Clinical characteristics and diagnostic imaging of epidermoid tumors

Hearing Preservation and Functional Outcomes After Resection of Epidermoid Lesions of the Cerebellopontine Angle With High Hearing Risk

OBJECTIVES

To assess a decade of experience of treating patients with high hearing risk cerebellopontine angle (CPA) epidermoid lesions and examine factors influencing postoperative outcomes, particularly hearing preservation.

STUDY DESIGN

Retrospective chart review.

SETTING

Single tertiary-referral center.

PATIENTS

Adults with CPA epidermoid lesions who presented with hearing loss or evidence of lesion involving vestibulocochlear nerve.

INTERVENTIONS

The studied intervention was microsurgical resection.

MAIN OUTCOME MEASURES

Main outcome measures included extent of resection, hearing preservation rate for patients with postoperative audiograms, and disease progression.

RESULTS

Twenty-three adults with an average tumor volume of 15.63 ± 16.2 cm3 were included. Five lesions (22%) involved the full internal auditory canal (IAC), 11 (48%) had partial involvement, and 5 (22%) were IAC sparing. Most patients with IAC involvement (88%) had circumferential invasion of the canal. Patients underwent either a retrosigmoid (18, 79%) or combined retrolabyrinthine transpetrosal approach (5, 22%), and gross total resection was achieved in most cases (13, 57%). Of 12 patients with postoperative audiograms, 10 (83%) had preoperative hearing preserved. There was no statistically significant change in hearing scores with treatment based on preoperative extent of IAC involvement. Ten patients (43%) had residual lesions postoperatively, and 6 exhibited progression. One patient ultimately required reoperation 6 years after initial surgery.

CONCLUSIONS

Preoperative hearing was preserved in the majority of the patients who underwent resection of CPA epidermoids via a retrosigmoid or transpetrosal approach. CPA epidermoids often invaded the IAC; however, degree of invasion was not associated with hearing outcomes.

Transcerebellar ventriculoperitoneal shunt for management of presumed arachnoid diverticulum in the fourth ventricle of a dog

OBJECTIVE

To describe the approach for placement of a transcerebellar fourth ventriculoperitoneal shunt for management of presumed fourth ventricle arachnoid diverticulum and secondary obstructive hydrocephalus of a dog. To describe the outcome of this procedure.

STUDY DESIGN

Case report.

ANIMALS

Male entire English springer spaniel, 3 years 9 months of age.

METHODS

The dog was initially presented for management of acute, progressive, and multifocal brainstem and forebrain dysfunction. Magnetic resonance imaging revealed internal obstructive hypertensive hydrocephalus. The dog was managed via ventriculoperitoneal shunting from the left lateral ventricle and made an excellent recovery. The dog acutely deteriorated 18 months after initial discharge and follow-up magnetic resonance imaging confirmed the ventricular shunt remained in situ with normal-sized lateral ventricles but revealed a cystlike lesion within the fourth ventricle, presumed to be a fourth ventricle arachnoid diverticulum. The diverticulum was causing mass effect and resultant compression of adjacent neuroparenchyma. A second ventriculoperitoneal shunt was subsequently placed into the fourth ventricle via the caudal cranial fossa and cerebellum. This was attached to a three-way connector, to which the existing shunt (within the left lateral ventricle) was also attached, and then secured to the existing medium-pressure valve.

RESULTS

Postoperatively, the dog immediately developed mild vestibular-cerebellar ataxia, with a marked improvement after 3 months. There were no shunt-associated complications. Long-term follow up at 40 months after the second surgical procedure revealed a normal neurological examination.

CONCLUSION

Transcerebellar ventriculoperitoneal shunt placement for treatment of a presumed fourth ventricle arachnoid diverticulum was performed and was associated with a favorable long-term outcome.

Optimizing Surgical Outcomes for Intracranial Epidermoid Tumors: A Retrospective Analysis of Clinical Predictors, Surgical Decisions, and Patient Clustering

BACKGROUND/OBJECTIVE

Intracranial epidermoid tumors (ETs) are rare, benign lesions that present significant challenges in neurosurgical management due to their propensity to encase vital neurovascular structures. We aimed to evaluate the impact of clinical, demographic, and tumor-specific factors on surgical decisions (gross total resection [GTR] vs. subtotal resection [STR]) and outcomes and identify patient clusters with distinct profiles and outcomes post-resection.

METHODS

We retrospectively analyzed 72 patients with ET treated from 1998 to 2022, employing multivariable logistic regression for GTR versus STR predictors and Kaplan-Meier curves for progression-free survival (PFS). K-prototype clustering classified patients based on clinical data.

RESULTS

The mean age of our cohort was 39.8 ± 20.1 years. About 13.9% of patients had a recurrence, with a median PFS of 108 months (interquartile range: 57 -206). Seizures significantly predicted GTR (P < 0.05), whereas adherence to critical structures reduced GTR likelihood (P < 0.05). Initial surgeries more often achieved GTR, correlating with longer PFS (P < 0.0001) and reduced recurrence (P < 0.01) versus re-operations. Cluster analysis identified three distinct groups, with the initial GTR cluster showing superior PFS and the lowest recurrence (P < 0.0001 and P < 0.01, respectively). Statistically significant predictors of PFS included age and preoperative seizure presence, with older age favoring longer PFS (P < 0.01) and seizures associated with reduced PFS (P < 0.01). In addition, patients with previous surgeries showed a trend toward shorter PFS (P < 0.05).

CONCLUSIONS

This study emphasizes the importance of tailored surgical strategies in managing intracranial ETs, advocating for GTR to optimize long-term outcomes where possible. Future prospective studies are essential to further refine treatment approaches, enhancing survival for ET patients.

Case report: Intracranial epidermoid cyst in a cat

A 9-year-old American Shorthair, castrated male, weighing 4.3 kg was presented to our hospital because of intermittent ataxia and tetraparesis for 6 weeks. On presentation, the cat was in a stupor and on recumbency, and had vertical nystagmus in both eyes. These clinical signs suggested a brainstem disorder. MRI showed a mass lesion in the caudal aspect of the fourth ventricle with hyperintensity on T2-weighted and FLAIR imaging, low-intensity on T1-weighted imaging, and enhanced margins on post-contrast T1-weighted imaging. The mass compressed the fourth ventricle, causing obstructive hydrocephalus. A second cystic lesion was found rostral to the cerebellum. After MRI, the cat experienced respiratory difficulties and the mass was removed by emergency craniectomy. Although the mass including the cyst wall was successfully removed, the cat was euthanized because spontaneous breathing did not return. The mass was histopathologically diagnosed as epidermoid cyst. A biopsy to the rostral cystic lesion had not been performed and therefore the etiology of this lesion remained unclear. This is the first case of feline intracranial epidermoid cyst in which MRI and surgical excision were performed. MRI findings were similar to those in humans and dogs, suggesting that imaging studies are useful in cats for the diagnosis of intercranial epidermoid cyst.

