Glioblastoma is the most aggressive form of malignant tumor with a poor prognosis due to its exceptionally rapid growth and intense surrounding tissue infiltration. Long-term survival is unlikely, even with multidisciplinary therapies combining chemotherapy, surgery, and radiation therapy. The emergence of new treatments is, therefore, eagerly awaited. Chimeric antigen receptor gene-transduced T cell (CAR-T cell) therapy is an adoptive cell therapy that gives T cells the antibody-like capability of recognizing a surface antigen. CAR-T cells explicitly recognize antigens expressed by target malignant cells in a non-major histocompatibility complex (MHC)-restricted manner and launch a powerful attack on malignant cells. CAR-T cell therapy is becoming a promising approach for the treatment of glioblastoma. Here, we review the fundamentals of CAR-T cell therapy, advancement of its clinical application for hematological malignancies, and the scientific breakthroughs achieved with it in the treatment of glioblastoma in preclinical models and clinical trials.

Objective: Endoscopic surgery is useful for the treatment of hydrocephalus, and it is more important in the treatment of specific cases such as multilocular hydrocephalus and postencephalocele hydrocephalus. We examined the effectiveness of endoscopic surgery in patients with specific hydrocephalus at our hospital.

Material and Methods: We performed a retrospective review of eight cases with specific hydrocephalus treated by neuroendoscopy in Shizuoka Children’s Hospital between July 2007 and December 2018. We divided the patients into two groups: one comprising patients with multilocular hydrocephalus and the other comprising patients with postencephalocele hydrocephalus. Each group was further divided into two subgroups: group A (before the introduction of navigation and rigid endoscope) and group B (after the introduction of navigation and rigid endoscope). Subsequently, we examined whether navigation was used, the type of neuroendoscope used, and the result of the treatment.

Results: Navigation was used in all the patients in group B. Both rigid and flexible endoscopes were used in group B of the multilocular hydrocephalus group. Only a flexible endoscope was used in the remaining patients. In the multilocular hydrocephalus group, group A required two ventricular catheters for ventriculoperitoneal shunting, whereas group B required only one. In the postencephalocele hydrocephalus group, a ventriculoperitoneal shunt was required in group A but not in group B.

Conclusions: Endoscopic surgery plays a crucial role in managing specific hydrocephalus, and early intervention is necessary.

Background: Pediatric skull defects usually close naturally; however, cranioplasty is required in patients in whom adequate closure of defects does not occur. Although alloplastic materials are commonly used for cranioplasty in adults, autologous bone flap cranioplasty is preferred in pediatric patients considering the continued calvarial growth in this patient population. We report split calvarium cranioplasty and its outcomes.

Patients and Methods: We investigated the background and treatment outcomes in 10 patients who underwent split calvarium cranioplasty at our hospital between 2011 and 2018. Briefly, split calvarium cranioplasty was performed as follows: We harvested calvarial bone from an area showing an adequately formed diploic layer on preoperative imaging. Using a bone saw, we split the harvested bone into two layers; the lamina externa was returned to its original position, and the lamina interna was placed in the cranial defect and fixed with absorbable sutures.

Results: The study included 10 patients (6 males and 4 females, aged 5-21 years [mean 12.3 years]). The mean interval between the diagnosis of the cranial defect and cranioplasty was 3.4 years (0-12.5 years), with a mean follow-up period of 2.5 years (0.2-7.8 years). This study included 3 patients with calvarial Langerhans cell histiocytosis, 3 patients with fibrous dysplasia, and one patient each with osteoma, encephalocele, decompressive craniectomy after acute subdural hematoma, and bone resorption after brain tumor resection. The mean maximum diameter of skull defects was 32.2 mm (16.2-65.2 mm). Most recent computed tomography (CT) performed after cranioplasty revealed good bony fusion in all patients, and the mean maximum diameter of the skull defect was 4.0 mm (0.3-9.7 mm). The mean transplanted bone thickness at the time of transplantation was 2.3 mm (1.7-4.6 mm), and the transplanted bone thickness observed on the most recent CT was slightly increased to a mean thickness of 2.6 mm (1.7-5.3 mm). However, no patient showed diploë formation.

