Intraparenchymal Tumor Research Articles

Primary intracranial pediatric ganglioneuroblastoma-report of two cases and review of an unusual masquerader.

Ganglioneuroblastoma (GNB) is a rare neurogenic tumor with a predilection for extracranial sites. Its primary intracranial occurrence is anecdotal, with less than ten cases reported in pediatric literature. We report two cases of this unusual entity. The first was a 1-year-old boy who presented with a progressive scalp swelling that radiologically appeared to be a mesenchymal tumor. The tumor was resected completely, and its histopathological examination was suggestive of a pigmented GNB. The clinico-radiological presentation and melanin pigmentation of the tumor were unique features of the case. The second case was a 7-year-old girl who presented with left hemiparesis and raised intracranial pressure due to a large right parietal intraparenchymal tumor that histologically proved to be a GNB. The child succumbed to disease progression a month after undergoing near-total resection of the tumor. Analysis of our cases in the light of a literature review reveals that pediatric intracranial GNBs have diverse clinico-radiological features and can easily be confused for commoner pathologies in both intra- and extra-axial locations.

DIFFUSE LEPTOMENINGEAL GLIONEURONAL TUMOR: A RARE CAUSE OF MALIGNANT PLEURAL EFFUSION

DIFFUSE LEPTOMENINGEAL GLIONEURONAL TUMOR: A RARE CAUSE OF MALIGNANT PLEURAL EFFUSION

Prognostic factors in diffuse leptomeningeal glioneuronal tumor (DLGNT): a systematic review

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare tumor, first described by the WHO Classification of Central Nervous System Tumors in 2016. The clinical course is variable. Most tumors have low-grade histological findings although some may have more aggressive features. The goal of this systematic review was to identify prognostic factors for poor overall survival (OS). We performed a systematic review using three databases (PubMed, Google Scholar, and Embase) and the following search terms: diffuse leptomeningeal glioneuronal tumor, DLGNT, DLMGNT. Statistical analysis was performed using Statistica 13.3. We included 34 reports in our review comprising 63 patients, published from 2016 to 2022. The median OS was 19months (range: 12-51months). Using multivariable Cox survival analysis, we showed that Ki-67 ≥ 7%, age > 9years, symptoms of elevated intracranial pressure (ICP) at admission, and the presence of contrast-enhancing intraparenchymal tumor are associated with poor OS. Receiver operating characteristic (ROC) analysis identified Ki-67 ≥ 7% as a significant predictor of poor OS. Signs or symptoms of increased ICP with imaging findings of diffuse leptomeningeal enhancement should raise suspicion for DLGNT. In our systematic review, Ki-67 ≥ 7% was the most important prognostic factor for OS in DLGNT. The presence of intraparenchymal tumor with contrast enhancement was thought to represent disease progression and, together with patient age, was associated with poor OS.

Abstract 5498: Plinabulin, a novel tubulin targeting agent, collapses the proinvasion tumor microtube network in primary and recurrent patient derived glioblastoma cell lines to inhibit neurosphere invasion and survival

