Cyst with a mural nodule tumor of the brain

Nomograms Based on MRI Radiomics for Differential Diagnosis and Predicting BRAFV600E Expression in Pleomorphic Xanthoastrocytoma and Ganglioglioma

RATIONALE AND OBJECTIVES

This study was designed to investigate the value of nomograms based on MRI radiomics and clinical semantic features in identifying pleomorphic xanthoastrocytoma (PXA) and ganglioglioma (GG) as well as predicting BRAFV600E expression.

MATERIALS AND METHODS

This study included 265 patients histologically diagnosed with PXA (n = 113) and GG (n = 152). T1WI, T2WI, and CET1 sequences were utilized to extract radiomics features. Univariate analysis, Spearman correlation analysis, and the least absolute shrinkage and selection operator were used for dimensionality reduction and feature selection. Following this, logistic regression was utilized to establish the radiomics model. Univariate and multivariate analyses of clinical semantic features were applied, and clinical models were constructed. The nomograms were established by merging radiomics and clinical features. Furthermore, ROC curve analysis was used for examining the model performance, whereas the decision curve analysis (DCA) examined the clinical utility of the nomograms.

RESULTS

Nomograms achieved the best predictive efficacy compared to clinical and radiomics models alone. Concerning the differentiation between PXA and GG, the area under the curve (AUC) values of the nomogram were 0.879 (0.828-0.930) and 0.887 (0.805-0.969) for the training and testing cohorts, respectively. For predicting BRAFV600E expression, the AUC values of the nomogram were 0.873 (0.811-0.936) and 0.851 (0.740-0.963) for the training and testing cohorts, respectively. DCA confirmed the clinical utility of the nomograms.

CONCLUSION

Nomograms based on radiomics and clinical semantic features were noninvasive tools for differential diagnosis of PXA and GG and predicting BRAFV600E expression, which may be helpful for assessing patient prognosis and developing individualized treatment strategies.

Cerebellar Metastasis Manifesting as a Cyst with Mural Nodule(s): Differentiating It From Hemangioblastoma on MRI

BACKGROUND

A cyst with mural nodule(s) (CMN) is a rare imaging finding of cerebellar metastasis (CMET). It is a great challenge to differentiate it from cerebellar hemangioblastoma (CHB). In the present study, we explore the differences in the magnetic resonance imaging (MRI) characteristics of the 2 tumors.

METHODS

Patients with pathologically confirmed CMET or CHB at our hospital from July 2009 to September 2021 were enrolled in the present study. All the patients underwent conventional head MRI (before and after contrast administration) before surgery and had ≥1 lesion in the cerebellum that presented as CMN on MRI. The clinical and MRI features were compared between the 2 groups.

RESULTS

A total of 33 patients (10 with CMET and 23 with CHB) met the study criteria. The CMET patients were significantly older than were the CHB patients (median age, 59.5 years vs. 37 years; P = 0.002). Compared with the CHB group, the CMET group showed significantly higher occurrence rates of multiple mural nodules (72.7% vs. 8.7%), lack of vascular flow voids (100% vs. 65.2%), isointense or hypointense mural nodules on fluid-attenuated inversion recovery imaging (100.0% vs. 22.7%), restricted diffusion of mural nodules (22.2% vs. 0.0%), mildly enhanced mural nodules (90.9% vs. 4.3%), and a ring-enhanced pattern of the cyst wall (100% vs. 8.7%; P < 0.05 for all).

CONCLUSIONS

When CMN is detected in the cerebellum on MRI, older age, multiple mural nodules, absence of vascular flow voids, isointense or hypointense mural nodule on fluid-attenuated inversion recovery sequence, restricted diffusion of the mural nodule, mildly enhanced mural nodules, and a ring-enhanced pattern of the cyst wall are the clinical and imaging features that strongly indicate the likelihood of metastasis, rather than CHB.

