Cerebellopontine angle epidermoid cysts: clinical presentations and surgical outcome

Long term management of intracranial epidermoids balancing extent of resection and functional preservation in a 20 year institutional experience

Epidermoid lesions account for 1% of intracranial neoplasms. Surgical management is challenging due to their adhesion to critical neurovascular structures and tendency for recurrence. The current study examines surgical outcomes, extent of resection, and recurrence rates during long-term follow-up. A retrospective analysis was conducted on patients treated for epidermoid lesions between 2000 and 2021, focusing on clinical and radiological outcome and long-term symptom development. Among 55 patients (56.4% male), the majority harbored lesions in the cerebellopontine angle (75.3%). The mean age at surgery was 41.3 years, with an average follow-up of 82 months. Total removal was achieved in 61% of cases, with 75% of them remaining recurrence-free. In comparison, 35% of near-total removal and 25% of subtotal removal remained recurrence-free. Immediate symptom improvement was similar after total and non-total removal (12.6% vs. 10.5%), but long-term improvement was higher after total removal (43% vs. 27%). Transient cranial nerve deficits occurred in 25% of total and in 32% of non-total removal cases, with similar rates of minor complications. Total removal provided better long-term symptom control and lower recurrence rates without significantly increasing neurological deficits, supporting it as the preferred surgical strategy while maintaining functional preservation.

Intracranial epidermoid cysts: Demographics, surgical strategies, and postoperative outcomes in a retrospective cohort study

Background

Intracranial epidermoid cysts are infrequent, benign, and slow-growing lesions derived from ectodermal vestiges. Although extremely uncommon, these lesions represent a great challenge from a diagnostic and surgical point of view because they are located close to major neurovascular structures with great potential for complications. Our work aims to analyze demographic, clinical, radiological, and surgical features in patients with intracranial epidermoid cysts and to assess post-surgical outcomes to define better management strategies.

Methods

We conducted a retrospective cohort study of patients diagnosed with histologically confirmed intracranial epidermoid cysts and treated surgically at Dr. Said Al-Witry's Neuroscience Hospital from January 2020 to September 2024. Demographic data, clinical presentations, imaging findings, surgical approaches, and postoperative complications were analyzed using descriptive statistics and Chi-square tests. Statistical significance was set at P < 0.05.

Results

Out of 40 patients, 75% were male, with headaches being the most common symptom (50%). Magnetic resonance imaging (MRI) findings demonstrated T1 hypo-intensity in 95% and T2 hyper-intensity in all cases. The retrosigmoid approach was the most frequently employed surgical method (60%), followed by frontotemporal (30%) and midline suboccipital (10%) approaches. Postoperative complications occurred in 35% of cases, including facial nerve palsy (15%), aseptic meningitis (10%), cerebrospinal fluid leaks (5%), and hydrocephalus (5%). Chi-square analysis showed significant associations between surgical approaches and postoperative complications (P = 0.048).

Conclusion

Intracranial epidermoid cysts show a high incidence in males and present mostly with nonspecific symptoms such as headaches and seizures. MRI remains the key investigation modality. The retrosigmoid approach shows less complication rate when compared to other techniques. Even though surgery has evolved, complications such as meningitis and nerve palsy persist, so much attention to detail is required in preoperative planning and follow-up in the long run for optimum outcomes for the patients.

Symptomatic Progression, Recurrence, and Long-Term Follow-Up of Patients With Intracranial Epidermoid Cysts

BACKGROUND AND OBJECTIVES

Intracranial epidermoid cysts are rare, slow-growing but highly recurrent tumors with incompletely understood symptoms, progression, complications, and outcomes. The aim of the study was to characterize the symptomatology, surgical management, and long-term outcomes of these tumors.

METHODS

This single-center retrospective analysis identified patients with pathologically confirmed intracranial epidermoid cysts from 1989 to 2023. Demographic and clinical variables were collected at diagnosis, before and after each resection, and at the latest follow-up. Differences across time points were evaluated using analysis of variance with post hoc Tukey's honestly significant difference tests and Pearson χ2 test with posthoc Bonferroni-corrected z-tests for independent proportions (significance: P ≤ .05). Kaplan-Meier, Cox regression, and multivariate logistic regression analyses were used to investigate predictors for recurrence-free survival and 30-day readmission following first surgery, respectively.