Discussion: Although split calvarium cranioplasty is associated with the disadvantage of performing an operation on healthy bone along with an increase in the size of the skin incision, this procedure achieves good bone fusion with a low risk of deformation owing to the use of autologous bone. We recommend split calvarium cranioplasty as preferred treatment for pediatric patients.

Objective: Ventriculoperitoneal (VP) shunt for hydrocephalus in patients with cerebrospinal fluid (CSF) dissemination of a brain tumor has a consequential risk of peritoneal seeding of the tumor cells. On the other hand, in usual ventricular drainage, there is a risk of tube infection or removal and difficulty in long-term maintenance. In order to avoid CSF leakage and infection during long-term chemotherapy in these patients, the authors used the VP shunt system as an external ventricular drain.

Materials and Methods: The shunt valve was placed under the skin of the head and peritoneal tube of the VP shunt was brought out from the chest wall and connected to the drainage bag. We performed this method in 5 cases. Case 1 was a 3-year-old girl with an atypical teratoid/rhabdoid tumor, case 2 was a 2-month-old girl with an immature teratoma, case 3 was a 9-year-old boy with a medulloblastoma, case 4 was a 6-year-old boy with a pineoblastoma, and case 5 was a 9-year-old boy with an embryonal tumor with multilayered rosettes. In these cases, hydrocephalus was not resolved following tumor removal, and the authors performed ventricular drainage using a VP shunt tube because of a positive CSF cytology. In cases 1, 2, 3, and 4, the CSF cytology was negative after chemotherapy. In cases 1 and 2, ventricular drainage was changed to a VP shunt. In case 3 and 4, the ventricular drainage was removed. In case 5, he died of the tumor 90 days after drainage.

Results: The duration of drainage was 200 days or longer except for case 5. CSF infection or shunt slipping did not occur during the drainage period. When necessary, by carrying the drainage bag in the backpack, the patient could walk around and stay out of the hospital overnight.

Discussion: Using a VP shunt tube as ventricular drainage reduces the possibility of peritoneal seeding of the tumor, minimizes the risk of CSF infection and leakage, prevents the tube from slipping, and enhances daily life activities. With this method, physical and mental challenges in the patient’s daily life can be considerably reduced.

Unilateral hydrocephalus (a situation whereby one lateral ventricle is dilated) is a relatively rare condition. Many cases result from morphological obstruction of the foramen of Monro (congenital atresia, tumor, cyst, etc.) or membranous obstruction of the foramen of Monro (inflammation due to infection or hemorrhage). However, we report a case of a 4-year-old boy who presented with unilateral hydrocephalus without an obvious obstruction of the foramen of Monro. It was discovered accidentally while exploring the cause of optic disc edema. We performed a neuroendoscopic exploration before surgery because of the unilateral hydrocephalus caused by a membranous obstruction of the foramen of Monro. However, neuroendoscopic observation revealed stenosis of the foramen of Monro, covered by the choroid plexus, suggesting some check valve function. After endoscopic septostomy, there was a marked dilatation of one lateral ventricle and relieve of the optic disc edema. In this case, we demonstrated the pathophysiology of unilateral hydrocephalus and the usefulness of endoscopic treatment.

It is well-known that Down syndrome is sometimes associated with leukemia. A relationship between Down syndrome and brain tumors has also been reported. We report the case of an 8-year-old boy with Down syndrome who developed right hemiparesis. Computed tomography and magnetic resonance imaging revealed a mass lesion in the left basal ganglia. Needle biopsy was performed. Histological evaluation of the surgical specimen revealed a germinoma. The patient underwent chemotherapy and irradiation. In patients with Down syndrome, solid tumors are extremely rare. We reviewed such rare cases of intracranial germ cell tumors in patients with Down syndrome.

