Neuroendoscopic biopsy of brain lesions: accuracy and complications

Neuropathological Applications of Microscopy with Ultraviolet Surface Excitation (MUSE): A Concordance Study of Human Primary and Metastatic Brain Tumors

Whereas traditional histology and light microscopy require multiple steps of formalin fixation, paraffin embedding, and sectioning to generate images for pathologic diagnosis, Microscopy using Ultraviolet Surface Excitation (MUSE) operates through UV excitation on the cut surface of tissue, generating images of high resolution without the need to fix or section tissue and allowing for potential use for downstream molecular tests. Here, we present the first study of the use and suitability of MUSE microscopy for neuropathological samples. MUSE images were generated from surgical biopsy samples of primary and metastatic brain tumor biopsy samples (n = 27), and blinded assessments of diagnoses, tumor grades, and cellular features were compared to corresponding hematoxylin and eosin (H&E) images. A set of MUSE-treated samples subsequently underwent exome and targeted sequencing, and quality metrics were compared to those from fresh frozen specimens. Diagnostic accuracy was relatively high, and DNA and RNA integrity appeared to be preserved for this cohort. This suggests that MUSE may be a reliable method of generating high-quality diagnostic-grade histologic images for neuropathology on a rapid and sample-sparing basis and for subsequent molecular analysis of DNA and RNA.

[Microsurgical ventriculostomy of the third ventricle with access through a burrhole in the treatment of midly located deep-seated brain tumors]

BACKGROUND

Currently, endoscopic third ventriculostomy and simultaneous biopsy of deep midline brain tumors are a generally accepted option in neurooncology. Nevertheless, effectiveness of this surgery and diagnostic accuracy of biopsy are not without drawbacks. An alternative to endoscopic surgery may be simultaneous microsurgical third ventriculostomy and biopsy of deep midline tumors.

OBJECTIVE

To evaluate effectiveness and safety of burr hole microsurgical third ventriculostomy in the treatment of deep midline brain tumors.

MATERIAL AND METHODS

We used transcortical (25 cases) and transcallosal (8 cases) approaches for microsurgical third ventriculostomy.

RESULTS

Initially scheduled biopsy was performed in 19 cases, partial resection in 6 cases, subtotal resection in 4 cases and total resection in 4 cases. All patients underwent microsurgical third ventriculostomy. In 12 cases, stenting of stoma was performed in addition to ventriculostomy. Biopsy was informative in all cases. Postoperative follow-up period ranged from 3 to 44 months (mean 29 months). There was no postoperative hydrocephalus and need for shunting procedure.

CONCLUSION

Burr hole microsurgery may be an alternative to endoscopic surgery for the treatment of pineal, periaqueductal and third ventricular tumors.

5-Aminolevulinic acid fluorescence-guided endoscopic surgery for deep-seated intraparenchymal tumors

AIM

The usefulness of 5-aminolevulinic acid (5-ALA) fluorescence-assisted surgery for maximum resection of malignant gliomas has been established. However, its usefulness when combined with endoscopic surgery for deep-seated tumors has not been well established. In this study, whether 5-ALA photodynamic diagnosis (PDD) is feasible and useful for endoscopic surgery was investigated.

METHODS

A specially designed endoscope for PDD that delivers white light or blue light (375-440 nm) as excitation light was used. The fluorescence emitted by the tumor was evaluated in the cavity during resection or at the tip of the sheath during biopsy. The intensity of fluorescence was classified into three categories: strong, vague, and negative.

RESULTS

A total of 30 intraparenchymal tumors were observed with a neuroendoscope and 5-ALA PDD; 16 patients underwent resection, and 14 underwent biopsy. Overall, 67% (20/30) of tumors showed positive fluorescence of protoporphyrin IX. High-grade gliomas (HGGs) including glioblastoma (GBM) and anaplastic astrocytoma (AA) showed strong fluorescence in 47% (7/15), vague fluorescence in 33% (5/15), and negative fluorescence in 20% (3/15) of cases. Low-grade gliomas (LGGs) showed vague fluorescence in 33% (1/3) and negative fluorescence in 67% (2/3). Diffuse large B-cell lymphoma (DLBCL) showed vague fluorescence in 38% (3/8) and negative fluorescence in 63% (5/8). Metastatic tumors showed strong fluorescence in 25% (1/4) and vague fluorescence in 75% (3/4). In the comparison of fluorescence evaluation, a significant difference was observed only in the comparison between HGGs and DLBCL (p = 0.049).