Endoscopic endonasal resection of an epidermoid cyst in the cavernous sinus: A case report and literature review

Background

Epidermoid cysts of cavernous sinus (CS) are rare congenital neoplasms of the central nervous system. In previous literature reports, the treatment for CS epidermoid cysts was mainly microsurgical resection, and the surgical methods included simple microsurgery and endoscope-assisted microsurgery. The present case report demonstrates the first case of complete resection of a CS epidermoid cyst by a simple endoscopic endonasal transcavernous (EET) approach.

Case presentation

A 54-year-old woman presented with chronic persistent headaches and occasional syncope. Brain MRI demonstrated a space-occupying lesion of the left CS, and digital substruction angiography (DSA) showed a small aneurysm at the beginning of the left ophthalmic artery. Thrombotic therapy of carotid-ophthalmic aneurysms was performed first, and the patient underwent resection of the CS lesion secondary. Considering the location of the lesion and the neuroendoscopy technology and experience of the doctor, we made bold innovations and used an EET approach to achieve complete resection of the lesion. The postoperative pathological results were consistent with the characteristics of epidermoid cyst. During the 1-year follow up, the patient showed no apparent signs of recurrence on head MRI.

Conclusion

Epidermoid cyst of cavernous sinus is a rare benign occupying lesion in cavernous sinus. Reviewing the previous literature, the main treatment is microneurosurgery, and neuroendoscopy is only used as an auxiliary equipment. We present the first case of complete endoscopic resection of CS epidermoid cyst by EET approach according to CARE guidelines, aiming to share the new surgical plan for CS epidermoid cyst and provide more surgical options for this disease for neurosurgery colleagues.

Epidermoid cyst of the cerebellar vermis: Case report of a rare medial topography

Intracranial epidermoid cysts are very rare benign tumors representing less than 2% of intracranial tumors. They are located preferentially in the cerebellopontine angles, parasellar, and temporal regions. We report here the case of an epidermoid cyst of very uncommon medial location in the cerebellar vermis, in a 61-year-old female patient complicated with tumor protrusion into the foramen magnum and active hydrocephalus.

Combined endoscopic and exoscopic resection of intracranial epidermoid cysts

OBJECTIVE

This article aims at introducing an endoscopic-exoscopic technique for the resection of epidermoid cysts.

METHODS

We retrospectively analyzed the intracranial epidermoid cysts patients who received whole course combined endoscopic and exoscopic resection between 2017 and 2020 at our institution, to explore the benefit of combined endoscopic and exoscopic resection of intracranial epidermoid cysts and evaluated the clinical utility of endoscopic-exoscopic technique.

RESULTS

A total of 17 patients were enrolled in the study. Of all patients, 6 patients (6/17, 35.3%) underwent total resection, 10 patients (10/17, 58.8%) underwent subtotal resection (residual capsule and/or) and 1 patient (1/17, 5.9%) underwent partial resection. Postoperative surgical complications were seen in 3 patients (3/17, 17.6%), including intracranial infection in 2 patients （2/17, 11.8%） , and a delayed postoperative hematoma observed in the seventh day after operation for 1 patient (1/17, 5.9%), who was treated in a conservative manner and recovered smoothly from the hemorrhage. The median follow-up time was 33.3 months (range 14.5-54.5 months). During the follow-up period, there was no recurrence of the tumors that received total resection. 2 patients developed residual tumor regrowth but did not show any symptom therefore no further surgery was required.

CONCLUSIONS

Endoscopic-exoscopic technique is safe and efficient in the resection of intracranial epidermoid cysts with panoramic views and superior maneuverability. With further development and accumulation of practical experiences, the endoscopic-exoscopic technique can also be applied in the resection of other intracranial tumors.

Assessment of epidermoid cyst with trigeminal neuralgia before neuroendoscopy: A high-resolution MR study based on 3D-FIESTA and MR angiography

PURPOSE

To assess the value of preoperative 3D-FIESTA and MR angiography (MRA) in endoscopic resection of epidermoid cysts presenting with trigeminal neuralgia (TN).

METHODS

3D-FIESTA and MRA were performed before neuroendoscopy in 32 cases of epidermoid cysts with TN, and the tumors were grouped into types A, B, C, and D according to the relationship between the tumor and adjacent nerves and arteries (Hitoshi Kobata's classification). Evaluation of the neuroendoscopic resectability of different types of tumors, included gross total tumor removal (GTR), subtotal tumor removal (STR), and partial tumor removal (PTR). During the 5-year follow-up, symptoms were assessed based on facial pain relief using the Barrow Neurological Institute (BNI) score.

RESULTS

The coincidence rate between MRI classification of the tumor and the operation was 100%. Type B tumors were the most common (18/32, 56.3%). Type A tumors showed the highest resectability (9/9, 100%), followed by type B tumors (14/18, 77.8%). Moreover, microvascular decompression was performed in all 4 cases of type C and 1 case of type D tumors. During follow-up, 23 patients showed marked improvement in symptoms (15, 8 of BNI I or II), 8 cases showed partial improvement (BNI III), and only 1 case of type C tumor was associated with poor facial pain relief, which recurred 5 years later (BNI IV).

CONCLUSIONS

Preoperative high-resolution MR can accurately analyze the relationship between epidermoid cysts and adjacent nerves and arteries. It could act as a powerful tool in the evaluation of tumor resectability and the prognosis of surgery.

Radio-pathological characteristics of malignant transformation of an epidermoid cyst in the cerebellopontine angle: A case report

Background

Intracranial epidermoid cysts are rare congenital neoplasms that are clinically indolent and histologically benign. They rarely show malignant transformation, and several such cases have been reported. Some radiological features that suggest malignant transformation have been reported. However, histopathological features that indicate a high risk of malignant transformation have not been reported to date.

Case Description

We report a 59-year-old woman with a benign epidermoid cyst in the cerebellopontine angle that showed malignant transformation after 6 years. Magnetic resonance imaging (MRI) at the time of initial onset displayed a high-intensity signal on diffusion-weighted imaging (DWI), no peritumoral edema, and no enhancement on contrast-enhanced T1-weighted imaging. On the other hand, MRI at the time of malignant transformation showed a low-intensity signal on DWI, peritumoral edema, and enhancement of the tumor capsule on contrast-enhanced T1-weighted imaging. Pathological findings at the time of the first surgery differed from normal benign epidermoid cysts, in that stratified squamous epithelial metaplasia was observed, and immunohistochemical (IHC) analysis showed positive p53 staining. In addition, IHC analysis at the time of malignant transformation demonstrated positive p16 staining.

Conclusion

In benign epidermoid cysts, it is considered to cause malignant transformation when squamous metaplasia or p53 mutation is observed. Therefore, strict follow-up is required while paying attention to the characteristic changes in MRI for early detection and timely treatment of malignant transformation.

Long-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients

OBJECTIVE

The authors' objective was to reevaluate the role of microsurgery for epidermoid tumors by examining the associations between extent of resection (EOR), tumor control, and clinical outcomes.

