Optimizing perampanel monotherapy for surgically resected brain tumors.

Perampanel (PER) is an antiseizure medication (ASM) with a unique mechanism of action, which was approved in Japan for use in combination therapy in 2016 and as a monotherapy in 2020. It has exerted antitumor effects against several types of tumors in vitro. However, the efficacy of PER monotherapy for seizure control is not well-established in patients with brain tumor. In the present study, 25 patients with brain tumor treated using PER monotherapy at our institution were analyzed and compared with 45 patients treated using the most commonly prescribed ASM, levetiracetam (LEV). The PER group was younger and had a higher frequency of glioma cases. During drug administration, seizures were observed in two patients from the PER group (8.0%) and five patients from the LEV group (11.1%); however, the difference was not significant. The incidence of adverse effects did not significantly differ between the groups (12.0 and 2.2%, respectively). In the PER group, mild liver dysfunction was observed in two patients and drug rash in one. In the LEV group, a drug-induced rash was observed in one patient. PER monotherapy may be safe and effective for seizure treatment or prophylaxis in patients with brain tumor. Further large-scale clinical studies are warranted.

The Role of Genetic Analysis in Distinguishing Multifocal and Multicentric Glioblastomas: An Illustrative Case.

Introduction: Glioblastomas can manifest as multiple, simultaneous, noncontiguous lesions. We genetically analyzed multiple glioblastomas and discuss their etiological origins in this report. Case Presentation: We present the case of a 47-year-old woman who presented with memory impairment and left partial paralysis. Radiographic imaging revealed three apparently noncontiguous lesions in the right temporal and parietal lobes extending into the corpus callosum, leading to diagnosis of multicentric glioblastomas. All three lesions were excised. Genetic analysis of the lesions revealed a TERT promoter C228T mutation, a roughly equivalent amplification of EGFR, and homozygous deletion of CDKN2A/B exclusively in the two contrast-enhanced lesions. Additionally, the contrast-enhanced lesions exhibited the same two-base pair mutations of PTEN, whereas the non-enhanced lesion showed a partially distinct 13-base pair mutation. The other genetic characteristics were consistent. Rather than each having arisen de novo, we believe that they had developed by infiltration and are therefore best classified as multifocal glioblastomas. Conclusion: Our findings underscore anew the possibility of infiltration by glioblastomas, even within regions devoid of signal alterations on T2-weighted images or fluid-attenuated inversion recovery images. Genetic analysis can play a crucial role in differentiating whether multiple glioblastomas are multifocal or multicentric.

Case report: meningeal lymphangiogenesis around ependymoma forming along the dura matter.

Recently, there has been growing interest in the presence and function of meningeal lymphatic vessels, with no direct evidence linking these vessels to primary brain tumors. We report a unique case of recurrent ependymoma in the dura mater, showing histopathological signs of lymphatic proliferation at the tumor attachment site. The patient initially presented with a headache, and was diagnosed with ZFTA fusion-positive supratentorial ependymoma, central nervous system WHO Grade 3. Following multiple dura mater recurrences and surgery, the fifth procedure revealed numerous tumors contralateral to the original site, with genetic testing confirming ZFTA fusion positivity, indicating recurrent ependymoma. Immunohistochemical analysis showed D2-40+ lymphatic vessel proliferation around tumor attachment sites within the dura mater. Elevated expression of ZEB1, which is an epithelial-to-mesenchymal transition factor, was also observed, implicating potential involvement in the unique pathophysiology. The present case suggests a new process of metastasis through meningeal lymphatic vessels, although we were unable to visually confirm tumor cell infiltration into the lymphatic vessels. This case is the first report suggesting ependymoma metastasis through dural lymphatic vessels, underlining the need for further case accumulation and study to understand the mechanisms of this phenomenon.