RESULTS

Of 146 patients in the final cohort, the average age at diagnosis was 40.3 years, and 52.1% of patients were female. The mean maximum tumor dimension at presentation was 4.3 cm. Most presenting symptoms were significantly reduced at the latest follow-up, including headaches (presentation: 40.4%/latest follow-up: 8.8%, P < .001), vertigo/nausea/vomiting (33.1%/3.7%, P < .001), ataxia/incoordination (22.8%/4.4%, P < .001), and seizures (11.8%/2.9%, P < .005). Similarly, significant improvements were observed in cranial nerve (CN) II deficits (11.0%/3.7%, P = .020) and CN V (11.8%/3.7%, P = .012) and CN VIII excitatory symptoms (11.8%/2.9%, P = .005). Following the first resection, 12.5% of patients were readmitted within 30 days; lumbar drain placement was associated with higher odds of readmission (adjusted odds ratio [95% CI] = 8.26 [1.29-88.19]). Evidence of tumor remnant on the immediate postoperative MRI was associated with a shorter time to recurrence following the first surgery (P = .023).

CONCLUSION

The clinical progression of intracranial epidermoid cysts is marked by a spectrum of troublesome presenting symptoms and a notable tendency for recurrence, particularly following subtotal resection. Nevertheless, symptomatic improvement is the rule even if reoperations are needed, and mortality is exceedingly rare.

Posterior fossa epidermoid tumors: a single-center study and proposed classification system

BACKGROUND

Epidermoid tumors of the cerebellopontine angle and posterior fossa account for approximately 1% of all intracranial tumors. Classifications that may guide surgical planning in the current neurosurgical practice are lacking. This study aimed to focus on the surgical outcome and suggest a classification system that may aid neurosurgeons in determining the goal of resection to minimize morbidity and mortality rates.

METHODS

The study population comprised patients who underwent surgery and follow-up for tissue-proven epidermoid tumors between 2015 and 2020. Patients' data, including demographic features, clinical symptomatology, the extent of surgical resection, and postoperative outcomes, were retrospectively evaluated. A new classification system was designed based on the anatomical-radiological findings and was evaluated in terms of clinical symptomatology, radiological features, surgical approach, and postoperative outcomes.

RESULTS

The patient population comprised 22 women (57.9%) and 16 men (42.1%), with a mean age of 34.9 years. A practical classification system based on the radiological-anatomical vertical (1, 2, and 3) and horizontal (a, b, and c) tumor extensions was designed. No significant differences were found in the patients in terms of sex/age. The most commonly observed symptom was gait disturbance (34.2%). The preoperative tumor diameter was significantly larger in the subtotal resection (STR) group than in the gross total resection (GTR) and near-total resection (NTR) groups. Significantly more cistern involvement was observed in the STR group than in the GTR group. The GTR, NTR, and STR rates were higher in grade 1, 3, and 2 cases, respectively. The subgroup 'a' was correlated with higher resection rates (GTR and NTR), whereas the subgroup 'b' was correlated with STR.

CONCLUSIONS

Our suggested classification system represents a simple and practical model that may guide neurosurgeons in predicting the goal of resection during surgical planning and in minimizing potential morbidity.

Neurobrucellosis presenting as an infected cerebellopontine cistern epidermoid cyst

Neurobrucellosis is a rare complication of brucella infection which presents as meningitis, meningoencephalitis, subdural empyema, brain abscess, myelitis, and radiculo- neuritis. We report the first case of neurobrucellosis presenting as an infected cerebellopontine cistern epidermoid cyst in a young immunocompetent male who presented with fever and acute raised intracranial pressure. MRI brain showed an extra-axial mass in the right cerebellopontine angle cistern with peripheral rim enhancement and diffusion restriction. Emergency surgery unveiled a well-encapsulated lesion containing thick pus and keratinous material, confirming an infected epidermoid cyst. Intriguingly, the culture revealed Brucella infection, but the source of the infection remained unclear.

Intracranial Epidermoid Cyst: A Volumetric Study of a Surgically Challenging Benign Lesion

BACKGROUND

Intracranial epidermoid cysts are rare, benign tumors. Nevertheless, the microsurgical removal of these cysts is challenging. This is due to their capacity to adhere to the neurovascular tissue, as well as the associated difficulties in microsurgically peeling off their capsular wall hidden in dead angles. To better understand the rate of recurrence after surgical intervention, we have performed preoperative and postoperative volumetric analysis of epidermoid cysts, allowing the estimation of their growth rate after resection.