CONCLUSION

These results suggest that 5-ALA PDD-assisted endoscopic surgery is feasible and useful for deep-seated intraparenchymal tumors.

The role of 3-Tesla magnetic resonance perfusion and spectroscopy in distinguishing glioblastoma from solitary brain metastasis

OBJECTIVES

This study aimed to assess the value of magnetic resonance perfusion (MR perfusion) and magnetic resonance spectroscopy (MR spectroscopy) in 3.0-Tesla magnetic resonanceimaging (MRI) for differential diagnosis of glioblastoma (GBM) and solitary brain metastasis (SBM).

MATERIAL AND METHODS

This retrospective study involved 36 patients, including 24 cases of GBM and 12 of SBM diagnosed using histopathology. All patients underwent a 3.0-Tesla MRI examination with pre-operative MR perfusion and MR spectroscopy. We assessed the differences in age, sex, cerebral blood volume (CBV), relative CBV (rCBV), and the metabolite ratios of choline/N-acetylaspartate (Cho/NAA) and Cho/creatine between the GBM and SBM groups using the Mann-Whitney U-test and Chi-square test. The cutoff value, area under the curve, sensitivity, specificity, positive predictive value, and negative predictive value of the significantly different parameters between these two groups were determined using the receiver operating characteristic curve.

RESULTS

In MR perfusion, the CBV of the peritumoral region (pCBV) had the highest preoperative predictive value in discriminating GBM from SBM (cutoff: 1.41; sensitivity: 70.83%; and specificity: 83.33%), followed by the ratio of CBV of the solid tumor component to CBV of normal white matter (rCBVt/n) and the ratio of CBV of the pCBV to CBV of normal white matter (rCBVp/n). In MR spectroscopy, the Cho/NAA ratio of the pCBV (pCho/NAA; cutoff: 1.02; sensitivity: 87.50%; and specificity: 75%) and the Cho/NAA ratio of the solid tumor component (tCho/NAA; cutoff: 2.11; sensitivity: 87.50%; and specificity: 66.67%) were significantly different between groups. Moreover, combining these remarkably different parameters increased their diagnostic utility for distinguishing between GBM and SBM.

CONCLUSION

pCBV, rCBVt/n, rCBVp/n, pCho/NAA, and tCho/NAA are useful indices for differentiating between GBM and SBM. Combining these indices can improve diagnostic performance in distinguishing between these two tumors.

5-Aminolevulinic acid fluorescence-guided endoscopic surgery for intraventricular tumors

Background:

In recent years, the efficacy of 5-aminolevulinic acid photodynamic diagnosis (5-ALA PDD) has been reported for various types of brain tumors, including malignant glioma. In addition, many reports have been published on the usefulness of neuroendoscopic surgery for intraventricular lesions. However, no systematic report is available on the combined use of 5-ALA PDD and neuroendoscopy for various intraventricular tumors.

Methods:

We report 17 consecutive patients with intraventricular tumors. All patients received oral 5-ALA preoperatively and underwent endoscopic surgical treatment (resection or biopsy). We use a rigid endoscope with a built-in PDD system for intraoperative observation.

Results:

Seven resections and 10 biopsies were performed. Histopathological diagnosis was confirmed in all 17 cases. Gross total resection was achieved in six of seven cases. The fluorescence positivity rates for each tumor were glioblastoma 100% (2/2), low-grade glioma 67% (2/3), subependymoma 0% (0/1), medulloblastoma 100% (1/1), pineoblastoma 0% (0/1), germ cell tumor 75% (3/4), diffuse large B-cell lymphoma 33% (1/3), and metastatic tumor 100% (2/2).