Abstract Glioblastoma multiforme (GBM) is the most common adult primary brain malignancy. Aggressive, diffuse invasion is regulated by a dynamic cytoskeleton and significantly contributes to poor survival. Intraparenchymal tumor cell dissemination prevents complete surgical resection and compromises essential brain functions. Invasive cells are inherently less sensitive to traditional cytotoxic therapies. Recent investigation into targeted therapies has failed to address invasion/cytoskeleton based GBM therapy resistance. Furthermore, established GBM cell line modeling in 2 or 3 dimensions (3D) does not capture the genetic diversity or clinical relevance of patient derived primary (1') GBM cell lines, which may uncover/predict differential responses in tumors to novel therapies. Cytoskeleton remodeling and cell invasion in patient-derived primary GBM cells generates unique structures called tumor microtubes (TMs) not seen in established, cultured GBM cell lines. TMs are ultralong, pro-invasive, tubulin-enriched protrusions that promote chemo- and radioresistance in GBM patient derived primary cells. Using our extensive GBM cell line biobank derived from 1' and/or therapy resistant recurrent (2') tumors, we investigated the effects of a novel drug targeting the microtubule cytoskeleton. Plinabulin is a tubulin targeting agent that crosses the blood brain barrier and demonstrated anticancer efficacy in Phase III trial patients with non-small cell lung carcinoma. Plinabulin also has antiproliferative properties in 2D GBM cells. Here, we evaluate the efficacy of plinabulin treatment upon 3D neurosphere viability and invasion in 5 GBM 1' and 2' recurrent patient derived cell lines. Within 24h of matrigel embedding, 3D GBM patient neurospheres generate robust pro-invasive TMs. Plinabulin treatment (10-30 nM) at embedding followed by drug washout after 24h eliminated existing TMs and inhibited single cell invasion (>80% relative to controls) in both 1' and 2' GBM patient neurospheres. Cell survival was significantly reduced in plinabulin treated neurospheres (>30 nM). Plinabulin efficacy was evaluated in a clinically relevant therapeutic ITR model: GBM patient neurospheres invaded (I) for 48h to establish TM networks; were treated (T) with 1-50 nM plinabulin for 24h prior to drug washout; and recovered (R) for 96h. In 1', 2', or matched 1' and 2' cell line pairs from the same patient, 10-40 nM plinabulin sustained invasion inhibition (>90%) through 96h post washout and completely blocked TM extension relative to controls, consistent with established clinical concentrations of plinabulin. This study reveals plinabulin as a potent GBM therapeutic targeting pro-invasion TM networks and survival in 1' and therapy resistant 2' GBM patient cell lines. Citation Format: Kathryn M. Eisenmann, Kenneth Lloyd, Krista M. Pettee, Kathryn N. Becker, Jason Schroeder, Kevin Reinard, James R. Tonra, Ramon Mohanlal, Lan Huang. Plinabulin, a novel tubulin targeting agent, collapses the proinvasion tumor microtube network in primary and recurrent patient derived glioblastoma cell lines to inhibit neurosphere invasion and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5498.

Lacrimal Gland Intravascular Micrometastasis From a Human Papillomavirus-Driven Anorectal Squamous Cell Carcinoma With a Review of Metastatic Disease to the Lacrimal Gland

To document a unique case of anorectal squamous cell carcinoma that was metastatic to the microvasculature of the lacrimal gland in a patient with human immunodeficiency virus and to review previously reported cases of metastases to the lacrimal gland. Both a retrospective chart review and comprehensive literature review were performed. The unusual histopathologic pattern of the current case was illustrated with immunohistochemical studies (CD31, D2-40, pancytokeratin, p16, and p63) and in situ hybridization studies for high-risk human papillomavirus types 16 and 18. The authors describe the first case of metastatic anorectal squamous cell carcinoma to the lacrimal gland. Only 24 cases of metastatic disease to the lacrimal gland have been reported, the majority from breast carcinomas. The metastasis did not form a macroscopic lesions, instead was composed of microscopic intravascular and intraparenchymal tumor deposits, a subtle phenomena. Immunohistochemistry confirmed the presence of the intravascular neoplastic cells. p16 served as a surrogate marker for human papillomavirus-associated squamous cell carcinoma and was confirmed with in situ hybridization for human papillomavirus 16 and 18. This testing, combined with the clinical history, defined the diagnosis and confirmed human papillomavirus as the tumor driver. Metastases to the lacrimal gland remain rare, but clinicians and pathologists alike must be attuned to the possibility of subtle microscopic foci of tumor as a pattern of metastasis in scenarios without a discrete mass-forming lesion, as this may portend a poor prognosis.

RARE-47. DIFFUSE LEPTOMENINGEAL DISSEMINATED GLIONEURONAL TUMOR: CASE-SERIES

Diffuse leptomeningeal disseminated glioneuronal tumor (DL-GNT) is a rare brain tumor that presents as a plaque-like subarachnoid tumor, commonly involving the basal cisterns and interhemispheric fissure of children but lacking intraparenchymal tumor. Here we report two cases focusing on clinicopathologic features. In all patients, radiography revealed characteristic leptomeningeal thickening and enhancement with minor superficial parenchymal lesions. The broadcast of the knowledge about this type of disease is important to increase awareness on this subject.