METHODS

Imaging data from 22 patients diagnosed and surgically treated for an intracranial epidermoid cyst between 2000 and 2022 were retrospectively collected from 2 European neurosurgical centers with microsurgical expertise. Volumetric analysis was performed on magnetic resonance imaging data.

RESULTS

Average cyst volume at diagnosis, before any surgery, measured in 12 patients was 28,877.6 ± 10,250.4 mm3 (standard error of the mean [SEM]). Estimated growth rate of incompletely resected epidermoids after surgery was 1,630.05 mm3 ± 729.95 (SEM). Assuming linear growth dynamics and normalizing to postoperative residual volume, the average postoperative growth rate corresponded to 61.5% ± 34.3% (SEM) of the postoperative residual volume per year. We observed signs of recurrence during a radiologic follow-up period of 6.0 ± 2.8 years (standard deviation) in more than 50% of our patients.

CONCLUSIONS

Due to their slow-growing nature, epidermoid cysts can often reach a complex multicompartmental size before resection, even in young patients, thus requiring complex approaches with challenging capsular resection, which implies a high risk of nerve and vascular injury per se. Tumor recurrence may be predicted on the basis of postoperative volumetry.

Epidermoid cyst of the craniovertebral junction-A case report

An epidermoid cyst is a benign tumor in many locations. The symptoms of an epidermoid cyst depend on its location. The brain or spine MRI can confirm the lesion. Removing total decompression is the first choice in treatment with a symptomatic cyst.

Fully neuroendoscopic resection of cerebellopontine angle tumors through a retrosigmoid approach: a retrospective single-center study

The objective of this study is to preliminarily investigate the surgical safety, efficacy, techniques, and clinical value of fully neuroendoscopic surgery for the resection of cerebellopontine angle (CPA) tumors via a retrosigmoid approach. The clinical data of 47 cerebellopontine angle area (CPA) tumors that were treated by full neuroendoscopic surgery from June 2014 to June 2023 were retrospectively analyzed. The efficacy and advantages of the surgical techniques were evaluated based on indicators such as duration of the surgery, neuroendoscopic techniques, intraoperative integrity of nerves and blood vessels, extent of tumor resection, outcomes or postoperative symptoms, and incidence of complications. The 47 cases of cerebellopontine angle tumors include 34 cases of epidermoid cysts, 7 cases of vestibular schwannomas, and 6 cases of meningiomas. All patients underwent fully neuroendoscopic surgery. Twenty tumors were removed using the one-surgeon two-hands technique, and 27 tumors were removed using the two-surgeons four-hands technique. The anatomical integrity of the affected cranial nerves was preserved in all 47 cases. None of the patients suffered a postoperative hemorrhage, cerebrospinal fluid leak, and aseptic or septic meningitis, or died. The rate of total tumor resection was 72.3% (34/47), and the symptom improvement rate was 89.4% (42/47). All patients were followed up for 2 to 12 months, and none died nor showed any signs of tumor recurrence. By analyzing 47 fully neuroendoscopic resections of CPA tumors using the posterior sigmoid sinus approach in our center, we believe that such method allows complete, safe, and effective resection of CPA tumors and is thereby worthy of clinical promotion.

Anatomy and Pathology of the Skull Base: Malignant and Nonmalignant Lesions

The skull base (SB) is the osseous foundation of the cranial vault. It contains many openings that allow communication between the extracranial and intracranial structures. This communication is crucial in normal physiologic processes yet may also arrow spread of disease. This article provides a comprehensive review of SB anatomy including important landmarks and anatomic variants relevant to SB surgery. We also illustrate the diverse pathologies affecting the SB.

Clinicopathological report on epidermoid cysts of the brain: A case series and literature review from an African perspective

INTRODUCTION

Epidermoid cysts are rare benign lesions of the central nervous system which accounts for approximately 1-2 % of all intracranial tumours. They are commonly located in the parasellar region, cerebellopontine angle; however, brain parenchyma origin is rare. We report clinicopathological features of these rare lesions.

