Extra-axial Tumors Research Articles

Histomorphological Spectrum of Pediatric Supratentorial CNS Tumors: A 3-year Retrospective Study in a Tertiary Care Center.

ABSTRACTObjective:Central nervous system (CNS) tumors are the second most common neoplasms in children and they differ from their adult counterparts in terms of incidence, topography, clinical features, histology, and outcome. This article analyzes the incidence of supratentorial tumors, various histopathological entities, and their characteristics in pediatric patients <18 years of age.Materials and Methods:This was a retrospective study conducted at the Department of Neuropathology, Institute of Neurosurgery, MMC/RGGGH Chennai from January 2017 to December 2019. Data of supratentorial tumors in children less than 18 years of age procured and their histomorphological profile were analyzed.Results:In our institution, of a total of 1134 CNS and spinal neoplasms, 117 pediatric intracranial and 7 spinal neoplasms were reported and the incidence of supratentorial pediatric tumors was 44.44% (52 cases). Among which intraaxial tumors account for 38.46% with 20 cases, extraaxial tumors 51.92% with 27 cases, and intraventricular tumors 9.61% with five reported cases. Most common tumors reported were astrocytomas, craniopharyngioma, followed by ependymoma among othersConclusion:Though posterior fossa neoplasms are more common in children, supratentorial tumors show a rising trend worldwide in the pediatric population. Our study gives an overview of the incidence and histopathological profile of supratentorial CNS tumors.

Extra-Axial spinal Lumbar Neoplastic Lesions. A Rare Meningotelial entity: Fibroblastic Meningioma. Case Report and Revision of Litterature

Background and Importance In the field of spinal tumors, and in particular among extra-axial spinal and peripheral nerve tumors, the occurrence of dumbbell lumbar meningioma has not been reported in the literature. In the present study we describe a case of a patient suffering from dumbbell-shaped lumbar meningioma. This tumor resulted, after postoperative histological examination, a fibroblastic meningioma, WHO I grade, a very rare entity. Dumbbell meningiomas are extremely uncommon, comprising only 2–3.6 %. Clinical Presentation An 81-year-old man presented with history of gradually increasing lumbar pain, not related with decubitus and axial load, and right sciatica for 6 months. Another clinical feature was sensitive and motor (4/5 BMRCI) deficits at level of right L5 radicular territory. MRI shows a dumbell lesion in right neuroforamen L5-S1. With the patient in a prone position, we exposed and excised the tumor via a one stage posterolateral approach, through a hemi-laminictomy of L5, starting from a midline lumbar right L5-S1 interlaminar approach, extended to far lateral right articular and extra-articular region. We pre-operatively assumed the mass was a schwannoma because of its location and dumbbell shape, and planned the surgical procedure with use of continuous intraoperative neurophysiological neuromonitoring, to minimize the concrete risk of a possible intraoperative neurologic damage and preoperative neurological deficits worsening. Patient did not develop more deficits and the tumor resulted a fibroblastic meningioma. Patient recovered upright posture and walking during the first postoperative day, with the aid of a lumbar corset. The surgical wound was regular and subfascial lumbar drainage was removed on the first postoperative day. During postoperative recovery no additional neurological deficits appare and the low back pain and the right sciatic pain partially improved. On the fifth postoperative day patient was discharged from the hospital with the indications to wait for the histological examination result for any possible subsequent terapie and for the appropriate follow-up. Conclusion This patient-case report suggests that dumbbell shape of a spinal tumor (in particular at level of lumbar spine) has to be underwent to a very careful differential diagnosis, considering the possibility to discover, among the most frequent histology neoplastic lesions, the presence of histologically more rare tumors. This knowledge is very important from the beginning of surgical and therapeutic planning to the diagnostic and possible postoperative adiuvant therapeutic follow-up of patient.

Giant primary dural lymphoma with vault involvement

A 52-year-old immunocompetent man presented with frontal headaches. Physical examination showed a painful frontal hump (A). Computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a giant bifrontal extra-axial tumor (B, C). He benefited from total removal of the tumor. Pathological examination of the resected mass led to the diagnosis of anaplastic large B-cell lymphoma (cell immunopositivity for CD30 and anaplastic lymphoma kinase) (D). He was transferred to the oncology unit for chemo and radiotherapy with good clinical evolution. Primary dural lymphoma (PDL) is extremely rare, accounting for 7% of all primary central nervous system lymphomas. PDL usually involves sites that are rich in meningothelial cells, and results in a localized mass or plaque-like thickening of the dura that radiologically resembles a number of other diseases, such as meningioma or subdural hematomas. Although there is as yet no optimal treatment for PDL, surgical excision followed by radiotherapy and chemotherapy are recommended.