METHODS

This was a retrospective study of patients with microsurgically treated intracranial epidermoid tumors. The recurrence-free and intervention-free rates were calculated using the Kaplan-Meier method. EOR was graded as gross-total resection (GTR) (total resection without residual on MRI), near-total resection (NTR) (a cyst lining was left in place), subtotal resection (STR) (> 90% resection), and partial resection (PR) (any other suboptimal resection) and used to stratify outcomes.

RESULTS

Sixty-three patients with mean clinical and radiological follow-up periods of 87.3 and 81.8 months, respectively, were included. Sixteen patients underwent second resections, and 5 underwent third resections. The rates of GTR/NTR, STR, and PR were 43%, 35%, and 22%, respectively, for the initial resections; 44%, 13%, and 44% for the second resections; and 40%, 0%, and 60% for the third resections (p < 0.001). The 5- and 10-year cumulative recurrence-free rates after initial resection were 64% and 32%, respectively. When stratified according to EOR, the 10-year recurrence-free rate after GTR/NTR was marginally better than that after STR (61% vs 35%, p = 0.130) and significantly better than that after PR (61% vs 0%, p < 0.001). The recurrence-free rates after initial microsurgery were marginally better than those after second surgery (p = 0.102) and third surgery (p = 0.065). The 5- and 10-year cumulative intervention-free rates after initial resection were 91% and 58%, respectively. When stratified according to EOR, the 10-year intervention-free rate after GTR/NTR was significantly better than that after STR (100% vs 51%, p = 0.022) and PR (100% vs 27%, p < 0.001). The 5-year intervention-free rate after initial surgery was marginally better than that after second surgery (52%, p = 0.088) and significantly better than that after third surgery (0%, p = 0.004). After initial, second, and third resections, permanent neurological complications were observed in 6 (10%), 1 (6%), and 1 (20%) patients, respectively. At the last follow-up visit, 82%, 23%, and 7% of patients were free from radiological recurrence after GTR/NTR, STR, and PR as the initial surgical procedure, respectively.

CONCLUSIONS

GTR/NTR seems to contribute to better disease control without significantly impairing functional status. Initial resection offers the best chance to achieve better EOR, leading to better disease control.

Endoscopic Keyhole Approach for Intracranial Epidermoid

Objective  In contemporary neurosurgical practice, keyhole endoscopic approach has established its role in various neurosurgical pathologies. Intracranial epidermoid is an ideal pathology for endoscopic keyhole approach as epidermoid is well encapsulated, extra-axial, avascular, and easily suckable. The objective of this study is to share our experience of endoscopic keyhole approach for intracranial epidermoids at various locations as a new minimally invasive neurosurgical approach to deal with these lesions. Materials and Methods  We conducted a retrospective study on 26 patients who underwent keyhole pure endoscopic excision of intracranial epidermoid between July 2015 and December 2019. Patient's demographics, clinical features, radiological imaging, and postoperative complications were noted. Follow-up outcome of preoperative symptoms and postoperative complications were also analyzed. Results  The mean age of the study population was 30.5 years with a mean follow-up of 30 months. The common presenting features were headache, hearing loss, and trigeminal neuralgic pain. Gross total resection was achieved in 73.1% cases, while near total resection and subtotal resection were achieved in 19.2 and 7.7% cases, respectively. In the follow-up, maximal improvement was seen in trigeminal neuralgic pain (83%) and headache (66.7%). Major postoperative complications were facial nerve paresis, lower cranial nerve paresis, and transient facial hypoesthesia, most of which improved over time. None of the patients required resurgery till date. Statistical Analysis  Patients' data were analyzed using SPSS software version 23 (Statistical Package for Social Sciences, IBM, Chicago, United States). Conclusion  This study demonstrates that with careful patient selection, endoscopic keyhole excision of epidermoid is a good alternative to conventional microsurgical excision with comparable surgical and functional outcomes.

The role of apparent diffusion coefficient as a predictive factor for tumor recurrence in patients with cerebellopontine angle epidermoid tumor

Intracranial epidermoid tumors are slowly growing benign tumors, but due to adjacent critical neurovascular structures, surgical resection is challenging, with the risk of recurrence. The apparent diffusion coefficient (ADC) has been used to evaluate the characteristics of brain tumors, but its utility for intracranial epidermoid tumors has not been specifically explored. This study analyzed the utility of preoperative ADC values in predicting tumor recurrence for patients with intracranial epidermoid tumors. Between 2008 and 2019, 21 patients underwent surgery for cerebellopontine angle (CPA) epidermoid tumor, and their preoperative ADC data were analyzed. The patients were divided into two groups: the recurrence group, defined by regrowth of the remnant tumor or newly developed mass after gross total resection on magnetic resonance imaging (MRI); and the stable group, defined by the absence of growth or evidence of tumor on MRI. Receiver operating characteristic (ROC) analysis was used to obtain the ADC cutoff values for predicting tumor recurrence. The prognostic value of the ADC was assessed using Kaplan-Meier curves. The minimum ADC values were significantly lower in the recurrence group than in the stable tumor group (P = 0.020). ROC analysis showed that a minimum ADC value lower than 804.5 × 10^-6 mm²/s could be used to predict higher recurrence risk of CPA epidermoid tumors. Non-total resection and mean and minimum ADC values lower than the respective cutoffs were negative predictors of recurrence-free survival. Minimum ADC values could be useful in predicting the recurrence of CPA epidermoid tumors.

Importance of appropriate surgical approach selection for radical resection of cerebellopontine angle epidermoid cysts with preservation of cranial nerve functions: our experience of 54 cases

BACKGROUND

Although many reports state that only the lateral suboccipital retrosigmoid approach (LSO) should be used for removal of cerebellopontine angle (CPA) epidermoid cysts, it is preferable to use various surgical approaches as appropriate for each patient, for radical resection with an optimal operative field under direct visualization, and for the preservation of cranial nerve (CN) functions. In the present study, we hence focused on the importance of surgical approach selection for removal of CPA epidermoid cysts and analyzed the results of CPA epidermoid cysts after surgery in our series.

METHODS

Fifty-four patients who underwent surgery for CPA epidermoid cysts were retrospectively analyzed, regarding their surgical approaches, removal rates, preservation rates of CN function 1 year after surgery, and recurrence. Surgical approaches were selected for patients according to the size and extension of the tumor.

RESULTS

Surgical approaches consisted of LSO (20 cases), anterior transpetrosal approach (ATP; 3 cases), combined transpetrosal approach (27 cases), and ATP + LSO (4 cases). Mean tumor content removal and capsule removal rates were 97.4% and 78.3%, respectively. Preservation rates of facial nerve function and useful hearing were 94.4% and 90.7%, respectively. The mean postoperative follow-up time was 62.8 months, and there were two cases of recurrence requiring reoperation about 10 years after surgery.

CONCLUSIONS

For CPA epidermoid cyst surgeries, selection of the appropriate surgical approach for each patient and radical resection with an optimal operative field under direct visualization enable tumor removal without the need for reoperation for a long time, with preservation of CN functions.

