From the archives of the AFIP. Cerebral intraventricular neoplasms: radiologic-pathologic correlation

Atypical choroid plexus papilloma: Diagnosis and differentials: A case report

Atypical choroid plexus papilloma is a rare World Health Organization grade 2 intraventricular tumor arising from the epithelium of the plexus choroid with intermediate clinical-pathological features between the benign choroid plexus papilloma and the malignant choroid plexus carcinoma. The main criteria for differentiation are histopathologic, with difficulties in distinguishing it from choroid plexus papilloma based on imaging features. We report the case of a 4-year-old female presenting with headaches and altered mental status. Brain magnetic resonance imaging revealed a right lateral ventricular mass with some atypical characteristics, which were confirmed on pathological examination as an atypical choroid plexus papilloma.

Imaging of supratentorial intraventricular masses in children: a pictorial review-part 2

PURPOSE

This article is the second in a two-part series aimed at exploring the spectrum of supratentorial intraventricular masses in children. In particular, this part delves into masses originating from cells of the ventricular lining, those within the septum pellucidum, and brain parenchyma cells extending into the ventricles. The aim of this series is to offer a comprehensive understanding of these supratentorial intraventricular masses, encompassing their primary clinical findings and histological definitions.

METHODS

We conducted a review and analysis of relevant epidemiological data, the current genetics/molecular classifications as per the fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (WHO CNS5), and imaging findings. Each supratentorial intraventricular mass was individually evaluated, with a detailed discussion on its clinical and histological features.

RESULTS

This article covers a range of supratentorial intraventricular masses observed in children. These include colloid cysts, subependymal giant cell astrocytomas, ependymomas, gangliogliomas, myxoid glioneuronal tumors, central neurocytomas, high-grade gliomas, pilocytic astrocytomas, cavernous malformations, and other embryonal tumors. Each mass type is characterized both clinically and histologically, offering an in-depth review of their individual imaging characteristics.

CONCLUSION

The WHO CNS5 introduces notable changes, emphasizing the vital importance of molecular diagnostics in classifying pediatric central nervous system tumors. These foundational shifts have significant potential to impact management strategies and, as a result, the outcomes of intraventricular masses in children.

Imaging of supratentorial intraventricular masses in children:a pictorial review- part 1

PURPOSE

This article is the first in a two-part series designed to provide a comprehensive overview of the range of supratentorial intraventricular masses observed in children. Our primary objective is to discuss the diverse types of intraventricular masses that originate not only from cells within the choroid plexus but also from other sources.

METHODS

In this article, we review relevant epidemiological data, the current genetics/molecular classification as outlined in the fifth edition of the World Health Organization's Classification of tumours of the Central Nervous System and noteworthy imaging findings. We conduct an exhaustive analysis of primary choroid plexus tumours as well as other conditions such as choroid plexus hyperplasia, choroid plexus cyst, choroid plexus xanthogranuloma, atypical teratoid rhabdoid tumour, meningioma, arteriovenous malformation and metastasis.

RESULTS

We comprehensively evaluated each supratentorial intraventricular mass, providing an in-depth analysis of their unique clinical and histological characteristics. The fifth edition of the World Health Organization Classification of Tumours of the Central Nervous System introduces major modifications. These important changes could potentially have a profound impact on the management strategies and subsequent outcomes of these tumours.

CONCLUSION

Intraventricular masses in children can arise from various sources. Surgical intervention is key for certain supratentorial intraventricular masses in paediatric patients, with preoperative neuroimaging essential to decide the best treatment approach, surgical or otherwise, as some cases may not require surgery.

"Soap bubble" sign as an imaging marker for posterior fossa ependymoma Group B

PURPOSE

To investigate the predictive value of the "soap bubble" sign on molecular subtypes (Group A [PFA] and Group B [PFB]) of posterior fossa ependymomas (PF-EPNs).

METHODS

MRI scans of 227 PF-EPNs (internal retrospective discovery set) were evaluated by two independent neuroradiologists to assess the "soap bubble" sign, which was defined as clusters of cysts of various sizes that look like "soap bubbles" on T2-weighted images. Two independent cohorts (external validation set [n = 31] and prospective validation set [n = 27]) were collected to validate the "soap bubble" sign.

RESULTS

Across three datasets, the "soap bubble" sign was observed in 21 PFB cases (7.4% [21/285] of PF-EPNs and 12.9% [21/163] of PFB); none in PFA. Analysis of the internal retrospective discovery set demonstrated substantial interrater agreement (1st Rating: κ = 0.71 [0.53-0.90], 2nd Rating: κ = 0.83 [0.68-0.98]) and intrarater agreement (Rater 1: κ = 0.73 [0.55-0.91], Rater 2: κ = 0.74 [0.55-0.92]) for the "soap bubble" sign; all 13 cases positive for the "soap bubble" sign were PFB (p = 0.002; positive predictive value [PPV] = 100%, negative predictive value [NPV] = 44%, sensitivity = 10%, specificity = 100%). The findings from the external validation set and the prospective validation set were similar, all cases positive for the "soap bubble" sign were PFB (p < 0.001; PPV = 100%).

CONCLUSION

The "soap bubble" sign represents a highly specific imaging marker for the PFB molecular subtype of PF-EPNs.