Spinal epidermoid cysts are a rare pathology that accounts for approximately 1% of all spinal cord tumors and can be classified as either congenital or acquired. Most congenital spinal epidermoid cysts are associated with spinal dysraphism. Herein, we report the case of a 39-month-old female patient developed a congenital lower thoracic intramedullary epidermoid cyst unrelated to spinal dysraphism combined with the retained medullary cord. The patient was admitted with progressive paraparesis. Magnetic resonance imaging (MRI) revealed a well-defined intramedullary mass lesion at the T11-12 level exhibiting isointensity on the T1-weighted and hyperintensity on the T2- and diffusion-weighted images. Furthermore, MRI findings demonstrated the retained medullary cord extending to the lower position due to tapering of the conus without visual clue interruption. Surgical removal of the spinal tumor was accomplished via T9-T12 laminectomy. Following a dorsal midline myelotomy, a milky colored fluid seeped out of the tumor cavity, and a dark-reddish wall structure was identified on the surface that was then near-totally removed. The pathology-confirmed diagnosis was an epidermoid cyst with stratified squamous epithelium. The incidence of pediatric intramedullary spinal epidermoid cyst is rare. Postoperatively, the patient’s neurological symptoms completely recovered within a few weeks with no recurrence, and full Karnofsky Performance Status was achieved at the 2-year follow-up. Continuous patient follow-up will be necessary for several years.

Background: A retained medullary cord (RMC) is a rare, closed spinal dysraphism caused by regression failure of the medullary cord during secondary neurulation. An RMC is a robust elongated cord-like structure extending continuously from the conus medullaris to the dural cul-de-sac. An RMC often causes tethered cord syndrome, evident by the absence of conus medullaris and filum terminal formation on magnetic resonance imaging (MRI) and intraoperative observation. The histopathology of the resected RMC is characterized by an ependyma-lined stratified cavity with a neuroglial core. A three-dimensional (3D) exoscope has recently become available for use in neurosurgical operations. It is compact; therefore, it provides a larger working space than that attained with the operating microscope. Herein, we report a case of an RMC with terminal meningocele that was surgically treated using a 3D exoscope.

Case presentation: A 2-month-old girl presented with a sacrococcygeal dimple at birth. She had no neurological deficits. MRI at 6 days old revealed a robust elongated spinal cord without formation of the conus medullaris and a cystic lesion on the ventrocaudal side of the dural sac. The lesion did not appear hyperintense on diffusion-weighted images. T2-weighted MRI obtained at 2 months revealed another cyst protruding into the subcutaneous tissue. We performed untethering and repair of the meningocele using a 3D exoscope. After opening the dura, a cord-like structure and a cyst at the ventrocaudal side of the dural sac were detected. The non-functioning cord-like structures were identified and resected to achieve untethering of the cord. The histopathology of the resected lesion showed a pseudostratified ependyma-lined cavity. Considering the above findings, we diagnosed the patient with an RMC. As there was no communication between the intra-arachnoid space and sacrococcygeal dimple, dermal sinus was excluded. Total resection of the RMC should be performed if the RMC is associated with a dermoid or epidermoid cyst. It is essential to keep RMC in mind and formulate a preoperative treatment strategy in cases of tethered cord with terminal meningocele.

We report a case of delayed radiation necrosis of the cerebellum that occurred 16 years after the treatment of medulloblastoma. A 24-year-old male who had a history of radiotherapy for medulloblastoma when he was 8 years old, visited our hospital because of mild ataxia. MRI revealed a 1 cm-size Gd-enhanced lesion in the right middle cerebellar peduncle. Open biopsy was performed, and the lesion was diagnosed as radiation necrosis. When a new lesion appears during a long-term follow-up after treatment for medulloblastoma, the possibility of radiation necrosis should be reminded.

We report the case of a patient in whom a radiation-induced cerebellar glioblastoma occurred 36 years after radiation therapy for germinoma. The patient had received cobalt irradiation (whole brain, 50 Gy) for germinoma treatment when he was 14 years old. Magnetic resonance imaging revealed a tumor in the left cerebellar hemisphere when the patient turned 50 years old, and this tumor was removed. The histopathological diagnosis of the tumor confirmed that it was a glioblastoma NOS. He received chemoradiotherapy with temozolomide and CyberKnife. It is necessary to perform a long-term follow-up after radiation therapy, and patients should be informed about the adverse effects of radiation therapy.