Various degrees of peritumoral brain edema (PTBE) are observed in patients with intracranial meningiomas. Factors affecting the occurrence of PTBE in intracranial meningioma were investigated. PTBE was investigated retrospectively for 110 patients with primary intracranial meningiomas. Predictive factors related to PTBE were analyzed, for example patient age, sex, magnetic resonance imaging features (contrast enhancement, tumor shape, tumor location, tumor volume), angiographical features (tumor stain, pial-cortical arterial supply, venous obstruction), and histopathological features (histological subtypes, mindbomb homolog 1 labeling index (MIB1-LI)). Histological subtypes were classified into World Health Organization (WHO) grade I common type (meningothelial, transitional, fibrous), grade I uncommon type, and grade II and III types. The extent of PTBE was assessed by calculation of the edema index (EI). PTBE was present in 53 cases (48 %). Male sex, heterogeneous enhancement, superficial location, tumor volume (≥10 cm(3)), remarkable tumor stain, pial supply, venous obstruction, malignant pathology, and MIB1-LI ≥4 % were correlated with PTBE in univariate analysis. Pial supply and remarkable tumor stain were correlated with PTBE in multivariate analysis. WHO grade I uncommon type had obviously higher EI than WHO grade I common type, and WHO grade II and III types (P < 0.001). Seven cases with prominently high EI (EI ≥10) were all WHO grade I uncommon type, including angiomatous, microcystic, secretory, and lymphoplasmacyte-rich meningioma. Prominently extensive PTBE might indicate the presence of WHO grade I uncommon type meningioma.

Adult cerebellar high-grade gliomas (HGG) are rare and their molecular basis has not been fully elucidated. Although a diffuse midline glioma H3 K27M-mutant, a recently characterized variant of HGG, was reported to occasionally occur in the cerebellum, adult cases were rarely tested for this mutation; only five mutant cases have been reported to date. It currently remains unknown whether H3 K27M-mutant cerebellar gliomas share common histological features or have a uniformly dismal prognosis. In the present study, we assessed the prevalence of histone H3 K27M mutations in ten adult cerebellar HGG, identifying two H3F3A-mutant cases. One case was a 70-year-old female with a cystic lesion. Histologically, the tumor was considered to be glioblastoma; however, a part of the tumor exhibiting low proliferative activity appeared to be consistent with long-standing H3 K27M-mutant tumors in the literature. Another case was a 69-year-old male. The tumor showed a distinct circumscribed histology with minimal astrocytic differentiation, suggesting a nosological issue in the diagnosis of diffuse midline glioma. More cerebellar tumors need to be tested for H3 K27M mutations to clarify the clinical and histopathological spectra of this tumor.

Several kinds of unusual cells have been pathologically identified in epileptic patients. CD34-positive, nestin-positive and tau-positive cells are some of them. However, no reports have investigated the significance of these cells. We examined 14 cases of seizure-associated glioneuronal lesions to investigate the incidences and distributions of these cells and the association between their incidence and clinical parameters. CD34-positive and nestin-positive cells were seen in 43% and 50% of cases, respectively. In the regions with structural anomalies, there were increased numbers of CD34-positive cells and nestin-positive cells, but they were identified as different cells. Both examinations showed many abnormal processes in oligodendroglial-like cells with round nuclei. In contrast, few reactive astrocytes that demonstrated immunoreactivity for glial fibrillary acidic protein were found in this area. Tau accumulation was present in 37% of cases. There was no correspondence with the regions showing increasing numbers of nestin or CD34-positive cells. There were no significant associations between epileptic clinical parameters and the incidences of the abovementioned immunopositive cells. CD34-positive cells and nestin-positive cells are found as frequently as balloon cells and are associated with abnormal reconstitution of the cortex. These findings support the assertion that increases in the numbers of these cells might contribute to promoting epilepsy. In addition, these immunopositive cells are valuable findings for the pathological identification of epileptogenic lesions.

OBJECTIVEVisual acuity impairment due to sellar and suprasellar tumors is not fully understood. The relationship between these tumors and disturbance of visual function was examined using preoperative MRI.METHODSThis study reviewed 93 consecutive patients with sellar and suprasellar tumors. Best-corrected visual acuity (BCVA) and visual impairment score (VIS) were used for estimation of visual impairments. Preoperative MR images were examined to obtain several values for estimation of chiasmatic compression. Additionally, the optic nerve–canal bending angle (ONCBA) was newly defined as the external angle formed by the optic nerve in the optic canal and the optic nerve in the intracranial subarachnoid space at the junction, using preoperative sagittal T2-weighted MR images.RESULTSThe mean ONCBA was about the same on the right (44° ± 25°) and the left (44° ± 24°). Sagittal ONCBA was defined as large (> 45°) and moderate (≤ 45°) on each side. Preoperative VIS was found to be significantly worse if the right or left ONCBA (or both) was large (right side: ONCBA large [median 20, IQR 8–30] > ONCBA moderate [median 10, IQR 3–17], p = 0.003, Mann-Whitney U-test; left side: ONCBA large [median 22, IQR 9–30] > ONCBA moderate [median 10, IQR 2–16], p = 0.001). A large ONCBA showed a significant relationship with unfavorable ipsilateral BCVA (> logMAR, 0; right side, p = 0.001, left side, p = 0.001, chi-square test). The ONCBA had a positive correlation with ipsilateral BCVA (right: r = 0.297, p = 0.031; left: r = 0.451, p = 0.000, Pearson’s correlation coefficient). Preoperative BCVA was significantly lower on the same side in the large ONCBA group compared with the moderate ONCBA group (right side: large ONCBA 0.169 ± 0.333 [logMAR, mean ± standard deviation] vs moderate ONCBA 0.045 ± 0.359, p = 0.026, Student t-test; left side: large ONCBA 0.245 ± 0.346 vs moderate ONCBA 0.025 ± 0.333, p = 0.000). This visual acuity impairment improved after resection of the tumors.CONCLUSIONSSagittal bending of the optic nerve at the entrance from the intracranial subarachnoid space to the optic canal may be related to ipsilateral deterioration of visual acuity in sellar and suprasellar lesions. Sagittal T2-weighted MRI is recommended for preoperative estimation of the optic nerve bending.

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