Glioblastoma masquerading as a cystic brain lesion: A case report and evidence-based review

INTRODUCTION AND IMPORTANCE

In adults, glioblastomas account for approximately 12-15 % of primary intracranial neoplasms. In current standard-of-care treatment, glioblastomas have a 5-year survival rate of ~7.5 % and a median survival of ~15 months. Glioblastoma exhibits a highly variable imaging appearance, but the thick and irregular ring enhancement surrounding a necrotic core with infiltrative growth is the most prevalent imaging pattern. Glioblastoma with a cystic component (also known as cystic glioblastoma) is a rare presentation that can be misleading and often mistaken for other cystic brain lesions.

CASE PRESENTATION

In this report, we present a case of a 43-year-old woman who presented to the emergency department with a 2-month history of progressive neurologic manifestations that was attributed to a right-sided cystic brain lesion detected on routine imaging studies, which was later characterized as a cystic glioblastoma based on specific imaging and molecular studies.

CLINICAL DISCUSSION

We highlight the importance of combining radiological and molecular modalities with clinical suspicion for a better characterization of cystic brain lesions and including glioblastoma in the list of potential diagnoses. Furthermore, we provide a comprehensive, evidence-based review of the entity of cystic glioblastoma and how the existence of the cystic component might affect the management and the overall prognosis.

CONCLUSION

Several characteristics make cystic glioblastoma unique. However, it is also capable of mimicking other benign cystic brain lesions, delaying definitive diagnosis and hence the most appropriate management plan.

T2-fluid attenuated inversion recovery mismatch in tumefactive multiple sclerosis

The T2-fluid attenuated inversion recovery (FLAIR) mismatch sign has been suggested as an imaging marker of isocitrate dehydrogenase-mutant 1p/19q non-codeleted gliomas with 100% specificity. Tumefactive demyelination is a common mimic of neoplasm that has led to unnecessary biopsies and even resections. We report a case of tumefactive multiple sclerosis in a 46-year-old male without prior symptomatic demyelinating episodes that demonstrates the T2-FLAIR mismatch sign. Our findings suggest the T2-FLAIR mismatch sign should not be used as a differential feature between glioma and tumefactive demyelination. Because typical isocitrate dehydrogenase-mutant 1p/19q non-codeleted gliomas typically do not demonstrate significant enhancement, such diagnosis should be reserved when post-contrast images are unavailable.

Neuropathologic features of central nervous system hemangioblastoma

Hemangioblastoma is a benign, highly vascularized neoplasm of the central nervous system (CNS). This tumor is associated with loss of function of the VHL gene and demonstrates frequent occurrence in von Hippel-Lindau (VHL) disease. While this entity is designated CNS World Health Organization grade 1, due to its predilection for the cerebellum, brainstem, and spinal cord, it is still an important cause of morbidity and mortality in affected patients. Recognition and accurate diagnosis of hemangioblastoma is essential for the practice of surgical neuropathology. Other CNS neoplasms, including several tumors associated with VHL disease, may present as histologic mimics, making diagnosis challenging. We outline key clinical and radiologic features, pathophysiology, treatment modalities, and prognostic information for hemangioblastoma, and provide a thorough review of the gross, microscopic, immunophenotypic, and molecular features used to guide diagnosis.

Imaging diagnosis and treatment selection for brain tumors in the era of molecular therapeutics

Currently, most CNS tumors require tissue sampling to discern their molecular/genomic landscape. However, growing research has shown the powerful role imaging can play in non-invasively and accurately detecting the molecular signature of these tumors. The overarching theme of this review article is to provide neuroradiologists and neurooncologists with a framework of several important molecular markers, their associated imaging features and the accuracy of those features. A particular emphasis is placed on those tumors and mutations that have specific or promising imaging correlates as well as their respective therapeutic potentials.

Differentiation between supratentorial pilocytic astrocytoma and extraventricular ependymoma using multiparametric MRI

BACKGROUND

The differentiation of supratentorial pilocytic astrocytomas (STPAs) and supratentorial extraventricular ependymomas (STEEs) is clinically pivotal because of distinct therapeutic management and prognosis, which is sometimes challenging to both neuroradiologists and pathologists.

PURPOSE

To explore and compare the conventional and advanced magnetic resonance imaging (MRI) features between STPA and STEE.