Significance of BRAFV600E mutation in intra-axial brain tumor in Malaysian patients: case series and literature review.

To date, BRAF mutations in brain tumor patients have not been characterized in the Malaysian population. Based on the numerous reported studies, there are main mutations that exist in BRAF gene in various types of cancers. A missense mutation in codon 600of the BRAF nuclear oncogene (BRAFV600E) is the most prevalent hotspot point mutation that has been identified in multiple human malignancies. We here aimed to find out the frequency of BRAFV600E mutation in a series of Malaysian patients with brain tumors and if any association exists between BRAFV600E mutation and clinicopathological features of patients. Fresh frozen tumor tissue samples from 50Malaysian brain tumor patients were analyzed for BRAFV600E mutational status, and its correlation with clinicopathological features (including age, gender, and tumor localization such as intra-axial: within the brain substance or extra-axial: outside the brain substance) was examined. The overall BRAFV600E mutation frequency was determined to be 22% (in 11of 50patients). BRAFV600E was significantly correlated with the tumor location group, which shows BRAFV600E was more frequent in the intra-axial tumor than the extra-axial tumor group. In this study, we also observed that male patients were slightly more susceptible to BRAFV600E mutation, and this mutation was predominant in patients of the age group<40years. However, these parameters did not translate to statistical significance. The data demonstrate that BRAFV600E mutation is observed significantly more often in intra-axial brain tumor patients, which can serve as baseline information for further research on genetic alteration that occurs during brain tumor progression in the Malaysian population.

Spinal drop of atypical choroid plexus papilloma in an adult patient: A case report and literature review

Background: Choroid plexus papillomas (CPPs) are benign extra-axial tumors that originate from the choroid plexus; these tumors rarely have metastases, being at the spinal level the location with few reported cases.Case Description: We report the case of a 48-year-old man with a history of atypical fourth ventricular CPP and gross total resection (GTR) in 2008. In 2015, he presented with radicular pain, decreased strength, and paresthesia in the left leg. Magnetic resonance imaging revealed a well-defined intradural ovoid lesion in the vertebral canal at the level of the L3-L4 intersomatic space. Subtotal resection of the tumor was performed. The patient recovered well, with relief of pain and no neurological deficit. A literature research few cases of CPP metastasis in adults. We describe here a fifth-decade male patient with a lumbar neoplasm, which according to the histopathologic characteristics and location is the first case of an atypical papilloma implant of the choroid plexus at this spinal level.Conclusion: GTR of primary lesions and associated implants remains the gold standard for surgical treatment of CPP. Radiotherapy, stereotactic radiosurgery, and chemotherapy are adjuvant therapies for CPP but there is no definitive protocol for the management of implants. Proper follow-up of these patients is essential since spinal drop can appear many years after the initial presentation of CPP.