METHOD AND MATERIAL

This is a retrospective study of epidermoid cyst of the brain diagnosed between 01 January 2014 and 31 December 2020.

RESULTS

The four patients had mean age of 30,8 years (range: 3-63), one male and 3 females. All four patients presented with headache and one associated with seizures. Radiological images showed two posterior fossa; each occipital and temporal locations. All tumours were successfully removed and histopathological assessment confirmed epidermoid cysts. All patients showed clinical improvement and were discharged home.

CONCLUSION

Epidermoid cysts of the brain are rare and still remain a preoperative clinico-radiological conundrum as they may be indistinguishable from other intracranial tumours. Therefore, collaboration with histopathologists is advised in the management of these cases.

Spectrum of intracranial and spinal epidermoids including unusual locations and imaging findings: A pictorial review

Intracranial and spinal epidermoids are benign slow-growing congenital lesions. They are predominantly intradural, extra-axial in location, with intra-axial locations (intra-parenchymal and spinal intramedullary) being rare. The most common locations of intradural epidermoids are cerebellopontine angle cistern followed by supra- and para-sellar regions, and fourth ventricle. Less common locations include inter-hemispheric fissure, sylvian fissure, lateral ventricle, intracerebral, velum interpositum cistern, superior cerebellar cistern and pineal gland. They can also be extradural, usually arising in the diploic space of the calvaria, though they are less common. Magnetic resonance imaging is the primary modality for diagnosis and knowing the extent of the lesion. In this pictorial review, we intend to illustrate their classical and unusual locations, atypical imaging findings including calcifications, rare complications like haemorrhage or spontaneous rupture.

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.

Strategies for intraoperative management of the trigeminal nerve and long-term follow-up outcomes in patients with trigeminal neuralgia secondary to an intracranial epidermoid cyst

Background

Epidermoid cysts (ECs) are one of the most common causes of secondary trigeminal neuralgia (TGN). However, most previous studies have primarily focused on whether complete tumor resection was achieved, and few studies have discussed the primary goal of pain relief.

Objective

The present study provides intraoperative strategies for trigeminal nerve (TN) management in patients with TGN secondary to an EC and observed long-term follow-up outcomes.

Methods

A total of 69 patients with TGN secondary to an EC at our hospitals were included (January 2011–June 2021). The same surgical team performed all surgeries using a retrosigmoid approach. After EC removal, different methods for TN management were used, including microvascular decompression (MVD), sharp capsulectomy, nerve combing and embedded cholesterol crystal excision. The epidemiological, clinical, and surgical data were extracted.

Results

The total EC removal rate was 92.8% (64/69). All patients achieved initial pain relief postoperatively, and 12 patients (17.4%) experienced varying degrees of hemifacial hypesthesia, which was relieved within 3–6 months. Three patients (4.3%) reported partial pain recurrence within a median follow-up period of 5.5 (0.5–10.5) years, which was relieved completely after low-dose carbamazepine administration.

Conclusion

The primary goal of surgical tumor removal for patients with TGN secondary to an EC is relief of the main symptom of tormenting pain. The selection of an appropriate strategy for TN, including MVD, sharp capsulectomy, nerve combing or embedded cholesterol crystal excision, should depend on the patient's situation.

How I do it: cerebellopontine angle epidermoid cyst removal with endoscopic assistance

BACKGROUND

Epidermoid cyst in the cerebellopontine angle (CPA) can involve numerous critical structures. Endoscopic assistance following microscopic removal via a retrosigmoid approach can expand the surgical corridor, allowing for more complete resection.

METHOD

We describe in a stepwise fashion the surgical steps for the microscopic removal of an epidermoid cyst of the CPA with endoscopic assistance.

CONCLUSION

Endoscopically assisted microscopic removal for CPA epidermoid cysts provides wide access to the CPA and its adjacent structures and shows to be an effective option in selected cases.

Cerebellopontine Angle Epidermoids: Comparative Results of Microscopic and Endoscopic Excision Using the Retromastoid Approach”

Background Densely packed neurovascular structures, often times inseparable capsular adhesions and sometimes a multicompartmental tumor extension, make surgical excision of cerebellopontine angle epidermoids (CPEs) a challenging task. A simultaneous or an exclusive endoscopic visualization has added a new dimension to the classical microscopic approaches to these tumors recently.