Imaging of the septum pellucidum: normal, variants and pathology

The septum pellucidum is a largely neglected anatomical midline structure during post-natal neuroimaging interpretation. Conversely, it is one of the anatomical landmarks used on pre-natal ultrasound to access normal midline formation. Because of its importance during the pre-natal period, the awareness of its primary malformative abnormalities is much higher than its disruptive acquired pathologies, often leading the misinterpretation. In this article, we will review the normal septum pellucidum formation, anatomy, and anatomical variants and will describe the imaging findings in primary malformative and secondary disruptive abnormalities affecting the septum pellucidum.

Deciphering Machine Learning Decisions to Distinguish between Posterior Fossa Tumor Types Using MRI Features: What Do the Data Tell Us?

Machine learning (ML) models have become capable of making critical decisions on our behalf. Nevertheless, due to complexity of these models, interpreting their decisions can be challenging, and humans cannot always control them. This paper provides explanations of decisions made by ML models in diagnosing four types of posterior fossa tumors: medulloblastoma, ependymoma, pilocytic astrocytoma, and brainstem glioma. The proposed methodology involves data analysis using kernel density estimations with Gaussian distributions to examine individual MRI features, conducting an analysis on the relationships between these features, and performing a comprehensive analysis of ML model behavior. This approach offers a simple yet informative and reliable means of identifying and validating distinguishable MRI features for the diagnosis of pediatric brain tumors. By presenting a comprehensive analysis of the responses of the four pediatric tumor types to each other and to ML models in a single source, this study aims to bridge the knowledge gap in the existing literature concerning the relationship between ML and medical outcomes. The results highlight that employing a simplistic approach in the absence of very large datasets leads to significantly more pronounced and explainable outcomes, as expected. Additionally, the study also demonstrates that the pre-analysis results consistently align with the outputs of the ML models and the clinical findings reported in the existing literature.

The Cerebellar Mutism Syndrome: Risk Assessment, Prevention and Treatment

Cerebellar mutism syndrome (CMS) has received increasing attention over the last decades as a complication of posterior fossa tumour surgery in children. Risk factors, aetiological aspects, and treatment measures of the syndrome have been investigated, yet the incidence of CMS remains unchanged. Overall, we are currently able to identify patients at risk, but we are unable to prevent it from occurring.Once CMS sets in, several symptomatic pharmacological treatments have been suggested, but only in smaller case series and not in randomized controlled trials, and it is not clear whether the treatment or time itself had a helpful effect.Within weeks to months, most patients regain their ability to speak after a phase with mutism or severely reduced speech; however, many patients continue to have speech and language deficits. At this point, anti-cancer treatment with chemotherapy and radiotherapy may be of focus more than the prognosis of CMS; however, many patients continue to have speech and language problems for months and years to come, and they are at high risk of other neurocognitive sequelae as well.Without reliable measures to prevent or treat the syndrome, we may look towards improving the prognosis of speech and neurocognitive functioning in these patients. As speech and language impairment is the cardinal symptom and late effect of CMS, the effect of intense and early-onset speech and language therapy as a standard of care in these patients should be investigated in relation to its effect on regaining speech capacity.

Machine learning–based multiparametric magnetic resonance imaging radiomics model for distinguishing central neurocytoma from glioma of lateral ventricle

OBJECTIVES

To develop a machine learning-based radiomics model based on multiparametric magnetic resonance imaging (MRI) for preoperative discrimination between central neurocytomas (CNs) and gliomas of lateral ventricles.

METHODS

A total of 132 patients from two medical centers were enrolled in this retrospective study. Patients from the first medical center were divided into a training cohort (n = 74) and an internal validation cohort (n = 30). Patients from the second medical center were used as the external validation cohort (n = 28). Features were extracted from contrast-enhanced T1-weighted and T2-weighted images. A support vector machine was used for radiomics model investigation. Performance was evaluated using the sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). The model's performance was also compared with those of three radiologists.

RESULTS

The radiomics model achieved an AUC of 0.986 in the training cohort, 0.933 in the internal validation cohort, and 0.903 in the external validation cohort. In the three cohorts, the AUC values were 0.657, 0.786, and 0.708 for radiologist 1; 0.838, 0.799, and 0.790 for radiologist 2; and 0.827, 0.871, and 0.862 for radiologist 3. When assisted by the radiomics model, two radiologists improved their performance in the training cohort (p < 0.05) but not in the internal or external validation cohorts.

CONCLUSIONS

The machine learning radiomics model based on multiparametric MRI showed better performance for distinguishing CNs from lateral ventricular gliomas than did experienced radiologists, and it showed the potential to improve radiologist performance.

KEY POINTS

• The machine learning radiomics model shows excellent performance in distinguishing CNs from gliomas. • The radiomics model outweighs two experienced radiologists (area under the receiver operating characteristic curve, 0.90 vs 0.79 and 0.86, respectively). • The radiomics model has the potential to enhance radiologist performance.

Case report: Ventricular primary central nervous system lymphoma with partial hypointensity on diffusion-weighted imaging

Introduction

Primary central nervous system lymphoma (PCNSL) is infrequent and represents 3. 1% of primary brain tumors. And the lesions that are restricted to the ventricular system, particularly the third ventricle, are even rarer. There are few pieces of literature or case reports to date. We report a case of PCNSL with partial hypointense on diffusion-weighted imaging (DWI) located in the lateral and third ventricles. Then we reviewed almost all case reports of ventricular PCNSLs in the last 20 years, discuss the imaging presentation, other ventricular tumors with similar imaging findings, and primary treatment measures.