BIOM-62 SENSITIVE DETECTION AND DISCRIMINATION OF INTRACRANIAL TUMORS BY BLOOD

Abstract BACKGROUND The diagnosis of intracranial tumors relies on tissue specimens obtained by invasive surgery. Non-invasive diagnostic approaches, particularly for patients with brain tumours, provide an opportunity to avoid surgery and mitigate unnecessary risk to patients. We reasoned that DNA methylation profiles of circulating tumor DNA in blood can be used as a clinically useful biomarker for patients with brain tumors, given the specificity of DNA methylation profiles for cell-of-origin. METHODS We generated methylation profiles on the plasma of 608 patients with cancer (219 intracranial, 388 extracranial) and 60 healthy controls using a cell-free methylated DNA immunoprecipitation combined with deep sequencing (cfMeDIP-seq) approach. Using machine-learning approaches we generated and evaluated models to distinguish brain tumors from extracranial cancers that may metastasize to the brain, as well as additional models to discriminate common brain tumors included in the differential diagnosis of solitary extra-axial and intra-axial tumors. RESULTS We observed high sensitivity and discriminative capacity for our models to distinguish gliomas from other cancerous and healthy patients (AUC=0.99, 95%CI 0.96–1), with similar performance in IDH mutant and wildtype gliomas as well as in lower- and high-grade gliomas. Excluding non-malignant contributors to plasma methylation did not change model performance (AUC=0.982, 95%CI 0.93–1). Models generated to discriminate intracranial tumors from each other also demonstrated high accuracy for common extra-axial tumors (AUCmeningioma=0.89, 95%CI 0.80–0.97; AUChemangiopericytoma=0.95, 95%CI 0.73–1) as well as intra-axial tumors ranging from low-grade indolent glial-neuronal tumors (AUC 0.93, 95%CI 0.80 – 1) to diffuse intra-axial gliomas with distinct molecular composition (AUCIDH-mutant glioma = 0.82, 95%CI 0.66 -0.98; AUCIDH-wildtype-glioma = 0.71, 95%CI 0.53 – 0.9). Plasma cfMeDIP-seq signals originated from corresponding tumor tissue DNA methylation signals (r=0.37, p&amp;lt; 2.2e-16). CONCLUSIONS These results demonstrate the potential for cfMeDIP-seq profiles to not only detect circulating tumor DNA, but to accurately discriminate common intracranial tumors that share cell-of-origin lineages.

Epidermoid Cyst Extending Along Trigeminal Nerve Pathway with Unusual Imaging Findings

Epidermoid cysts (ECs) are benign extraaxial tumors. They frequently occur at the cerebellopontine angle and parasellar regions. However, they rarely occur in the Meckel's cave. Typically, ECs appear as a hypointense mass on T1-weighted magnetic resonance imaging (MRI) and hyperintense on T2-weighted MRI. However, ECs may occasionally present as hyperintense on T1-weighted imaging and hypointense on T2-weighted imaging. When this occurs, they are known as white epidermoid cysts. We present a case of a 25-year-old woman with a 3-month history of hypoesthesia in the distribution of the right trigeminal nerve. MRI showed a lesion located within the Meckel's cave. The MRI signal was heterogeneous, with hyperintense areas on T1-weighted images, being hypointense on T2-weighted imaging. Preoperative suspicion was trigeminal schwannoma with unusual radiologic features. Finally, the pathologic diagnosis was epidermoid cyst. Therefore to establish a proper preoperative diagnosis, one should be aware that ECs can occur in Meckel's cave and with unusual radiologic features, as occurred in the case described earlier.

The Supraorbital Eyebrow Craniotomy for Intra- and Extra-Axial Brain Tumors: A Single-Center Series and Technique Modification.

The supraorbital (SO) eyebrow craniotomy provides minimally invasive access to the anterior and middle fossae and parasellar region. To present a series of patients treated with the SO approach to assess outcomes, the impact of endoscopy, and describe a modified pericranial flap aimed at reducing postoperative frontalis paresis and hypesthesia. A retrospective analysis was undertaken of our prospective database of patients who underwent SO craniotomy for tumor/cyst removal. Patients were evaluated based on pathology, utility of endoscopy, extent of resection, complications, and functional/esthetic recovery. From 2007 to 2018, 129 operations were performed in 117 patients (54% women; mean age 60±16.5 yr). The most common lesions were meningiomas (43%), gliomas (15%), and metastases (15%). Prior surgery and/or radiation had been performed in 37% and 26% of patients, respectively. Endoscopy was used in 76 (61%) operations and allowed more complete tumor removal in 38 (50%). For first-time operations, gross-total removal was achieved in 78%. Major complications included stroke (3%), cranial nerve deficit (3%), acute hematoma (1%), and cerebrospinal fluid leak (1%). The modified pericranial flap technique used in 18 recent patients resulted in a shorter duration of transient frontalis paresis and forehead hypesthesia with complete functional recovery in all 18. The SO craniotomy is an effective keyhole approach for intra- and extra-axial tumors. Endoscopic assistance may allow additional tumor removal in almost 30% of the cases. The modified pericranial flap appears to accelerate functional recovery, although additional patients and follow-up are required to better assess this technique.

