Suprasellar masquerader: Chordoid glioma.

BACKGROUND: Chordoid glioma is a rare well-circumscribed glial neoplasm arising in adults and predominantly affects females. Tanycytes of the third ventricle have been proposed as the cell of origin owing to its location. It is characterized by chordoid features with myxoid and inflammatory stroma and recurrent PRKCA p.D463H missense mutation. CASE REPORT: We present two cases (30-year-old female and 45-year-old male) with similar complaints of behavioral change and headache. Midline suprasellar homogeneously enhancing mass was seen on contrast-enhanced magnetic resonance imaging. Histopathology and immunohistochemistry was characteristic of chordoid glioma with cords and clusters of epithelioid cells arranged in a solid pattern. There were variable amounts of myxoid stroma and lymphoplasmacytic infiltrate. No mitosis, necrosis, or brain invasion was noted. The cells expressed strong diffuse positivity for glial fibrillary acid protein (GFAP) and weak nuclear thyroid transcription factor (TTF-1). Epithelial membrane antigen (EMA)and brachyury were negative. Subsequently, the lady underwent gross total excision and died soon after the operation. The male patient received radiotherapy and is currently doing well after 6 months of follow-up. CONCLUSION: The rare occurrence as well as the radiological and morphological overlaps in chordoid gliomas make them a true masquerader. Combination of GFAP and TTF-1 in the immunohistochemical panel can be useful in differential diagnosis. Mainstay of treatment is complete surgical excision, with adjuvant radiotherapy becoming increasingly important.

Fourth ventricle tumors in children: complications and influence of surgical approach.

OBJECTIVES: The goal of this study was to characterize the complications and morbidity related to the surgical management of pediatric fourth ventricle tumors. METHODS: All patients referred to the authors' institution with posterior fossa tumors from 2002 to 2018 inclusive were screened to include only true fourth ventricle tumors. Preoperative imaging and clinical notes were reviewed to extract data on presenting symptoms; surgical episodes, techniques, and adjuncts; tumor histology; and postoperative complications. RESULTS: Three hundred fifty-four children with posterior fossa tumors were treated during the study period; of these, 185 tumors were in the fourth ventricle, and 167 fourth ventricle tumors with full data sets were included in this analysis. One hundred patients were male (mean age ± SD, 5.98 ± 4.12 years). The most common presenting symptom was vomiting (63.5%). The most common tumor types, in order, were medulloblastoma (94 cases) > pilocytic astrocytoma (30 cases) > ependymoma (30 cases) > choroid plexus neoplasms (5 cases) > atypical teratoid/rhabdoid tumor (4 cases), with 4 miscellaneous lesions. Of the 67.1% of patients who presented with hydrocephalus, 45.5% had an external ventricular drain inserted (66.7% of these prior to tumor surgery, 56.9% frontal); these patients were more likely to undergo ventriculoperitoneal shunt (VPS) placement at a later date (p = 0.00673). Twenty-two had an endoscopic third ventriculostomy, of whom 8 later underwent VPS placement. Overall, 19.7% of patients had a VPS sited during treatment.Across the whole series, the transvermian approach was more frequent than the telovelar approach (64.1% vs 33.0%); however, the telovelar approach was significantly more common in the latter half of the series (p < 0.001). Gross-total resection was achieved in 70.7%. The most common postoperative deficit was cerebellar mutism syndrome (CMS; 28.7%), followed by new weakness (24.0%), cranial neuropathy (18.0%), and new gait abnormality/ataxia (12.6%). Use of intraoperative ultrasonography significantly reduced the incidence of CMS (p = 0.0365). There was no significant difference in the rate of CMS between telovelar or transvermian approaches (p = 0.745), and multivariate logistic regression modeling did not reveal any statistically significant relationships between CMS and surgical approach. CONCLUSIONS: Surgical management of pediatric fourth ventricle tumors continues to evolve, and resection is increasingly performed through the telovelar route. CMS is enduringly the major postoperative complication in this patient population.

Minimally Invasive Parafascicular Surgical Approach for the Management of a Pediatric Third Ventricular Ependymoma: Case Report and Review of Literature.

