Ryotaro Suzuki

Localized overexpression of alpha-internexin within nodules in multinodular and vacuolating neuronal tumors.

Multinodular and vacuolating neuronal tumors (MVNT) have been recently referred to as a distinctive neuronal tumor entity based on histopathological findings. They are characterized by multiple tumor nodules, vacuolar alteration and widespread immunolabeling for human neuronal protein HuC/HuD. Only 13 cases have been reported in the literature to date and little is known about the histopathology of these tumors. Herein, we report a case of MVNT with additional confirmation of immunohistochemical features. A 22‐year‐old woman presented with a continuous headache. MRI showed a subcortical white matter lesion with multiple satellite nodules in the frontal lobe appearing as T2/fluid‐attenuated inversion recovery (FLAIR) hyperintensities. Histological examination of the resected lesion revealed well‐defined multiple nodules composed of predominant vacuolating tumor cells. The tumor cells exhibited consistent immunolabeling for doublecortin, as well as HuC/HuD, both representative neuronal biomarkers associated with earlier stages of neuronal development. Immunopositivity for oligodendrocyte transcription factor 2 (Olig2) and S100 was also detected in tumor cells. Additionally, significant overexpression of alpha‐internexin was observed in the background neuropil limited to tumor nodules. Neuronal nuclear antigen (NeuN), synaptophysin and neurofilament, markers for mature neurons, were either negative or weakly positive. The expression profile of neuronal biomarkers can be distinguished from that of classic neuronal tumors and is the immunohistochemical hallmark of MVNT. In summary, we identified the characteristic tumoral expression of HuC/HuD and doublecortin and the presence of abundant neuropil localized in MVNT tumor nodules, which exhibited widespread alpha‐internexin expression. These results supported the presumption that MVNT is a distinct histopathological entity.

Preoperative Embolization for Skull Base Meningiomas

Abstract The results of preoperative embolization for skull base meningiomas were retrospectively evaluated to confirm the efficacy of this procedure. Skull base meningiomas that were treated with preoperative embolization were evaluated in 20 patients. The occluded arteries, embolic materials, treatment time, excision rate, neurologic manifestations, and complications were analyzed. The embolic material was 80% liquid, 30% coils, and 15% particles. The surgery was normally completed within 3 to 5 hours. Blood loss was normally approximately 250 mL, excluding four patients having the following conditions: malignant meningioma, a large tumor located on the medial side of the sphenoidal ridge, the petroclival tumor, and infiltrated tumor into the sigmoid sinus. The mean excision rate was 90%, achieving a Simpson grade III, but 10% were graded as Simpson grade IV. No permanent complications due to the preoperative embolization occurred. No neurologic symptoms occurred after excision. Current cerebral endovascular treatment is sophisticated, and the complication rate has markedly decreased. Although it was impossible to compare directly with or without operative embolization, preoperative embolization should be actively used as part of the treatment for this benign tumor, with better understanding of dangerous anastomosis.

A Single Center Experience with Coil Embolization for Cerebral Aneurysms Greater than 10 mm in the Internal Carotid Artery

We investigated endovascular treatment for 10 mm or larger aneurysms in the internal carotid artery (IC), including the cavernous portion, the paraclinoid portion, and the posterior communication artery (PC). Between 2011 and 2014 at our hospital, there were 35 cases of aneurysms that were 10 mm or larger in the carotid artery. We analyzed these 35 cases retrospectively based on the size and location of the aneurysms, method of treatment, number of coils implanted, use of a stent, complications, rupture after treatment, ophthalmologic symptoms, and need for re-treatment. There was no bleeding after treatment. Of the 35 cases, four cases (11%) had permanent complications. Re-treatment was indicated in 11 cases (31%), including eight cases localized in the paraclinoid portion, two cases in the IC-PC, and one case in the cavernous portion. Among these re-treatment cases, two cases required a third treatment. Of the 16 cases with paraclinoid aneurysms, half required re-treatment. Of the 12 cases with ophthalmologic symptoms prior to treatment, 9 (75%) improved or had no change and 3 (25%) became worse. There were no complications in the 13 re-treatment procedures. Re-treatment is not uncommon, and a scheduled follow-up is needed. Coil embolization has been one of the main options for aneurysms that are 10 mm or larger in the IC. In the future, these large aneurysms will be treated with a flow diverter stent (FD).

