Comparison of Early Postoperative Diffusion Weighted Magnetic Resonance Imaging Findings After Resection of Gliomas and Meningiomas.

OBJECTIVE: Glioma and meningioma require vastly different surgical approaches, even if only involving a simple craniotomy procedure. Diffusion weighted imaging (DWI) is useful for the postoperative evaluation of ischemic damage. The present study evaluated the expected but unproven differences in DWI findings. METHODS: A total of 41 patients with meningiomas and 63 with gliomas met the inclusion criteria for adult cases with superficial lesions treated through simple supratentorial craniotomy. Postoperative DWI findings of DWI-positive rate, DWI-positive area type, and relationship with neurological deficits were evaluated. RESULTS: The DWI-positive rate (P = 0.01) and the proportion of rim-type lesions (P < 0.01) were significantly more common in gliomas. Patients with meningiomas and DWI-positive areas presented with higher rates of new neurological deficits (P < 0.01), and patients with meningiomas on the left side were more likely to develop new neurological deficits (P = 0.02). Patients with gliomas tended to develop new deficits with larger DWI-positive area volumes (P = 0.04). CONCLUSIONS: Postoperative early DWI-positive rate and rim-type lesions are more common after glioma resection than meningioma resection. Larger volumes of DWI-positive areas may be associated with postoperative neurological symptoms in gliomas. DWI-positive finding is less common after meningioma than glioma resection but more likely to be associated with new neurological symptoms. These differences are important for adequate postoperative DWI evaluation of common supratentorial brain tumors.

Sagittal bending of the optic nerve at the entrance from the intracranial to the optic canal and ipsilateral visual acuity in patients with sellar and suprasellar lesions.

OBJECTIVE: Visual 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. METHODS: This 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. RESULTS: The 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. CONCLUSIONS: Sagittal 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.

Combined supra-infrasellar approach to pituitary macroadenoma with oculomotor cistern extension: surgical strategy and experience.

BACKGROUND: Oculomotor cistern extension (OMCE) of pituitary adenoma through the oculomotor triangle may be one of the major characteristics of multi-lobulated adenoma. The OMCE may be hard to remove only through the endonasal approach. METHOD: We applied the simultaneous combined supra-infrasellar approach to remove pituitary adenoma with relatively large OMCE. Four (7.3%) of 55 consecutive patients with initially operated pituitary macroadenoma (> 10 mm) had OMCE. The combined supra-infrasellar approach was adopted in two cases with relatively large OMCE. RESULTS: The simultaneous combined supra-infrasellar approach was performed with the transcranial microscopic transsylvian anterior temporal approach and the nasal endoscopic approach. The medial main mass was removed through the nasal side. The lateral OMCE was also removed through the nasal side by pushing the tumor in the sellar direction from the transcranial side. The oculomotor nerve was confirmed with electrical nerve stimulation. The main medial mass and the OMCE were mostly removed in both cases. Remnant tumor in the cavernous sinus was treated by gamma knife radiosurgery. Endoscopic transsphenoidal removal was performed in the other two cases with relatively small OMCE. CONCLUSIONS: Pituitary macroadenomas with OMCE are a newly recognized form of progression with important implications for surgical strategy. The combined supra-infrasellar approach performed with the transcranial microscopic transsylvian anterior temporal approach using electrical nerve stimulation and the nasal endoscopic approach may be useful for this type of multi-lobulated pituitary adenoma.

Histone H3 K27M mutations in adult cerebellar high-grade gliomas.

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.

Preoperative Evaluation of Sellar and Parasellar Macrolesions by [18F]Fluorodeoxyglucose Positron Emission Tomography.