BACKGROUND: Minimally invasive parafascicular surgery (MIPS) has evolved into a safe alternative to access deep-seated subcortical and intraventricular pathologies. We present a case of a port-mediated resection of a pediatric third ventricular tumor. CASE DESCRIPTION: The patient is a 7-year-old boy who presented with worsening headache, nausea, vomiting, dizziness, unsteady gait, photophobia, and blind spots with positional changes. Magnetic resonance imaging (MRI) scan revealed a large isointense mass, with areas of hyperintensities suggestive of intratumoral hemorrhage, centered in the posterior segment of the third ventricle with extension into the aqueduct of Sylvius. The superior frontal sulcus was used as an access corridor for the port to the frontal horn of the lateral ventricle en route to the third ventricle. Intraoperative visualization was aided with a 3-dimensional exoscopic system. After cannulation, the tumor was seen within the foramen of Monro and tethered to the thalamostriate vein. The tumor was removed completely, with the exception of small residual attached to the thalamostriate vein, which was left intentionally. A flexible endoscope was placed through the port to verify the absence of residual along the superior wall of the third ventricle. Intraoperative MRI scan confirmed presence of residual, along with normal postoperative changes, including pneumocephalus. Postoperative MRI scan revealed cortical recovery along the sulcal path and resolution of ventriculomegaly. CONCLUSIONS: The patient improved from baseline, with no remaining visual deficits, headaches, or balance issues. Pathology reported a World Health Organization grade II tanycytic ependymoma. To our knowledge, few cases have reported the utilization of port-based MIPS in pediatric patients.

Squash cytology of a case of medulloblastoma with myogenic differentiation.

Medulloblastoma with myogenic differentiation is not a distinct entity but a pattern of differentiation seen in <1% of medulloblastomas. Although squash cytology of medulloblastoma is well described, there are no reports available describing squash cytomorphology of this unusual variant of medulloblastoma. Intraoperative squash smears on a 2-year-old girl with a midline posterior fossa space occupying lesion revealed features of an embryonal tumor composed of small, round, and blue cells. In addition, it had several large, round, eosinophilic rhabomyoblasts, and a few strap cells scattered among the sea of small blue cells. Subsequent histology showed features of a medulloblastoma, classic type with myogenic differentiation. Molecular subtyping, based on immunohistochemistry alone, was in keeping with a non-Wnt/non-SHH activated type. Here we describe the squash cytomorphological details of a case of medulloblastoma with myogenic differentiation, along with its cytological differentials.

Role of endoscopic surgical biopsy in diagnoses of intraventricular/periventricular tumors: review of literature including a monocentric case series.

The intra- and periventricular location tumor (IPVT) of a brain remains a hard challenge for the neurosurgeon because of the deep location and eloquent anatomic associations. Due to this high risk of iatrogenic injury, many surgeons elect to perform biopsies of such lesions to establish a diagnosis. On the one hand, stereotaxic needle biopsy (SNB) is a minimally invasive procedure but with a significant risk of complications and a high risk of lack of tissue for molecular analyses for this region [Fukushima in Neurosurgery 2:110-113 (1978)]; on the other hand, the use of endoscopic intraventricular biopsy (EIB) allows for diagnosis with minimal surgical intervention [Iwamoto et al. in Ann Neurol 64(suppl. 6):628-634 (2008)]. IPVTs and related CSF pathway obstructions can be safely and effectively treated with endoscopic techniques. It is not possible to compare EIB with diagnoses made by any other method or with the established treatment. We aim to analyze the accuracy of EIB results by comparing them with results of biopsies performed later, in other methods and thereby evaluating the treatment evolution considering our personal experience. The difficulties and complications encountered are presented and compared with those reported in the literature to obtain the best review possible for this topic. A systematic review of literature was done using MEDLINE, the NIH Library, PubMed, and Google Scholar yielded 1.951 cases for EIB and 1912 for SNB, according to standard systemic review techniques. Review was conducted on 50 studies describing surgical procedures for lesions intra- and para-ventricular. The primary outcome measure was a diagnostic success. We also consider 20 patients with IPVT treated in our department. Clinical characteristics and surgical outcome were evaluated and a systematic review of the literature was performed. Overall, all our biopsies were diagnostic, with a positive histologic sample in 100% of our patients. 8 patients underwent a concurrent endoscopic third ventriculostomy. 4 patients underwent a concurrent ventriculostomy combined with septostomy. For 1 patient was necessary the only septostomy combined with biopsy. Every case has obtained a histological diagnosis. The percentage of complications was very low with only 1 case of post-operative infection and 1 case of hemorrhage. It was impossible to create a specific comparison from literature data of IPVTs between a stereotactic and endoscopic procedure, it presents only the collection of pineal gland tumor [Kelly in Neurosurgery 25(02):185-194 (1989); Quick-Weller in World Neurosurgery 96:124-128 (2016)] or unknown location of the lesion in major review [Marenco-Hillembrand et al. in Front Oncol 8:558 (2018)]. The present study aims to report our experience with the surgical management of IPVTs. The EIB sample yields an accurate histologic diagnosis tumor, with a positive histologic sample in 87, 95% of patients. The choice of the appropriate procedure should consider not only the preference and the experience of the neurosurgeon but also the several other variables as the location. While some periventricular lesions are better approached by endoscopic techniques, others are more suited for stereotactic-guided approaches. The ability to perform an EIB and relieve tumor-associated hydrocephalus by neuroendoscopy is considered to be a benefit of this procedure since this is less invasive than other treatments.