Cerebellopontine Angle Epidermoid Cysts: Surgical Treatment Outcome

Background  Epidermoid cysts (ECs)are an uncommon slowly growing congenital lesions. The cerebellopontine angle (CPA) is the most common site. Surgical management for these lesions remains challenging due to the high-adherence of the cyst capsule to the surrounding structures and its tendency to present with invasion of multiple cisterns.

Objective The aim of this study was to evaluate the clinical and radiological outcome of surgically treated ECs in the CPA region.

Materials and Methods This is a retrospective study conducted on patients presenting with symptomatic CPA ECs. Clinical outcome was assessed in terms of improving or worsening of the presenting symptoms. Radiological outcome was assessed by comparing the tumor size, brainstem, and cerebellar compression in the preoperative and postoperative images.

Results In this study, 18 patients were included. All cases were operated upon by microsurgical evacuation of the cyst contents and excision of the nonadherent parts of the capsule. On admission, cranial nerve symptoms predominated. Improvement or resolution of preoperative deficits was seen in 15 patients. Preoperative symptoms worsened in two and new postoperative symptoms occurred in one patient. Seven patients needed additional ventriculoperitoneal (VP) shunt in the same setting due to the presence of hydrocephalus. During the follow-up period, symptomatic recurrence occurred in one patient, while asymptomatic recurrence occurred in one patient.

Conclusion Surgical management of CPA ECs, leaving remnants of the capsule on cranial nerves and brain stem can be considered as a relatively safe surgical procedure with a good clinical outcome and low-recurrence risks.

Extent of resection of epidermoid tumors and risk of recurrence: case report and meta-analysis

OBJECTIVE

Intracranial epidermoid tumors are slow-growing, histologically benign tumors of epithelial cellular origin that can be symptomatic because of their size and mass effect. Neurosurgical resection, while the treatment of choice, can be quite challenging due to locations where these lesions commonly occur and their association with critical neurovascular structures. As such, subtotal resection (STR) rather than gross-total resection (GTR) can often be performed, rendering residual and recurrent tumor potentially problematic. The authors present a case of a 28-year-old man who underwent STR followed by aggressive repeat resection for regrowth, and they report the results of the largest meta-analysis to date of epidermoid tumors to compare recurrence rates for STR and GTR.

METHODS

The authors conducted a systemic review of PubMed, Web of Science, and the Cochrane Collaboration following the PRISMA guidelines. They then conducted a proportional meta-analysis to compare the pooled recurrence rates between STR and GTR in the included studies. The authors developed fixed- and mixed-effect models to estimate the pooled proportions of recurrence among patients undergoing STR or GTR. They also investigated the relationship between recurrence rate and follow-up time in the previous studies using linear regression and natural cubic spline models.

RESULTS

Overall, 27 studies with 691 patients met the inclusion criteria; of these, 293 (42%) underwent STR and 398 (58%) received GTR. The average recurrence rate for all procedures was 11%. The proportional meta-analysis showed that the pooled recurrence rate after STR (21%) was 7 times greater than the rate after GTR (3%). The average recurrence rate for studies with longer follow-up durations (≥ 4.4 years) (17.4%) was significantly higher than the average recurrence rate for studies with shorter follow-up durations (< 4.4 years) (5.7%). The cutoff point of 4.4 years was selected based on the significant relationship between the recurrence rate of both STR and GTR and follow-up durations in the included studies (p = 0.008).

CONCLUSIONS

STR is associated with a significantly higher rate of epidermoid tumor recurrence compared to GTR. Attempts at GTR should be made during the initial surgery with efforts to optimize success. Surgical expertise, as well as the use of adjuncts, such as intraoperative MRI and neuromonitoring, may increase the likelihood of completing a safe GTR and decreasing the long-term risk of recurrence. The most common surgical complications were transient cranial nerve palsies, occurring equally in STR and GTR cases when reported. In all postoperative epidermoid tumor cases, but particularly following STR, close follow-up with serial MRI, even years after surgery, is recommended.

Cranial Nerve Imaging and Pathology

This review provides a symptom-driven approach to neuroimaging of disease processes affecting the cranial nerves. In addition to describing characteristic imaging appearances of a disease, the authors emphasize exceptions to the rules and neuroimaging pearls. The focus is on adult neurology although some important pediatric conditions are included. On reviewing this material, the reader should be able to (1) differentiate intra- and extra-axial causes of cranial nerve dysfunction and (2) appropriately use neuroimaging to investigate abnormalities of cranial nerve function.

Endoscopic resection of the third ventricular epidermoid cysts: A case review and review of literature

Background

Epidermoid cysts are benign, congenital lesions that originate from ectodermal cells, they are most commonly found in the cerebellopontine angle, but rarely in the ventricular system. There is limited literature regarding the different microsurgical techniques utilized to approach these lesions.

Methods

A 63-year-old female with a recurrent third ventricular epidermoid cyst underwent gross total resection utilizing an endoscopic technique. We also reviewed the various endoscopic/microsurgical approaches and outcomes reported in literature.

Results

We identified 15 cases, including our own. Nine of these were managed using microsurgical techniques, while six cases (including ours) were treated endoscopically; gross total resection was achieved in 10/15 cases (67%). Most commonly, surgeons utilized the interhemispheric transcallosal approach (five cases). Tumor recurrence was seen in two cases. Complications attributed to these resections included: disorders of the hypothalamic-pituitary axis (3) - diabetes insipidus, galactorrhea, and hypopituitarism; tumor recurrence (2); aseptic meningitis (1); and a transient Korsakoff syndrome (1).

Conclusion

Epidermoid cysts of the third ventricle are exceedingly rare, and surgical resection is generally well tolerated. Microsurgical transcortical, transcallosal, and endoscopic approaches each have advantages and disadvantages, and are associated with unique procedure-specific complications. Continuing technological improvement would favor endoscopic approaches for resection of tumors of the third ventricle in the future.

Radiotherapy for recurrent intracranial epidermoid cysts without malignant transformation: a single-institution case series

INTRODUCTION

Recurrent intracranial epidermoid cysts may be difficult to address surgically given their proximity to critical neurovascular structures of the skull base. There are emerging reports of using radiotherapy (RT) for the treatment of recurrent epidermoid cysts. Here, we report a case series of adjuvant fractionated external beam RT for recurrent intracranial epidermoid cysts.

METHODS

A single-institution review of all recurrent epidermoid cysts treated with adjuvant therapy between 2000 and 2017 was performed.

RESULTS

Eight patients with recurrent epidermoid cysts who underwent adjuvant external beam RT were identified. Average age at initial diagnosis was 42.2 years, and median clinical follow-up after initial diagnosis and RT was 16.4 and 2.9 years, respectively. The median number of surgical resections prior to RT was 3 (range 2-5). Rationale for RT included multiple recurrent disease, rapid recurrence following prior resection, increased risk of further surgical morbidity, and patient preference. Median dose was 50.4 delivered in 1.8 Gy fractions (median 28 fractions). By the date of last follow-up, no patient has demonstrated progression, and there have been no cases of malignant degeneration.