Case presentation

A 78-year-old man presented with memory loss and poor responsiveness for one week without obvious precipitating factors. Magnetic resonance imaging (MRI) showed lesions in the third ventricle and left lateral ventricles, which were slightly hypointense on T1-weighted imaging (T1WI), and isointense to slightly hypointense on T2-weighted imaging (T2WI). On DWI, the left lateral ventricular lesion was hyperintense, while the third ventricular lesion was hypointense. After the surgical procedure, the pathology and immunohistochemistry revealed diffuse large B-cell lymphoma (DLBCL).

Conclusions

Ventricular PCNSL is quite rare, and may be confused with other tumors in the same position. However, PCNSL differs from other central nervous system tumors in that it is primarily treated with chemotherapy and/or radiation therapy. So, it is important to recognize PCNSL and differentiate it from other tumors, considering its implications for management planning.

68Ga-FAPI-04 PET/CT in Solitary Choroid Plexus Metastasis From Renal Cell Carcinoma

ABSTRACT

Intraventricular metastasis from extracranial tumor is rare. We describe MRI and 68Ga-FAPI-04 PET/CT findings in a case of histologically proved solitary choroid plexus metastasis from clear cell renal cell carcinoma. The tumor showed remarkable enhancement on MRI and increased FAPI uptake with high tumor-to-background activity ratio on PET/CT. This case indicates FAPI PET may be useful for detection of intraventricular metastasis from renal cell carcinoma.

Diagnosis of symmetric bilateral lateral ventricular subependymomas: A case report

Subependymomas are rare benign tumors that are hypovascular and noninvasive. Subependymomas tend to present as solitary lesions in the fourth ventricle or the frontal horn of the lateral ventricle. When multiple lesions are present, determining the correct diagnosis between subependymoma and other intraventricular neoplasms can be challenging. The characterization of imaging features and enhancement patterns can help narrow down the list of potential differential diagnoses. In this article, we describe a case of bilateral subependymomas in the lateral ventricles in a 40-year-old Asian man, including the clinical features, imaging results from conventional magnetic resonance imaging, magnetic resonance spectroscopy, and magnetic resonance perfusion, histological outcomes, and the disease management approach.

Primary intraventricular tumors - Imaging characteristics, post-treatment changes and relapses

Primary intraventricular neoplasms are rare tumors that originate from the ependymal or subependymal, septum pellucidum, choroid plexus and the supporting arachnoid tissue. Knowledge of the common locations of these tumors within the ventricular system, together with key imaging characteristics and presentation age, can significantly narrow the differential diagnosis. In 2016, the WHO reorganized the classification of several primary CNS tumors by combining histopathological and molecular data. This study highlights the imaging characteristics, histopathological and molecular data, treatment strategies and post-treatment changes of primary intraventricular tumors. Molecular-based diagnosis can not only aid in patient stratification and personalized treatment, but it can also provide prognostic and predictive value independent of WHO classification.

The clinical and imaging features of infratentorial germinomas compared with supratentorial ectopic germinomas

BACKGROUND

Intracranial germinoma is very sensitive to chemoradiotherapy, while the risk of infratentorial operation is high. The accurate diagnosis can provide the more reasonable treatment, avoiding the unnecessary therapeutic risks.

PURPOSE

To evaluate the clinical and imaging features of infratentorial germinomas.

MATERIAL AND METHODS

The clinical and imaging data of 13 infratentorial germinomas were collected and compared with 17 supratentorial germinomas in the same period. The clinical and imaging findings were retrospectively analyzed.

RESULTS

Infratentorial germinomas were more common in female patients than supratentorial ones (53.85% vs. 11.76%, P = 0.020). The mean age of the infratentorial group (23.0 ± 10.2 years) was significantly older than that of supratentorial group (12.4 ± 3.3 years, P = 0.003). Most infratentorial germinomas (12/13, 92.31%) underwent surgical resection, while stereotactic biopsy was more common in the supratentorial group (11/17, 64.71%, P = 0.002). Infratentorial germinomas were significantly smaller than supratentorial ones (25.85 ± 8.13 mm vs. 37.18 ± 18.11 mm, P = 0.031). Cystic lesions were more common in supratentorial germinomas (12/17, 70.59%), while most infratentorial germinomas were solid lesions (10/13, 76.92%, P = 0.025). On post-contrast T1-weighted imaging, obvious enhancement was more common in infratentorial germinomas than in supratentorial ones (100% vs. 64.71%, P = 0.024).

CONCLUSION

In addition to the common findings with supratentorial germinomas, infratentorial lesions have some specific clinical and imaging features.

Malignant intraventricular meningioma: literature review and case report

Malignant intraventricular meningiomas (IVMs) are very rare with only a few reported cases. A midline search up to December 2020 selected 40 articles for a total of 65 patients. The inclusion criteria were series and case reports in English language, as well as papers written in other languages, but with abstracts written in English. Malignant IVMs at the first diagnosis (group A, 50 patients) and those with anaplastic transformation from previous WHO grades I and II tumors (group B, 15 patients) were separately analyzed. The unique personal case among 1285 meningiomas (0.078%) is also added. Malignant IVMs mainly occur in women (61%) with a median age of 45 years and are mainly located in the lateral ventricle (93%) and trigonal region (74%), with no cases in the fourth ventricle. Irregular borders (80%), heterogeneous enhancement (83%), and perilesional edema (76%) are the most frequent radiological findings. The histology was mainly pure anaplastic (85%), whereas papillary (7%), rhabdoid (5%), and mixed forms (3%) are very rare. The CSF spread was found in 60% of the cases. The prognosis is very dismal, with an overall median survival of 17.5 months after surgery for the anaplastic forms. Malignant IVMs at initial diagnosis (group A) show better overall survival (25 months) than those occurring from anaplastic transformation of lower grade tumors (group B) (10.1 months).