Is This Truly A "Leave-Me-Alone" Lesion? An Unusual Case of Multiple Ring-shaped Lateral Ventricular Nodules.

BACKGROUND: Ring-shaped lateral ventricular nodules (RSLVNs) are commonly considered as benign asymptomatic lesions, which are sporadically detected as incidental findings on routine brain magnetic resonance imaging scans. Despite their not irrelevant frequency, the exact biological nature of these lesions remains largely unknown due to the lack of histopathologic studies. Here we present the clinical, neuroradiologic, and histopathologic findings of an unusual case of symptomatic multiple RSLVNs. CASE DESCRIPTION: A 44-year-old otherwise healthy man presented with a recent history of headache and retching. Neuroradiologic imaging revealed the presence of multiple RSLVNs, the largest of which, located in the cella media of the right lateral ventricle, exerted a mild to moderate mass effect on adjacent brain parenchyma. This latter nodule was successfully removed, with complete resolution of the symptoms. Histopathology revealed glial differentiation, and the specimen was diagnosed as subependymoma. CONCLUSIONS: This report provides novel evidence characterizing RSLVNs as possible variants of subependymoma with a peculiar imaging appearance, also suggesting that, like subependymomas, they may occasionally grow large enough to cause mass effect-related symptoms, thus requiring neurosurgical intervention.

Diagnosis of a Rare Intraventricular Schwannoma.

BACKGROUND: Intraventricular schwannoma is extremely rare, with only 35 cases reported to date in the literature. Consequently, its etiology and pathogenesis are still unclear, and therefore require further investigations. Here, we report on and discuss a rare case of intraventricular schwannoma to elucidate on this matter. CASE DESCRIPTION: A 26-year-old man was admitted to our institution with a 1-month history of headaches and left hemianopsia. At diagnosis, magnetic resonance imaging of the brain revealed a well-demarcated mass with surrounding edema in the right lateral ventricle. Total resection of the tumor was performed by a transsulcal approach through the right parietal lobe. In surgery, it was observed that the tumor was attached to the choroid plexus without invading the wall of the right lateral ventricle. The respective histologic examination confirmed the diagnosis of intraventricular schwannoma. Six months after the surgery, there was no recurrence. Additionally, during this follow-up period, the patient did not develop any neurologic deficit, including visual field narrowing or parietal symptoms, such as acalculia and right-left, finger, and space agnosias. CONCLUSIONS: Although intraventricular schwannomas are rare, 35 cases have already been reported to date. We emphasize the importance of diagnosing such cases correctly to increase knowledge on the origin and pathogenesis of intraventricular tumors, which would facilitate disease management.

[Fourth ventricle meningiomas. A case report and literature review]. / Meningiomy IV zheludochka golovnogo mozga. Sluchai iz praktiki i obzor literatury.

Intraventricular meningiomas are rare and account for approximately 0.5 to 3% of all meningiomas and 9.8 to 14% of all intraventricular tumors. Most rarely, intraventricular meningomas occur in the third and fourth ventricles. The article reviews the literature devoted to meningiomas of a rare localization, in the fourth ventricle. On the basis of published surgical procedures and neuroimaging data, we divided posterior cranial fossa meningiomas into tumors completely located in the fourth ventricle cavity and those with a partial intraventricular component, which are not associated with any structures outside the ventricle. The reason for this study was our own clinical observation.

Rosette-forming and papillary glioneuronal tumors - A clinicopathological and molecular analysis.