CONCLUSION

Adjuvant RT should be considered in the context of recurrent epidermoid cysts to decrease the likelihood of further recurrences.

Executive Dysfunction After Fourth-Ventricle Epidermoid Cyst Resection

Intracranial epidermoid cysts are rare, comprising 0.2% to 1.8% of all primary intracranial expanding lesions, of which <5% occur within the fourth ventricle. Epidermoid cysts are frequently congenital, and patients often present in the fourth decade of life. These cysts produce symptoms as a result of mass effect on surrounding structures, most commonly the cerebellum and cranial nerves. Symptoms can include hearing impairment, trigeminal neuralgia (severe facial pain), facial tics, headaches, double vision, and facial palsy. However, no research has focused on the neuropsychological effects on a patient after surgical resection of these cysts. This case report presents the cognitive profile of a woman after resection of an epidermoid cyst in the fourth ventricle. The 49-year-old patient underwent neuropsychological assessment after removal of the cyst, completing a comprehensive set of cognitive tests of estimated premorbid intelligence, attention, memory, social cognition, language, visual perception, and executive functioning. Test results indicated executive dysfunction and reduced visuospatial memory in the acute stage after surgical removal of the epidermoid cyst. These findings suggest that cognitive deficits can occur after resection of space-occupying lesions in brain regions not typically associated with cognition. To our knowledge, this is the first report of the neuropsychological consequences of surgical removal of a congenital epidermoid cyst in the fourth ventricle. An understanding of the neuropsychological sequelae of this rare cerebral cyst will allow patients, families, and health professionals to better anticipate and manage postoperative difficulties.

Cranial Nerve Preservation Following Surgical Treatment for Epidermoid Cysts of the Posterior and Middle Fossae

Epidermoid cysts are rare lesions, accounting for 0.2 to 1.8% of all intracranial tumors. They most commonly occur in the cerebellopontine angle where they may cause a breadth of neurologic complications due to mass effect on the nearby cranial nerves (CN), vascular structures, and the brain stem. Treatment of epidermoid cysts is surgical, with the goal of complete resection using microsurgical technique and even more importantly preservation of the involved CNs, vasculature, and brain parenchyma. Successful surgery can result in total resolution of symptoms, but, in certain situations, may not be advisable due to adherence, scarring, or inflammation making dissection of CN fascicles difficult and possibly hazardous. We conducted a retrospective review from 1998 to 2016 and compiled a series of 28 skull base epidermoid cysts operated on at our institution. Cases were evaluated for presenting symptoms, history of prior resection, and postoperative results including CN function, extent of resection, residual tumor, and need for reoperations. The average tumor size (largest diameter) was 3.9 cm with a range of 1 to 7cm. Eighteen of twenty-eight (64%) patients underwent a gross total resection and ten underwent subtotal resection. No patients, whether presenting with CN deficits or not, experienced permanent worsening of CN function following surgery. Complete resection of epidermoid cysts should remain a high priority of therapy, but, in our opinion, preservation of CN function should be a primary goal, determining the extent of resection to provide patients with the highest quality of life possible following surgery.

Clinical Features and Surgical Management of Cerebellopontine Angle Cholesteatoma That Presented as Trigeminal Neuralgia

BACKGROUND

It is difficult to differentiate patients with cerebellopontine angle (CPA) cholesteatoma and patients with primary trigeminal neuralgia just according to early symptoms. We aimed to explore the clinical characteristics, early diagnosis, and microneurosurgical techniques for CPA cholesteatoma that presented as trigeminal neuralgia.

METHODS

The data of 26 patients who complained trigeminal neuralgia with CPA cholesteatoma between January 2009 and December 2015 were collected and studied retrospectively, they were diagnosed by magnetic resonance imaging preoperatively and confirmed by pathology postoperatively. All the tumors were resected through a retrosigmoidal approach. In 26 cases, 14 patients who underwent cholesteatoma resection and microvascular decompression were assigned to group A and 12 patients who underwent only cholesteatoma resection were assigned to group B. The clinical features and surgical results between groups A and B were compared. The complications and surgical results were followed up, and surgical techniques were summarized.

RESULTS

All patients presented as trigeminal neuralgia at the same side of the cholesteatoma. There was no statistical difference between the 2 groups in clinical features and surgical results between groups A and B. All patients with cholesteatoma showed clear and significant imaging characteristics. The tumors were totally removed in 18 patients and subtotally removed in 8 patients. Pain relief was satisfactory in all patients. Surgical complications included transient aseptic meningitis in 2 patients, facial numbness in 2 patients, mild tinnitus in 2 patients, mild and facial weakness in 1 patient. No death, hematoma, or acute hydrocephalus were reported in this series. During the follow-up of 12-80 months, no patient experienced recurrence of pain or tumor.

CONCLUSIONS

Cholesteatoma of the cerebellopontine angle often presented as trigeminal neuralgia. Magnetic resonance imaging is helpful for early diagnosis according to its distinct signal. Surgical treatment is often the first choice, the neuralgia relief was satisfactory after operation. Microvascular decompression is recommended simultaneously if some offending vessels were founded during the surgical resection of the tumor.

Primary Epidermoid Tumors of the Cerebellopontine Angle: A Review of 47 Cases

OBJECTIVE

To analyze disease presentation, treatment, and clinical course of a consecutive series of patients with primary cerebellopontine angle (CPA) epidermoids.

PATIENTS

Forty-seven consecutive patients with previously untreated CPA epidermoids.

INTERVENTION(S)

Observation and microsurgery.

MAIN OUTCOME MEASURES

Disease- and treatment-associated morbidity, recurrence.

RESULTS

Forty-seven patients (mean age 39 years; 53% women) were analyzed and the average duration of follow-up was 42 months. The most common presenting symptom was headache (27; 57%); 13 (28%) exhibited preoperative asymmetric sensorineural hearing loss, 3 (6%) facial nerve paresis, and 3 (6%) hemifacial spasm. Thirteen patients (28%) were initially observed over a mean interval of 56 months; however, five experienced disease progression requiring operation. Thirty-nine patients (83%) underwent surgical resection; 18 (46%) received gross total, 5 (13%) near total, and 16 (41%) aggressive subtotal resection. Three patients (8%) recurred at a median of 53 months; two after subtotal and one after gross total resection. Ninety-three percent of patients with useful hearing maintained serviceable hearing following treatment and one patient (3%) experienced mild long-term postoperative facial nerve paresis (HB II/VI). All patients with preoperative facial nerve paresis recovered normal function postoperatively. There were no episodes of stroke or death.

CONCLUSIONS

Surgical intervention is effective in alleviating symptoms of cranial neuropathy and brainstem compression from CPA epidermoids. Gross total resection is preferred; however, aggressive subtotal removal should be considered with adherent or extensive disease as reoperation rates are low, even in the setting of aggressive subtotal resection. Conservative observation with serial imaging is a viable initial strategy in asymptomatic or minimally symptomatic patients.