Methods Eighty-six patients (age: 31.6 ± 11.7 years, M:F = 1:1) were included. Nineteen patients (22.1%) had a multicompartmental tumor. Tumor extension was classified into five subtypes. Sixty-two patients underwent a pure microscopic approach (72%) out of which 10 patients (16%) underwent an endoscope-assisted surgery (11.6%) and 24 patients (28%) underwent an endoscope-controlled excision. Surgical outcomes were retrospectively analyzed.

Results Headache (53.4%), hearing loss (46.5%), and trigeminal neuralgia (41.8%) were the leading symptoms. Interestingly, 21% of the patients had at least one preexisting cranial nerve deficit. Endoscopic assistance helped in removing an unseen tumor lobule in 3 of 10 patients (30%). Pure endoscopic approach significantly reduced the hospital stay from 9.2 to 7.3 days (p = 0.012), and had a statistically insignificant yet a clearly noticeable lesser incidence of subtotal tumor excision (0 vs. 10%, p = 0.18) with comparable cranial nerve deficits but with a higher postoperative cerebrospinal fluid (CSF) leak rate (29% vs. 4.8%, p = 0.004).

Conclusion Endoscope assistance in CPE surgery is a useful addition to conventional microscopic retromastoid approach. Pure endoscopic excision in CPE is feasible, associated with a lesser duration of hospital stay, better extent of excision in selected cases, and it has a comparable cranial nerve morbidity profile albeit with a higher rate of CSF leak.

Long-term surgical oncological and functional outcome of large spetroclival and cerebellopontine angle epidermoid cysts: a multicenter study

Cranial nerve (CN) disorders are the foremost symptoms in cerebellopontine angle (CPA) and petroclival area (PCA) epidermoid cysts (EC).The aim of this work was to  assess the long-term surgical results on CN function and tumor control in these patients EC. We performed a retrospective cohort study about 56 consecutive patients operated on for a CPA or PCA EC between January 2001 and July 2019 in six participating French cranial base referral centers. Sixteen patients (29%) presented a PCA EC and 40 a CPA EC (71%). The median clinical and radiological follow-up was 46 months (range 0-409). Preoperative CN disorders were present in 84% of patients (n = 47), 72% of them experienced CN deficits improvement at the last follow-up consultation (n = 34): 60% of cochlear and vestibular deficits (n = 9/15 in both groups), 67% of trigeminal neuralgia (n = 10/15), 53% of trigeminal hypoesthesia (n = 8/15), 44% of lower cranial nerve disorders (n = 4/9), 38% of facial nerve deficits (n = 5/8) and 43% of oculomotor deficits (n = 3/7) improved or were cured after surgery. New postoperative CN deficits occurred in 48% of patients (n = 27). Most of them resolved at the last follow-up, except for cochlear deficits which improved in only 14% of cases (n = 1/7). Twenty-six patients (46%) showed evidence of tumor progression after a median duration of 63 months (range 7-210). The extent of resection, tumor location, and tumor size was not associated with the occurrence of new postoperative CN deficit or tumor progression. A functional nerve-sparing resection of posterior fossa EC is an effective strategy to optimize the results on preexisting CN deficits and reduce the risk of permanent de novo deficits.

Dysfunctions and anatomical relationships of cranial nerves in epidermoids of the cerebellopontine angle

OBJECTIVE

To evaluate the correlation of neurological symptoms with anatomical relationships of cranial nerves, lesions and vessels in patients with epidermoids of the cerebellopontine angle.

MATERIAL AND METHODS

We analyzed neurological symptoms, magnetic resonance data, intraoperative findings and postoperative functional outcomes in 25 patients (14 females and 11 males aged 22-77 years) with epidermoids of the cerebellopontine angle.

