Subependymoma (SE) is a rare, usually asymptomatic, brain tumor predominantly affecting older adults and occurring in the fourth and lateral ventricles. We report a rare case of SE with intratumoral hemorrhage that could be removed by neuroendoscopy. The 81-year-old patient had been followed as an outpatient for 10 years due to an intraventricular tumor. It did not grow over the patient\'s lengthy follow-up. The patient was transferred to our hospital after he fainted near his home; at the time of admission, he had mild consciousness disturbance, and his Glasgow Coma Scale score was 10 points (E3V3M4). Computed tomography showed intratumoral hemorrhage and slight ventricular enlargement. Magnetic resonance (MR) imaging showed a 4 cm-sized tumor in the anterior horn of the right lateral ventricle. The lesion appeared as a mixed-intensity solid tumor and showed irregular enhancement with gadolinium. The patient underwent neuroendoscopic tumor resection on the 30th day of the patient\'s hospital stay. A histopathological examination revealed small tumor cells with round nuclei scattered in the glial fibrillary background. Immunostaining was positive for glial fibrillary acidic protein; these findings are consistent with an SE diagnosis. The patient in this study had hypertension and used anticoagulants, risk factors for intratumoral hemorrhage. For intraventricular tumors with bleeding-particularly in older or more physically frail patients-minimally invasive neuroendoscopic surgery should be considered an option for tumor resection.

Trigeminal neuralgia (TN) is characterized by lightning pain paroxysms in the somatosensory distribution of the trigeminal nerve accompanied by hypersensitivity to non-nociceptive stimuli. Epidermoid cysts sometimes cause TN. To plan the surgery, constructive interference in steady state (CISS) image is useful for understanding the tumor\'s location, extent, and relationship against the cranial nerves, and epidermoid cysts are shown as hypointense compared to cerebrospinal fluid (CSF). However, we herein describe a case with TN due to epidermoid cysts, whose intraoperative findings are different from the preoperative and postoperative CISS image. A 49-year-old woman has suffered from TN. CISS images revealed the prolonged trigeminal nerve and the hypointense tumor compared to the CSF at the right cerebellopontine angle. CISS image suggested that the tumor would surround the trigeminal nerve, reach into the Meckel cavity, and offend and compress the trigeminal nerve\'s root entry zone (REZ). However, contrary to our expectation, the trigeminal nerve was not surrounded by the tumor. Neuroendoscope revealed that the tumor compressed the REZ, but the tumor was not present in the Meckel cavity. We performed partial tumor removal around the trigeminal nerve, and her symptoms improved. However, the postoperative CISS image was similar to the preoperative one, and so we could not evaluate the remaining tumor. The pathological diagnosis was epidermoid cysts. Intraoperative findings are sometimes different from the pre- and postoperative CISS images, making it difficult to follow up the remaining part of the epidermoid cyst.

Intraorbital tumor could be approached by numerous surgical methods. The neuroendoscopic endonasal approach could provide a feasible corridor for indicated tumors. Herein we present a series of 6 consecutive intraorbital tumors from April 2018 to October 2020, which received endonasal endoscopic resection. Cadaveric dissection was performed for the intraconal approach, and the literature was also reviewed. Five tumors were located intraconally, while one extraconally. The pathology revealed 1 angioleiomyoma, 1 cavernous hemangioma, 1 pilocytic astrocytoma, 1 meningioma, and 2 schwannomas. Five of the six achieved gross total resection, including 3 tumors with lateral extension beyond the optic nerve. Preoperative visual deterioration was observed in 4 of the 6 patients, and all got improvement postoperatively. Transient oculomotor nerve palsy was presented in one patient postoperatively. No cerebrospinal fluid leakage, enophthalmos, or strabismus was observed. The median follow-up time is 27 months (11~41 months). At the 6-month follow-up, the visual acuity remained unchanged compared with that at discharge. Proptosis was resolved in 2 of the 3 patients; diplopia was improved in one patient. In conclusion, endoscopic endonasal intraconal approach could be suitable for selected pathological conditions, and for both medial or beyond medial extraconal and intraconal orbital tumors.