INTRODUCTION: Rosette-forming glioneuronal tumors (RGNT) and papillary glioneuronal tumors (PGNT) account for < 1% of brain tumors. Genetic data regarding RGNT and PGNT is still evolving. We aimed to perform a detailed clinicopathological analysis on rosette-forming and papillary glioneuronal tumors and to evaluate these for common, known genetic mutations. MATERIALS AND METHODS: Our cohort consisted of 6 cases of these rare glioneuronal tumors diagnosed over a period of 5 years. IDH1, ATRX, p53, and BRAF V600E mutations were evaluated on immunohistochemistry, and cases of RGNT were screened for the mutations in PIK3CA gene at hotspots exon 4, 9, and 20. RESULTS AND CONCLUSIONS: Our findings confirm the presence of PIK3CA gene mutations in RGNT along with two novel mutations in PIK3CA gene, of which one is proposed to be of prognostic significance.
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Unusual Intraventricular Tumor Mimicker; Choroid Plexus Arteriovenous Malformation.

Arteriovenous malformations (AVMs) are basically abnormal vessel networks consisting of one or more feeding arteries, central nidus, and dilated drainage veins. They are divided into subtypes as fistulose, mixed (fistulose-plexiform), or plexiform. Intraventricular location of AVMs is unusual. In this location, the lesion may mimic neoplastic processes. Here the authors reported uncommon case of an AVM located in the right choroid plexus presenting with intraventricular hemorrhage.

Visual-Controlled Endoscopic Biopsy of Paraventricular Intraparenchymal Tumors.

OBJECTIVE: Frame-based stereotaxy represents the gold standard for biopsy of deep-seated lesions. Visual control of possible bleeding in these lesions is not possible. Neuroendoscopic biopsy represents an alternative procedure for tissue sampling in deep-seated intraventricular lesions. The authors present a technique for transventricular-navigated endoscopic biopsy of lesions that are located in the paraventricular region. METHODS: Biopsy of paraventricular pathologies was performed in 6 male and 6 female patients between March 2013 and September 2018. The patient age ranged from 18 to 82 years. All patients underwent a pure endoscopic procedure over a burr hole trepanation supported by frameless navigation of the sedan probe. RESULTS: Histologic diagnoses were established in all biopsies. In all patients, a direct control of the biopsy area was feasible, and hemostasis could be obtained. In 5 patients, endoscopic third ventriculostomy was performed first due to obstructive hydrocephalus. In 1 patient suffering from obstructive hydrocephalus, a pellucidotomy was performed. In 9 cases, the initial postoperative course was uneventful. Three patients suffered from persistent hydrocephalus and had to be treated with ventriculoperitoneal shunt insertion. CONCLUSIONS: Endoscopically conducted biopsies with the aid of navigated tracking of the probe represent a possible additional technique in selected paraventricular intraparenchymal pathologies. The endoscopic approach enables the direct visualization of the intraventricular surface and its vessels. In contrast to standard stereotactic biopsy, direct visual control of hemostasis can be obtained even in paraventricular tumors.

Supratentorial high-grade astrocytoma with leptomeningeal spread to the fourth ventricle: a lethal dissemination with dismal prognosis.

PURPOSE: Leptomeningeal spread to the fourth ventricle (LSFV) from supratentorial high-grade astrocytoma (HGA) is rarely investigated. The incidence and prognostic merit of LSFV were analyzed in this study. METHODS: A consecutive cohort of 175 patients with pathologically diagnosed HGA according to the 2016 WHO classification of brain tumors was enrolled. LSFV was defined as radiological occupation in the fourth ventricle at the moment of initial progression. Clinical, radiological, and pathological data were analyzed to explore the difference between HGA patients with and without LSFV. RESULTS: There were 18 of 175 (10.3%) HGAs confirmed with LSFV. The difference of survival rate between patients with LSFV or not was significant in both overall survival (OS) (14.5 vs. 24 months, P = 0.0007) and post progression survival (PPS) (6.0 vs. 11.5 months, P = 0.0004), while no significant difference was observed in time to progression (TTP) (8.5 months vs. 9.5 months P = 0.6795). In the Cox multivariate analysis, LSFV was confirmed as an independent prognostic risk factor for OS (HR 2.06, P = 0.010). LSFV was correlated with younger age (P = 0.044), ventricle infringement of primary tumor (P < 0.001) and higher Ki-67 index (P = 0.013) in further analysis, and the latter two have been validated in the Logistic regression analysis (OR 18.16, P = 0.006; OR 4.04, P = 0.012, respectively). CONCLUSION: LSFV was indicative of end-stage for supratentorial HGA patients, which shortened patients' PPS and OS instead of TTP. It's never too cautious to alert this lethal event when tumor harbored ventricle infringement and higher Ki-67 index in routine clinical course.