MATERIAL AND METHODS

A total of 23 patients with STPAs and 23 patients with STEEs were reviewed in this study. All patients performed conventional MRI, susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI), and 34 patients (17 with STPAs and 17 with STEEs) examined dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in addition. Clinical data, conventional MRI features, minimum relative apparent diffusion coefficient ratio (rADC_min), and maximum relative cerebral blood volume ratio (rCBV_max) were compared between the two groups and subgroups. The optimal cutoff values of rADC_min and rCBV_max with sensitivity and specificity were calculated.

RESULTS

STPA manifested similar to STEE as a solid-cystic mass but more frequently presented with a marked enhancing deep nodule (P = 0.02), no peritumoral edema (P = 0.036), higher rADC_min value (2.0 ± 0.5 vs. 0.9 ± 0.2; P < 0.001), and lower rCBV_max value (2.1 ± 0.4 vs. 14.4 ± 5.5; P < 0.001). The cutoff value of >1.39 for rADC_min and ≤ 2.81 for rCBV_max produced a high sensitivity of 95.65% and 100.0%, respectively, and all produced a specificity of 100.0% in differentiating STPAs from STEEs.

CONCLUSION

Multiparametric MRI techniques including conventional MRI, DWI, and DSC-PWI contribute to the differential diagnosis of STPA and STEE.

Unique imaging appearance of neurosarcoidosis as a solitary cystic mass with mural enhancement

Background:

Sarcoidosis is an idiopathic, granulomatous, and multi-system inflammatory disorder that can also involve the central nervous system in the form of meningeal, parenchymal, or cranial nerve involvement. Imaging findings can be non-specific and may overlap with other inflammatory, infectious and neoplastic processes, and posing diagnostic challenges. Parenchymal involvement in neurosarcoidosis (NS) predominantly manifests as either non-enhancing white matter lesions or as enhancing parenchymal granulomas. Granulomas usually manifest as multiple solid lesions with nodular enhancement.

Case Description:

A 72-year-old man presented with right-eye visual field changes with the non-contrast head computed tomography showing a large cystic lesion in the left frontoparietal lobe. Subsequent contrast-enhanced magnetic resonance imaging study revealed a large cystic mass with irregular rim enhancement and mural nodule concerning for glial neoplasm. Cyst decompression with biopsy and histopathological analysis revealed gliosis and prominent perivascular granulomatous inflammation with mixed picture of CD4 and CD8-positive cells suggestive of sarcoidosis. Further subsequent work-up showed mediastinal and cervical lymphadenopathy which on biopsy showed non-necrotizing granulomatous inflammation, consistent with sarcoidosis.

Conclusion:

Herein, we report unique imaging findings of a NS case manifesting as a solitary cystic intraparenchymal lesion with an enhancing nodular component, mimicking primary intra-cranial tumor. This appearance is highly atypical and rarely been reported earlier.

Role of diffusion weighted imaging for differentiating cerebral pilocytic astrocytoma and ganglioglioma BRAF V600E-mutant from wild type

PURPOSE

BRAF V600E mutation is a distinctive genomic alteration of pediatric low-grade gliomas with prognostic and therapeutic implications. The aim of this retrospective multicenter study was to analyze imaging features of BRAF V600E-mutant and wild-type cerebral pilocytic astrocytomas (PAs) and gangliogliomas (GGs), focusing on the role of diffusion weighted imaging (DWI).

METHODS

We retrospectively evaluated 56 pediatric patients with histologically proven, treatment-naïve PAs and GGs who underwent conventional MRI, DWI, and molecular analysis for BRAF V600E mutation. Twenty-three subjects presented BRAF V600E-mutant (12 PAs and 11 GGs) and 33 BRAF V600E wild-type (26 PAs and 7 GGs) tumors. Imaging studies were reviewed for dominant site, margin definition, hemorrhage, calcification, cystic components, contrast enhancement, and relative mean and minimum ADC values (rADCmean and rADCmin). Statistics included Fisher's exact test, Student t test, general linear model, and receiver operating characteristic (ROC) analysis.

