Dysembryoplastic neuroepithelial tumour in the cerebellum: case report and literature review.

BACKGROUND: Dysembryoplastic neuroepithelial tumours (DNETs) are benign brain tumours that most commonly arise at supratentorial sites. The cerebellum is an extremely rare location for DNETs. We report a case of cerebellar DNET along with literature review. CASE DESCRIPTION: A girl aged 2 years and 3 months presented with gait instability. Imaging examination showed a very large cystic-solid mass with mixed densities/signal intensities in the cerebellum. The entire lesion was successfully removed, and the patient achieved a good prognosis. CONCLUSION: Cerebellar DNET lacks characteristic imaging-based signs, and the diagnosis mainly relies on pathological examination. However, this diagnosis should be considered when a cerebellar lesion in child consists of cystic-solid mass with mixed densities/signal intensities.

Preoperative evaluation and surgical management of infants and toddlers with drug-resistant epilepsy.

OBJECTIVE Despite perioperative risks, epilepsy surgery represents a legitimate curative or palliative treatment approach for children with drug-resistant epilepsy (DRE). Several factors characterizing infants and toddlers with DRE create unique challenges regarding optimal evaluation and management. Epilepsy surgery within children < 3 years of age has received moderate attention in the literature, including mainly case series and retrospective studies. This article presents a systematic literature review and explores multidisciplinary considerations for the preoperative evaluation and surgical management of infants and toddlers with DRE. METHODS The study team conducted a systematic literature review based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, targeting studies that investigated children < 3 years of age undergoing surgical treatment of DRE. Using the PubMed database, investigators selected peer-reviewed articles that reported seizure outcomes with or without developmental outcomes and/or perioperative complications. Studies were eliminated based on the following exclusion criteria: sample size < 5 patients; and inclusion of patients > 3 years of age, when demographic and outcomes data could not be separated from the cohort of patients < 3 years of age. RESULTS The study team identified 20 studies published between January 1990 and May 2017 that satisfied eligibility criteria. All selected studies represented retrospective reviews, observational studies, and uncontrolled case series. The compiled group of studies incorporated 465 patients who underwent resective or disconnective surgery (18 studies, 444 patients) or vagus nerve stimulator insertion (2 studies, 21 patients). Patient age at surgery ranged between 28 days and 36 months, with a mean of 16.8 months (1.4 years). DISCUSSION The study team provided a detailed summary of the literature review, focusing on the etiologies, preoperative evaluation, surgical treatments, seizure and developmental outcomes, and potential for functional recovery of infants and toddlers with DRE. Additionally, the authors discussed special considerations in this vulnerable age group from the perspective of multiple disciplines. CONCLUSIONS While presenting notable challenges, pediatric epilepsy surgery within infants and toddlers (children < 3 years of age) offers significant opportunities for improved seizure frequency, neuro-cognitive development, and quality of life. Successful evaluation and treatment of young children with DRE requires special consideration of multiple aspects related to neurological and physiological immaturity and surgical morbidity.

Dysembryoplastic neuroepithelial tumours: clinical, radiological, pathological features and outcome.

OBJECT: To analyse the clinical, imaging and histopathological data of patients who were diagnosed to have Dysembrioplastic Neuroepithelial Tumour (DNET) and underwent surgery between 1995-2015. MATERIALS AND METHODS: Age at seizure onset, age at surgery, gender, disease duration, seizure outcome of 44 patients were analysed together with Magnetic Resonance Imaging (MRI) of 21 patients. MRI types were classified as type 1 (cystic/polycystic-like, well-delineated, strongly hypointense T1), type 2 (nodularlike,heterogeneous), type 3 (dysplastic-like, iso/hyposignal T1, poor delineation, gray-white matter blurring). RESULTS: Histopathological classification revealed simple form in 19, complex in 14 and non-specific in 11 patients. Lobar distribution of the lesions was as follows: 21 Temporal (47.7%), 12 parietal (27.3%), 8 frontal (18.2%) and 3 occipital (6.8%). Type 1 MRI was observed in 10, type 2 was in 7, and type 3 in 4 patients on radiological evaluation. All cases with type 1 MRI corresponded to either simple or complex forms and all cases with type 3 MRI corresponded to nonspecific form. The histopathological distribution of cases with type 2 MRI was 4 as non-specific, 2 as simple, 1 as complex. There was no significant difference in the age of onset, age at operation and duration of epilepsy between the patients with different MRI subtypes. The majority of patients (N:36) had Engel I outcome (81,8%). In groups with Engel II and III outcome, duration of epilepsy was significantly higher (p:0,014) and simple form of DNET has significantly higher seizure freedom after surgery compared to complex and nonspecific forms of DNET (p:0,002). CONCLUSION: Patients with DNET constitute a group with favorable outcomes after epilepsy surgery especially with early referral to surgery. Longer duration of epilepsy was associated with worse seizure outcome for DNET patients. There was significant correlation between radiological and histopathological types of DNET especially in type 1 and 3.

