Diversity and inclusion are required to improve the efficiency of social activities. The clinical field is no exception. The involvement of people from various social backgrounds and the convergence and resonance of different views and ideas make it possible to address complex medical issues. This paper examined the prospects of treating pediatric brain tumors based on this concept.

  First, pediatric brain tumors are a very diverse group of diseases. The age of onset also varies widely. In other words, since children are growing and developing, the physical, psychological, and environmental factors differ greatly depending on the child's age. Therefore, the tumors that develop are also very different from those in adults. Furthermore, the classification of pediatric brain tumors and the definitions of tumor types are changing dramatically. The molecular biological characteristics of pediatric brain tumors are more reflective of the clinical presentations than the classifications based on histopathological similarities. Therefore, advances in molecular physical analysis techniques have inevitably led to new classifications of tumor types.

  Under a newly proposed classification, medulloblastomas is divided into at least four clinically and molecularly distinct groups, which have been further subdivided into 12 subtypes. Ependymal tumors are classified into nine subsets. What was once a single tumor type has been subdivided into multiple subtypes.

  However, no appropriate treatment has been proposed for each tumor subtype. Consequently, new classifications do not necessarily lead to an improved prognosis. In the future, it is necessary to find a treatment for each of these tumor types through the collaborative efforts of individuals with various knowledge and expertise in this field. To this end, promoting follow-ups and social acceptance after the cure of pediatric brain tumors is essential. It is expected that the treatment and prognosis of pediatric brain tumors will improve as society becomes more inclusive.

  Cerebrovascular disease in children is classified by age into perinatal stroke and childhood stroke. Pathophysiologically, the condition can also be classified as arterial ischemic stroke (AIS), cerebral sinovenous thrombosis, and hemorrhage. AIS is the most common cause of perinatal stroke, while hemorrhage is the dominant pathophysiology in childhood stroke. Infants with moyamoya disease (MMD) exhibit poor outcomes and a high prevalence of cerebral infarction. Preventing cerebral infarction in infants with MMD awaiting surgery is an important priority. The internal carotid artery bifurcation is a common site of cerebral aneurysms in children. Children are also characterized by a high prevalence of giant aneurysms. Moreover, in children with new and enlarging aneurysms, comorbidities, the fusiform shape, and parent artery occlusion are significant risk factors. The hemorrhage-related mortality rates of arteriovenous malformations (AVMs) in children are higher than those in adults. The resection of AVMs in children is safe and associated with high rates of angiographically confirmed obliteration. The outcomes of stereotactic radiosurgery for AVMs in children are comparable to those in adults. Long-term post-resection follow-up imaging is necessary to promptly detect AVM recurrence in children.

  Diagnosis of fetal hydrocephalus is challenging, and ventriculomegaly unassociated with increased intracranial pressure is often misdiagnosed as fetal hydrocephalus. Several conditions including chromosomal abnormalities and multiple anomaly syndromes may cause ventricular dilatation, and diagnosis and prediction of prognosis based solely on imaging studies is difficult.

  Diagnosis of fetal ventriculomegaly is defined based on the atrial width (AW). AW does not exceed 10 mm from week 15 to 40 of gestation; therefore, an AW of ≥10 mm is defined as ventriculomegaly. In addition to ventricular dilatation, disappearance of the subarachnoid space or enlargement of the head circumference leads to a high index of clinical suspicion for hydrocephalus. Despite technological advances in fetal diagnostics, accurate diagnosis remains limited, and extensive knowledge regarding potential underlying causes is warranted.

  Between 2012 and 2020, 104 fetuses diagnosed with ventriculomegaly at our hospital underwent fetal magnetic resonance imaging at a mean gestational age of 27 weeks. We detected hydrocephalus in the narrow sense in 47 fetuses, and 57 fetuses had ventricular enlargement without hydrocephalus. The underlying etiology consisted of 19 diseases, and 20 cases were undiagnosed.

  In this report, we present a brief overview of intrauterine myelomeningocele treatment and pre-implantation diagnosis of X-linked hydrocephalus.

  Extraventricular neurocytoma (EVN) is a rare neuronal neoplasm that originates outside the ventricle. We report the case of a 27-year-old woman with an EVN involving the sellar region. The patient had irregular menstruation and visited our hospital for evaluation. Brain magnetic resonance imaging (MRI) revealed a solid sellar mass. She underwent endoscopic endonasal transsphenoidal surgery (eTSS), and the tumor was partially resected. Histopathological evaluation showed a glial tumor. Follow-up MRI performed 18 months later revealed enlargement of the residual lesion. The patient underwent repeat eTSS for subtotal resection of the lesion. Histopathological findings showed oligodendroglia-like cells, and immunohistochemical analysis showed cells that were immunopositive for synaptophysin and neuronal nuclei and immunonegative for glial fibrillary acidic protein and isocitrate dehydrogenase 1 R132H. The patient was definitively diagnosed with EVN. She underwent Gamma knife radiosurgery postoperatively with reduction in the size of the residual lesion.

  Rete middle cerebral artery (MCA), a relatively rare variant, has a plexiform arterial network and stenosis or occlusion at the proximal legion. Rete MCA is also called twig-like or unfused MCA. We demonstrate three cases of rete MCA. One case presented with intracranial hemorrhage and a hematoma was removed. The other cases were incidentally noted and one of them had a plexiform arterial network at the M2 legion. Rete MCA is sometimes misdiagnosed as moyamoya disease or degenerative steno-occlusive disease. No diagnostic criteria of rete MCA have been determined, nor has the best treatment strategy been determined. We need further studies that decide treatment strategies of each case.

  This report describes a case of granulomatous amebic encephalitis (GAE) that was detected early and treated.

  We report the case of a 43-year-old man. He was taken by ambulance to his previous hospital with the left hemiplegia. Cranial magnetic resonance imaging (MRI) revealed sporadic multiple mass lesions in the bilateral cerebral hemispheres and widespread cerebral edema in the right frontal lobe. Subsequently, the patient was referred to our hospital. Diffusion-weighted imaging (DWI) of MRI showed high signals in the lesions. Contrast-enhanced computed tomography revealed a ring-like enhancement. Susceptibility-weighted imaging (SWI) of MRI revealed microhemorrhage within the lesions. Craniotomy was performed to collect biopsy samples. Periodic acid-Schiff staining suggested amebic encephalitis. Medication therapy was initiated at an early postoperative stage, and the patient was temporarily in remission. However, because some of the lesions grew in size, craniotomy was performed again to remove them. Based on the results of the scrutiny at the National Institute of Infectious Diseases, the GAE caused by Balamuthia mandrillaris or other free-living amoebas was diagnosed. As of 1 year after the initial examination, we are continuing pathological investigation while treating the patient on an ambulatory basis.

  Although amebic encephalitis has a high fatality rate, there have been reports of survival that was achieved by the combination of medical and surgical treatments. The key is to obtain a diagnosis at an early stage. This case also suggested the effectiveness of SWI in understanding hemorrhagic changes in lesions.