Solitary Metastasis of Colon Adenocarcinoma Mimicking Colloid Cyst of the Third Ventricle

Metastatic lesions to the choroid plexus, although far less common than colloid cysts, can present very similarly both symptomatically and radiographically. Choroid plexus metastases are most common in the lateral ventricles, however, when they occur in the third and fourth ventricles they may cause obstructive hydrocephalus typical of a colloid cyst lesion. Renal cell carcinoma is the most common primary cancer, but many rare primaries have been reported. When patients are presenting with symptoms typical of colloid cysts it is important to consider past oncological history and if past medical history is significant for cancer using MR spectroscopy may be valuable in distinguishing between cystic and metastatic lesions.

Pediatric choroid plexus papilloma arising from the cerebellopontine angle: systematic review with illustrative case

INTRODUCTION

Choroid plexus tumors are uncommon intraventricular tumors that develop from the choroid plexus of the central nervous system. Choroid plexus papillomas arising from the cerebellopontine angle have been reported to almost exclusively occur in adults and are rarely found in children.

METHODS

We report a systematic review conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines of SCOPUS and PubMed databases for case reports and case series of choroid plexus papillomas arising in the cerebellopontine angle in the pediatric population and discuss clinical presentation, imaging features, management options, and outcomes. We also report a case managed at our center.

RESULTS

Ten cases of pediatric choroid plexus papillomas arising in the cerebellopontine angle were identified from the systematic review in addition to the case reported here, resulting in a total of eleven cases. The patients' median age was 8 years with a slight female sex predilection (1.2:1). Patients most commonly presented with headache, cerebellar signs, and cranial nerve palsies with median duration of symptoms at 4 months. All patients underwent surgical treatment with majority achieving gross total excision. No deaths were reported at median follow-up of 12 months. Complete neurologic recovery was attained in seven cases while partial recovery was seen in two cases.

CONCLUSION

Choroid plexus papillomas found in the cerebellopontine angle in the pediatric population are extremely rare but they should be considered in the differential diagnosis. Complete surgical resection is the mainstay of treatment with excellent outcomes achievable in majority of patients.

Cytologic Features of Ventricular Tumors of the Central Nervous System: A Review with Emphasis on Diff-Quik Stained Smears

BACKGROUND

Neoplasms from the ventricular system share a common location but have highly variable histogenesis. Many are slowly growing tumors that behave in a benign fashion. They can be classified as primary and secondary tumors. The most common primary tumors are ependymomas, subependymomas, subependymal giant cell astrocytomas, central neurocytomas, choroid plexus tumors, meningiomas, germinomas, pineal parenchymal tumors, papillary tumors of the pineal region, chordoid gliomas, rosette-forming glioneuronal tumors of the fourth ventricle, and craniopharyngiomas. Pilocytic astrocytomas, medulloblastomas, and atypical teratoid/rhabdoid tumors often show secondary involvement of the ventricular system.

SUMMARY

Advances in neurosurgery have facilitated access to the ventricular system increasing the number of cases in which such tumors can be biopsied. In this context, cytology has been proven to be an extremely useful diagnostic tool during intraoperative pathologic consultations. Many ventricular tumors are infrequent, and the cytologic information available is limited. In this review, we describe the cytologic features of the uncommon ventricular tumors and report on unusual findings of the more common ones. For the cytologic evaluation of brain tumors, many neuropathologists prefer formalin fixation and hematoxylin and eosin staining. In this review, we highlight the cytologic findings as seen with Diff-Quik, a very popular staining method among cytopathologists. In fact, when pathologists are unfamiliar with cytology, it is common to request the assistance of cytopathologists during the evaluation of intraoperative procedures. Key Message: Ventricular tumors of the central nervous system comprise a group of heterogeneous tumors with very different cytologic features. The cytomorphology of these tumors, including rare entities, is often very characteristic, allowing a precise recognition during intraoperative pathologic consultations. Diff-Quik is a valuable staining method that can be used alone or as a complement to hematoxylin and eosin staining. Diff-Quik allows for clear visualization of the overall architecture, cytoplasmic details, and extracellular material.

Intraventricular neuroepithelial tumors: surgical outcome, technical considerations and review of literature

Background

Intraventricular neuroepithelial tumors (IVT) are rare lesions and comprise different pathological entities such as ependymomas, subependymomas and central neurocytomas. The treatment of choice is neurosurgical resection, which can be challenging due to their intraventricular location. Different surgical approaches to the ventricles are described. Here we report a large series of IVTs, its postoperative outcome at a single tertiary center and discuss suitable surgical approaches.

Methods

We performed a retrospective chart review at a single tertiary neurosurgical center between 03/2009–05/2019. We included patients that underwent resection of an IVT emphasizing on surgical approach, extent of resection, clinical outcome and postoperative complications.

Results

Forty five IVTs were resected from 03/2009 to 05/2019, 13 ependymomas, 21 subependymomas, 10 central neurocytomas and one glioependymal cyst. Median age was 52,5 years with 55.6% (25) male and 44.4% (20) female patients. Gross total resection was achieved in 93.3% (42/45). 84.6% (11/13) of ependymomas, 100% (12/21) of subependymomas, 90% (9/10) of central neurocytomas and one glioependymal cyst were completely removed. Postoperative rate of new neurological deficits was 26.6% (12/45). Postoperative new permanent cranial nerve deficits occurred in one case with 4th ventricle subependymoma and one in 4th ventricle ependymoma. Postoperative KPSS was 90% (IR 80–100). 31.1% of the patients improved in KPSS, 48.9% remained unchanged and 20% declined. Postoperative adverse events rate was 20.0%. Surgery-related mortality was 2.2%. The rate of shunt/cisternostomy-dependent hydrocephalus was 13.3% (6/45). 15.4% of resected ependymomas underwent adjuvant radiotherapy. Mean follow-up was 26,9 (±30.1) months.