Precise discrimination between meningiomas and schwannomas using time-to-signal intensity curves and percentage signal recoveries obtained from dynamic susceptibility perfusion imaging

Background and purposeMeningiomas and schwannomas are common extra-axial brain tumors. Discrimination is challenging in some locations when characteristic imaging features are absent. This study investigated the accuracy of percentage signal recoveries obtained from dynamic susceptibility contrast perfusion imaging (DSC-PI) in discriminating meningiomas and schwannomas. Material and methodsRetrospective database research was conducted. Sixty nine meningioma and 15 schwannoma having DSC-PI between January 2016 and February 2020 were included. Time to signal intensity curves (TSIC) were analyzed and grouped as T1-dominant leakage, T2*-dominant leakage and return to baseline. Relative cerebral blood volume (rCBV), relative mean transit time (rMTT), percentage signal recovery 1 (PSR 1) and PSR 2 values were calculated. The differences between the groups were investigated. Receiver operating characteristic curves were operated. ResultsrCBV, rMTT, PSR 1 and PSR 2 values were statistically different between meningiomas and schwannomas. PSR 2 provided the best discrimination. With the cut off value of 1.08 for PSR 2, meningiomas and schwannomas were differentiated with 95.7% sensitivity and 93.3% specificity. TSICs were also different between two groups. Most of meningiomas showed T2*-dominant leakage (78.2%), whereas most of shwannomas showed T1-dominant leakage (93.3%). ConclusionDSC-PI is a useful imaging tool for non-invasive discrimination of meningiomas and schwannomas. Particularly, percentage signal recoveries discriminates meningiomas and schwannomas with high sensitivity and specificity.

Intracranial kaposiform hemangioendothelioma presenting as epistaxis: a rare case report with review of literature

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of intermediate malignancy with tendency for local invasion and recurrence. The tumor almost exclusively occurs in children, especially in infants. Intracranial KHE are extremely rare with only two cases reported in the literature. We report the clinical and pathological features of this rare tumor arising from basitemporal region in a 21-month child. Our case did not present with Kasabach-Merritt phenomenon. Histopathological examination confirmed the diagnosis of KHE. KHE should be considered in the differential diagnosis of intracranial extra-axial neoplasm in children, and histopathological examination plays an important role in distinguishing KHE from its morphologic mimics. It is essential to diagnose KHE due to its locally aggressive nature.

Atypical meningeal hemangiopericytoma presenting with punched-out calvarial erosion

Meningeal hemangiopericytoma (HPC) is an infrequent but distinct entity affecting the craniospinal axis. A previously healthy 48-year-old man sustained a gradually progressing motor weakness in the left lower extremity. CT showed a hyperdense mass in the right frontal lobe. On MRI, it was 29 × 30 × 36 mm in dimension, appeared isointense on T1 and hyperintense on T2, and was intensely enhanced with erosive changes in the inner table adjacent to the tumor. The patient underwent tumor resection. Reflection of the bone flap revealed a punched-out erosion in the inner table with a defect of the dura over the upper part of the tumor. Microscopic findings were consistent with grade III HPC with dural invasion. A punched-out calvarial erosion and dural defect caused by an extra-axial tumor may be a high-grade HPC that requires extensive surgical resection.

Clinicopathological characteristics of intracranial meningiomas

Background: Meningioma comprises 25-30% of total central nervous system tumors detected. Ninety percent of meningiomas are benign, 6% are atypical, and 2% are malignant. Complete resection is often curative.&#x0D; Objectives: The objective of this study is to give ideas about the descriptive epidemiology, clinical presentation and histopathology of current scenario at National Neurosurgical Referral Center, Nepal.&#x0D; Methods: This is a prospective study from the period of January 2015 to September 2019 in the department of neurosurgery, National Academy of Medical Science, Bir Hospital. Inclusion criteria consists of all the histopathological proven cases of meningioma during the study period.&#x0D; Result: A total of 150 meningioma cases were operated during the study period. The average age of presentation was 42 years. Male to female ratio was 1:2. Most common affected age group was 30-50 years. The most common clinical symptoms for intracranial meningioma were headache followed by vomiting and paresis. Among intracranial meningioma, the most common location was convexity meningioma followed by sphenoid wing meningiomas and parasagittal meningiomas. Most common histopathological variety encountered was transitional meningioma, World health organization grade I.&#x0D; Conclusion: Meningiomas are slow growing, extra-axial tumor, usually benign which are most commonly located along convexities, sphenoid ridge and parasagittal area. Most are cured if completely removed, which is not always possible.