Natural history of lesions with the MR imaging appearance of multinodular and vacuolating neuronal tumor.

PURPOSE: Multinodular and vacuolating neuronal tumor (MVNT) have been recently added to the WHO classification of CNS tumors and has not been extensively reported upon in the radiological literature. We report the first radiological and the largest series of cases, aiming to highlight the natural history of lesions with the imaging appearance of MVNT with long follow-up time. METHODS: In this retrospective study, we collected cases with the imaging appearance of MVNT. All lesions were evaluated by using routine MR imaging, with follow-up of up to 93 months. Patient demographics, clinical course, and MRI features of the lesions were recorded. RESULTS: Twenty-four subjects were enrolled, f/m = 16:8, age range 24-59 years, with a median age of 45 years. The patients' symptoms were often episodic and most frequently due to headaches in 12 (50%), visual symptoms in 6 (25%), seizures in 5 ± 1 (20-25%), paresthesia in 4 (~17%), cognitive difficulties in 4 (~17%), in addition to other variable neurological symptoms, or incidental. A total of 30 lesions identified, 77% of the lesions had gadolinium-enhanced MRI and only 13% showed enhancement. A 6.7% of the lesions that had MRI followed up showed progression, while the rest remained stable up to 93 months interval. All patients had intact neurological examinations (except one case that was diagnosed with optic neuritis), were managed conservatively, and did well. CONCLUSION: The natural history of lesions with imaging features of MVNT is overall stable from a clinical and imaging appearance over time.

Occurrence of DNET and other brain tumors in Noonan syndrome warrants caution with growth hormone therapy.

Noonan syndrome (NS) is an autosomal dominant developmental disorder caused by mutations in the RAS-MAPK signaling pathway that is well known for its relationship with oncogenesis. An 8.1-fold increased risk of cancer in Noonan syndrome has been reported, including childhood leukemia and solid tumors. The same study found a patient with a dysembryoplastic neuroepithelial tumor (DNET) and suggested that DNET tumors are associated with NS. Herein we report an 8-year-old boy with genetically confirmed NS and a DNET. Literature review identified eight other reports, supporting the association between NS and DNETs. The review also ascertained 13 non-DNET brain tumors in individuals with NS, bringing to 22 the total number of NS patients with brain tumors. Tumor growth while receiving growth hormone (GH) occurred in our patient and one other patient. It is unknown whether the development or progression of tumors is augmented by GH therapy, however there is concern based on epidemiological, animal and in vitro studies. This issue was addressed in a 2015 Pediatric Endocrine Society report noting there is not enough data available to assess the safety of GH therapy in children with neoplasia-predisposition syndromes. The authors recommend that GH use in children with such disorders, including NS, be undertaken with appropriate surveillance for malignancies. Our case report and literature review underscore the association of NS with CNS tumors, particularly DNET, and call attention to the recommendation that clinicians treating NS patients with GH do so with awareness of the possibility of increased neoplasia risk.

Beneficial impact of high-field intraoperative magnetic resonance imaging on the efficacy of pediatric low-grade glioma surgery.