Neuroendoscopic Intraoperative Ultrasound-Guided Technique for Biopsy of Paraventricular Tumors.

Different tumors can be encountered in the paraventricular regions, and whereas their deep location often make them difficult to access surgically, they may be amenable to chemotherapy and/or radiotherapy. Therefore, tumor biopsy and histologic diagnosis are mandatory to optimize treatment. Different technical procedures have been recommended; the neuroendoscopic approach is accepted and widely used, in particular with an enlarged ventricular system. However, specifically with paraventricular tumors, tissue sampling may be challenging. In such a scenario, the use of intraoperative ultrasonography technique can add some advantages regarding diagnostic accuracy and procedure safety. Accordingly, in this study we describe a novel technical procedure in 7 selected patients in whom tumor tissue biopsy was performed in a coupled neuroendoscopic and ultrasound-guided environment. We define a neuroendoscopic intraoperative ultrasound technique. The main advantages of this technique are the identification of the tumor that may not been clearly identified underneath the ventricular ependymal through the neuroendoscopic window alone, and furthermore, that this technique gives the possibility to detect the depth of the needle advance∖ment in the selected tissue while labeling the lesion beneath the ventricular ependyma. Moreover, intraoperative ultrasonography can reveal in a real-time fashion intracranial hemorrhages that may occur after tissue biopsy, therefore providing a useful tool to achieve valid and directed hemostasis when needed.

Flexible Neuroendoscopic Diagnosis and Management of Ventricular Tumors: A Retrospective Cohort Study.

BACKGROUND: Ventricular tumors (VTs) represent approximately 10% of intracranial lesions and are associated with hydrocephalus in 73.9%-100% of patients. We present our experience using flexible neuroendoscopy as a diagnostic and hydrocephalus-related treatment strategy for paraventricular and intraventricular tumors. METHODS: This retrospective cohort included 27 pediatric and 21 adult patients with paraventricular or intraventricular tumors treated with flexible neuroendoscopy. Terminally ill patients and patients with incomplete data were excluded. RESULTS: Male and female patients comprised 52% and 48% of the population, respectively. Mean patient age was 20.45 years (±18.65 SD). The most common tumor location was the thalamic and pineal region. Conclusive pathologic diagnosis was obtained in 40 patients (83.3%); the most common type of tumor was astrocytoma. Hydrocephalus was present in 38 (79.1%) patients, who were treated successfully with endoscopic procedures. There were no major complications. CONCLUSIONS: Flexible neuroendoscopy is a strategic tool for diagnosis of VTs, especially in patients with associated hydrocephalus and VTs unreachable by other means. Flexible neuroendoscopy has a high rate of definitive diagnosis with low associated complications. More studies evaluating the long-term efficacy of flexible neuroendoscopy for hydrocephalus associated with VTs are needed.

Schwannoma of the Fourth Ventricle: Report of Two Cases and Review of Literature.

BACKGROUND: Schwannomas have been reported in several unusual intracranial locations. Here we report 2 cases of extremely rare schwannomas originating in the fourth ventricle, without attachment to the surrounding structures. The clinical course, radiologic and pathological features, treatment, and follow-up are described. CASE DESCRIPTION: Case 1 was a 49-year-old man who presented with symptoms of paroxysmal dizziness and vomiting. Magnetic resonance imaging (MRI) showed a mixed solid-cystic mass occupying the inferior half of the fourth ventricle. Complete excision of the tumor was performed via midline suboccipital craniectomy. The histological diagnosis was intraventricular schwannoma. Case 2 was an 18-year-old man with chronic vertigo and progressive gait unsteadiness. MRI revealed a heterogeneously enhancing lesion completely filling the fourth ventricle. An Ommaya tube was placed in the ventricle to relieve symptoms of hydrocephalus, followed by tumor resection performed via a suboccipital craniotomy. Histopathological examination confirmed the diagnosis of schwannoma. CONCLUSIONS: Fourth ventricular schwannomas are rare but should be considered in the differential diagnosis of contrast-enhancing intraventricular tumors in both children and adults. Although their etiopathological origin may differ from that of extra-axial schwannomas, their imaging, histology, and clinical course appear to be identical, and these tumors should be managed similarly.