RESULTS

Cranial nerve dysfunctions were noted in 15 patients. Involvement of cochlear (n=9) and trigeminal (9 cases including 4 ones with sensory impairment and 5 patients with neuralgia) nerves was the most common. There were 10 patients with ataxia, hemiparesis and seizures without cranial nerve dysfunction. In 15 patients, epidermoids spread to supratentorial space and contralateral cerebellopontine angle. Lesion-induced brainstem compression was found in 22 cases. Cranial nerves and cerebellar arteries were partially or completely enclosed by lesion in all cases. Severe compression and dislocation of the nerve root entry/exit zone were found in all cases. One patient with trigeminal neuralgia had vascular compression of trigeminal nerve caused by superior cerebellar artery. Total resection was achieved in 16 patients. Small capsule remnants were left on vessels, nerves or brainstem in 9 patients. Postoperative complete or partial restoration of cranial nerve functions was noted in 11 cases. Deterioration of preoperative neurological deficit in 4 patients and postoperative neurological symptoms de novo in 3 patients were temporary.

CONCLUSION

Cranial nerve dysfunctions are caused by compression of the nerve root entry/exit zones by epidermoids of the cerebellopontine angle. Surgical intervention is effective in alleviating symptoms of cranial neuropathy and brainstem compression. Vascular decompression should be performed in patients with trigeminal neuralgia.

A Pilot With Electrical Pain in the Face

An intracranial epidermoid cyst is an unusual but treatable cause of trigeminal neuralgia.

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.

Fully Endoscopic Resection of an Epidermoid Cyst of the Cerebellopontine Angle: Bilateral Resection via a Unilateral Approach

BACKGROUND AND IMPORTANCE

Epidermoid cysts are rare, benign intracranial neoplasms that typically arise at the cerebellopontine angle (CPA) and can be extensive lesions that intricately involve many critical neurovascular structures. We describe the case of a patient who presents with the classic picture of CPA epidermoid cyst and describe the value of the 4K endoscope for resection, which is illustrated in our accompanying surgical video.

CLINICAL PRESENTATION

The patient presents with headache, nausea, and vomiting accompanied by dizziness and balance issues. Radiographic imaging demonstrated a large lesion highly consistent with epidermoid cyst which involved the left CPA, encircled the basilar artery, and extended to the opposite side. Surgery was planned with a small left-sided retrosigmoid craniotomy with use of a 2-dimensional 4K endoscope to aid in resection, particularly of the contralateral side. This approach was successful with gross total resection apparent at 14-mo follow-up.

CONCLUSION

We describe the use of a fully endoscopic technique from a unilateral approach for resection of a lesion that extended in the CPA bilaterally. Additionally, we highlight the relevant neuroanatomical and neurovascular structures in this highly critical intracranial region which is well-visualized through endoscopy in the associated surgical video.

Surgical management of cerebellopontine angle epidermoid cysts: an institutional experience of 10 years

BACKGROUND

Cerebellopontine angle (CPA) epidermoids, although of benign nature, are of considerable neurosurgical interest because of their close proximity and adherence to the cranial nerves and brain stem. In this paper, we describe our experience and attempt to correlate the final outcomes with the extent of surgical removal. The main objectives were to study various modes of surgical management of CPA epidermoids with regard to removal and preservation of the cranial nerves and also to evaluate the role of endoscopic assisted microsurgical excision thereby minimizing recurrences. This case series is one of the largest series reported so far worldwide.

MATERIALS AND METHODS

From 2006 to 2016, 139 patients with CPA epidermoids were operated at Grant Medical College and J. J. Hospital, Mumbai. All patients underwent detailed magnetic resonance imaging (MRI) of brain. Lesions were classified according Rogelio Revuelta-Gutiérrez et al. with respect to their anatomic extent: grade I- within the boundaries of the CPA, grade II- extension to the suprasellar and perimesencephalic cisterns, and grade III-parasellar and temporomesial region involvement. Retrosigmoidal and sub temporal approaches were taken to excise the lesions. Endoscopic assisted microsurgical excision was done in cases with extensions beyond the CPA. Patient follow-up was based on outpatient repeated brain MRI studies.

RESULTS

The mean duration of symptoms before surgery was 42 months (range, 2 months to 6 years). The mean follow-up period was 27 months (range, 2-60 months). The main presenting sympt om was headache in 69% (96/139) of the cases and trigeminal neuralgia in 30% cases was the second most common cause of consultation. Seventy-five percent of patients had some degree of cranial nerve (CN) involvement. Retrosigmoid approach was taken in 92% patients and 7 patients with supratentorial extension were operated by combined retrosigmoidal and subtemporal approach. Endoscopic assisted microsurgical excision was done in 40% cases. Use of angled views by an endoscope helped to excise residual tumor in 47 (83%) patients. Complete excision was achieved in 67% of cases. In 33% patients, small capsular remnants could not be removed completely because of their adherence to vessels, brainstem and cranial nerves. Compared with their preoperative clinical status, 74% improved and 20% had persistent cranial nerve deficits in the first year of follow up.