OBJECTIVE: Intraoperative MRI (iMRI) is assumed to safely improve the extent of resection (EOR) in patients with gliomas. This study focuses on advantages of this imaging technology in elective low-grade glioma (LGG) surgery in pediatric patients. METHODS: The surgical results of conventional and 1.5-T iMRI-guided elective LGG surgery in pediatric patients were retrospectively compared. Tumor volumes, general clinical data, EOR according to reference radiology assessment, and progression-free survival (PFS) were analyzed. RESULTS: Sixty-five patients were included in the study, of whom 34 had undergone conventional surgery before the iMRI unit opened (pre-iMRI period) and 31 had undergone surgery with iMRI guidance (iMRI period). Perioperative data were comparable between the 2 cohorts, apart from larger preoperative tumor volumes in the pre-iMRI period, a difference without statistical significance, and (as expected) significantly longer surgeries in the iMRI group. According to 3-month postoperative MRI studies, an intended complete resection (CR) was achieved in 41% (12 of 29) of the patients in the pre-iMRI period and in 71% (17 of 24) of those in the iMRI period (p = 0.05). Of those cases in which the surgeon was postoperatively convinced that he had successfully achieved CR, this proved to be true in only 50% of cases in the pre-iMRI period but in 81% of cases in the iMRI period (p = 0.055). Residual tumor volumes on 3-month postoperative MRI were significantly smaller in the iMRI cohort (p < 0.03). By continuing the resection of residual tumor after the intraoperative scan (when the surgeon assumed that he had achieved CR), the rate of CR was increased from 30% at the time of the scan to 85% at the 3-month postoperative MRI. The mean follow-up for the entire study cohort was 36.9 months (3-79 months). Progression-free survival after surgery was noticeably better for the entire iMRI cohort and in iMRI patients with postoperatively assumed CR, but did not quite reach statistical significance. Moreover, PFS was highly significantly better in patients with CRs than in those with incomplete resections (p < 0.001). CONCLUSIONS: Significantly better surgical results (CR) and PFS were achieved after using iMRI in patients in whom total resections were intended. Therefore, the use of high-field iMRI is strongly recommended for electively planned LGG resections in pediatric patients.

Endoscopic supraorbital eyebrow approach for the surgical treatment of extraaxialand intraaxial tumors.

OBJECT: The supraorbital eyebrow approach is a minimally invasive technique that offers wide access to the anterior skull base region and parasellar area through asubfrontal corridor. The use of neuroendoscopy allows one to extend the approach further to the pituitary fossa, the anterior third ventricle, the interpeduncular cistern, the anterior and medial temporal lobe, and the middle fossa. The supraorbital approach involves a limited skin incision, with minimal soft-tissue dissection and a small craniotomy, thus carrying relatively low approach-related morbidity. METHODS: All consecutive patients who underwent the endoscopic supraorbital eyebrow approach were retrospectively analyzed for lesion location, pathology, length of stay, complications, and cosmetic results. RESULTS: During a 56-month period, 97 patients (mean age 58.5 years) underwent an endoscopic eyebrow approach to resect extra- and intraaxial brain lesions. The most common pathologies treated were meningiomas (n = 41); craniopharyngiomas (n = 22); dermoid tumors (n = 7); metastases (n = 4); gliomas (n = 3); and other miscellaneous frontal, parasellar, and midbrain (n = 23) lesions. The median length of postoperative hospital stay was 2.7 days (range 1-8 days). In 82 patients a total removal of the lesion was performed, while in 15 patients a near-total or subtotal removal was achieved. There were no postoperative hematomas, cerebrospinal fluid leaks, or severe neurological deficits, with the exception of 2 cases of visual deterioration and 1 case each of meningitis, stroke, and third cranial nerve paresis. Other complications directly related to the approach included 2 cases of skin burn as a direct result of heat transmission from the microscope light, 1 case of right frontal palsy, 2 cases of frontal numbness, and 1 case of bone remodeling 1 year after surgery. CONCLUSIONS: The endoscopic supraorbital eyebrow approach is a safe and effective minimally invasive approach to remove extra- and intraaxial anterior skull base, parasellar, and frontal lesions, promoting a rapid recovery and short hospital stay. The location of the eyebrow incision demands a meticulous cosmetic closure, but, with proper technique, cosmetic results are excellent.

Long-term seizure outcome after epilepsy surgery of neuroglial tumors.