Safety and Oncologic Outcomes of Magnetic Resonance Imaging-Guided Cryoablation of Renal Cell Carcinoma: A 10-Year Single-Center Experience.

Magnetic resonance imaging guidance has been sporadically reported for renal tumor cryoablation (CA); therefore, clinical experience with this modality is still limited.The aim of this study is to retrospectively analyze our 10-year experience with renal tumor CA performed on a 1.5 T magnetic resonance imaging unit with the intent of reporting procedural safety and oncologic outcomes. We included 143 patients (102 men; 41 women; median age, 73 years; range, 34-91 years) with 149 tumors (median size, 2.6 cm; range, 0.6-6.0 cm), treated between 2009 and 2019. Patient, tumor, procedure, and follow-up data were collected and analyzed. The Kaplan-Meier method was used to estimate local recurrence-free (LRFS), metastasis-free (MFS), disease-free (DFS), cancer-specific, and overall (OS) survival. Univariate and multivariate models were used to identify factors associated with complications, LRFS, MFS, DFS, and OS. The overall complication rate was 10.7% (16/149 tumors), with 1 major (1/149 [0.7%]; 95% confidence interval, 0.0%-3.7%) hemorrhagic complication. Other minor complications (15/149 [10.1%]; 95% confidence interval, 0.6%-16.1%) did not include any cases of injury to nearby organs. There were no factors associated with complications.Five-year estimates of LRFS (primary/secondary), MFS, DFS, cancer-specific survival, and OS were 82.8%/91.5%, 91.1%, 75.1%, 98.2%, and 89.6%, respectively. Increasing tumor size (hazard radio [HR], 1.8; P = 0.02) and intraparenchymal tumor location (HR, 5.6; P < 0.01) were associated with lower LRFS; increasing patient's age (HR, 0.5; P = 0.01), high tumor grade (HR, 23.3; P < 0.01) and non-clear-cell/nonpapillary histology (HR, 20.1; P < 0.01) with metastatic disease; and high tumor grade (HR, 3.2; P = 0.04) with lower DFS. Magnetic resonance imaging-guided CA of renal tumors is associated with acceptable morbidity and high survival estimates at 5-year follow-up. Given the absence of complications resulting from injuries to nearby organs, further studies are required to evaluate whether the potential reduced incidence of these adverse events justifies large-scale implementation of this interventional modality.

Diffuse leptomeningeal glioneuronal tumor: a double misnomer? A report of two cases

Diffuse leptomeningeal glioneuronal tumor (DLGNT) was introduced, for the first time, as a provisional entity in the 2016 WHO classification of central nervous system tumors. DLGNT mainly occur in children and characterized by a widespread leptomeningeal growth occasionally associated with intraspinal tumor nodules, an oligodendroglial-like cytology, glioneuronal differentiation and MAP-Kinase activation associated with either solitary 1p deletion or 1p/19q codeletion in the absence of IDH mutation.We report here two unexpected DLGNTs adult cases, characterized by a unique supratentorial circumscribed intraparenchymal tumor without leptomeningeal involvement in spite of long follow-up. In both cases, the diagnosis of DLGNT was made after DNA-methylation profiling which demonstrated that one case belonged to the DLGNT class whereas the other remained not classifiable but showed on CNV the characteristic genetic findings recorded in DLGNT. Both cases harbored 1p/19q codeletion associated with KIAA1549:BRAF fusion in one case and with BRAF V600E and PIK3CA E545A mutations, in the other.Our study enlarges the clinical and molecular spectrum of DLGNTs, and points out that the terminology of DLGNTs is not fully appropriate since some cases could have neither diffuse growth nor leptomeningeal dissemination. This suggests that DLGNTs encompass a wide spectrum of tumors that has yet to be fully clarified.

Randomized phase III study of high-dose methotrexate and whole brain radiotherapy with or without concomitant and adjuvant temozolomide in patients with newly diagnosed primary central nervous system lymphoma: JCOG1114C.