OBJECTIVE: Various diseases can occur in the sellar and suprasellar regions. The potential of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) for the preoperative evaluation of sellar and parasellar lesions was investigated. METHODS: A total of 49 patients aged 8-82 years with sellar and parasellar macroscopic lesions (≥10 mm) underwent FDG PET. Twenty-two patients had pituitary adenomas, including 14 nonfunctioning and 8 growth hormone-secreting adenomas. Eleven patients had craniopharyngiomas, including 5 adamantinomatous and 6 squamous-papillary types. Eight patients had chordoma, 4 had meningioma, and 4 had a Rathke cleft cyst. The maximum standardized uptake value (SUVmax), and the ratio of the SUVmax in the tumor to the mean standardized uptake value in the normal cortex (T/N ratio) or in the normal white matter (T/W ratio) were calculated. The relationships between SUVmax, T/N ratio, and T/W ratio, and lesion disease were evaluated. RESULTS: Uptakes of FDG, including SUVmax, T/N ratio, and T/W ratio, were lower in chordoma and Rathke cleft cyst compared with pituitary adenoma. SUVmax, T/N ratio, and T/W ratio of nonfunctioning adenoma were significantly higher than those of growth hormone-secreting adenoma. SUVmax, T/N ratio, and T/W ratio of squamous-papillary type were significantly higher than those of the adamantinomatous type of craniopharyngioma. CONCLUSIONS: FDG PET is useful for the preoperative diagnosis of sellar and parasellar macrolesions. High uptake in nonfunctioning pituitary adenoma, and low uptake in chordoma are significant. The difference in FDG uptake dependent on the histologic subtype may be related to the specific genetics of the craniopharyngioma subtype.

Cytoplasmic iron deposition is associated with the expression of oxidative DNA damage marker in meningiomas.

Angiomatous meningiomas are rare meningioma subtypes, which are characterized by abundant, well-formed vessels. We encountered two cases of newly diagnosed angiomatous meningiomas exhibiting tumor cells with brown pigments, which were histochemically proven to be iron. In an attempt to understand its pathological significance, we assessed this unusual finding in representatives for each grade of meningiomas and immunoexpression of transferrin receptor (CD71) and the oxidative DNA damage marker, 8-hydroxy-2'-deoxyguanosine (8-OHdG). Iron deposition in the tumor cells was observed in 8/15 (53%) angiomatous meningioma cases, 2/6 (33%) microcystic meningiomas and 2/20 (10%) meningothelial meningiomas, which included clustered microvessels, but not in fibrous, atypical or anaplastic meningiomas (P = 0.001). Cytoplasmic CD71 expression was largely negative in angiomatous meningioma cases, but positive in meningothelial and high-grade meningiomas, suggesting that the transferrin-dependent iron transporter was involved in iron uptake in meningiomas. Nuclear expression of 8-OHdG was observed in ≥ 50% of the tumor cells in all 15 cases of angiomatous meningioma and was associated with the presence of regressive histopathological findings, such as hyalinized vessels and cystic changes. In addition, the fraction of iron-containing tumor cells was correlated to those expressing 8-OHdG (P = 0.005). Our finding indicates that cytoplasmic iron deposition in tumor cells is characteristic of highly vascularized benign meningiomas and related to increased oxidative DNA damage markers.

Mattress anastomosis in micro vascular reconstruction: technical note.

BACKGROUND: Superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis is a common procedure for neurosurgeons. The surgery necessarily requires accurate and speedy manipulation of microscope, for which a specific training is needed. Unexpected bypass occlusion sometimes happen during surgery. OBJECTIVE: Generally, conventional interrupted or continuous suture has been used for vascular anastomosis, despite various ideas have been attempted in the other surgery fields. We propose a horizontal mattress suture technique for intracranial microvascular bypass surgery. This is the first report ever published on intracranial vascular anastomosis. METHODS: We had four patients of STA-MCA bypass surgery with "mattress anastomosis" from March to May of 2012. RESULTS: During the procedure, there was no bypass occlusion and good patency was confirmed in all cases. CONCLUSION: Intimae of the recipient and the donor blood vessel contact each other precisely with this technique. Although a long-term assessment of patency is needed, it is useful for the intracranial bypass surgery.

Factors affecting peritumoral brain edema in meningioma: special histological subtypes with prominently extensive edema.

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.

An immunohistochemical finding in glioneuronal lesions associated with epilepsy: the appearance of nestin-positive, CD34-positive and tau-accumulating cells.

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.