CONCLUSIONS

Epidermoid cysts are challenging entities in current neurosurgery practice due to tumor adhesions to neurovascular structures. Meticulous surgical technique with the aid of neurophysiological monitoring is crucial to achieve safe and effective total or subtotal removal of these lesions. A conservative approach is indicated for patients in whom the fragments of capsule is adhered closely to blood vessels, nerves, or the brainstem, in order to avoid risk of serious neurological deficits related to an inadvertent damage of these structures. Use of angled views by endoscope at the conclusion of the surgery may assure the surgeon of total removal of the tumor.

Giant Epidermoid Cyst of Posterior Fossa-Our Experience and Literature Review

INTRODUCTION

Intracranial epidermoid cysts are the most frequent congenital intracranial lesion. They rare and benign tumors that can present in different clinical situations depending on location and extension of the disease. Diagnosis is obtained with radiological imaging with RM and non-enhanced TC as elective investigating methods. Elective treatment is surgery, based on total/subtotal excision sparring healthy neurovascular structures, considering the benign nature of this lesion.

CASE REPORT

In this study we present the case of a 79-year-old woman affected by recidivist epidermal cyst of the posterior fossa. Clinical presentation was characterized by positional subjective vertigo, intense headache localized in the right part of the head increased by Valsalva maneuver and retroarticular subcutaneous swelling. Radiological investigation found a giant epidemoid cyst of the posterior fossa (8,4 x 4,8 x 5,8 cm), treated with surgery. In the postoperative, the patient was fine and no neurological deficit has been encounterd.

REVIEW

In this study, we present a review of the literature regarding giant epidermoid cysts of posterior fossa. Only 11 cases were reported before ours, which actually is one of the largest ever described.

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.

Radiosurgery for Epidermoid Tumors: Dramatic Pain Relief from Trigeminal Neuralgia

Purpose 

The purpose of this study is to discuss the long-term effects of radiosurgery for epidermoid tumors, including the symptoms of trigeminal neuralgia and/or facial spasm, which we have originally reported before.

Background

Intracranial epidermoids are slow-growing tumors that can become symptomatic once they develop into large tumors. The mainstay of the treatment is surgery. However, eradicating the whole tumor is often difficult and some tumors may recur. In addition to their mass effects on the brain, these tumors are often associated with hyperactive nerve dysfunction syndromes such as trigeminal neuralgia, glossopharyngeal neuralgia, and/or facial spasm.

Cases and methods 

We report 13 cases of epidermoid tumors, 12 of which were located in the cerebellopontine angle (CPA), which were treated using 14 radiosurgery procedures. The inclusion criteria for radiosurgery were the presence of well-localized small tumors and/or severe associated neuralgia or facial spasms. The mean target volume ranged from 0.17 to 9.5 cm³ with a mean of 2.85 cm³. The lesions were treated with a mean maximum and a marginal dose of 28.2 Gy and 14.2 Gy, respectively.

Results

Among the 14 gamma knife procedures that were performed in 13 patients, dose planning to ensure total and partial coverage for relief from hyperactive cranial nerve dysfunction (HCND) was performed. Six cases were totally and another eight were partially covered at the dose planning. The irradiated tumors showed a minor decrease or no remarkable changes during a mean follow-up period of 86.1 months. Tumor progression requiring a second surgery was seen in two cases. The trigeminal neuralgias either improved or disappeared soon after the procedure, enabling the discontinuation of the medication.

Conclusion 

Radiosurgery led to a dramatic improvement in HCND. In fact, the immediate cure of neuralgia after the radiosurgery was observed in several cases, even after partial coverage with radiosurgery. The interface between the tumor and the nerve was the main target. The definite mechanisms for this favorable outcome have not been verified yet, but the functional modulation by the radiosurgery could be one. Electrophysiological alteration at the interface between the tumor and nerve has been considered. When the tumors were totally covered with radiosurgery, persistent tumor control was expected. Sufficient tumor control is possible if the tumor can be covered entirely with radiosurgery. Functional modulation of trigeminal neuralgia and facial spasms can also be attained even by partial dose planning for the nerve-tumor interface.