RESULTS

PA and GG BRAF V600E-mutant had significantly lower rADCmean (p < 0.001) and rADCmin (p < 0.001) values than wild type, regardless of tumor histology and location. ROC analysis demonstrated similar performances between these parameters in predicting BRAF V600E status (rADCmean: AUC 0.831, p < 0.001; rADCmin: AUC 0.885, p < 0.001). No significant differences regarding additional imaging features emerged between BRAF V600E-mutant and wild-type lesions, with the exception of the number of tumors with cystic components, significantly higher in BRAF V600E-mutant PAs (p = 0.011) CONCLUSION: Assessment of the DWI characteristics of GGs and PAs may assist in predicting BRAF V600E status, suggesting a radiogenomic correlation and prompt molecular characterization of these tumors.

Unusual Radiological Presentation of Intracranial Dermoid Cyst: A Case Series

Intracranial dermoids are rare congenital lesions of the brain that account for < 1% of all intracranial tumors. Even though they are rare, typical computed tomography (CT) scan and magnetic resonance imaging (MRI) features along with location allow radiological diagnosis in the majority of patients. Radiologically, dermoid cysts typically appear as nonenhancing low-density masses on CT scan and are hyperintense on T1-weighted (T1-W) MRI sequences with variable signal on T2-W sequences. We describe two cases of dermoid with unusual imaging appearance with the presence of mural nodule in both the cases. The recognition of atypical radiological features can avoid diagnostic pitfalls and is clinically relevant for overall surgical management.

Sporadic Hemangioblastoma of the Cavernous Sinus and Meckel's Cave

Objectives  To describe an extremely rare case of sporadic hemangioblastoma (HB) within the cavernous sinus and Meckel's cave with extension to the cerebellopontine angle (CPA) cistern. Methods  A 73-year-old male presented with hearing loss, unilateral ptosis, and facial numbness. Results  The imaging showed a complex cystic-solid mass centered at the left cavernous sinus and Meckel's cave with extension to the CPA cistern. Patient underwent retrosigmoid craniectomy for partial resection of the CPA angle component of the mass. Surgical pathology confirmed the diagnosis of HB and patient was scheduled for subsequent radiotherapy of the residual mass. Conclusions  We present an exceptional case of supratentorial HB without associated von Hippel-Lindau (VHL) disease, which was predominantly located in the cavernous sinus and Meckel's cave and led to multiple cranial nerve symptoms. We describe imaging characteristics and radiologic-pathologic correlation of this atypically located HB, which can be difficult to consider in the differential diagnosis presurgically.

A Rare Tumor in Childhood Desmoplastic Infantile Astrocytoma: Two Case Reports

Desmoplastic infantile astrocytomas (DIAs), are rare supratentorial tumors, usually observed in the first 24 months of life. Despite their aggressive appearance, they tend to follow a favorable clinical course. Total or near total resection of tumor is usually the treatment option. Desmoplastic Infantile Ganglioglioma (DIG) and DIA are WHO grade I tumors that have similar clinical and morphological findings. The only criterion in differential diagnosis is the neural component of DIG. These tumors both have dense fibroblastic stroma and positive staining with glial fibrillar acidic protein (GFAP) and CD34.

A rare case of desmoplastic infantile astrocytoma presenting with right side partial seizures presented in a 1-year-old child.

A rare case of desmoplastic infantile astrocytoma presenting with focal onset generalized seizures presented in a 1-year-old child.

Despite their radiological and histological properties, these tumors have a benign course. After 3-year follow-up for the first case and 1-year follow-up for the second case, there was no recurrence.

The usefulness of fibrin glue as a support in the dissection of malignant cystic brain tumors

BACKGROUND

If the complete microsurgical resection of a brain tumor is a logical oncologic goal, the surgical strategy for the cystic component remains controversial secondary to the risk of morbidity. The objective of this study was to analyze the interest of using fibrin glue in the resection of malignant cystic brain tumors (MCBT).