Conclusion

Our surgical findings emphasize satisfactory complete resection throughout all entities. Surgical treatment can remain feasible, if institutional experience is given. Satisfying long-term survival and cure is possible by complete removal. Gross total resection should always be performed under function-remaining aspects due to mostly benign or slow growing nature of IVTs. Further data is needed to evaluate standard of care and alternative therapy options in rare cases of tumor recurrence or in case of patient collective not suitable for operative resection.

Intracranial calcifications in childhood: Part 2

This article is the second of a two-part series on intracranial calcification in childhood. In Part 1, the authors discussed the main differences between physiological and pathological intracranial calcification. They also outlined histological intracranial calcification characteristics and how these can be detected across different neuroimaging modalities. Part 1 emphasized the importance of age at presentation and intracranial calcification location and proposed a comprehensive neuroimaging approach toward the differential diagnosis of the causes of intracranial calcification. Pathological intracranial calcification can be divided into infectious, congenital, endocrine/metabolic, vascular, and neoplastic. In Part 2, the chief focus is on discussing endocrine/metabolic, vascular, and neoplastic intracranial calcification etiologies of intracranial calcification. Endocrine/metabolic diseases causing intracranial calcification are mainly from parathyroid and thyroid dysfunction and inborn errors of metabolism, such as mitochondrial disorders (MELAS, or mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; Kearns-Sayre; and Cockayne syndromes), interferonopathies (Aicardi-Goutières syndrome), and lysosomal disorders (Krabbe disease). Specific noninfectious causes of intracranial calcification that mimic TORCH (toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], rubella, cytomegalovirus, and herpes) infections are known as pseudo-TORCH. Cavernous malformations, arteriovenous malformations, arteriovenous fistulas, and chronic venous hypertension are also known causes of intracranial calcification. Other vascular-related causes of intracranial calcification include early atherosclerosis presentation (children with risk factors such as hyperhomocysteinemia, familial hypercholesterolemia, and others), healed hematoma, radiotherapy treatment, old infarct, and disorders of the microvasculature such as COL4A1- and COL4A2-related diseases. Intracranial calcification is also seen in several pediatric brain tumors. Clinical and familial information such as age at presentation, maternal exposure to teratogens including viruses, and association with chromosomal abnormalities, pathogenic genes, and postnatal infections facilitates narrowing the differential diagnosis of the multiple causes of intracranial calcification.

A Rare Case of Choroid Plexus Papilloma of the Third Ventricle in an Adult

Colloid cysts are the commonest masses of the third ventricle. Third ventricle neoplasms are uncommon. They include tumors arising from the choroid plexus (papillomas, carcinomas), tumors arising from other than the choroid plexus (ependymomas, meningiomas), metastases, and lymphoma. Choroid plexus tumors usually occur in the lateral ventricle in children and fourth ventricle in adults, and often present with hydrocephalus. We herein describe the extremely rare occurrence of third ventricle choroid plexus papilloma in a 35-year-old man who presented to the emergency department with a long history of intermittent headaches, occasionally associated with photophobia. CT and MR imaging revealed a lobulated ovoid lesion in the third ventricle with minimal extension into the right lateral ventricle through the foramen of Monro, causing mild ventricular dilatation. Surgical resection was performed and histopathology revealed choroid plexus papilloma.

Intraventricular Pilocytic Astrocytoma With KIAA1549/BRAF Fusion Arising in a 44-Year Old

Rare pilocytic astrocytomas (PA) have been described to arise in the ventricles of children. They are even less common in this location for the adult population. We present the case of a 44-year old man presenting with vision and mental status changes. Brain imaging revealed an intraventricular mass within the right ventricular atrium, most consistent with a meningioma. Microscopic examination revealed a neoplasm composed of elongated to plump bipolar astrocytes arranged in a fascicular architecture, accompanied by foci containing numerous Rosenthal fibers. By immunohistochemistry, the tumor cells were positive for vimentin and glial fibrillary acid protein, whereas negative for epithelial membrane antigen. Isocitrate dehydrogenase 1 (R132H) was also negative. By fluorescence in situ hybridization, we detected a KIAA1549/BRAF fusion gene. These findings supported the diagnosis of intraventricular PA arising in an adult.

Pediatric Brain Tumors

Pediatric central nervous system (CNS) tumors are the most common solid tumors in children and comprise 15% to 20% of all malignancies in children. Presentation, symptoms, and signs depend on tumor location and age of the patient at the time of diagnosis. This article summarizes the common childhood CNS tumors, presentations, classification, and recent updates in treatment approaches due to the increased understanding of the molecular pathogenesis of pediatric brain tumors.

Temporal horns subependymomas: A report of two cases of an intraventricular neoplasm in an atypical location

Slow-growing intraventricular masses are sometimes imaging findings in asymptomatic patients. The neuroimaging characteristics frequently help making the correct diagnosis and the treatment decision. Subependymomas usually present as single lesions poorly vascularized, without invasion into adjacent brain parenchyma or cerebrospinal fluid dissemination. Ependymoma is considered the main differential diagnosis. We report two cases of this tumour who share the unusual location: The temporal horns. The lack of enhancement (or heterogeneous when present) and advanced neuroimaging techniques can be very useful in differentiating them from other lesions.