Purpose: Neuroglial tumors are frequently associated with pharmacorefractory epilepsies. However, comprehensive knowledge about long-term outcomes after epilepsy surgery and the main prognostic factors for outcome is still limited. We sought to evaluate long-term outcomes and potential influencing factors in a large cohort of patients who underwent surgery for neuroglial tumors in a single-center setting. Methods: The study analyzed the outcomes of 107 patients who underwent epilepsy surgery for neuroglial tumors between 2001 and 2020 at the Department of Epileptology, University Hospital Bonn, in Germany. The outcomes were evaluated using Engel classification. Differences in outcome related to potential prognostic factors were examined using the Chi2-test, Fisher's exact test and sign test. Additionally, stepwise logistic regression analysis was employed to identify independent prognostic factors. Results: Complete seizure freedom (Engel Class IA) was achieved in 75% of the operated patients at 12 months, and 56% at the last follow-up visit (70.4 ± 6.2 months, median: 40 months). Completeness of resection was a crucial factor for both 12-month follow-up outcomes and the longest available outcomes, whereas lobar tumor localization, histology (ganglioglioma vs. dysembryoplastic neuroepithelial tumor), history of bilateral tonic-clonic seizures prior to surgery, invasive diagnostics, side of surgery (dominant vs. non-dominant hemisphere), age at epilepsy onset, age at surgery, and epilepsy duration did not consistently impact postsurgical outcomes. Among temporal lobe surgeries, patients who underwent lesionectomy and lesionectomy, including hippocampal resection, demonstrated similar outcomes. Conclusion: Neuroglial tumors present as excellent surgical substrates in treating structural epilepsy. To achieve an optimal postsurgical outcome, a complete lesion resection should be pursued whenever possible.

[Long-term epilepsy-associated tumors]. / Glioneironal'nye opukholi, assotsiirovannye s epilepsiei.

OBJECTIVE: The goal of this review is to summarize data concerning radiological and histological diagnosis of epileptogenic tumors, as well as to discuss their surgical treatment. MATERIAL AND METHODS: PubMed literature database was searched for relevant articles, we also used our own clinical experience. RESULTS: Benign glioneuronal tumors are the second most common cause of drug resistant epilepsy in adults after hippocampal sclerosis. Exceptionally slow growth (more than 2 years), localization in the brain cortex, presence of differentiated neuronal tissue in tumoral body and long history of epilepsy are the key features of these tumors called LEAT (long-term epilepsy-associated tumors). Management of LEAT requires epileptological as well as neurooncological approach. The epileptogenic zone commonly spreads beyond the tumor borders and simple lesionectomy alone may not be sufficient for achieving seizure freedom. CONCLUSION: LEAT typically exhibit low proliferative activity, however they should be thoroughly differentiated from more aggressive glial tumors; while this task is sometimes quite challenging, it's achievable by means of histological and immunohistochemical examination.

Mini Temporal Craniotomy Using Anatomical Surface Landmarks for Temporal Lobe Epilepsy: Technical Note and Clinical Outcomes.

Background: Patients with temporal lobe epilepsy are subjected to standard temporal lobectomy wherever indicated. This is performed using a reverse question mark flap and a standard frontotemporal craniotomy. We describe the technique of minitemporal craniotomy (3 × 3cms) for temporal lobe epilepsy (TLE) and analyze the clinical outcomes of patients operated using this approach. Objectives: To describe the technique of minitemporal craniotomy for TLE without navigation guidance and to analyze the clinical outcomes of patients operated using this approach. Materials and Method: This was a retrospective analysis of all consecutive TLE cases operated at our institute from 2014 to 2019, via minitemporal craniotomy, using surface landmarks only without navigation guidance. The surgical technique, indications for surgery, and their clinical outcomes were analyzed. Results: A total number of 48 patients underwent surgery for TLE. There were no complications except three patients who had transient hemiparesis. The average duration of hospital stay was 4 days following surgery. Out of 28 patients with mesial temporal sclerosis, 22 (82%) had international league against epilepsy, Class I seizure outcome, 4 (12.5%) had Class II outcome and 2 (5.5%) had Class III outcome. 9 patients with dysembryoplastic neurectodermal tumor (DNET), 4 gangliogliomas, 2 neurocystecercosis (NCC), all had Class I outcome. Out of the five patients with MTS and associated anterior temporal focal cortical dysplasia (FCD), four (80%) had a Class I outcome, whereas one (20%) had Class II outcome. Conclusion: Utilizing surface anatomical landmarks, minitemporal craniotomy can be performed in even peripheral centers without neuronavigation, with good cosmesis, seizure outcomes.

A paediatric dysembryoplastic neuroepithelial tumour (DNET) with deregulated stem cell markers: a case report.