METHODS

Seven patients (median: 60-years-old (range [52-72]/sex ratio M/F: 2.5) were analyzed prospectively in the Neurosurgery Department at Strasbourg University Hospital, from October 2014 to November 2016. The surgical technique consisted of injecting fibrin glue into the tumor cyst after partial drainage. After the solidification of the glue, the cysts walls were removal by following the dissection plan around the fibrin glue. The primary objective was to evaluate the quality of surgical resection on brain MRI scans postoperatively with the use of ITK-SNAP software for precise measurements of tumor volume.

RESULTS

Four metastases and 3 glial lesions were operated on with this technique. An average reduction in cystic volume of 64.6% (P=0.016) and 82.1% (P=0.016) for contrast enhancement volume were observed. If two cases (#2 and #7) were excluded, the average contrast enhancement reduction was respectively 94% and 72% for the cystic volume. In addition, there were no complications, tumor recurrence or difference between gliomas and metastases and the Karnofsky score increased by at least 10% in all patients.

CONCLUSION

This procedure allowed to extend the resection to the cystic component of MCBT without increasing the risk of morbidity related to injury on the underlying parenchyma.

An Infratentorial Pure Pleomorphic Xanthoastrocytoma Arising from Middle Cerebellar Peduncle: A Rare Location of an Uncommon Tumor

BACKGROUND

Pleomorphic xanthoastrocytomas are rare tumors of glial origin comprising <1% of all astrocytic tumors of brain. These tumors are rare in the infratentorial compartment and were not known to arise from the middle cerebellar peduncle.

CASE DESCRIPTION

We discuss the case of a 16-year-boy who presented with altered sensorium and features of increased intracranial pressure and was found to have a 4 × 4 × 3 cm mass arising from the middle cerebellar peduncle.

CONCLUSION

We also discuss the histopathologic features of these tumors suggesting their resemblance to other maldevelopmental tumors, the rarity of pure World Health Organization grade II pleomorphic xanthoastrocytoma in the infratentorial compartment, as well as the appropriate management.

Brain Granuloma: Rare Complication of a Retained Catheter

BACKGROUND

Ventriculoperitoneal (VP) shunt is the most frequent treatment for hydrocephalus. VP shunt malfunction is a very common problem in neurosurgical practice, often requiring shunt revision procedures. In some cases, complete removal of a VP shunt may present difficulties, leading the surgeon to leave the ventricular catheter in situ. This decision is often made to avoid possible adverse events, primarily risk of life-threatening hemorrhage. However, a nonfunctioning catheter left in the ventricular system may lead to further complications.

CASE DESCRIPTION

We report the case of an adult man who presented with a tumor-like cystic lesion, with mural and nodular postcontrast enhancement, caused by a huge granuloma formed around the tip of a retained ventricular catheter.

CONCLUSIONS

This occurrence is extremely rare, and this is the first reported case in the literature. Preoperative differential diagnosis was challenging and included infection, metastasis, dysembryogenetic lesions, and rare reversible porencephalic cysts. According to several physiopathogenetic theories recently reported in the literature, the granuloma may develop as the result of persistent chronic inflammatory reactions between the ventricular catheter left in situ and the brain parenchyma. Application of neuroendoscopic techniques is improving management of VP shunt revisions, allowing safe removal of catheters stuck or lost in the ventricular system. Neuroendoscopy may represent an additional option to avoid possible complications related to retained ventricular catheters.

Current Clinical Brain Tumor Imaging

Neuroimaging plays an ever evolving role in the diagnosis, treatment planning, and post-therapy assessment of brain tumors. This review provides an overview of current magnetic resonance imaging (MRI) methods routinely employed in the care of the brain tumor patient. Specifically, we focus on advanced techniques including diffusion, perfusion, spectroscopy, tractography, and functional MRI as they pertain to noninvasive characterization of brain tumors and pretreatment evaluation. The utility of both structural and physiological MRI in the post-therapeutic brain evaluation is also reviewed with special attention to the challenges presented by pseudoprogression and pseudoresponse.