Solitary Metastasis of Adenocarcinoma of Submandibular Gland to Choroid Plexus in Cerebellopontine Angle: First Case Reported in Literature

BACKGROUND

Adenocarcinoma of the salivary gland (AdCASG) is a rare and malignant tumor of the salivary glands. Albeit, metastatic lesions occur anecdotally in the choroid plexus and most rarely in the cerebellopontine angle (CPA). We report the first case of metastatic AdCASG to the choroid plexus of the lateral recess of the fourth ventricle located in CPA, emphasizing the clinical presentation and neuroradiologic findings.

CASE DESCRIPTION

A 40-year-old man was referred with signs of increased intracranial pressure and a unilateral hearing problem. Magnetic resonance imaging showed a pear-shaped, vividly enhancing tumor in the left CPA. The tumor was a metastatic AdCASG. Gross total resection of the lesion was followed by a conventional radiotherapy lead in a 5-year tumor-free control interval.

CONCLUSIONS

Metastatic lesions to the choroid plexus may show a pedunculated shape in magnetic resonance imaging. It is hypothesized that tumor seeding may occur through the veins, lymphatics, and nerve sheaths in the skull base region. Tissue specimen is necessary to confirm such rare pathology.

Updates in the Neuoroimaging and WHO Classification of Primary CNS Gliomas: A Review of Current Terminology, Diagnosis, and Clinical Relevance From a Radiologic Prospective

As new advances in the genomics and imaging of CNS tumors continues to evolve, a standardized system for classification is increasingly essential to diagnosis and management. The molecular markers introduced in the 2016 WHO classification of CNS tumors bring both practical and conceptual advances to the characterization of gliomas, strengthening the prognostic and predictive value of terminology while shedding light on the underlying mechanisms that drive biologic behavior. The purpose of this article is to provide a succinct overview of primary intracranial gliomas from a neuroradiologic prospective and according to the 5th edition WHO classification that was revised in 2016. An update of the molecular markers pertinent to defining the major lineages of brain gliomas will be provided, followed by discussion of the terminology, grading and imaging features associated with individual entities. Neuroradiologists should be aware of the key genomic and radiomic features of common brain gliomas, and familiar with an integrated approach to their diagnosis and grading.

Choroid Plexus Papilloma of the Fourth Ventricle: A Pediatric Patient

Choroid plexus papilloma is a low-frequency entity in both the adult and pediatric populations. Its clinical presentation is very variable as it depends on its location and length. We must always do the differential diagnosis between papilloma and other intraventricular pathologies. This article is about a case report of a pediatric patient with a Choroid plexus papilloma located in the fourth ventricle, a location that is atypical for the pediatric population.

Choroid plexus tumours on MRI: similarities and distinctions in different grades

Background

The therapeutic planning varies for different grades of choroid plexus tumours (CPTs). The aim of this study was to define the similarities and distinctions among MRIs for different grades of CPTs, providing more guidance for clinical decisions.

Methods

We reviewed the MRI findings in 35 patients with CPT verified by surgical pathology, including 18 choroid plexus papillomas (CPPs, grade I), 11 atypical choroid plexus papillomas (aCPPs, grade II), and 6 choroid plexus carcinomas (CPCs, grade III). Nonparametric testing based on ranks was performed to evaluate the association of pathological grade with MRI findings.

Results

Among the 35 CPTs, 29 were located in the ventricular system. The tumours were generally slightly hypo- or isointense on T1WI, slightly hyper- or isointense on T2WI, and moderately or strongly enhanced in post-contrast imaging. Twenty cases were accompanied by hydrocephalus. The median tumour longest diameters of CPPs, aCPPs, and CPCs were 28.6, 44.6, and 60.6 mm, respectively. Four cases were purely cystic, 6 were papillary, 10 were lobulated, and 2 were irregular. Three cases had necrosis. The median oedema diameters of CPPs, aCPPs, and CPCs were 0, 0, and 24.1 mm, respectively. The grades of CPTs were statistically associated with tumour longest diameter (r_s = 0.68, P < 0.001), internal morphology (χ² = 10.32, P = 0.016), necrosis (Z = 2.27, P = 0.023), and oedema diameter (r_s = 0.72, P < 0.001).

Conclusion

CPTs typically appeared as intraventricular papillary or lobulated lesions, often accompanied by hydrocephalus. Larger tumour, irregular or fuzzy internal morphology, presentation of necrosis and wide-ranging peritumoural oedema might increase the likelihood of malignancy.

Reliability of Imaging-Based Diagnosis of Lateral Ventricular Masses in Children

OBJECTIVE

We studied the accuracy of the radiologic diagnosis of lateral ventricular masses in children (<20 years of age).

METHODS

In this retrospective study, data were collected from children with lateral ventricular masses managed in our unit between 2001 and 2016. There were 43 patients (26 boys and 17 girls; mean age, 12.1 years; range, 8 months to 20 years). Magnetic resonance imaging was available for 36 patients, whereas in 7 patients only a contrast-enhanced computed tomography scan was available. The images were read independently by 3 radiologists, who were blinded to the pathology. Two differential diagnoses were offered for each patient. The agreement between the 3 radiologists was calculated using the Fleiss κ statistic.