Conclusion:

Our method has the potential to improve detection of residual tumors in blind spots and deep areas, as well as the accuracy and safety of biopsy procedures for intraventricular lesions that are difficult to view and treat under a microscope.

Reassessing the Role of Brain Tumor Biopsy in the Era of Advanced Surgical, Molecular, and Imaging Techniques-A Single-Center Experience with Long-Term Follow-Up

Brain biopsy is the gold standard in order to establish the diagnosis of unresectable brain tumors. Few studies have investigated the long-term outcomes of biopsy patients. The aim of this single-institution-based study was to assess the concordance between radiological and histopathological diagnoses, and the long-term patient outcome. Ninety-three patients who underwent brain biopsy in the last 5 years were analyzed. We included patients treated with stereotactically guided needle, open, and neuroendoscopic biopsies. Most patients (86%) received needle biopsy. Gliomas and primary brain lymphomas comprised 88.2% of cases. The diagnostic yield was 95.7%. Serious complication and death rates were 3.2% and 2.1%, respectively. The concordance rate between radiological and histological diagnoses was 93%. Notably, the positive predictive value of radiological diagnosis of lymphoma was 100%. Biopsy allowed specific treatment in 72% of cases. Disease-related neurological worsening was the main reason that precluded adjuvant treatment. Adjuvant treatment, in turn, was the strongest prognostic factor, since the median overall survival was 11 months with vs. 2 months without treatment (p = 0.0002). Finally, advanced molecular evaluations can be obtained on glioma biopsy specimens to provide integrated diagnoses and individually tailored treatments. We conclude that, despite the huge advances in imaging techniques, biopsy is required when an adjuvant treatment is recommended, particularly in gliomas.

Stereotactic biopsy for lesions in brainstem and deep brain: a single-center experience of 72 cases

Stereotactic biopsies for lesions in the brainstem and deep brain are rare. This study aimed to summarize our 6-year experience in the accurate diagnosis of lesions in the brain stem and deep brain and to discuss the technical note and strategies. From December 2011 to January 2018, 72 cases of intracranial lesions in the brainstem or deep in the lobes undergoing stereotactic biopsy were retrospectively reviewed. An individualized puncture path was designed based on the lesion's location and the image characteristics. The most common biopsy targets were deep in the lobes (43 cases, 59.7%), including frontal lobe (33 cases, 45.8%), temporal lobe (4 cases, 5.6%), parietal lobe (3 cases, 4.2%), and occipital lobe (3 cases, 4.2 %). There were 12 cases (16.7%) of the brainstem, including 8 cases (11.1%) of midbrain, and 4 cases (5.6%) of pons or brachium pontis. Other targets included internal capsule (2 cases, 2.8%), thalamus (3 cases, 4.2%), and basal ganglion (12 cases, 16.7%). As for complications, one patient developed acute intracerebral hemorrhage in the biopsy area at 2 h post-operation, and one patient had delayed intracerebral hemorrhage at 7 days post-operation. The remaining patients recovered well after surgery. There was no surgery-related death. The CT-MRI-guided stereotactic biopsy of lesions in the brainstem or deep in the brain has the advantages of high safety, accurate diagnosis, and low incidence of complications. It plays a crucial role in the diagnosis of atypical, microscopic, diffuse, multiple, and refractory lesions.

Differential diagnosis of atypical encephalopathy in critical care: a case report

Background

A lower level of consciousness is a common presentation in critical care, with many different causes and contributory factors, of which more than one may be present concurrently.

