Olfactory groove meningioma: discussion of clinical presentation and surgical outcomes following excision via the subcranial approach

Supraorbital Approaches for Anterior Skull Base and Parasellar Lesions: Insights From a Single-Center Experience

BACKGROUND

Modern neurosurgery has undergone significant evolution to include minimally invasive procedures, with the supraorbital approach (SOA) being a prime example. In this study, we aim to explore the surgical techniques and outcomes of this approach in the surgical treatment of frontal lobe, anterior skull base, and parasellar lesions.

METHODS

This study included 33 patients aged 36-83 years who underwent surgery using the SOA for lesions in the inferior frontal lobe, anterior skull base, and parasellar area between 2015 and 2024. There were 25 cases of meningioma, 2 cases of brain abscess, 2 cases of glioma, and one case each of craniopharyngioma, hemangioma, metastasis, and Rathke's cleft cyst. The medical data and follow-up results were retrospectively analyzed.

RESULTS

The mean size of lesion was 3.38±3.05 cm. The mean follow-up period was 48.8 months. Gross total resection was achieved in 25 patients (75.8%). There were no perioperative deaths, cases of cerebrospinal fluid rhinorrhea, or infections. Two cases of morbidity were reported as complications: one case of delayed intracerebral hemorrhage and one case of infarction due to vascular injury. All patients exhibited satisfactory cosmetic results.

CONCLUSION

In comparison to the conventional pterional approach, the SOA represents a safe and effective keyhole method for the removal of both extra-axial and intra-axial skull base tumors. This is particularly beneficial for lesions in the orbitofrontal region and parasellar area, as it allows for minimal disruption of normal brain parenchyma. Moreover, the SOA promotes a swift recovery and short hospital stay. Additionally, the SOA yields superior cosmetic results, including the prevention of temporalis muscle atrophy.

Surgical Morbidity in Relation to the Surgical Approach for Olfactory Groove Meningiomas-A Pooled Analysis of 1016 Patients and Proposal of a New Reporting System

Background: There is currently no consensus in the field regarding whether a frontal or lateral approach is superior for microsurgical resection of olfactory groove meningiomas (OGM). Due to the lack of uniformity in classifying lesions and inherent differences in reporting outcomes after varying operative approaches, the best practice for approaching these lesions is yet to be determined. Objective: This study aimed to assess various surgical approaches undertaken for OGMs, investigate procedural aspects influencing the extent of resection, and analyze the respective complication rate associated with each approach. We performed a comprehensive literature review of presenting signs and symptoms in OGM patients, their surgical management, and the reported surgical outcomes. To address the lack of uniform data reporting across studies and to take more recent translational studies into account, we developed a new classification system for OGMs that can remedy the existing deficiencies in comparability of reporting. Methods: We conducted a PRISMA-guided literature search for surgical reports on OGMs published in the MRI era using broad search terms such as 'olfactory groove meningioma' and 'surgery', which yielded 20,672 results. After title screening and removal of duplicates, we assessed 871 studies on the specific surgical management of olfactory groove meningiomas. Following the application of exclusion criteria and abstract screening, a set of 27 studies was chosen for the final analysis of a pooled cohort of these reported patient outcomes. Results: The final twenty-seven studies included in our in-depth analysis identified a total of 1016 individual patients who underwent open microsurgical resection of OGMs. The approaches used included: pterional/unilateral, bifrontal with variations, and anterior interhemispheric approaches. Across all studies, gross total resection (Simpson Grades I or II) was achieved in 91.4% of cases, and subtotal resection (Grades III and IV) was reported in 8.6% of cases. A cumulative twenty-seven percent of surgical OGM patients sustained some form of complications. Minor issues accounted for 22.2% (CSF leak, seizures, infection, transient cranial nerve palsies, hydrocephalus), whereas major issues comprised 4.7% (hemorrhage, ischemic infarct, malignant cerebral edema). We then examined the correlation between these complications and the surgical approach chosen. Among pooled cohort of 426 patients who underwent unilateral approaches, 14% experienced minor complications, and 2.1% experienced major complications. For the mixed cohort of 410 patients who underwent bifrontal approaches, 24.6% experienced minor complications, and 7% experienced major complications. Conclusions: Unilateral approaches appear to have lower complication rates for the resection of OGMs compared to bilateral approaches. However, the extent of resection is not uniformly reported, making it difficult to identify differences. The use of an improved preoperative classification and scoring system can help establish a more coherent system to select the most suitable approach and to uniformly report surgical outcomes, such as EOR and complication rates specific to a given OGM and its surgical approach.