RESULTS

The common pathologic diagnoses were subependymal giant cell astrocytoma (SEGA) (20.9%), low-grade astrocytoma (16.3%), high-grade astrocytoma (9.3%), choroid plexus papilloma (9.3%), and meningioma (9.3%). The sensitivity, specificity, and accuracy of the radiologic diagnoses were 62%, 96.7%, and 94.2%, respectively. Low-grade tumors such as low-grade gliomas, SEGAs, choroid plexus papillomas, and meningiomas were diagnosed with a high level of accuracy. High-grade gliomas, choroid plexus carcinomas, and other malignant neoplasms were difficult to diagnose on imaging. Cavernous angiomas were also difficult to diagnose. There was only fair agreement between the 3 radiologists (Fleiss κ = 0.24).

CONCLUSIONS

The pathologic spectrum of lateral ventricular tumors in children is wide, and identifying the pathology on imaging is difficult for malignant tumors. Benign tumors such as SEGAs, low-grade astrocytomas, and choroid plexus papillomas are relatively easier to diagnose. There is significant interobserver variability in the radiologic diagnosis of these tumors.

Tumor control of third ventricular central neurocytoma after gamma knife radiosurgery in an elderly patient: A case report and literature review

RATIONALE

Central neurocytoma is rare benign tumor that occurs in high probability in young adults in the lateral ventricle. Herein, we report an unusual case of an elderly woman who was diagnosed with central neurocytoma isolated to the third ventricle. This deeply located tumor was effectively treated using gamma knife radiosurgery (GKR).

PATIENT CONCERNS

A 79-year-old woman was admitted to hospital with gait disturbance and cognitive dysfunction.

DIAGNOSIS

Brain magnetic resonance imaging (MRI) revealed a homogenously enhancing multilobulated mass in the posterior third ventricle measuring 1.8 cm in size. The tumor was diagnosed as a central neurocytoma isolated to the third ventricle.

INTERVENTIONS

Neuronavigation-guided endoscopic third ventriculostomy and biopsy were performed. One week following surgery, GKR was performed using a prescribed dose of 14 Gy with 50% isodose lines, and a target volume of 1.62 cc.

OUTCOMES

Three months after GKR, brain MRI revealed a decrease in the size (to 1.4 cm) of the multilobulated strong enhancing mass in the posterior third ventricle, and the patient's symptom of confusion was improved.

LESSONS

Previous studies have reported that tumors in unusual locations, such as those isolated to the third ventricle, are different according to age, either in young children or elderly individuals. Although complete surgical resection is an effective treatment for central neurocytoma, it is often difficult to approach these tumors through surgery. GKR could, therefore, be an alternative primary treatment option for deeply located central neurocytomas in elderly patients.

Surgical outcome in cortical ependymoma: A single centre experience of 18 cases

Cortical ependymomas (CE) are rare subset of supratentorial ependymoma which are located in the peripheral cortical rim without any connection to the ventricular lining. With limited cases previously reported, current knowledge on diagnosis and management of tumors is lacking. We present the largest single center experience on CE reported so far and highlight their clinico-radiological aspects, histopathological features as well the results of their surgical excision. We studied 18 CE patients undergoing surgical excision at our center between September 2009 to November 2017. Clinical, radiological, histopathological and operative data was obtained from hospital records. Functional assessment of our patients were done using the Karnofsky's performance score (KPS). Survival analysis was done using Kaplan-Meier method and log rank test. Mean age of patients in our study group was 19 ± 11.1 years. Frontal lobe was the most frequently involved region. Features of raised intracranial pressure like holocranial headache (n = 15, 83.33%) and vomiting (n = 9, 50%) were most common presenting complaints in our study. Gross total resection of tumor was achieved in eleven patients (61.11%). Histopathology showed equal number (n = 9) of WHO grade 2 and 3 ependymoma. During 111 months follow-up, four patients (22.22%) developed recurrence and three patients (16.66%) died. Five years overall survival (OS), progression-free survival (PFS) rate were 74.3% and 70.7%. In view of higher risk of progression to higher histo-pathological grade and local recurrence years after surgical excision, a long clinical and radiological follow-up is advised.

Paranoid Syndrome as the First Sign of Central Neurocytoma: A Case Report

Central neurocytoma (CN), first described in 1982 by Hassoun and colleagues, is a rare tumor accounting for 0.25% to 0.5% of all tumors of the central nervous system. The tumor is a neoplasm of neuroepithelial origin, with intermediate malignancy (WHO grade II), detectable with both computed tomography and magnetic resonance imaging. Complete excision of the tumor gives favorable long-term results, with infrequent recurrences and/or metastases. Only 3 previous cases in which CN presented with co-occurring psychotic symptoms were found in the PubMed database. This report presents the case of a 27-year-old patient with paranoid syndrome without neurological symptoms, in whom magnetic resonance imaging confirmed a large intracranial tumor located predominantly in the right lateral ventricle and third ventricle reaching down to the hypothalamus. Resection of the tumor (histopathologically a CN) resulted in complete remission of the psychotic symptoms. This case supports the need for neuroimaging in all patients with first-episode psychosis because of the possibility of neurologically silent brain tumors. Quick diagnosis in such cases is crucial for the selection of treatment methods and prognosis.