A 68-year-old female was admitted to our hospital with right-sided hemianopsia. Magnetic resonance imaging (MRI) demonstrated a well-enhanced tuberculum sellae region tumor. The patient underwent surgical tumor resection via an extended endoscopic endonasal trans-sphenoidal approach and the tumor was totally removed. The mass was extremely soft and there was no clear attachment between it and the dura mater. Furthermore, the histopathological findings obtained for the tumor during intra-operative rapid diagnosis were divergent from typical meningioma. We therefore diagnosed the tumor intra-operatively as a pituitary adenoma. However, the post-operative pathological diagnosis for the tumor was chordoid meningioma (CM). CM is a rare subtype of meningioma, and most of such tumors arise in the convexity. In the preoperative MRI in the present case, meningioma was suspected; however, since we did not consider CM for differential diagnosis, we failed to reach an accurate diagnosis during the operation. Tuberculum sellae CM is very rare, and only a few cases have been reported previously. The surgical strategy will differ greatly depending on whether the tumor is a meningioma or a pituitary adenoma, especially when treatment involves the dura mater. The pre and/or intra-operative diagnosis is thus very important for developing an accurate treatment strategy. We report here the details of our rare case and describe the intra-operative features of tuberculum sellae CM.

Migrating intracranial tumors are extremely rare occurrences in the neurosurgery literature. Introduction of any factor causing disequilibrium in cerebrospinal fluid circulation and pressure can potentially precipitate transventricular migration of pedunculated intraventricular lesions. The identification of such factors, prior to excision of intraventricular pedunculated tumors, is imperative to avoid intraoperative mismanagement. We report an extremely rare case of transventricular migration of a choroid plexus carcinoma in an infant, possibly precipitated by a ventriculoperitoneal (VP) shunt on the opposite side. This resulted in intraoperative confusion and a subsequent re-exploration of the opposite side for excision of the tumor. The literature provided only two similar occurrences in the past; however, in both cases, the migration was within the same ventricle and was documented prior to definitive resection. We report the first instance of transventricular migration of a tumor to the opposite ventricle following VP shunt which resulted in a negative intraoperative finding requiring a subsequent re-intervention on the opposite side. We believe that for any pedunculated intraventricular lesion, where an emergency management of hydrocephalus takes priority, a repeat neuroimaging is a must prior to definitive resection.

UNASSIGNED: Basilar aneurysms represent 5%-7% of all intracranial aneurysms. The main goal of open surgery is to achieve complete obliteration of the aneurysmal sac using minimal invasive technique while emphasizing on avoidance of complication.
UNASSIGNED: We performed a retrospective cohort study of nine cases of unruptured basilar tip aneurysm referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Japan. The objective of the study was to analyze the surgical outcomes of unruptured basilar tip aneurysm.
UNASSIGNED: Nine patients with unruptured basilar tip aneurysm were referred to our hospital between 2015 and 2017. The median size of the aneurysm and age were 4.00 mm (interquartile range [IQR] = 3.25-6.75 mm) and 58 years (IQR = 54-70 years), respectively. Five patients (55.6%) were presented with multiple intracranial aneurysms. Surgical adjuncts such as intraoperative neuromonitoring, intraoperative indocyanine green (ICG) angiography with dual-image videoangiography (DIVA), and neuroendoscope were used. Two patients developed transient postoperative oculomotor nerve palsy which resolved spontaneously. The median duration of surgery and days of hospitalization were 292 min (IQR = 237.5-350.5 min) and 12 days (IQR = 12-25 days), respectively. There was no mortality recorded in this case series.
UNASSIGNED: Microsurgical clipping of basilar tip aneurysm is safe in unruptured basilar tip aneurysm with a low risk of postoperative mortality or morbidity. All complications reported in this case series were transient with no long-term sequalae. The improved safety profile of microsurgical technique is due to the availability of intraoperative neuromonitoring, neuroendoscope, ICG, and DIVA. The application of multimodality technique in neurovascular surgery has also helped to achieve complication avoidance. The obliteration of the aneurysmal sac helps to restore the laminar blood flow in the bifurcation and distal blood vessels and improves the brain perfusion.