Visual Loss As Primary Manifestation of Olfactory Groove Meningioma

Differential diagnosis of vision loss in a space-occupying lesion can be exhaustive. Olfactory groove meningioma (OGM) is a rare, benign, slow-growing tumour originating from the anterior cranial base. OGM is one of the differential diagnoses of intracranial tumours. We report a case of an OGM compressing the optic nerve and frontal lobe causing bilateral vision loss for six months. Multidisciplinary management by ophthalmologists, neurosurgeons, radiologists, and pathologists led to the diagnosis and tumour resection of OGM in the patient. Possible mechanisms of vision loss, imaging features, and treatment are discussed in this report.

Two-step staged resection of giant olfactory groove meningiomas

Background

The surgical treatment of giant olfactory groove meningiomas (OGMs) with marked perilesional brain oedema is still a surgical challenge. After tumour resection, increase of brain oedema may occur causing dramatic neurological deterioration and even death of the patient. The objective of this paper is to describe surgical features of a two-step staged resection of these tumours performed to counter increase of postoperative brain oedema.

Methods

This two-step staged resection procedure was carried out in a consecutive series of 19 patients harbouring giant OGMs. As first step, a bifrontal craniectomy was performed followed by a right-sided interhemispherical approach. About 80% of the tumour mass was resected leaving behind a shell-shaped tumour remnant. In the second step, carried out after the patients’ recovery from the first surgery and decline of oedema, the remaining part of the tumour was removed completely followed by duro- and cranioplasty.

Results

Ten patients recovered quickly from first surgery and the second operation was performed after a mean of 12.4 days. In eight patients, the second operation was carried out later between day 25 and 68 due to surgery-related complications, development of a trigeminal zoster, or to a persisting frontal brain oedema. Mean follow-up was 49.3 months and all but one patient had a good outcome regardless of surgery-related complications.

Conclusions

Our results suggest that a two-step staged resection of giant OGMs minimizes the increase of postoperative brain oedema as far as possible and translates into lower morbidity and mortality.

Comparison of Three Surgical Approaches for Frontobasal Meningiomas: Purely Endoscopic Endonasal, Purely Microscopic Bifrontal Transcranial, and Combined Endoscopic and Microscopic Supraorbital Transciliary Approaches