Case presentation

We described a woman with poorly controlled diabetes and steroid-dependent asthma who presented in a deep coma. She was found to have Streptococcus intermedius bacteremia and pyogenic ventriculitis that originated from right middle lobe pneumonia. Also, multiple small parenchymal lesions were observed on brain magnetic resonance imaging and increased protein concentration was noted in cerebral spinal fluid. Initially, her coma was thought to be due to diabetic ketoacidosis and septic encephalopathy. However, her lowered level of consciousness was disproportionate to either diabetic ketoacidosis or septic encephalopathy, and her clinical course was not as expected for these two conditions. Treatment with antibiotic, corticosteroid and antihelminthic drugs was administered resulting in improving consciousness. The Streptococcus intermedius pneumonia progressed to form a large cavity that needed an early surgical lobectomy and resulted in the unexpected diagnosis of chronic cavitary pulmonary aspergillosus.

Conclusions

In critical care, a lowered level of consciousness may have many etiologies, and critical care clinicians should be familiar with the signs and symptoms of all possible causes to enable prompt diagnosis and appropriate treatment.

A Review of Common Endoscopic Intracranial Approaches

With the evolution of surgical techniques, endoscopy has emerged as a suitable alternative to many instances of more invasive methods. In this review article, we aim to discuss the endoscopic advancements, procedural details, indications, and outcomes of the most commonly practiced neuroendoscopic procedures. We have also summarized the uses, techniques, and challenges of neuroendoscopy in select neurosurgical pathologies.

Role of endoscopic surgical biopsy in diagnoses of intraventricular/periventricular tumors: review of literature including a monocentric case series

The intra- and periventricular location tumor (IPVT) of a brain remains a hard challenge for the neurosurgeon because of the deep location and eloquent anatomic associations. Due to this high risk of iatrogenic injury, many surgeons elect to perform biopsies of such lesions to establish a diagnosis. On the one hand, stereotaxic needle biopsy (SNB) is a minimally invasive procedure but with a significant risk of complications and a high risk of lack of tissue for molecular analyses for this region [Fukushima in Neurosurgery 2:110-113 (1978)]; on the other hand, the use of endoscopic intraventricular biopsy (EIB) allows for diagnosis with minimal surgical intervention [Iwamoto et al. in Ann Neurol 64(suppl. 6):628-634 (2008)]. IPVTs and related CSF pathway obstructions can be safely and effectively treated with endoscopic techniques. It is not possible to compare EIB with diagnoses made by any other method or with the established treatment. We aim to analyze the accuracy of EIB results by comparing them with results of biopsies performed later, in other methods and thereby evaluating the treatment evolution considering our personal experience. The difficulties and complications encountered are presented and compared with those reported in the literature to obtain the best review possible for this topic. A systematic review of literature was done using MEDLINE, the NIH Library, PubMed, and Google Scholar yielded 1.951 cases for EIB and 1912 for SNB, according to standard systemic review techniques. Review was conducted on 50 studies describing surgical procedures for lesions intra- and para-ventricular. The primary outcome measure was a diagnostic success. We also consider 20 patients with IPVT treated in our department. Clinical characteristics and surgical outcome were evaluated and a systematic review of the literature was performed. Overall, all our biopsies were diagnostic, with a positive histologic sample in 100% of our patients. 8 patients underwent a concurrent endoscopic third ventriculostomy. 4 patients underwent a concurrent ventriculostomy combined with septostomy. For 1 patient was necessary the only septostomy combined with biopsy. Every case has obtained a histological diagnosis. The percentage of complications was very low with only 1 case of post-operative infection and 1 case of hemorrhage. It was impossible to create a specific comparison from literature data of IPVTs between a stereotactic and endoscopic procedure, it presents only the collection of pineal gland tumor [Kelly in Neurosurgery 25(02):185-194 (1989); Quick-Weller in World Neurosurgery 96:124-128 (2016)] or unknown location of the lesion in major review [Marenco-Hillembrand et al. in Front Oncol 8:558 (2018)]. The present study aims to report our experience with the surgical management of IPVTs. The EIB sample yields an accurate histologic diagnosis tumor, with a positive histologic sample in 87, 95% of patients. The choice of the appropriate procedure should consider not only the preference and the experience of the neurosurgeon but also the several other variables as the location. While some periventricular lesions are better approached by endoscopic techniques, others are more suited for stereotactic-guided approaches. The ability to perform an EIB and relieve tumor-associated hydrocephalus by neuroendoscopy is considered to be a benefit of this procedure since this is less invasive than other treatments.