Surgical Resection of Cerebellopontine Epidermoid Cysts: Limitations and Outcome

Objective  Epidermoid cysts are benign slowly growing tumors commonly involving the cerebellopontine angle (CPA). The aim of this study was to analyze the surgical limitations, surgical strategies, complications, and outcome of resection of these lesions. Material and Methods  The clinical data and outcome of 32 cases operated for CPA epidermoid between 2007 and 2015 were retrospectively analyzed. The mean follow-up period was 42.6 months, and all patients were followed up at least for a whole year. Results  There were 15 males and 17 females. The median age was 37.6 years. Headache and cranial nerves dysfunction were the most common presenting symptoms. Surgery was performed in all patients using the standard lateral suboccipital retrosigmoid approach. In three cases, microvascular decompression of an arterial loop was performed in addition to tumor excision. Total resection was accomplished in 19 out of 32 cases (59.4%), subtotal resection in 7 cases (21.9%), and only partial excision was achieved in 6 cases (18.7%). There was no recurrence or regrowth of residual tumor during the follow-up period. We had a single postoperative mortality due to postoperative pneumonia and septic shock. New cranial nerves deficits occurred in 15.6% of cases but were transient in most of them. Conclusion  The favorable outcome of total resection of CPA epidermoids should always be weighed against the critical risks that accompany it especially in the presence of tight adhesions to vital neurovascular structures. The retrosigmoid approach is suitable for the resection of these tumors even if they were large in size.

Dermoid Cyst of the Prepontine Cistern and Meckel's Cave: Illustrative Case and Systematic Review

Objective  Dermoid cysts are benign, congenital malformations that account for ∼0.5% of intracranial neoplasms. The authors describe a 42-year-old female with a prepontine dermoid cyst who underwent apparent gross total resection (GTR) but experienced cyst recurrence. To date, very few cases of prepontine dermoid cysts have been reported. The prevalent region where these cysts are located can be difficult to determine. In addition, the authors systematically review the literature to characterize the clinical presentation, anatomical distribution, and surgical outcomes of intracranial dermoid cysts. Design  Systematic review. Setting/Participants  PubMed, Web of Science, and Scopus databases. Main Outcome Measures  Extent of resection, symptom improvement, and recurrence rates. Results  A total of 69 patients with intracranial dermoid cysts were identified. Three (4.3%) intracranial dermoid cysts were located in the prepontine cistern. The average age of patients was 33.3 years. The most common presenting symptoms were headache (52.2%) and visual disturbances (33.3%). Intracranial dermoid cysts were distributed similarly throughout the anterior, middle, and posterior cranial fossae (29.0%, 36.2%, and 29.0%, respectively). GTR was achieved in 42.0% of cases. Thirty-four (49.3%) patients experienced symptom resolution. Recurrence rate was 5.8% at a mean follow-up of 2.1 years. Conclusions  Intracranial dermoid cysts most often present as headaches and visual disturbances. Intracranial dermoid cysts were found in the anterior, middle, and posterior cranial fossae at similar frequencies but with clear predilections for the Sylvian fissure, sellar region, and cerebellar vermis. Outcomes following surgical excision of intracranial dermoid cysts are generally favorable despite moderate rates of GTR.

Predictors of Outcomes in Fourth Ventricular Epidermoid Cysts: A Case Report and a Review of Literature

OBJECTIVE

To present an illustrative case of fourth ventricular epidermoid cyst and review the literature to identify predictors of surgical outcomes.

METHODS

A case of fourth ventricular epidermoid cyst is presented and a systematic review of 5 popular databases was performed by independent authors. Stepwise logistic regression was performed to identify clinical predictors of outcomes.

RESULTS

A 21-year-old woman presented with 3 months of headaches and visual obscurations and was diagnosed with a multilobulated mass in the fourth ventricle. The patient underwent suboccipital craniotomy. Complete removal of the mass was achieved and the final diagnosis was consistent with an epidermoid cyst. The systematic review identified 23 studies that reported 37 patients. Mean age was 42.8 years. Mean length of time between symptom onset and diagnosis was 4.43 years. Age (P = 0.049) and duration of symptoms (P < 0.001) were significantly different between patients who experienced symptom improvement and those who did not. Duration of symptom onset to diagnosis was a significant predictor of poor outcomes (odds ratio, 1.19, 95% confidence interval, 1.003-4.785).

CONCLUSIONS

Our review found that in patients with fourth ventricular epidermoid cysts, unfavorable outcomes were predicted by older age and by longer intervals from symptom onset to diagnosis. Clinicians should maintain a high index of suspicion for fourth ventricular epidermoid cysts in patients presenting with cerebellar signs and visual disturbances.

Evaluating the utility of a scoring system for lipomas of the cerebellopontine angle

BACKGROUND

Cerebellopontine angle (CPA) lipomas are rare, benign, slow-growing masses. Resections are considered in symptomatic patients who are refractory to targeted medical therapies, but at those stages the lipomas have often reached considerable sizes and encompass critical neurovascular structures. The objective of this study is to develop and to evaluate the utility of a scoring system for CPA lipomas. The hypothesis is that CPA lipomas with lower scores are probably best managed with early surgery.

METHODS

The PubMed database was searched using relevant terms. Data on patient and lipoma characteristics were extracted and used to design a scoring system. CPA lipomas were stratified by scores with corresponding managements and outcomes analyzed.

RESULTS

One hundred and seventeen patients with CPA lipomas were identified and 40 CPA lipomas were scored. The remaining CPA lipomas were deficient in data and not scored. No lipomas were scored as 1. Score 2 lipomas (n = 12; 30%) most often underwent serial surveillances (n = 5; 41.6%), with the majority of symptoms remaining unimproved (n = 2; 40%). Patients with score 2 CPA lipomas treated with medical therapies (n = 3; 25%) often experienced symptom resolution (n = 2; 66.6%) (p = 0.0499). Patients with score 2 CPA lipomas undergoing surgical resections (n = 3; 25%) all experienced symptom resolution (n = 3; 100%) (p = 0.0499). Score 3 was most common (n = 16; 40%) and these lipomas were often surgically resected (n = 10; 62.5%). The majority of patients with score 3 CPA lipomas having undergone surgical resections (n = 10; 62.5%) experienced symptom improvement (n = 1; 10%) or resolution (n = 4; 40%).

CONCLUSIONS

Score 2 CPA lipomas are smaller and would be deemed non-surgical in general practice. However, our data suggest that these lipomas may benefit from either medical therapies or early surgical resections. The advantages of early surgery are maximal resection, decreased surgical morbidity, and improved symptom relief.