ABSTRACT

Surgical removal of frontobasal meningiomas (FBMs) can be achieved using different techniques, including endoscopic, transcranial, and combined approaches. The advantages and disadvantages of the outcomes of these approaches should be compared to provide the most convenient surgical treatment to the patient. This study aimed to compare 3 surgical approaches for FBMsin terms of outcomes and determine the superiority of each on the basis of anatomical, surgical, and clinical efficacy. Systematic review was performed to identify studies comparing techniques for the surgical removal of FBMs. Each group included 13 patients; 39 patients with FBMshad undergone surgery. These groups were endoscopic endonasal approach (EEA), microscopic bifrontal transcranial approach (MTA), and endoscopic plus microscopic combined supraorbital transciliary approach (STA) groups. Data on the demographics of patient population, pre- and post-operative neurological examination, tumor properties, imaging studies, and surgical complications were extracted. The mean age at the time of surgery for the patient population was 53.2 years. Among the groups, no statistically significant differences were observed with regard to sex (P = 0.582). The mean follow-up time was 56.7 months. A statistically significant difference was observed in the mean tumor volume among the groups; the MTA group showed the highest mean tumor volume. However, no significant difference was found in the mean tumor volume between EEA and STA groups. Regarding operation duration, the STA group had the shortest operation time (mean = 281.5 minutes), whereas the average surgical duration in MTA group was the longest (mean = 443.8 minutes). The average bleeding volume was highest in the MTA group (mean = 746.2 ml) and lowest in the EEA group (mean = 320.8 ml). Tumor removal was incomplete in three patients (two in the EEA group and one in the MTA group). Recurrence was detected in two cases. One patient with recurrence was operated using the endoscopic surgical approach, whereas the other patient underwent the microscopic bifrontal approach. Post-operative hyposmia/anosmia or decreased olfactory function was the most common complication observed in 5 patients, 2 patients each in the EEA and MTA groups and one in the STA group. The second most common complication was wound infection in one patient in the MTA group and two patients in the STA group (7.7%). Both cerebrospinal fluid (CSF) leakage and meningitis were present in two patients (5.1%), one patient each from the EEA and STA groups. Pre-operative visual disturbances were reported in 13 patients (33.3%), all of which resolved post-operatively No statistical differences were found among the groups. Mortality occurred in a patient in the MTA group (2.6%) caused by cardiac arrest on post-operative day 1. This is the first study comparing the surgical outcomes of three surgical approaches for FBMs. Although recent literature suggests that both endoscopic and transcranial approaches have their own advantages and disadvantages, the authors showed that none of the surgical approaches have obvious superiority over the others with regard to outcomes. Thus, the selection of the ideal surgical approach should be based on surgical experience and tumor characteristics.

The endoscope-assisted supraorbital "keyhole" approach for anterior skull base meningiomas: an updated meta-analysis

INTRODUCTION

The gold-standard treatment for symptomatic anterior skull base meningiomas is surgical resection. The endoscope-assisted supraorbital "keyhole" approach (eSKA) is a promising technique for surgical resection of olfactory groove (OGM) and tuberculum sellae meningioma (TSM) but has yet to be compared with the microscopic transcranial (mTCA) and the expanded endoscopic endonasal approach (EEA) in the context of existing literature.

METHODS

An updated study-level meta-analysis on surgical outcomes and complications of OGM and TSM operated with the eSKA, mTCA, and EEA was conducted using random-effect models.

RESULTS

A total of 2285 articles were screened, yielding 96 studies (2191 TSM and 1510 OGM patients). In terms of effectiveness, gross total resection incidence was highest in mTCA (89.6% TSM, 91.1% OGM), followed by eSKA (85.2% TSM, 84.9% OGM) and EEA (83.9% TSM, 82.8% OGM). Additionally, the EEA group had the highest incidence of visual improvement (81.9% TSM, 54.6% OGM), followed by eSKA (65.9% TSM, 52.9% OGM) and mTCA (63.9% TSM, 45.7% OGM). However, in terms of safety, the EEA possessed the highest cerebrospinal fluid leak incidence (9.2% TSM, 14.5% OGM), compared with eSKA (2.1% TSM, 1.6% OGM) and mTCA (1.6% TSM, 6.5% OGM). Finally, mortality and intraoperative arterial injury were 1% or lower across all subgroups.

CONCLUSIONS

In the context of diverse study populations, the eSKA appeared not to be associated with increased adverse outcomes when compared with mTCA and EEA and offered comparable effectiveness. Case-selection is paramount in establishing a role for the eSKA in anterior skull base tumours.

Child Abuse: The Consequence of an Undiagnosed Giant Olfactory Groove Meningioma?

