular HBL presenting with subarachnoid hemorrhage (SAH) in the frame of VHL. We describe the microsurgical approach. CONCLUSION: Complete microsurgical in bloc resection has been performed. Postoperative course was uneventful.