Norichika Hashimoto

Nestin expression in astrocytic tumors delineates tumor infiltration

Nestin is an intermediate filament protein expressed in undifferentiated cells during central nervous system development, and glioma is known to be a highly infiltrative tumor. We determined whether nestin was expressed in astrocytic tumors and could identify infiltrating tumor cells. We screened 65 archival, paraffin-embedded adult astrocytic tumors using immunohistochemical staining and computerized overlaid photographs. Normal biopsied brains and metastatic brain tumors were also examined. The intensity of nestin expression corresponded to the tumor grade. All 33 glioblastoma cases showed positive and extensive staining, which was less positive in diffuse astrocytoma. Overlaid images showed that nestin immunostaining delineated tumor invasion into adjacent gray and white matter. Nestin is a useful marker for examining the infiltration of malignant cells into surrounding tissue.

Lymphomatosis cerebri: clinical characteristics, neuroimaging, and pathological findings

Lymphomatosis cerebri is a rare variant of primary central nervous system lymphoma. We present a case involving a 56-year-old immunocompetent woman who complained of rapid deterioration of her higher brain function over a 4-month period. Magnetic resonance imaging showed extensive white-matter lesions. During brain biopsy, a diffusely infiltrating lymphoma with distinctive immunohistochemical features was detected. Awareness of this unique presentation and early tissue diagnosis provide the best hope for instituting appropriate treatments.

Proliferation of vascular smooth muscle cells in glioblastoma multiforme

OBJECT Glioblastomas multiforme (GBM) contain a higher number of alpha-smooth muscle actin (SMA)-positive vascular smooth muscle cells (VSMCs) than those in the respective normal neuronal tissue. The role of VSMCs during angiogenesis is unclear, and it is also uncertain whether and to what extent angiogenic factors might be involved in GBM VSMCs. In GBMs, the contribution of VSMCs in angiogenesis accompanying endothelial proliferation and the correlation of VSMC proliferation with vascular endothelial growth factor (VEGF) expression were examined using an immunohistochemical method. METHODS The examined material, including surrounding brain tissue, came from 12 cases (6 men and 6 women) with classic GBM. Microvessel densities (MVDs) of CD31-immunoreactive vessels (CD31-MVD) and SMA-immunoreactive vessels (SMA-MVD) were obtained in areas selected from white matter, boundary, tumor (concentrated area of tumor cells), and perinecrosis. Subsequently, the SMA-MVD/CD31-MVD (SMA/CD31) rate, representing the percentage of vessels with VSMCs in the region, was calculated in each area. The VEGF immunoreactivity of tumor cells was examined, and cases were divided into 2 groups: < 30% VEGF expression of tumor cells (low VEGF group) and > 30% VEGF expression of tumor cells (high VEGF group). RESULTS The SMA/CD31 rate of the boundary was significantly lower than that of the tumor (p < 0.005) and perinecrosis (p < 0.001). The SMA/CD31 rate of the high VEGF group was significantly higher than that of the low VEGF group (p < 0.05) in the tumor. CONCLUSIONS In GBMs, the transformation and proliferation of VSMCs may accompany neovascularization and may also be induced by angiogenic factors.

A report of supratentorial leptomeningeal hemangioblastoma and a literature review

Hemangioblastomas of the CNS are solid or cystic vascular‐rich tumors, most common in the cerebellum, less frequent in the brainstem or spinal cord, and rare in supratentorial locations with meningeal involvement. We document a case in a 58‐year‐old man who presented with about 2 months history of motor weakness and speech dysfunction. The tumor was a heterogeneously enhanced dural‐based tumor with high vascularity and perifocal edema in the left frontal lobe. The tumor was completely removed followed by embolization and preoperative radiotherapy. Histologic examination revealed a hemangioblastoma with features resembling angiomatous meningioma. Immunohistochemistry for epithelial membrane antigen (EMA) and S100 may be helpful to make differential diagnosis. Electron microscopic investigation is essential to differentiate between meningiomas and other leptomeningeal tumors.

CD98 immunoreactivity in multinucleated giant cells of glioblastomas: An immunohistochemical double labeling study

CD98, which is identical to fusion regulatory protein‐1 (FRP‐1), has been reported to induce and regulate cell fusion and multinucleated giant cell formation. To investigate the association between CD98 and multinucleated giant cells (MNGCs) in glioblastomas, we investigate the CD98 immunoreactivity of MNGCs and the proliferative potential in CD98 immunoreactive MNGCs in paraffin‐embedded sections obtained from patients with glioblastomas. Double immunohistochemical staining for CD98 and Ki67 as a mitotic marker were performed in formalin‐fixed and paraffin‐embedded specimens obtained from 16 patients with primary glioblastomas including MNGCs. Most CD98 immunoreactive (CD98+) tumor cells were negative for Ki67. CD98+ MNGCs were identified in 15 cases. CD98+ Ki67– MNGCs were identified in 14 cases and ranged in number from one to 48 (6.7 ± 11.5). CD98– Ki67+ MNGCs were identified in 15 cases and ranged in number from one to 32 (11.1 ± 9.6). Mitotic index (MI) of CD98+ MNGCs (4.8 ± 2.7%) was significantly lower than that of CD98– MNGCs (91.1 ± 24.6%) (P < 0001). These results suggest that multinucleated giant cell formation may be developed by fusion among CD98– producing cells in glioblastomas.