Olfactory groove meningiomas are slow-growing tumors that manifest with headaches, changes in vision, and personality changes. The anatomic location of these tumors makes psychiatric disturbances more common early in the stage of tumors than focal neurological deficits. The case study here describes a unique instance of an undiagnosed giant olfactory groove meningioma in a young mother who was charged with a felony of aggravated child abuse for the death of her toddler daughter. The patient underwent gross tumor resection and radiation therapy, which halted the visual decline, resolved the frontal headaches, and the patient showed improved mood. In this patient, the insidious onset of personality changes without obvious focal neurologic deficits until late as well as a history of depression likely contributed to the delayed diagnosis. Failure to notice these initial behavioral manifestations in these patients allows for further psychiatric and cognitive decline, which can result in devastating social consequences.

Resection of Olfactory Groove Meningiomas Through Unilateral vs. Bilateral Approaches: A Systematic Review and Meta-Analysis

Introduction: Consensus is limited regarding optimal transcranial approaches (TCAs) for the surgical resection of olfactory groove meningiomas (OGMs). This systematic review and meta-analysis aims to examine operative and peri-operative outcomes of unilateral compared to bilateral TCAs for OGMs. Methods: Electronic databases were searched from inception until December 2019 for studies delineating TCAs for OGM patients. Patient demographics, pre-operative symptoms, surgical outcomes, and complications were evaluated and analyzed with a meta-analysis of proportions. Results: A total of 27 observational case series comparing 554 unilateral vs. 451 bilateral TCA patients were eligible for review. The weighted pooled incidence of gross total resection is 94.6% (95% CI, 90.7-97.5%; I ² = 59.0%; p = 0.001) for unilateral and 90.9% (95% CI, 85.6-95.4%; I ² = 58.1%; p = 0.003) for bilateral cohorts. Similarly, the incidence of OGM recurrence is 2.6% (95% CI, 0.4-6.0%; I ² = 53.1%; p = 0.012) and 4.7% (95% CI, 1.4-9.2%; I ² = 55.3%; p = 0.006), respectively. Differences in oncologic outcomes were not found to be statistically significant (p = 0.21 and 0.35, respectively). Statistically significant differences in complication rates in bilateral vs. unilateral TCA cohorts include meningitis (1.0 vs. 0.0%; p = 0.022) and mortality (3.2 vs. 0.2%; p = 0.007). Conclusions: While both cohorts have similar oncologic outcomes, bilateral TCA patients exhibit higher post-operative complication rates. This may be explained by underlying tumor characteristics necessitating more radical resection but may also indicate increased morbidity with bilateral approaches. However, evidence from more controlled, comparative studies is warranted to further support these findings.

[An anatomical study on the applicability of direct endoscopic exclusion of the ethmoid arteries for devascularization of the anterior skull base structures]

The anterior skull base structures are the site of initial growth of histologically different tumors. The difficulties in their removal are often associated with significant vascularization, which may limit the amount of resection due to abundant intraoperative blood loss. Midline tumors are primarily fed by the ethmoid arteries that are not accessible to embolization. The aim of this work was a comparative experimental study of various direct approaches to the ethmoid arteries.

MATERIAL AND METHODS

The study was conducted on anatomical specimens of 12 cadaveric heads of deceased people without pathology of the anterior skull base structures, orbits, nasal cavity, and paranasal sinuses (24 sides). In all specimens, the internal and external carotid arteries were stained with silicone. During anatomical dissection, four surgical approaches for exclusion of the ethmoid arteries were studied: 1) transorbital approach to the arteries using a bicoronal incision; 2) endoscopic retro-caruncular approach; 3) endoscopic endonasal transethmoidal approach to the ethmoid artery canals; 4) endoscopic endonasal transethmoidal transorbital approach to the ethmoid arteries in the orbit.

RESULTS

We described a surgical technique for exclusion of the ethmoid arteries using the approaches and analyzed their advantages and disadvantages. We formulated an algorithm for choosing the method for direct endoscopic exclusion of the ethmoid arteries, depending on the surgical approach chosen for removal of the tumor and features of the tumor extracranial spread.