2500 Background: Temozolomide (TMZ) is an oral alkylating agent that penetrates the blood-brain barrier with moderate toxicity, and has shown anti-tumor activity in primary central nervous system lymphoma (PCNSL) in single arm studies. Our goal was to determine whether the addition of concomitant and adjuvant TMZ chemotherapy to standard treatment of high-dose methotrexate (HD-MTX) and whole brain radiotherapy (WBRT) for PCNSL improves survival in a randomized controlled trial. Methods: We did an open-label, randomized phase III trial at 30 hospitals in Japan enrolling immunocompetent patients (pts) aged 20-70 years with histologically confirmed newly diagnosed PCNSL. Pts enrolled at step 1 registration received HD-MTX (MTX; 3.5 g/m2 at day 1, 15, 29). Pts who received at least 1 cycle of HD-MTX were randomly assigned (1:1) at step 2 registration to receive WBRT (30 Gy) ± 10 Gy boost (control arm: A) or WBRT ± boost with concomitant TMZ (75 mg/m2 daily) and adjuvant TMZ (150-200 mg/m2 daily for 5 days every 28 days) for two years after initiation of HD-MTX or until tumor progression (experimental arm: B). Randomization was adjusted by institution, PS (0-1 / 2-3), age (≤60/≥61 years), presence or absence of intraparenchymal tumor after HD-MTX. The primary endpoint was overall survival (OS). The planned sample size was 130 pts in total, to provide an 80% power to detect a 0.52 hazard ratio (65% vs 80% in 2y-OS) for arm B to A and a one-sided alpha of 5%. Results: Between September 29, 2014 and October 15, 2018, 134 pts were enrolled, of whom 122 were randomly assigned and analyzed; 62 to arm A and 60 to arm B. At the planned interim analysis, the 2-y OS was 86.8% (95% CI: 72.5-94.0) in arm A and 71.4% (56.0-82.2) in arm B. The hazard ratio was 2.18 (95% CI: 0.95 to 4.98) with predictive probability for showing the superiority of arm B at the final analysis was calculated to be 1.3%. The study was terminated due to futility. The 2-y progression-free survival was 60.6% (43.6-73.8) in arm A and 49.9% (34.4-63.5) in arm B with a hazard ratio of 1.54 (0.88 to 2.70). The most common grade 3 and 4 toxicities were lymphopenia, observed in 7 (11.5%) pts during WBRT in arm A, 18 (30%) pts during WBRT + concomitant TMZ and 18 (37.5%) pts during adjuvant TMZ in arm B. Conclusions: This study failed to demonstrate the benefit of the addition of TMZ to WBRT and adjuvant TMZ in newly diagnosed PCNSL. Possible biomarkers including methylation status of the MGMT promoter in the tumors will be analyzed. Clinical trial information: jRCTs031180207 .

1048 - CT measurement of intraparenchymal tumor volume as predictor of renal function after robotic partial nephrectomy

1048 - CT measurement of intraparenchymal tumor volume as predictor of renal function after robotic partial nephrectomy

An elderly patient presenting with a primary spinal multifocal intradural extramedullary pilocytic astrocytoma: a case report and review of the literature

BackgroundPilocytic astrocytoma is a low-grade central nervous system tumor most commonly seen in children. Dissemination from a primary intracranial tumor along the neuroaxis has been described at both presentation and disease progression. However, the development of an intradural extramedullary pilocytic astrocytoma independent of a primary intraparenchymal tumor in an adult patient with no history of pilocytic astrocytoma has rarely been reported.Case presentationA 69-year-old woman presented with progressive myelopathic symptoms and thoracic radicular pain. MRI imaging of the whole spine showed an enhancing intradural extramedullary lesion extending from the cervical cord to T11 causing cord compression. Laminectomies were performed for surgical decompression and histopathology was consistent with pilocytic astrocytoma. Complete staging was done that included imaging of the brain and cerebrospinal fluid cytology. No other tumor was found by these methods. Postoperatively the patient was treated with large field spinal radiation and concurrent chemotherapy followed by adjuvant chemotherapy. She has thus far been clinically and radiographically stable.ConclusionThis is a rare case of an adult with multiple spinal pilocytic astrocytomas in an intradural extramedullary location, typically the result of cerebrospinal fluid dissemination of neoplastic cells from a primary intracranial tumor site (i.e. drop metastasis). No conventional primary tumor was identified in this patient, suggesting these tumors may arise from heterotopic gliomas.