Background: Dysembryoplastic neuroepithelial tumours (DNETs) are rare, with only a few reported lethal cases. Currently, there are focused efforts by neuro-oncology professionals to reveal the molecular characterisations of individual central nervous system tumours (CNSTs). Here, we report the status of cancer stem cell (CSC) genes associated with resilience and drug resistance in a paediatric DNET, since the deregulations and variations of CSC genes may prove critical to these tumours' molecular characterisations. Case Description: Immunofluorescence, clonogenic assay and whole exome sequencing (WES) were applied to the patient's tissue and its corresponding cell line. The case is for of a 6-year-old boy with intractable epilepsy and unremarkable physical and neurological examinations. Following magnetic resonance imaging (MRI) and histopathological tests, the patient was diagnosed with DNET. The child underwent a right posterior temporoparietooccipital neuronavigation-assisted craniotomy. Several CSC markers were upregulated in situ, including the metastasis-related protein, anterior gradient 2 (AGR2; 67%), and the Wnt-signalling-related protein, frizzled class receptor 9 (FZD9; 79%). The cell line possessed a similar DNA profile as the original tissue, stained positive for the tumorigenic marker [BMI1 proto-oncogene (BMI)] and CSC markers, and displayed drug resistance. Variants identified in the tissue DNA, which are listed in the catalogue of somatic mutations in cancer (COSMIC) database for genes previously known to be necessary for the development of the embryonic brain, included variants in the cell division cycle 27 (CDC27) gene. Conclusions: we report the in situ and in vitro presence of CSCs in a paediatric DNET.

New Imaging Features of Multinodular and Vacuolating Neuronal Tumor Revealed by Alcohol and Illicit Drugs Consumption.

It has been almost a decade since the multinodular and vacuolating neuronal tumor (MVNT) was first described. In 2021, WHO classified it as a defined entity, and it is considered one of the glioneuronal and neuronal tumors. Due to its similarities with dysembryoplastic neuroepithelial tumors (DNET), some authors consider it a variant of these, ranking in the category of malformations, but genetic alterations favor a neoplastic origin. We present a 29-year-old male with a generalized onset tonic-clonic seizure after a nightclub party. Imaging studies revealed a right temporal multinodular and vacuolating neuronal tumor confirmed by biopsy. It is considered a nonaggressive, "leave me alone" brain lesion, which does not require biopsy because of well-defined MRI characteristics. Surgery is indicated only in symptomatic cases. We consider that this lesion was revealed by his seizure, most probably provoked (with normal video EEG recording) by the consumption of a lot of alcohol, illicit drugs, and sleep loss after a club party. We recommended close monitoring, but our patient preferred the surgery. Our case added more imaging details corroborated with the histopathology features of MVNT. FLAIR images revealed hypointense nodules surrounded by hyperintense peripheral rings and areas of high signal intensity between the nodules, which correspond to the histopathological architecture. To our knowledge, this is the first case of MVNT with diffusion tensor imaging and fiber tractography imaging studies.

Intraventricular dysembryoplastic neuroepithelial tumor in the temporal horn with Broad involvement of the ependyma.

Though typical dysembryoplastic neuroepithelial tumors (DNETs) are located in the cerebral cortex, an atypical DNET could occur in the temporal horn of the lateral ventricle and broadly involve the ependyma. Awareness of this atypical form of DNET is of value for the wright diagnosis and management of atypical DNETs.

Multinodular and Vacuolating Neuronal Tumor: Incidental Diagnosis of a Rare Brain Lesion.

Multinodular and vacuolating neuronal tumor (MVNT) is a rare benign brain lesion, commonly found in middle-aged adults. The patients experience a range of symptoms from being asymptomatic to epileptic seizures, with headache being the most common symptom. Here we report a case of an incidental diagnosis of MVNT in a young female. A 25-year-old female with a past medical history of occasional headaches without seizures or any focal neurological deficit presented after a motor vehicle rollover. The MRI brain revealed an incidental finding of a subcortical lesion in the right parietal lobe with T2-FLAIR (fluid-attenuated inversion recovery) hyperintensity between the cystic portions, indicative of a possible MVNT, with a less probable chance of dysembryoplastic neuroepithelial tumor based on the subcortical location of the lesion. No neurosurgical intervention was recommended. With one-year follow-up, no changes were noted on neuroimaging, and the patient remained stable without any neurological symptoms. The MVNT is a rare brain lesion that presents with benign features. In patients with epileptic symptoms, surgical resection of the lesion can be curative. However, in asymptomatic patients, careful monitoring may be sufficient, as described in this case.

5-Aminolevulinic acid-assisted resection of pediatric dysembryoplastic neuroepithelial tumor: illustrative case.