CONCLUSION

The decision on tumor devascularization is based on assessment of tumor blood supply (CT angiography or MR angiography data). Our study demonstrated the advantages and disadvantages of various approaches to the ethmoid arteries for their exclusion in order to early devascularize anterior skull base tumors. All these approaches are less traumatic and characterized by a good cosmetic and functional outcome.

The endoscopic endonasal approach is not superior to the microscopic transcranial approach for anterior skull base meningiomas-a meta-analysis

Object

In the past decade, the endonasal transsphenoidal approach (eTSA) has become an alternative to the microsurgical transcranial approach (mTCA) for tuberculum sellae meningiomas (TSMs) and olfactory groove meningiomas (OGMs). The aim of this meta-analysis was to evaluate which approach offered the best surgical outcomes.

Methods

A systematic review of the literature from 2004 and meta-analysis were conducted in accordance with the PRISMA guidelines. Pooled incidence was calculated for gross total resection (GTR), visual improvement, cerebrospinal fluid (CSF) leak, intraoperative arterial injury, and mortality, comparing eTSA and mTCA, with p-interaction values.

Results

Of 1684 studies, 64 case series were included in the meta-analysis. Using the fixed-effects model, the GTR rate was significantly higher among mTCA patients for OGM (eTSA: 70.9% vs. mTCA: 88.5%, p-interaction < 0.01), but not significantly higher for TSM (eTSA: 83.0% vs. mTCA: 85.8%, p-interaction = 0.34). Despite considerable heterogeneity, visual improvement was higher for eTSA than mTCA for TSM (p-interaction < 0.01), but not for OGM (p-interaction = 0.33). CSF leak was significantly higher among eTSA patients for both OGM (eTSA: 25.1% vs. mTCA: 10.5%, p-interaction < 0.01) and TSM (eTSA: 19.3%, vs. mTCA: 5.81%, p-interaction < 0.01). Intraoperative arterial injury was higher among eTSA (4.89%) than mTCA patients (1.86%) for TSM (p-interaction = 0.03), but not for OGM resection (p-interaction = 0.10). Mortality was not significantly different between eTSA and mTCA patients for both TSM (p-interaction = 0.14) and OGM resection (p-interaction = 0.88). Random-effect models yielded similar results.

Conclusion

In this meta-analysis, eTSA was not shown to be superior to mTCA for resection of both OGMs and TSMs.

Electronic supplementary material

The online version of this article (10.1007/s00701-017-3390-y) contains supplementary material, which is available to authorized users.

Limitations of the endonasal endoscopic approach in treating olfactory groove meningiomas. A systematic review

OBJECTIVE

To review current management strategies for olfactory groove meningioma (OGM)s and the recent literature comparing endoscopic endonasal (EEA) with traditional transcranial (TCA) approaches.

METHODS

A PubMed search of the recent literature (2011-2016) was performed to examine outcomes following EEA and TCA for OGM. The extent of resection, visual outcome, postoperative complications and recurrence rates were analyzed using percentages and proportions, the Fischer exact test and the Student's t-test using Graphpad PRISM 7.0Aa (San Diego, CA) software.

RESULTS

There were 444 patients in the TCA group with a mean diameter of 4.61 (±1.17) cm and 101 patients in the EEA group with a mean diameter of 3.55 (± 0.58) cm (p = 0.0589). GTR was achieved in 90.9% (404/444) in the TCA group and 70.2% (71/101) in the EEA group (p < 0.0001). Of the patients with preoperative visual disturbances, 80.7% (21/26) of patients in the EEA cohort had an improvement in vision compared to 12.83%(29/226) in the TCA group (p < 0.0001). Olfaction was lost in 61% of TCA and in 100% of EEA patients. CSF leaks and meningitis occurred in 25.7% and 4.95% of EEA patients and 6.3% and 1.12% of TCA patients, respectively (p < 0.0001; p = 0.023).