Predictive Factors for the Occurrence of Visual and Ischemic Complications After Open Surgery for Paraclinoid Aneurysms of the Internal Carotid Artery

OBJECTIVE To investigate the predictive factors for visual and ischemic complications after open surgery for paraclinoid aneurysms of the internal carotid artery (ICA). MATERIALS AND METHODS Thirty-eight consecutive patients with unruptured paraclinoid aneurysms of ICA operated on between 2009 and 2013 were included in this study. The male:female ratio was 6:32 and the ages ranged from 33 to 81 (mean: 60 ± 2). Twenty cases were asymptomatic and 18 had ophthalmological symptoms. The sizes of the aneurysms ranged from 2 to 35 mm (mean: 10.6 ± 9 mm). Twenty-three patients were treated by clipping and 15 by trapping with bypass (high-flow bypass in 11, and low-flow in 4). Twenty-four patients underwent removal of the anterior clinoid process. Among them, 8 underwent en bloc anterior clinoidectomy with a high-speed drill, and 16 had piecemeal excision with a microrongeur or ultrasonic bone curette. Intraoperative monitoring was performed using motor-evoked potentials (MEP) and visual-evoked potentials (VEP) in 27 and 15 cases, respectively. RESULTS Complete obliteration of the aneurysm was achieved in 37 cases (97.4 %). The patency rate of bypass was 100 %. Postoperative worsening of visual acuity, including one case of blindness, was observed in six cases (11 %). Worsening of visual field defects occurred in 14 cases (38 %), but 10 of them were transient. Transient oculomotor nerve palsy occurred in six cases (15 %). Postoperative stroke was detected by diffusion-weighted imaging (DWI) in five cases (13 %), four of which were symptomatic. Statistical analysis showed that piecemeal anterior clinoidectomy was significantly safer than en bloc removal in preserving visual function. Trapping with high-flow bypass had a significantly greater risk of postoperative stroke than direct clipping. CONCLUSIONS Intraoperative VEP monitoring might be useful for preventing postoperative worsening of visual function. Two-stage treatment with bypass and endovascular trapping might be safer than single-stage trapping alone.

Pathological examination of cerebral amyloid angiopathy in patients who underwent removal of lobar hemorrhages

Cerebral amyloid angiopathy (CAA) is a degenerative disorder characterized by amyloid-β (Aβ) deposition in the brain microvessels. CAA is also known to contribute not only to cortical microbleeds but also lobar hemorrhages. This retrospective study examined CAA pathologically in patients who underwent direct surgeries for lobar hemorrhage. Thirty-three patients with lobar hemorrhage underwent open surgery with biopsy from 2007 to 2016 in our hospital. Cortical tissues over hematomas obtained surgically were pathologically examined using hematoxylin, eosin stain, and anti-Aβ antibody to diagnose CAA. We also investigated the advanced degree of CAA and clinical features of each patient with lobar hemorrhage. In the 33 patients, 4 yielded specimens that were insufficient to evaluate CAA pathologically. Twenty-four of the remaining 29 patients (82.8%) were pathologically diagnosed with CAA. The majority of CAA-positive patients had moderate or severe CAA based on a grading scale to estimate the advanced degree of CAA. About half of the CAA-positive patients had hypertension, and four took anticoagulant or antiplatelet agents. In five patients who were not pathologically diagnosed with CAA, one had severe liver function disorder, three had uncontrollable hypertension, and one had no obvious risk factor. Our pathological findings suggest that severe CAA with vasculopathic change markedly contributes to lobar hemorrhage. The coexistence of severe CAA and risk factors such as hypertension, anticoagulants or antiplatelets may readily induce lobar hemorrhage.

Deflation of a Rathke cleft cyst triggered rupture of a superior hypophyseal artery aneurysm: a case report

Abstract A 57-year-old woman was diagnosed as a Rathke cleft cyst (RCC). Endoscopic transsphenoidal surgery (TSS) was performed uneventfully. She developed subarachnoid haemorrhage on postoperative day 3. The vessels adhered the cyst had been pulled into the pituitary fossa, causing an aneurysm.

The Adaptation of a Neuroendoscopic Sheath to a Leksell Stereotactic Frame to Make it Suitable for Approaching Small Ventricles: A Technical Note

Efficient endoscopic surgery in cases involving small ventricles is difficult but possible. The authors describe a neuroendoscopic sheath that has been improved to make it suitable for use with a Leksell stereotactic frame, which enabled us to accurately insert a stereotactic needle into the small ventricle and provided an adequate surgical corridor. A biopsy was performed on a 6-year-old girl who had a primary central nervous system lymphoma in the pineal body without hydrocephalus.