A distinctive pediatric case of low-grade glioma with extensive expression of CD34.

A 12-year-old girl presented with a generalized convulsion. She had regularly consulted pediatricians for an adjustment disorder over the course of 2 years and had experienced a transient episode of unconsciousness without convulsion 5 months earlier. A mental status examination revealed depressed affect, but general physical and neurological examinations were unremarkable. Computerized tomography scans showed a cystic lesion with calcifications in the left temporal lobe (Fig. 1a). A 3.2 9 2.2 cm solid tumor nodule with a unilocular cyst involving the left middle temporal gyrus was detected by magnetic resonance imaging (MRI). The solid tumor nodule was heterogeneously hyperintense on T2-weighted, T1-weighted, and FLAIR images and isointense on diffusion-weighted images with a heterogeneous contrast enhancement (Fig. 1b– d). The patient underwent surgery because of poor seizure control with anticonvulsant drugs, and the nodule was totally resected. The thickened cyst wall was partially removed to preserve the essential language center of the brain. Intraoperative findings demonstrated a gray-pink, soft tumor nodule with a visually indistinct tumor border and yellowish cyst wall. The patient was immediately seizure free, and the mental disorders showed improvement after surgery. MRI at the 6-month postoperative follow-up demonstrated no evidence of tumor recurrence despite receiving no further therapy. Microscopically, the neoplasm was predominantly composed of packed oval or round cells with small nuclei (Fig. 2a–b). Neither mitosis nor significant nuclear atypia were identified in the predominant tumor cells. The tumor border included neurons with prominent nuclei and nucleoli and ample cytoplasm which were relatively well ordered without particular dysmorphism, suggesting entrapped pre-existing elements. The tumor lesion included increased capillaries with nuclear atypia on the endothelial cells, and the surrounding tumor cells demonstrated capillary-like tubule formation (Fig. 2c–d). These findings suggested the possibility of tumor cells converting into tumoral endothelial cells. Scattered calcifications were noted predominantly in the peritumoral region. Necrotic foci were absent. Tumor cells did not extend into the subarachnoid space. Silver staining confirmed the absence of reticulin fibers among the individual tumor cells (Fig. 2e). The tumor was devoid of Rosenthal fibers, eosinophilic granular bodies, and a biphasic compact/microcystic pattern as well as cellular polymorphism and xanthomatous changes, which are the characteristics of pilocytic astrocytoma and pleomorphic xanthoastrocytoma (PXA), respectively. Immunohistochemistry revealed intense immunopositivity for S100, Olig2, MGMT, vimentin, CD34 and nestin on the tumor cells (Fig. 2f–i). The tumor cells showed focally positive for p53, but showed negative for epithelial membrane antigen, asmooth muscle actin, neurofilament, neuronal nuclear antigen, glial fibrillary acidic protein (GFAP), and mutant IDH1 staining (Fig. 2j). Immunostaining with nestin confirmed that the tumor cells infrequently contain cytoplasmic process. The MIB-1 labeling index was 1.1 %. The relatively distinct border between the tumor region and & Masaya Nagaishi nagaishi-nsu@umin.ac.jp

Double-balloon Remodeling for Coil Embolization of a Primitive Trigeminal Artery Variant Aneurysm: A Case Report

Here we describe the case of a patient with a wide-necked unruptured aneurysm arising at origin of a persistent primitive trigeminal artery (PTA) variant from the right internal carotid artery (ICA), supplying the territory of the right superior cerebellar artery and the anterior inferior cerebellar artery. To preserve the ICA and the PTA variant, coil embolization of the aneurysm was performed using a double-balloon remodeling technique (HyperForm™ and Hyper-Glide™ Occlusion Balloon Systems; ev3 Endovascular Inc., Irvine, CA, USA). The association of a PTA variant with an aneurysm is very rare. To our knowledge, this is the first description of the use of coil embolization using double-balloon remodeling to treat a PTA variant aneurysm. This technique permits complete embolization and reduces the risk of cerebral and cerebellar ischemia.