Study of Supratentorial Tumours by Computed Tomography

Background: Brain neoplasms may be classified by the location of supratentorial, infratentorial and midline tumours. Of the supratentorial neoplasms, meningiomas are the most frequent extra-axial neoplasms. CT has become the most important diagnostic procedure in evaluating patients suspected of harboring an intracranial tumor. It is still considered the basic radiologic study since it gives specific information for the management of brain tumours and is minimally invasive. The purpose of this study was to assess the distribution, features, localization and extent of supratentorial neoplasms. Subjects and Methods: Fifty cases with symptoms of intracranial pathology and on CT found to have supratentorial tumours were studied. Results: The CT patterns of 50 supratentorial tumours were reviewed, out of which 30 cases i.e. 60%, were found to be intra- axial and 20 i.e. 40% extra-axial tumours. GBM formed the major group of the intra axial tumours i.e. 18 %, and meningiomas formed the major extra-axial tumours forming 26%. Conclusion: CT proves to be a valuable modality of imaging in evaluating the distribution, features, localizing and assessing the extent of various intra and extra-axial tumours in the supratentorial region.

Dural-based atypical teratoid/rhabdoid tumor in an adult: DNA methylation profiling as a tool for the diagnosis

Atypical teratoid/rhabdoid tumor (ATRT) is a malignant CNS embryonal tumor that mostly occurs in childhood, adult cases are rare. We report a case of a 23-year-old male with an extra-axial dura-based lesion in the left frontal area, previously diagnosed as gliosarcoma. After 6 years, the patient had a recurrence and the previous slides were reviewed. Tumor was positive for vimentin and negative for INI1. The differential diagnosis for this extra-axial tumor with long survival was rhabdoid meningioma with INI1 loss or ATRT. DNA methylation profiling was performed to reach the final and the most definitive diagnosis; the result was ATRT. Our case suggests the usefulness of DNA methylation profiling for diagnosing challenging CNS tumors.

Application of intra-operative magnetic resonance imaging for intracranial epidermoid cysts

The effectiveness and safety of intraoperative magnetic resonance imaging (iMRI) are evident from many reports over the past decade. However, these reports have mainly concerned surgeries for glioma and other intra-axial tumours, and applications of this approach for extra-axial tumours are poorly documented. We retrospectively examined three cases in which iMRI was used to assist in the removal of epidermoid cysts. T2-weighted images and diffusion-weighted images were acquired during the surgeries. The value to surgeons of images generated by iMRI, the length of interruption of surgery, and the safety of the patients were assessed. In this study, the images obtained through iMRI provided were clear representations of remnant tumours, even with a low-field system (0.4 Tesla). These images generated enough information to help surgeons decide whether to use an assistance device, such as an endoscope, to remove remnant tumours and whether further retraction of the brain was safe for patients and useful in tumour removal. Intraoperative MRI has long been thought unnecessary for surgery for tumours that are well demarcated and clearly visible under a surgical microscope; in this study, however, intraoperative MRI proved to be useful and safe for patients undergoing epidermoid cyst resection.

Coexistence of Dural and Intraventricular Meningioma-A Rare Entity

Meningiomas are extra-axial tumors that are majorly benign and constitute nearly one-quarter of all intracranial tumors...

Mutation of Tp53 in a Patient with Aggressive Central Nervous System Solitary Fibrous Tumor/Hemangiopericytoma

Introduction: Central Nervous System (CNS) Solitary Fibrous Tumor (SFT) / Hemangiopericytoma (HPC) is a fibroblastic mesenchymal tumor of the meninges that accounts for < 1% of intracranial tumours. The natural history of CNS SFT / HPC is characterized by a high rate of local (60%) and distant (20%) failure following gross total resection (GTR), and treatment options are limited. The identification of new genomic markers could be of interest to improve the understanding and management of CNS SFT / HPC. We present the results of a search for molecular alterations by next-generation sequencing (NGS) in a patient diagnosed with CNS SFT / HPC who experienced rapid distant failure. Case Description: A 64-year-old Caucasian man was diagnosed with a right hemisphere extra-axial frontal tumor after being referred for persistent headaches in October 2017. The patient underwent surgical resection followed by adjuvant radiation therapy of the operative cavity. A diagnosis of grade III HPC of the CNS was established. A diffuse metastatic recurrence with multiple bone lesions occurred rapidly after the initiation of radiation therapy. In July 2018, a CT-guided biopsy of the left iliac crest confirmed a highly proliferative metastatic recurrence and a FoundationOne CDx TM test was performed, which showed a somatic mutation of the tumor suppressor gene TP53 (Tumor Protein p53) (R175H). The microsatellite status was stable and the Tumor Mutational Burden (TMB) was low (1 Muts/Mb). A massive disease evolution of the disease occurred in September 2018. The patient died in November 2018 after neurological decline. Conclusion: This case report shows that an anatomopathological examination alone is insufficient to correctly classify these rare tumors and predict their aggressiveness. In this case report, the somatic mutation of TP53 (R175H) was associated with a very poor prognosis (survival of 13 months). Further studies including systematic NGS of CNS SFT / HPC are warranted to investigate the role of TP53 in prognostic assessment to adapt future treatment strategies.