BACKGROUND: 5-Aminolevulinic acid (5-ALA) is approved as an adjunct for the resection of high-grade gliomas and is associated with improved outcomes. Dysembryoplastic neuroepithelial tumors (DNETs) are benign glioneural tumors occurring primarily in pediatric patients and often manifesting with seizure disorder. The goal of the surgical intervention is to obtain gross-total resection, which is associated, in the majority of cases, with seizure freedom. OBSERVATIONS: The authors present the first case report of a pediatric patient who underwent gross-total resection of a 5-ALA-positive DNET with no evidence of recurrent seizures (Engel class I). LESSONS: Fluorescence-guided surgery using 5-ALA facilitated gross-total resection of the mass.

ILAE Neuroimaging Task Force highlight: Review MRI scans with semiology in mind.

The ILAE Neuroimaging Task Force aims to publish educational case reports highlighting basic aspects related to neuroimaging in epilepsy consistent with the educational mission of the ILAE. It is important to obtain MRI scans early in the clinical course of epilepsy, using an optimized protocol. Furthermore, it is critical that MRI scans are reviewed by experts who have been provided with all the clinical information and results from other investigations. We report a patient with a 21-year history of drug-resistant seizures who was admitted from another centre for presurgical evaluation. She had four previous MRI scans from this centre which were reported as unremarkable. However, a review of the MRI scan obtained on the day of admission, with the patient's ictal semiology in mind, resulted in identification of an epileptogenic lesion which was later confirmed by video-EEG monitoring and interictal PET. This lesion was present on all previous MRI scans and showed no change. The patient underwent lesionectomy, and histopathology of the resected specimen was consistent with a dysembryoplastic neuroepithelial tumour. The patient remains seizure-free, 2.5 years after surgery. This case highlights the importance of obtaining detailed descriptions of seizure semiology and considering them when reviewing MR images.

Full-count PET recovery from low-count image using a dilated convolutional neural network.

PURPOSE: Positron emission tomography (PET) is an essential technique in many clinical applications that allows for quantitative imaging at the molecular level. This study aims to develop a denoising method using a novel dilated convolutional neural network (CNN) to recover full-count images from low-count images. METHODS: We adopted similar hierarchical structures as the conventional U-Net and incorporated dilated kernels in each convolution to allow the network to observe larger, more robust features within the image without the requirement of downsampling and upsampling internal representations. Our dNet was trained alongside a U-Net for comparison. Both models were evaluated using a leave-one-out cross-validation procedure on a dataset of 35 subjects (~3500 slabs), which were obtained from an ongoing 18 F-Fluorodeoxyglucose (FDG) study. Low-count PET data (10% count) were generated by randomly selecting one-tenth of all events in the associated listmode file. Analysis was done on the static image from the last 10 minutes of emission data. Both low-count PET and full-count PET were reconstructed using ordered subset expectation maximization (OSEM). Objective image quality metrics, including mean absolute percent error (MAPE), peak signal-to-noise ratio (PSNR), and structural similarity index metric (SSIM), were used to analyze the deep learning methods. Both deep learning methods were further compared to a traditional Gaussian filtering method. Further, region of interest (ROI) quantitative analysis was also used to compare U-Net and dNet architectures. RESULTS: Both the U-Net and our proposed network were successfully trained to synthesize full-count PET images from the generated low-count PET images. Compared to low-count PET and Gaussian filtering, both deep learning methods improved MAPE, PSNR, and SSIM. Our dNet also systematically outperformed U-Net on all three metrics (MAPE: 4.99 ± 0.68 vs 5.31 ± 0.76, P < 0.01; PSNR: 31.55 ± 1.31 dB vs 31.05 ± 1.39, P < 0.01; SSIM: 0.9513 ± 0.0154 vs 0.9447 ± 0.0178, P < 0.01). ROI quantification showed greater quantitative improvements using dNet over U-Net. CONCLUSION: This study proposed a novel approach of using dilated convolutions for recovering full-count PET images from low-count PET images.

Long-Term Epilepsy-Associated Tumors (LEATs): A Single-Center, Retrospective Series and Review of Literature on Factors Affecting the Seizure Outcome.