CONCLUSIONS

Our updated literature review demonstrates that despite more experience with endoscopic resection and skull base reconstruction, the literature still supports TCA over EEA with respect to the extent of resection and complications. EEA may be an option in selected cases where visual improvement is the main goal of surgery and postoperative anosmia is acceptable to the patient or in medium-sized tumors with existing preoperative anosmia. Nevertheless, based on our results, it seems more prudent at this time to use TCA for the majority of OGMs.

[Choosing an anterior midline approach to skull base tumors]

The purpose of this review is to analyze used anterior midline approaches to the skull base, identify their advantages and disadvantages, and, after reviewing the literature data, submit a developed algorithm for choosing an optimal approach to the approval of colleagues. We provide brief information on approach techniques, indications and contraindications, and advantages and disadvantages as well as analyze international experience of using the discussed approaches. On the basis of literature data, we have developed a prototype algorithm for choosing an optimal approach to medial tumors of the anterior skull base. The situation of choosing an optimal approach reveals the absence of a clear understanding of the boundaries between capabilities and limitations of approaches. To solve this problem, an original prospective study is required.

Transfrontal-Sinus-Subcranial Approach to Olfactory Groove Meningiomas: Surgical Results and Clinical and Functional Outcome in a Consecutive Series of 21 Patients

BACKGROUND

The transfrontal-sinus-subcranial approach (TFSSA) allows for direct exposure and removal of olfactory groove meningiomas (OGMs), without any brain retraction. Compared with other skull base approaches (e.g., fronto-orbitobasal, transbasal, subcranial, fronto-orbitozygomatic, and one-and-half approach), it could offer the same advantages but is less invasive.

OBJECTIVE

We report the results in a series of 21 consecutive patients with OGMs and operated on through TFSSA, to propose a viable alternative approach.

METHODS

Mean maximum tumor diameter was 45.9 ± 3.4 mm (range, 25-70 mm). The aim of surgery was Simpson grade I removal. Surgical, clinical, and functional outcomes were reported. Mean follow-up was 87 ± 7 months (range, 36-176 months).

RESULTS

In all patients, magnetic resonance imaging after surgery confirmed complete tumor removal. The recurrence-free survival rate was 100% and 85.7% at 5 and 10 years, respectively. Surgery-related mortality and major morbidity were 0% and 4.8%, respectively. Risk of anosmia significantly correlates with meningioma size (P < 0.001) and smell sense was preserved only in patients with tumors less than 4 cm in maximum diameter (4/7; 57.1%). A significant improvement of Mini Mental Standard Examination score was recorded at follow-up (P < 0.001) and no patients worsened their cognitive profile. Visual function improved in 7/8 (87.5%). Karnofsky Performance Scale score after surgery significantly increased (P < 0.001). According to the Glasgow Outcome Score, good outcome was achieved in 20 patients (95.2%).

CONCLUSIONS

Based on reported results, TFSSA allows complete tumor removal with good outcome and low complication rate. It may be proposed as a safe and effective approach to treat large and giant OGMs.

Frontobasal Midline Meningiomas: Is It Right To Shed Doubt on the Transcranial Approaches? Updates and Review of the Literature

BACKGROUND

Traditionally, the surgical removal of tuberculum sellae meningioma (TSM) and olfactory groove meningioma (OGM) requires transcranial approaches and microsurgical techniques, but in the last decade endoscopic expanded endonasal approaches have been introduced: transcribriform for OGMs and transtuberculum-transplanum for TSM. A comparative analysis of the literature concerning the two types of surgical treatment of OGMs and TSM is, however, difficult.

METHODS

We conducted a literature search using the PubMed database to compare data for endoscopic and microsurgical techniques in the literature. We also conducted a retrospective analysis of selected cases from our series presenting favorable characteristics for an endoscopic approach, based on the criteria of operability of these lesions as generally accepted in the literature, and we compared the results obtained in these patients with those in the endoscopic literature.

RESULTS

We believe that making the sample more homogeneous, the difference between microsurgical technique and endoscopic technique is no longer so striking. A greater radical removal rate, a reduced incidence of cerebrospinal fluid fistula and, especially, the possibility of removing lesions of any size are advantages of transcranial surgery; a higher percentage of improvement in visual outcome and a lower risk of a worsening of a pre-existing deficit or onset of a new deficit are advantages of the endoscopic technique.