The Accumulation of Tau-Immunoreactive Hippocampal Granules and Corpora Amylacea Implicates Reactive Glia in Tau Pathogenesis during Aging.

SummaryThe microtubule-associated tau protein forms pathological inclusions that accumulate in an age-dependent manner in tauopathies including Alzheimer's disease (AD). Since age is the major risk factor for AD, we examined endogenous tau species that evolve during aging in physiological and diseased conditions. In aged mouse brain, we found tau-immunoreactive clusters embedded within structures that are reminiscent of periodic acid-Schiff (PAS) granules. We showed that PAS granules harbor distinct tau species that are more prominent in 3xTg-AD mice. Epitope profiling revealed hypo-phosphorylated rather than hyper-phosphorylated tau commonly observed in tauopathies. High-resolution imaging and 3D reconstruction suggest a link between tau clusters, reactive astrocytes, and microglia, indicating that early tau accumulation may promote neuroinflammation during aging. Using postmortem human brain, we identified tau as a component of corpora amylacea (CA), age-related structures that are functionally analogous to PAS granules. Overall, our study supports neuroimmune dysfunction as a precipitating event in tau pathogenesis.

Stereotactic Radiosurgery and Stereotactic Radiotherapy for Malignant Skull Base Tumors.

The role of stereotactic radiosurgery/stereotactic radiotherapy (SRS/SRT) for malignant skull base tumors was summarized and discussed. The treatment of skull base tumors remains challenging. Their total resection is often difficult. SRS/SRT is one useful treatment option for residual or recurrent tumors after surgical resection in cases of primary skull base tumors. If skull base metastasis and skull base invasion are relatively localized, they can be candidates for SRS/SRT. Low rates of cervical lymph node involvement in early-stage (N0M0, no lymph node involvement or distant metastasis) nasal and paranasal carcinomas (NpNCa) and external auditory canal carcinomas (EACCa) have been reported in the literature. Such cases might be good candidates for SRS/SRT as the initial therapy. We previously reported the results of SRS/SRT for various malignant extra-axial skull base tumors. In addition, treatment results of early-stage head and neck carcinomas were summarized. Those of our data and those of other reported series were reviewed here to clarify the usefulness of SRS/SRT for malignant extra-axial skull base tumors.

Cost-Effective Method for 3-Dimensional Printing Dynamic Multiobject and Patient-Specific Brain Tumor Models: Technical Note

Three-dimensional (3D) printing is a powerful tool for replicating patient-specific anatomic features for education and surgical planning. The advent of "desktop" 3D printing has created a cost-effective and widely available means for institutions with limited resources to implement a 3D-printing workflow into their clinical applications. The ability to physically manipulate the desired components of a "dynamic" 3D-printed model provides an additional dimension of anatomic understanding. There is currently a gap in the literature describing a cost-effective and time-efficient means of creating dynamic brain tumor 3D-printed models. Using free, open-access software (3D Slicer) for patient imaging to Standard Tessellation Language file conversion, as well as open access Standard Tessellation Language editing software (Meshmixer), both intraaxial and extraaxial brain tumor models of patient-specific pathology are created. A step-by-step methodology and demonstration of the software manipulation techniques required for creating cost-effective, multidimensional brain tumor models for patient education and surgical planning are exhibited using a detailed written guide, images, and a video display. In this technical note, we describe in detail the specific functions of free, open-access software and desktop 3D printing techniques to create dynamic and patient-specific brain tumor models for education and surgical planning.