Clinical Characteristics of Benign Pediatric Cranial Vault Tumors: Surgical Considerations Based on 100 Cases

BACKGROUND/AIMS

Tumors of the cranial vault occur at every age of childhood. Although they are mostly benign lesions, their symptomatology is variable and requires extended diagnostics. The choice of therapeutic strategy strongly depends on histopathological diagnosis, and therefore surgical excision is the elective treatment in such cases. Despite several published papers, the literature still lacks reliable clinical characteristics regarding this heterogeneous group of lesions in pediatric patients.

METHODS

We present a series of 100 children (55 male, 45 female) with scalp and cranial vault masses (average age: 3.6 years; range: 1 month to 17 years). Eighty-three (83%) patients underwent surgical excision. Demographic data, clinical presentation, diagnostic studies, choice of therapy, and the results of treatment were evaluated.

RESULTS

All removed tumors were benign pathologies: pilar cysts (30%), epidermoid/dermoid cysts (21%), vascular malformations (11%), inflammatory tumors (5%), and dysraphic remnants (2%). However, underlying bone destruction was observed in 61% of cases. Cranial extension occurred in 34%. Recurrence was noted in 1 case.

CONCLUSIONS

Cranial vault tumors are characterized by constant growth and may penetrate the cranial cavity. Delayed surgery increases the risk of intracranial complications. Surgical problems include inappropriate planning, higher risk of intraoperative bleeding, and the need for subsequent cranioplasty.

Endoscopic Treatment of a Third Ventricular Epidermoid Cyst

Epidermoid cyst is a benign and congenital lesion of ectodermal origin. Traditionally, microsurgical techniques are used to treat these lesions, and their occurrence in the third ventricle is rare. Here, the authors report a case of epidermoid cyst in the third ventricle that presented with signs and symptoms of intracranial hypertension, which was treated safely and effectively using neuroendoscopic surgery.

Sellar and Parasellar Imaging

The skull base is a complex anatomical region that harbors many important neurovascular structures in a relatively confined space. The pathology that can develop at this site is varied, and many disease processes may present with similar clinical and neuroimaging findings. While computed tomography maintains a role in the evaluation of many entities and can, for instance, delineate osseous erosion with great detail and characterize calcified tumor matrices, magnetic resonance imaging (MRI) is the mainstay in the neuroimaging assessment of most pathology occurring at the skull base. Various MRI sequences have proven to be robust tools for tissue characterization and can provide information on the presence of lipids, paramagnetic and diamagnetic elements, and tumor cellularity, among others. In addition, currently available MRI techniques are able to generate high spatial resolution images that allow visualization of cranial nerves and their involvement by adjacent pathology. The information obtained from such examinations may aid in the distinction of these disease processes and in the accurate delineation of their extent prior to biopsy or treatment planning.

Management of symptomatic hemifacial spasm or trigeminal neuralgia

Hemifacial spasm (HFS) or trigeminal neuralgia (TN) is a kind of hyperactivity disorder of cranial nerves caused by vascular compression. However, sometimes, the disease may arise from nerve damage produced by tumors, which was called as symptomatic HFS/TN. Until now, little is known about the exact mechanism and the necessity of microvascular decompression (MVD) regarding the tumor-induced HFS/TN, which is necessary to be retrospectively analyzed in a considerable sample. Among the 4021 patients who underwent MVD in our department between 2006 and 2014, 44 were finally diagnosed as symptomatic HFS or TN. These patients were focused in this study and their clinical features as well as intraoperative findings and postoperative outcomes were retrospectively investigated. Data analysis exhibited the symptomatic HFS/TN cases accounted for 1.1 % in the study, which were caused by epidermoid in 18 (40.9 %) and meningioma in 15 (34.1 %) followed by neuroma in 7 (15.9 %) as well as aneurysm in 2 (4.5 %) and arteriovenous malformation in 2 (4.5 %). Compared to those with idiopathic HFS/TN, younger females were more susceptible (p < 0.05). After resection of the neoplasm, the offending vessel was identified in 26 (59.1 %), which were followed by MVD process. Postoperatively, the symptoms relief rate was 88.6 %. Our study showed that surgical management of patients with symptomatic HFS/TN may lead to a satisfactory result, yet those primary lesions should be removed firstly. In some cases, a microvascular decompression process might be unnecessary afterward, but the entire nerve root should be checked to exclude any vessel in contact with.

Epidermoid cysts of the cerebellopontine angle: Clinical features and treatment outcomes

OBJECTIVE

To report clinical characteristics, treatment outcomes and risk of recurrence in patients with surgically treated cerebellopontine angle epidermoids.

METHODS

In 1994-2013, we operated 17 patients, including 7 with tumor limited to the cerebellopontine angle, 7 with cerebellopontine angle tumor penetrating supratentorially, and 3 with cerebellopontine angle tumor extending along skull base to contralateral cerebellopontine angle. All patients were followed-up for the mean duration of 126 months.

RESULTS

On admission cranial nerve symptoms predominated. Total tumor removal was achieved in 5 patients, and incomplete removal (with small tumor remnants left on vessels, nerves, or brainstem) in 12 patients. Postoperatively, preoperative deficits worsened in 2 and new postoperative deficits occurred in 10 patients. The extent of tumor expansion had no effect on postoperative morbidity and risk of recurrence. During long-term follow-up, improvement or resolution of preoperative deficits was seen in 11 of 17 patients, and new postoperative deficits in 8 of 10 patients. Symptomatic recurrences after an average of more than 9 years were noted in 5 patients, 3 of whom were reoperated. Recurrences occurred in some younger patients and always in area of primary tumor. No effect of extent of tumor removal on risk of recurrence was found.

CONCLUSIONS

The extent of tumor removal had no effect on the risk of recurrence, and thus it may be acceptable to leave tumor capsule fragments adhering closely to nerves, vessels, or brainstem. During long-term follow-up, resolution or improvement of present preoperatively and new postoperative neurological deficits may be expected in most patients.

Ruptured pediatric cerebellopontine angle epidermoid cyst: a case report detailing radiographic evolution and clinical course

Epidermoid cysts (ECs) are uncommon pediatric tumors that often occur in the cerebellopontine angle. Although cyst rupture is a recognized complication, the radiographic evolution of an EC following rupture and the resultant parenchymal brainstem edema have not been reported. The authors present the case of a 13-year-old female with a newly diagnosed cerebellopontine angle EC who presented with worsening headaches, photophobia, and emesis. Magnetic resonance imaging demonstrated significant pericystic brainstem edema and mass effect with effacement of the fourth ventricle. Refractory symptoms prompted repeat imaging, revealing cyst enlargement and dense rim enhancement. Resection of the EC resolved both her symptoms and the brainstem edema. This case documents the radiographic evolution of EC rupture and subsequent clinical course.