Management of severe intraoperative hemorrhage during intraventricular neuroendoscopic procedures: the dry field technique

OBJECTIVE

The unexpected intraoperative intraventricular hemorrhage is a rare but feared and life-threatening complication in neuroendoscopic procedures because of loss of endoscopic vision. The authors present their experience with the so-called "dry field technique" (DFT) for the management of intraventricular hemorrhages during purely endoscopic procedures. This technique requires the aspiration of the entire intraventricular CSF to achieve clear visualization of the bleeding source.

METHODS

More than 500 neuroendoscopic intraventricular procedures were retrospectively analyzed over the last 24 years for documented severe hemorrhages, which were treated by the application of the DFT.

RESULTS

The technique was required in 6 cases, including tumor resection/biopsy, cyst resection, and intraventricular lavage. Additionally, the technique was applied as part of the planned strategy in 3 cases of endoscopic tumor removal. The hemorrhage was stopped in all cases and no associated postoperative deficits occurred.

CONCLUSIONS

Although severe hemorrhages are rare, the neurosurgeon needs to be aware of them and has to establish strategies for their management. Most hemorrhages can be stopped by constant irrigation and coagulation. In the other rare cases, the DFT is a safe, reliable technique and can be easily incorporated into endoscopic surgery.

Pineal cyst surveillance in adults - a review of 10 years' experience

Objective: Pineal cysts are common benign incidental findings in adults. There are no commonly accepted criteria for follow up or indications for intervention. We looked at our outcomes for this condition to explore their natural history and review our surveillance criteria.Method: Retrospective review of multidisciplinary team meetings at a tertiary neurosurgical centre over 10 years. Data relating to demographics, presenting symptoms, maximum diameter, duration of surveillance, final diagnosis and overall outcome were extracted from electronic patient records and available MRI. Data were analysed using IBM SPSS version 24.Result: Seventy-seven pineal cysts were identified. Female to male ratio was 1.43, female mean age was 38.6 and male mean age was 50.4. An increase in referral frequency was observed over the study period (mean increase of 1.4 cases per year). Presenting symptoms of headache in 45% and visual and hearing symptoms in 38.5% were recorded and baseline mean maximum diameter was 13.4mm. 20 patients were discharged on presentation, 54 were booked for at least one follow-up scan with a median follow up period of 14 months. The mean change in maximum diameter was 0.04mm over 18 months. Three patients (3.9%) underwent endoscopic biopsy and CSF diversion for cysts all more than 20mm with radiological evidence of hydrocephalus. In 100% of cases, the initial MDT diagnosis and final diagnosis were concordant.Conclusions: No patient under surveillance required surgical treatment and those managed surgically were symptomatic with large cysts and hydrocephalus on presentation. A majority of pineal cysts remained unchanged during the MRI follow-up, therefore our review suggests that routine follow-up of pineal cysts is not necessary in the absence of unusual radiological characteristics or related clinical symptoms.

Endoscopic biopsy of intra- and paraventricular brain tumors

Introduction

Selection of the optimal treatment method of intra- and paraventricular tumors often requires histopathological verification that can be obtained by endoscopic biopsy.

Aim

To discuss the usefulness of the method in their own experience.

Material and methods

The results of 32 biopsies carried out during a 15-year period were reviewed retrospectively. All tumors were located supratentorially, 25 of them were intraventricular and 7 paraventricular. In 18 patients the tumor was accompanied by internal hydrocephalus. If the ventricular system was narrow, the biopsy was supported by a neuronavigation system. A rigid neuroendoscope was used. The obtained material was subjected to intraoperative and final histopathological examination.