Endoscopy in Temporal Lobe Glioma and Metastasis Resection: Is There a Role?

Surgical access to the temporal lobe is complex with many eloquent white fiber tracts, requiring careful preoperative surgical planning. Many microsurgical approaches to the temporal lobes are described, each with their own disadvantages. The adoption of the endoscope in neurosurgery has increased the options available when treating these difficult access tumors. We present our experience of a novel, minimally invasive, endoscopic approach to resect temporal lobe tumors. All patients undergoing endoscopic temporal lobe tumor resection between December 1, 2011 and December 1, 2017, with a single surgeon, were included. Tumors were resected through a minicraniotomy using a high-definition rigid endoscope with a 0- and 30-degree viewing angle. Bimanual resection was performed using standard microsurgical technique. There were 45 patients (22 men and 23 women) with a mean age of 53 years. There were 23 (51%) glioblastoma multiforme, 11 (24%) metastases, 7 (16%) astrocytoma, 3 (7%) anaplastic astrocytoma, and 1 (2%) World Health Organization grade I glioneuronal tumor. In 82.2% of cases (37/45), >95% resection was achieved and 42.2% (19/45) of patients achieving gross total resection. The endoscope has a role in temporallobe intraparenchymal tumor surgery, especiallyin3illustrative scenarios: 1) medial temporal, parahippocampal-gyruslow-grade nonenhancing gliomas, 2) subcortical high-gradeglioma and metastases medial to the sagittal stratum, and 3) recurrent gliomas with cystic resection cavity. The endoscope offers a safe and useful adjunct to the surgeons' armamentarium in brain tumor surgery. A minimally invasive approach also reduces surgical morbidity and length of stay.

Role of computed tomography-calculated intraparenchymal tumor volume in assessment of patients undergoing partial nephrectomy.

To determine the complexity of renal masses by using an objective novel imaging parameter (intraparenchymal tumor volume) based on computed tomography scans, to correlate this parameter to perioperative outcomes and to the RENAL nephrometry score. After institutional review board approval, 87 patients who underwent partial nephrectomy between 2012 and 2016 at Singapore General Hospital, Singapore, were retrospectively analyzed. Preoperative computed tomography intravenous pyelogram scans were reviewed by a single senior radiologist who calculated the intraparenchymal tumor volume. Once the intraparenchymal tumor volume scores were obtained, they were compared with perioperative renal and surgical outcomes, and nephrometry scores. Furthermore, intraparenchymal tumor volume was subdivided into two categories, low and high intraparenchymal tumor volume, both using the 89th percentile. The mean patient age was 60 years, and the mean tumor size was 2.9 cm. The mean nephrometry score was 7.8, and the mean intraparenchymal tumor volume score was 12.7 cm³. The cut-off for high intraparenchymal tumor volume was >27.26 cm³. As a continuous variable, intraparenchymal tumor volume showed a significant relationship with the percentage of creatinine change (P = 0.009) and nephrometry scores (P < 0.001). As a categorical variable, high intraparenchymal tumor volume showed significance when compared with absolute creatinine change (P = 0.018), percentage of creatinine change (P = 0.004) and nephrometry score (P < 0.001). Intraparenchymal tumor volume represents a novel objective tool based on computed tomography imaging to determine the complexity of a renal mass. This tool correlates with renal functional outcomes of partial nephrectomy, and it also shows good correlation with RENAL nephrometry score.

Patient operated for an intraparenchymal brain tumor with serious lower limb weakness. The role of in-hospital physiotherapy

The aim of this case study is to present the role of hospital physiotherapy in a patient who was operated for an intraparenchymal brain tumor, from admission to intensive care unit until his discharge from hospital. Following acute surgical management, physiotherapy commenced and was devided in four phases: 1) Patient in ICU under mechanical support, 2) Patient in ICU without mechanical support, 3) Patient in step down unit, 4) Patient on the neurosurgical ward. During all phases of patient management, physiotherapy focused on daily assessment of respiratory and musculoskeletal function as well as the prevention and management of acute complications in intensive care unit and acquired physical impairments. Interventions included state of the art chest physiotherapy techniques as well as an early rehabilitation regimen from ICU to the step down unit and the ward. Significant improvements were noted before the patient was discharged, in respiratory function, muscle power and mobility. Planning and application of all physiotherapy techniques was in accordance to the most recent research evidence and clinical guidelines and contributed significantly to the patient’s overall clinical outcome.