Clinical features and neurosurgical treatment of trigonal cavernous malformations

The goals of this study were to analyze the incidence, clinical manifestations, neuroimaging findings, surgical treatments, and neurological outcomes of trigonal cavernous malformations (TCMs). Among 1395 cases of intracranial and intraspinal cavernous malformations (CMs) surgically treated between 2003 and 2016 at Beijing Tiantan Hospital, a series of 12 patients with TCM was chosen for analysis and their records were reviewed. We also performed an exhaustive literature search using PubMed to identify all previously reported cases in the literatures. TCMs accounted for 0.86% of the entire series of the central nervous system (CNS) CMs. The case series consisted of five male and seven female patients (ratio 1:1.4), with an average age at presentation of 32.9 years (7-53 years). In all the cases, headache was the most common initial symptom (66.7%). Complete resection without surgical mortality was achieved in all the cases. Postoperative complications included fever, lower limb weakness, sensory aphasia, and calculational capacity declination. Follow-up period after diagnosis was 15 to 74 months (mean 48.3 months); no patient was lost to follow-up. All the patients were considered to be in excellent clinical condition. TCMs are rare lesions; they can reach large size, and their symptoms and signs commonly resulted from mass effect. Surgical intervention is the treatment of choice for TCMs; patients can obtain favorable neurological outcomes after complete resection.

Extra-Axial and Clear Cell Type Ependymoma, Mimicking a Convexity Meningioma

A 33-year-old woman presented with tingling and paresthesia on left extremity for 2 months. Magnetic resonance imaging revealed that the tumor was iso- and hypo-intensity on T1-weighted image, mixed iso- and high-signal intensity on T2-weighted images and heterogeneously enhanced with rim enhancement. Neither arachnoid cleft nor dural tail was certain but mass was located extra-axially so meningioma was suspected. During operation, tumor wasn't attached to dura at all but arachnoid attachment was seen. Pathologically, clear cell type ependymoma was confirmed. Details of diagnosis and treatment of this tumor is described.

Infected colloid cyst

INTRODUCTION

Colloid cysts are the most common pathologic lesions of the third ventricle. Although they are histologically benign, they may grow and can cause the hydrocephalus. A 5-year-old male patient underwent to surgery with the diagnosis of colloid cyst. In operation, after the anterior transcallosal approach, the cyst was punctured by syringe and obviously pus aspirated.

CONCLUSION

Colloid cysts mostly remain silent and detected incidentally. Although it is rarely defined, rhinorrhea, hypopituitarism, diabetes insipidus, spasmodic torticollis, drop attack, aseptic meningitis, and coexistence with neurocysticercosis have been reported, but this is the first reported case of an infected colloid cyst.

Disparities in Brain Cancer in the United States: A Literature Review of Gliomas

In the human body, the central regulatory system of homeostasis is maintained by the brain. Its complexity is mesmerizing and many of its functions are largely uncharted. Unfortunately, its functionality is often impaired through neoplastic growths, like gliomas, which are devastating to patients and their families. Annually, gliomas are the most common primary brain tumours affecting over 20,000 people in the United States. However, despite their status as the third most common cause of cancer related death for individuals between ages 20 and 39, the aetiology of gliomas remains unknown. This paper aims to review the latest information regarding the 2016 World Health Organization (WHO) 4th edition classifications of gliomas, their malignant effects, and disparities within these classifications, as well as identify areas for further research. These suggestions for future inquiry may contribute to a better understanding of the pathology of these cancers enabling improvement in prevention, screening, and treatment.

MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma

PURPOSE

The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS).

METHODS

Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated.

RESULTS

Although a statistically significant difference (P < 0.0001) was observed in Cho/Cr among SIS, control spectra, and CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P < 0.0001). A statistically significant difference was observed in MI and/or Gly to Cr between SIS and control spectra (P = 0.03), and CNC and control spectra (P < 0.0006). There were no statistical differences between SIS and CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P < 0.0053), control spectra and CNC (P < 0.0016), and SIS and CNC (P < 0.0083) for Cr to USW. Lac inverted doublets were confirmed in two SISs. Triplets of Lac and Ala were detected in four spectra of CNC.

CONCLUSION

The present study showed that MRS can be useful in discriminating SIS from CNC.

Profile of Primary Pediatric Brain and Spinal Cord Tumors from North India

BACKGROUND AND OBJECTIVE

The study was carried out to find the profile of pediatric brain and spinal cord tumors during 2006-2015 in a tertiary referral center of North India.

MATERIALS AND METHODS

It was a retrospective medical record-based observational study. All children <18 years of age with confirmed histopathological diagnosis of cancer were included in the study.

RESULTS

Central nervous system (CNS) tumors constituted 5.6% of all pediatric solid malignancies in our hospital. A total of 54 brain tumors and 13 spinal cord tumors were studied. Medulloblastoma was the most common brain tumor (20.3%) followed by pilocytic astrocytoma (16.6%) and glioblastoma multiforme (9.2%). The most common spinal cord tumor was Ewing's sarcoma/primitive neuroectodermal tumor (30.7%) followed by ependymoma (23%). Mean age was 10.5 years and 12.1 years for brain and spinal cord tumors, respectively. There was male predominance in brain tumors while the sex ratio was almost equal in spinal cord tumors. Histomorphologically, necrosis and angiogenesis were associated with higher grades of tumor. Approximately 35% children were alive after a mean follow-up of 36 ± 6 months.

CONCLUSION

Compared with most international studies, we found a higher percentage of medulloblastoma in the brain, thus stressing the role of regional and ethnic influences in the pathogenesis of CNS tumors.

Pediatric central neurocytoma: Case report and review of literature

Central neurocytomas are slow-growing primary brain tumors of neuronal origin having a predilection to arise mostly in the lateral ventricles. We report a case of a 9-year-old girl who presented with headache and vomiting of 1-month duration. Her magnetic resonance imaging was suggestive of central neurocytoma of the third ventricle and was surgically managed, and tumor tissue was sent for histopathology and immunohistochemistry which confirmed the diagnosis.