CONCLUSION

At present, the microsurgical technique is still the gold standard for the removal of the anterior cranial fossa meningiomas of all sizes, and the endoscopic technique remains a second option in certain cases.

Magnetic resonance imaging fluid-attenuated inversion recovery sequence signal reduction after endoscopic endonasal transcribiform total resection of olfactory groove meningiomas

BACKGROUND

Olfactory groove meningiomas grow insidiously and compress adjacent cerebral structures. Achieving complete removal without further damage to frontal lobes can be difficult. Microsurgical removal of large lesions is a challenging procedure and usually involves some brain retraction. The endoscopic endonasal approaches (EEAs) for tumors arising from the anterior fossa have been well described; however, their effect on the adjacent brain tissue has not. Herein, the authors utilized the magnetic resonance imaging fluid attenuated inversion recovery (FLAIR) sequence signal as a marker for edema and gliosis on pre- and post-operative images of olfactory groove meningiomas, thus presenting an objective parameter for brain injury after surgical manipulation.

METHODS

Imaging of 18 olfactory groove meningiomas removed through EEAs was reviewed. Tumor and pre/postoperative FLAIR signal volumes were assessed utilizing the DICOM image viewer OsiriX(®). Inclusion criteria were: (1) No previous treatment; (2) EEA gross total removal; (3) no further treatment.

RESULTS

There were 14 females and 4 males; the average age was 53.8 years (±8.85 years). Average tumor volume was 24.75 cm(3) (±23.26 cm(3), range 2.8-75.7 cm(3)), average preoperative FLAIR volume 31.17 cm(3) (±39.38 cm(3), range 0-127.5 cm(3)) and average postoperative change volume, 4.16 cm(3) (±6.18 cm(3), range 0-22.2 cm(3)). Average time of postoperative scanning was 6 months (range 0.14-20 months). In all cases (100%) gross total tumor removal was achieved. Nine patients (50%) had no postoperative FLAIR changes. In 2 patients (9%) there was minimal increase of changes postoperatively (2.2 cm(3) and 6 cm(3) respectively); all others demonstrated image improvement. The most common complication was postoperative cerebrospinal fluid leakage (27.8%); 1 patient (5.5%) died due to systemic complications and pulmonary sepsis.

CONCLUSIONS

FLAIR signal changes tend to resolve after endonasal tumor resection and do not seem to worsen with this operative technique.

Subtle clinical signs of a meningioma in an adult: a case report

Background

Meningiomas are the most common brain tumor in the adult population. This case report describes the epidemiology, the clinical presentation as well as the current treatment options for this condition.

Case presentation

A 49 year-old man attended a chiropractic clinic with non-specific chronic low back pain. Upon the history taking and the systems review, he reported a loss of both smell and taste for which investigations conducted by two different otolaryngologists did not yield a specific diagnosis. The patient was referred to a neurologist who ordered a computer tomography scan that eventually revealed a compression brain tumor.

Brain tumors can produce a large variety of clinical presentations, such as upper motor neuron lesion symptoms, altered consciousness or vital functions which are easy to identify. However, subtle signs, such as those presented in this case, can be neglected.

Conclusion

Clinicians should be aware of uncommon clinical presentations including cranial nerve or neurological dysfunction and refer their patient to a specialist when detected.

Bilateral visual loss due to a giant olfactory meningioma

Olfactory groove meningiomas can present as large and insidious masses in the anterior cranial base. Due to their location and minimal clinical symptoms, these tumors can go undetected until they have grown extremely large. We present a clinical case and discuss the surgical management of a 63-year-old man who presented for an initial eye examination with bilateral visual loss for over 2 years due to a giant olfactory meningioma encompassing his entire frontal lobe and compressing on his optic nerves.