BACKGROUND: Tumors presenting with drug-resistant seizures are termed as long-term epilepsy-associated tumors (LEATs). LEATs are more common in the temporal lobe, occur predominantly in pediatric age, and focal neurological deficits are rare. In this article, we aim to highlight our surgical experience in terms of seizure outcome among LEATs and discuss the factors affecting outcome. METHODOLOGY: We have retrospectively analyzed all the operated cases of intra-axial brain tumors with seizures (2015-2019). The clinical and radiographic data were collected from the hospital record system. For comparison, 2 groups were made (group 1 with good seizure control, i.e., Engel 1; and group 2 poor seizure outcome, i.e., Engel 2 and 3). RESULTS: A total of 51 cases were included; the temporal lobe was the most common location (n = 27); 23 patients had seizure frequency of "more than 1 seizure per week." Focal unaware seizures/complex partial seizures were the most common type of seizures encountered (n = 28). At a mean follow-up of 39.60 months, 38 patients had Engel 1 (78.5%) outcome (35 cases [71.05%] had the seizure duration of ≤2 years). The median duration of symptoms (group 1, 25 months vs. group 2, 65 months) was significantly different (P = 0.002). On comparing patients with seizure duration, we found a statistically significant difference (P < 0.00001). CONCLUSION: A shorter duration of symptoms, younger age of the patient, partial/focal seizures, and gross total excision were predictors of a good seizure outcome. Histopathology of the tumor does not affect the outcome when one compares glioneuronal tumors with non-glioneuronal tumors.

Multinodular and vacuolating neuronal tumor of the cerebrum: Two cases and review of the literature.

BACKGROUND: Multinodular and vacuolating neuronal tumor (MVNT) recently described as a purely neuronal tumor. Although its nature as a genuine tumor is controversial, this new entity assumed benign lesion and mostly affecting adults. Herein, we introduce two cases of MVNT presumed low grade glial tumor (LGG) and focal cortical dyplasia (FCD) as a differential diagnosis. CASE DESCRIPTION: Case 1 has admitted to our hospital with headache which frequency and severity has increased within two months. Radiological examination revealed hyperintensity on T2-WI and T2 FLAIR images. Microsurgical resection was performed and histopathological findings were compatible with MVNT instead of low grade glial tumor as we thought. Case 2, who presented at our hospital with one episode seizure. MRI showed T2 hyperintensity and T1 hypointensity without contrast enhancement. We suspected FCD, thus performed microsurgical gross total resection with frontal craniotomy. Pathological findings confirmed MVNT as a diagnosis. Both cases were discharged on the 3rd day after surgery without any complications and with no regrowth of tumor at the 9-months and 3-months follow-up respectively. CONCLUSIONS: Radiological hallmarks may be helpful to prevent from aggressive treatment in case of patient is asemptomatic. Nevertheless further studies are necessary for the adoption of 'wait and see' philosophy and give a verdict about benign nature of these tumors.

Septal dysembryoplastic neuroepithelial tumor: a comprehensive clinical, imaging, histopathologic, and molecular analysis.

BACKGROUND: Dysembryoplastic neuroepithelial tumors (DNETs) are uncommon neural tumors presenting most often in children and young adults and associated with intractable seizures. Rare midline neoplasms with similar histological features to those found in DNETs have been described near the septum pellucidum and termed "DNET-like neoplasms of the septum pellucidum." Due to their rarity, these tumors have been described in just a few reports and their genetic alterations sought only in small series. METHODS: We collected 20 of these tumors for a comprehensive study of their clinical, radiological, and pathological features. RNA sequencing or targeted DNA sequencing was undertaken on 18 tumors, and genome-wide DNA methylation profiling was possible with 11 tumors. Published cases (n = 22) were also reviewed for comparative purposes. RESULTS: The commonest presenting symptoms and signs were related to raised intracranial pressure; 40% of cases required cerebrospinal fluid diversion. Epilepsy was seen in approximately one third of cases. All patients had an indolent disease course, despite metastasis within the neuraxis in a few cases. Radiologically, the septum verum/septal nuclei were involved in all cases and are the proposed site of origin for septal DNET (sDNET). Septal DNET showed a high frequency (~80%) of mutations of platelet derived growth factor receptor A (PDGFRA), and alterations in fibroblast growth factor receptor 1 (FGFR1) and neurofibromatosis type 1 (NF1) were also identified. In a genomic DNA methylation analysis alongside other neural tumors, sDNETs formed a separate molecular group. CONCLUSIONS: Genetic alterations that are different from those of cerebral DNETs and a distinct methylome profile support the proposal that sDNET is a distinct disease entity.