PJY09 - The role of computer tomography (CT) calculated intra-parenchymal tumour volume (IPV) in assessment of patients undergoing partial nephrectomy

PJY09 - The role of computer tomography (CT) calculated intra-parenchymal tumour volume (IPV) in assessment of patients undergoing partial nephrectomy

The Alternative Receptor for Complement Component 5a, C5aR2, Conveys Neuroprotection in Traumatic Spinal Cord Injury.

This study investigated the role of the alternative receptor for complement activation fragment C5a, C5aR2, in secondary inflammatory pathology after contusive spinal cord injury (SCI) in mice. C5ar2-/- mice exhibited decreased intraparenchymal tumor necrosis factor alpha and interleukin-6 acutely post-injury, but these reductions did not translate into improved outcomes. We show that loss of C5aR2 leads to increased lesion volumes, reduced myelin sparing, and significantly worsened recovery from SCI in C5ar2-/- animals compared to wild-type (WT) controls. Loss of C5aR2 did not alter leukocyte mobilization from the bone marrow in response to SCI, and neutrophil recruitment/presence at the lesion site was also not different between genotypes. Acute treatment of SCI mice with the selective C5aR1 antagonist, PMX205, improved SCI outcomes, compared to vehicle controls, and, importantly, fully alleviated the worsened recovery of C5ar2-/- mice compared to their WT counterparts. Collectively, these findings indicate that C5aR2 is neuroprotective and a novel target to restrain injurious C5a signaling after a major neurotraumatic event.

Deep Sylvian Meningioma: A Case Report and Review of the Literature

Introduction Meningiomas are extra-axial tumors. They usually display a dural attachment, although meningiomas without dural attachment are extremely rare and reported only occasionally in the literature. In this article, the authors present a new case of a deep sylvian meningioma and briefly review the relevant literature. Case Report We present the case of a 39-year-old man presented with 1- month history of headache associated with an episode of generalized tonic–clonic seizure. Neurological examination showed no abnormality. Magnetic resonance imaging (MRI) demonstrated a lesion located in the right temporo-frontal region which was isointense on T1 and hypointense on T2 with homogeneous enhancement after gadolinium administration. Coronal, axial, and sagittal MRI revealed no dural attachment and the mass appeared to be completely surrounded by brain parenchyma. Intraoperatively, the lesion was presented as a subcortical mass and was mainly in the posterior part of right sylvian fissure. The histological diagnosis showed a World Health Organization grade I meningioma, transitional type. Conclusion Deep sylvian meningiomas are a rare entity. Preoperative diagnosis is difficult. Nevertheless, neurosurgeons and neuropathologists should be aware of this possibility and should include this hypothesis in the differential diagnosis of an intraparenchymal tumor.

Avoidance of ischemic complications after resection of a brain lesion based on intraoperative real-time recognition of the vasculature using laser speckle flow imaging.

OBJECTIVE To avoid ischemic complications, it is important to consider the arteries in resection planning for lesions such as a vascular intraparenchymal tumor and arteriovenous malformation. Here, the clinical application of laser speckle flow imaging (LSFI) as a complementary method for the management of mass lesion-related arteries during surgery was evaluated. METHODS LSFI was performed in 12 patients with mass lesion-related arteries and brain tumor or arteriovenous malformation. The portable LSFI device was centered over the surgical field, and the relative cerebral blood flow (CBF) before and after the temporary interruption of the arteries was measured through continuous recording. CBF fluctuations permitted the classification of 3 kinds of artery-a feeding artery (FA), a "passing through" artery (PA), and a combined FA and PA (FA+PA)-based on decreased relative CBF in the inner resection area and unchanged CBF in the surrounding area (FA), unchanged CBF in the inner area and decreased CBF in the surrounding area (PA), or decreased CBF in both areas (FA+PA). This information allowed the appropriate management of these arteries and avoidance of postoperative ischemic complications. RESULTS Good visualization of CBF in the surgical field and relative CBF measurements in the regions of interest were achieved in real time with excellent spatiotemporal resolution. In 11 patients (92%) and 20 regions of interest, a decline in CBF was observed after temporary interruption of the FA (n = 8), PA (n = 2), and FA+PA (n = 2) types. There was a significant average reduction in CBF of 15.3% ± 29.0%. There were no ischemic complications, and only 1 patient had a postoperative ischemic lesion caused by resection through an artery that could not be viewed by LSFI due to a positional problem. CONCLUSIONS LSFI permits noninvasive and rapid intraoperative real-time recognition of mass lesion-related vasculature. This information can be used to avoid ischemic complications as a procedure complementary to neurophysiological monitoring.