Results

Viable diagnostic material was obtained from all patients. In 11 patients with tumor of the posterior portion of the third ventricle, cerebrospinal fluid was collected additionally for diagnostic tests. In 9 patients with obstructive hydrocephalus concomitant third ventriculostomy was performed. In 4 patients with tumor of the interventricular foramen, the tumor mass was reduced and in 2 cases septostomy was performed. In 3 (9.4%) cases the histopathological diagnosis was descriptive and did not explain the nature of the lesion. Four biopsies resulted in persistent bleeding, in 3 patients transient memory impairments were observed, and in 1 patient an epileptic seizure occurred. Five patients needed ventriculoperitoneal shunt placement.

Conclusions

Endoscopic biopsy is a safe method to verify the histopathological nature of intra- and paraventricular lesions. It enables sampling of cerebrospinal fluid, reduction of tumor size, and in cases of coexisting obstructive hydrocephalus also third ventriculostomy or septostomy.

Initial experience with endoscopic ultrasonic aspirator in purely neuroendoscopic removal of intraventricular tumors

OBJECTIVE Neuroendoscopic removal of intraventricular tumors is difficult and time consuming because of the lack of an effective decompression system that can be used through the working channel of the endoscope. The authors report on the utilization of an endoscopic ultrasonic aspirator in the resection of intraventricular tumors. METHODS Twelve pediatric patients (10 male, 2 female), ages 1-15 years old, underwent surgery via a purely endoscopic approach using a Gaab rigid endoscope and endoscopic ultrasonic aspirator. Two patients presented with intraventricular metastases from high-grade tumors (medulloblastoma, atypical teratoid rhabdoid tumor), 2 with subependymal giant cell astrocytomas (associated with tuberous sclerosis), 2 with low-grade intraparaventricular tumors, 4 with suprasellar tumors (2 craniopharyngiomas and 2 optic pathway gliomas), and 2 with pineal tumors (1 immature teratoma, 1 pineal anlage tumor). Hydrocephalus was present in 5 cases. In all patients, the endoscopic trajectory and ventricular access were guided by electromagnetic neuronavigation. Nine patients underwent surgery via a precoronal bur hole while supine. In 2 cases, surgery was performed through a frontal bur hole at the level of the hairline. One patient underwent surgery via a posterior parietal approach to the trigone while in a lateral position. The endoscopic technique consisted of visualization of the tumor, ventricular washing to dilate the ventricles and to control bleeding, obtaining a tumor specimen with biopsy forceps, and ultrasonic aspiration of the tumor. Bleeding was controlled with irrigation, monopolar coagulation, and a thulium laser. RESULTS In 7 cases, the resection was total or near total (more than 90% of lesion removed). In 5 cases, the resection was partial. Histological evaluation of the collected material (withdrawn using biopsy forceps and aspirated with an ultrasonic aspirator) was diagnostic in all cases. The duration of surgery ranged from 30 to 120 minutes. One case was complicated by subdural hygroma requiring a subduro-peritoneal shunt implant. CONCLUSIONS In this preliminary series, endoscopic ultrasonic aspiration proved to be a safe and reliable method for achieving extensive decompression or complete removal in the management of intra- and/or paraventricular lesions in pediatric patients.

Application of endoscopic ultrasonography to intraventricular lesions

BACKGROUND

Anatomical landmarks such as choroid plexus and foramen of Monro are very important to undergo intraventricular surgery safely and effectually. These landmarks would be unclear in cases with a huge cyst or repeat surgery. We report the usability and precautions to apply a bronchoscope with an ultrasonic convex probe to intraventricular surgery.

METHODS

Two patients diagnosed with obstructive hydrocephalus, one with a large cyst and the other with recurrent craniopharyngioma in the third ventricle, were applied to the EBUS system.

RESULTS

In both patients, the EBUS system was applied safely, and lesions beyond the wall of ventricles or the cyst were visible. Color Doppler ultrasonography detected choroid plexus and internal cerebral veins. Furthermore, we performed real-time ultrasound-guided cyst puncture safely on the case with a large cyst. The most important precaution is that the curved portion of the EBUS system is too long to be bent within cerebral ventricles.

CONCLUSIONS

The new EBUS system with an ultrasonic convex probe is a novel and effectual device to perform intraventricular surgery.