Triple pathological findings in a surgically amenable patient with mesial temporal lobe epilepsy

Mesial temporal sclerosis (MTS) is a well-recognized cause of intractable epilepsy; however, coexistence with focal cortical dysplasia (FCD) is less common. Middle fossa epidermoid cysts are rare and may involve the temporal lobe. Most epidermoids are clinically silent, slow-growing, and seldom associated with overt symptomatology, including seizures. We describe a patient with multiple comorbidities including left MTS and a large epidermoid cyst involving the left quadrigeminal plate cistern compressing upon the cerebellar vermis and tail of the left hippocampus, resulting in refractory left temporal lobe epilepsy. The patient underwent left anterior temporal lobectomy. The surgical pathology demonstrated a third pathological finding of left temporal FCD type Ia. The patient has been seizure-free since the surgery. This case provides additional information with regard to the understanding of epileptogenicity and surgical planning in patients with MTS and epidermoid cysts.

Diffusion-weighted MRI in neuro-oncology

Diffusion-weighted MRI (DW-MRI) provides image contrast dependent on the molecular movement of water. It has been most widely used in the diagnosis of cytotoxic edema secondary to acute cerebral ischemia, but has also proven useful in assessing tumor cellularity and grade, abscess formation, cysts and various forms of white matter disorders. Furthermore, DW-MRI is used to generate maps of subcortical white matter tracts and their relationship to structural brain lesions that may serve for preoperative planning and intraoperative guidance. We provide a comprehensive review of current practical applications of DW-MRI in the diagnosis and treatment of primary brain tumors, metastases and nonmetastatic neurologic complications of cancer. A detailed description of diffusion tensor imaging is beyond the scope of this review. We performed a comprehensive search of the PubMed database of the USA National Library of Medicine with use of various combinations of the following search terms: diffusion-weighted imaging, apparent diffusion coefficient, diffusion tensor imaging, diffusion tensor, brain, tumor, glioblastoma, lymphoma, primary CNS lymphoma, stroke, cancer, abscess, leukoencephalopathy, methotrexate, fluorouracil, capecitabine. We identified original articles and well-documented case reports of DW-MRI applications in patients with primary brain neoplasms, metastases and nonmetastatic neurologic complications that we judged to be of high impact on the field. We largely selected publications from the past 10 years, but did not exclude commonly referenced and highly regarded older publications. We also searched the reference lists of articles identified by this search strategy and selected those we judged relevant. Review articles are cited to provide readers with more details and more references than can be covered here.

Pure endoscopic removal of epidermoid tumors of the cerebellopontine angle

PURPOSE

Epidermoid tumors located in the cerebellopontine angle (CPA) are challenging lesions because they tend to grow slowly in the subarachnoid cisterns around delicate neurovascular structures and often extend into surgical anatomic corners. The aim of this paper is to demonstrate the advantages and limitations of purely endoscopic removal of the CPA epidermoids.

METHODS

Six patients harboring an epidermoid tumor located in the CPA were treated using an endoscope-controlled microsurgical technique. A retrosigmoid suboccipital approach was used in all patients. The cerebellomedullary cistern and the cisterna magna were opened to allow cerebrospinal fluid drainage and cerebellar drop, thus yielding a wide and straight working channel to the CPA. Then, the tumor and its capsule were removed by the modified microsurgical instruments.

RESULT

The symptoms caused by mass effect of the lesion resolved after surgery. There were no deaths, but permanent deficits occurred in one patient whose cranial nerves VII/VIII complex was accidentally lesioned. Tumors and their capsules were totally removed in five cases. All patients were discharged 3-5 days after surgery. To date, no recurrences have been observed (follow-up range 14-50 months).

CONCLUSION

The endoscope-controlled microsurgical technique enables a safe tumor removal even when parts of the lesion are not visible in a straight line in CPA epidermoids. By angled endoscopic lenses, tumor extending into adjacent cranial compartments or surgical anatomic corners can be removed through a single small craniotomy without retracting neurovascular structures.

Transpterygoid stent placement for management of a recurrent infratemporal fossa epidermoid cyst: a technical note

Epidermoid cysts (ECs) are benign congenital cysts that typically develop from misplaced stratified squamous epithelium during neural tube closure. They are most commonly encountered in the cerebellopontine angle, the fourth ventricle, and the region of the sella turcica. Recurrence of an EC or regrowth of residual components following surgery is known to occur, but the exact incidence is not defined. Repeat surgical removal is generally considered but may be complicated by significant morbidity. We present a novel endoscopic method by which to manage a recurrent EC of the infratemporal fossa using a silastic stent through a transpterygoid approach that permits periodic drainage of recurrent cyst material in the outpatient setting with minimal morbidity.

Hearing preservation in management of epidermoids of the cerebellopontine angle: CPA epidermoids and hearing preservation

OBJECTIVES

Surgical approaches for epidermoid cysts of the cerebellopontine angle (CPA) are dictated by tumor location. Previous reports have advocated the sacrifice of usable hearing to achieve maximal tumor resection in a single operation. The aim of the current study is to demonstrate the applicability of hearing preservation approaches in the neurotologic management of epidermoids of the CPA.

STUDY DESIGN

Retrospective chart review.

METHODS

A search of archived surgical cases at a single institution between January 1, 1997, and December 31, 2011, revealed 18 cases of epidermoid cysts involving the CPA.

RESULTS

Eighteen patients with a mean age 40.9 years underwent surgery. Average tumor size was 4.47 cm, and presenting symptoms included headache, vertigo, cranial neuropathies, and seizures. Thirteen patients underwent a retrosigmoid approach, 2 translabyrinthine, 2 pterional, and 1 retrolabyrinthine/presigmoid. Complications included CSF leak, pseudomeningocele, meningitis, cranial nerve dysfunction, and persistent imbalance. All but 5 patients had long-term follow-up imaging to chronicle tumor residua/recurrence, varying from 6 to 149 months postoperatively. The average length of follow-up was 71.4 months, and residual tumor was common, with most patients demonstrating a focal or small area of residual tumor on follow-up imaging. Two patients had undergone previous surgery for epidermoid excision elsewhere. Two patients required reoperation for epidermoid regrowth, and the times between surgeries were 44 and 78 months. Of the patients who underwent a retrosigmoid approach, 9 had postoperative audiograms. All of these patients maintained hearing at or near their preoperative level except for 2 patients whose hearing declined and one whose hearing significantly improved.

CONCLUSION

Hearing preservation approaches for epidermoids of the CPA is a feasible option for long-term control of these tumors. Resection from a retrosigmoid approach can provide years of useful hearing, and the majority of patients do not require reoperation.

Unusual complications of a benign tumour - our experience with midline posterior fossa epidermoids

Epidermoids of the brain are uncommon benign tumours. Their midline posterior fossa location is exceedingly rare. Fifteen patients with this condition were operated during a 14-year period. Majority of the patients presented in their middle age with mean duration of symptoms of 10 months. Gait imbalance was the commonest symptom observed. Seven patients had features suggestive of raised intracranial tension. Computed tomography scanning showed typical hypodense lesions. On MRI, tumours were hypo-intense on T1 weighted images and hyper-intense on T2 weighted images. All patients underwent microsurgical excision. We encountered certain complications in the post-operative period. This prompted us for a review of our case material and literature and is the basis of the present article. Implications of these findings are discussed.