Minimally Invasive Endoscopic Resection of Intraparenchymal Brain Tumors

The endoscope in neurosurgery has at times been accused of being a tool looking for a purpose. In many applications, it has successfully refuted this accusation: it is hard to imagine a cogent argument against using endoscopy for a third ventriculostomy or intraventricular tumor biopsy in the right setting. Also, although the entire field of endonasal anterior skull base surgery has not yet reached full maturity, few would argue that the subspecialty does not have value. The endoscope works best in open spaces, either air or fluid, such as the ventricle or nose. Therein the illumination, magnification, and wide angles of visualization allow the endoscope to be used to its full advantage. In such spaces, the freedom of movement provided to the endoscopist overcomes much of the potential clumsiness that comes from working with a view that is not coaxial to the working angle. The cerebral parenchyma has no open cavity, and it is largely for this reason that the brain “space” itself has been left as the last great frontier for the endoscope. The bar to be reached for any technique used in the removal of intrinsic and metastatic brain tumors must be that the technique provides less neuroanatomical and neurological impact and equal or better efficacy than the traditional microscope-based approach. It is far from a foregone conclusion that the conditions for such success will be met with new endoscopic techniques. In the article in a recent issue of WORLD NEUROSURGERY by Plaha et al., a nontubular, endoscopic technique for resecting intraparenchymal brain tumors is applied and evaluated prospectively for safety and efficacy. Using this method, the authors demonstrated gross total resection (GTR) in 48% of cases and near-total (greater than 95%) resection in 70% of cases. They show that GTR rates in this study were comparable with those published by other groups that used standard microsurgical resection for highgrade gliomas (where most evidence demonstrates that extent of resection plays a significant prognostic role). The authors conclude that the procedure can be performed safely, with only one major complication recorded secondary to anomalous anatomy (left anterior cerebral artery infarct), and a reported infection rate lower than that for other nonendoscopic craniotomy procedures at their institution. They conclude by suggesting that although their study does not imply superiority, it does support a role for this method of intraparenchymal tumor removal.

Primary diffuse leptomeningeal glioneuronal tumors

Diffuse leptomeningeal disseminated glioneuronal tumor (DL-GNT) is a rare brain tumor that presents as a plaque-like subarachnoid tumor, commonly involving the basal cisterns and interhemispheric fissure of children but lacking intraparenchymal tumor. Histologically, the tumors are composed of sheets of monotonous rounded cells. Here, we report three cases of DL-GNTs, focusing on clinicopathologic features. Two patients were adult male, but one patient was child. The patients presented with seizures (n = 1) or headaches (n = 2). In all patients, radiography revealed characteristic leptomeningeal thickening and enhancement with minor superficial parenchymal lesions. All three cases were diffusely positive for both GFAP and synaptophysin, and scattered positive for OLIG2 and NeuN, but negative for IDH-1 (H09). Electron microscopic examination showed astrocytic and neuronal differentiation. The patient with the anaplastic tumor died due to aggressive progression of the tumor, but the remaining two patients were stable without tumor recurrence for 23 and 37 months. Thus, these findings suggest that DL-GNT can occur in both children and adult and both supra- and infra-tentorial leptomeninges. It has unique radiological and histopathological features and biological behavior. Further clinicopathological data with molecular genetic study are required for establishing DL-GNT as a unique entity.