Fourth Ventricle Neurenteric Cyst Mimicking Hemangioblastoma

This report presents a case of fourth ventricle neurenteric cyst (NE cyst) mimicking hemangioblastoma, which developed in a 50-year-old woman. A tiny enhancing mural portion of the fourth ventricle in MRI suggested that the cyst was hemangioblastoma, but pathological evidence showed that the cyst was in fact NE cyst in the fourth ventricle. In order to make proper decision on to what extent of surgical resection should be done, considering every possibility in differential diagnosis might be helpful. This case reports an unusual pathology in 4th ventricle, considering the patient's age, and demonstrates that a rarer disease may share radiological features of a common disease.

Unusual Radiologic Finding of Intracranial Inflammatory Myofibroblastic Tumor Presenting a Cyst with Mural Nodule

An intracranial cyst tumor with a mural nodule can be representative of some types of brain tumors, but is a rare presentation of intracranial inflammatory myofibroblastic tumor (IMT). Herein, we report the case of an intracranial IMT in a 48-year-old woman presenting with the extremely unusual radiologic findings of a cyst with a mural nodule.

Modern brain tumor imaging

The imaging and clinical management of patients with brain tumor continue to evolve over time and now heavily rely on physiologic imaging in addition to high-resolution structural imaging. Imaging remains a powerful noninvasive tool to positively impact the management of patients with brain tumor. This article provides an overview of the current state-of-the art clinical brain tumor imaging. In this review, we discuss general magnetic resonance (MR) imaging methods and their application to the diagnosis of, treatment planning and navigation, and disease monitoring in patients with brain tumor. We review the strengths, limitations, and pitfalls of structural imaging, diffusion-weighted imaging techniques, MR spectroscopy, perfusion imaging, positron emission tomography/MR, and functional imaging. Overall this review provides a basis for understudying the role of modern imaging in the care of brain tumor patients.

Subcutaneously obstructed ventriculoperitoneal shuntogram

A 65-year-old man presented with headache, altered mental status, and somnolence. The patient had a ventriculoperitoneal (VP) shunt revised a month earlier. A CT of the head was performed, which demonstrated interval development of hydrocephalus compared with the prior examination done at the time of the shunt revision. Further evaluation of the VP shunt dynamics was obtained through a radionuclide shuntogram using 99mTcO4. The shuntogram demonstrated passage of the radiotracer down the VP shunt tubing. This case illustrates the utility of radionuclide shuntogram in demonstrating an unusual cause of hydrocephalus after VP shunt placement.

Supratentorial ependymoma presenting as a cortical cyst with a mural nodule in an adult

Supratentorial ependymoma is a rare tumour in the adult central nervous system. We present an unusual case of supratentorial ependymoma in a young adult that presented as a pure cortical cyst with a mural nodule and discuss the differential diagnosis of such lesions in the brain.

Pleomorphic xanthoastrocytoma in a case of tuberous sclerosis

Tuberous sclerosis is a known phakomatosis and the associated finding of a subependymal giant cell astrocytoma is common with this disorder. A case of tuberous sclerosis with a finding not previously reported, i.e. that of a pleomorphic xanthoastrocytoma, is presented here.

MR imaging features of intracranial primary CNS lymphoma in immune competent patients

We aimed to characterize specific MRI findings seen in immune competent patients with intracranial primary CNS lymphoma (PCNSL) and to determine their value in the management of such patients. Pre-treatment MRI examinations of 21 immunocompetent patients with biopsy-proven PCNSL were retrospectively evaluated. T1 and T2 signal characteristics as well as contrast enhancement features are described in all patients. Diffusion, perfusion and proton-MR-spectroscopy features are described in a subset of these patients. In the proper clinical and radiologic setting, suggesting the diagnosis of PCNSL can help institute proper treatment in a timely fashion and avoid unnecessary attempts at surgical resection and the associated morbidity.

MR and CT of brain's cava

The Cavum Septi Pellucidi (CSP), Cavum Vergae (CV) and Cavum Veli Interpositi, are anatomical variants located in the midline of the brain. It is important to identify these conditions to distinguish them from other entities that may require treatment. In this paper, our purpose is to describe MR and CT findings of CSP, CV and Cavum Veli Interpositi, explaining the differential diagnosis.