Microsurgical Resection of the Epidermoid Tumor in the Cerebellopontine Angle

In this video, we demonstrate epidermoid tumor microsurgical resection of the cerebellopontine angle (CPA) performed by the senior author (K.I.A.). Epidermoid tumors arise from ectoderm trapped within/displaced into the central nervous system. They show predilection for CPA Angle (up to 40%), 4th ventricle, suprasellar region, and spinal cord. 1 They are the 3rd most common CPA tumor, comprising approximately 7% of CPA pathology. CPA lesions can produce 5th and 7-12th cranial nerve neuropathies. 2 3 4 Recurrent episodes of aseptic meningitis caused by cyst content rupture may occur. Symptoms include fever, meningeal irritation, and hydrocephalus. A 26-year-old female presented with headaches. Head magnetic resonance imaging (MRI) revealed right CPA tumor with brain stem compression ( Fig. 1 , A - C ). There was evidence of restricted diffusion in diffusion-weighted imaging, typical of epidermoid tumor. Surgery was performed in prone position with head turned 25 degrees to the ipsilateral side using retrosigmoid craniotomy. 5 Tumor was ventral to the 7th and 8th cranial nerve complexes, between the 5th nerve as well as toward the brainstem. The surgical plan was gross total resection with tumor capsule resection to prevent recurrence. 6 (Small residuals can be left behind when capsule is adherent to critical structures.) Tumor was adherent to brain stem perforators which were preserved using meticulous dissection. Cranial nerves and vascular structures were also left intact. We irrigated with antibiotic saline and used perioperative treatment to prevent aseptic meningitis. The pathohistological diagnosis revealed epidermoid tumor cyst. Postoperative MRI revealed complete resection ( Fig. 1 , D - F ). The patient recovered fully and was neurologically intact. The link to the video can be found at: https://youtu.be/LyWl-KZUSGY .

Microsurgical Treatment of Epidermoids. Case Report and Literature Review

The aim of the research: study the features of surgical treatment of epidermoids.

Materials and methods. We present a literature review and the clinical case of surgical treatment of a patient with epidermoid. We have searched medical databases: Medline, Russian Science Citation Index, EMedicine, United Medical Knowledge Base. We considered the features of the clinic, diagnosis, and surgical intervention. The article presents a clinical example of successful surgical treatment of a patient with an epidermoid cyst of the posterior cranial fossa. The result of the literature review was the writing of a clinical lecture; the current state of the issue of etiopathogenesis, diagnosis and management of patients with epidermoids was studied.

Results. The authors found that total microsurgical removal is the method of choice, and the operative technique should be aimed at preventing postoperative aseptic meningitis. Although it was not possible to establish the cause of the development of aseptic meningitis, the authors assume that the mechanism of its formation lies in the self-breaking of the capsule of the epidermoid cyst, probability of which was confirmed by a number of studies. Further study of this pathology is a promising direction in neurosurgery.

Conclusion. Difficulties in the diagnosis and choice of surgical tactics point at the need for detailed preoperative planning of surgical intervention, performing a precise total removal of a lesion with compliance with preventive measures for aseptic meningitis to improve clinical results and reduce the incidence of perioperative complications.

Primary Petrous Apex Epidermoids With Skull Base Erosion

OBJECTIVE

To describe the clinical course and treatment outcomes for patients with petrous apex epidermoid with skull base erosion.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary-care academic center.

PATIENTS

Patients surgically managed for petrous apex epidermoids at a single-tertiary care institution from 2001 to 2017.

INTERVENTIONS

Surgical management of primary petrous apex epidermoids.

MAIN OUTCOME MEASURES

The presenting symptoms, imaging, pre- and postoperative clinical course, and complications were reviewed.

RESULTS

Seven patients were identified. The most common presenting symptoms included: sudden sensorineural hearing loss (n = 3), headaches (n = 1), vertigo (n = 2), and facial paralysis/paresis (n = 2). An epidermoid was discovered in two patients as an incidental finding after a head trauma and one patient after admission for altered mental status and meningitis. Two patients presented with complete facial paralysis (House-Brackmann 6/6). Preoperative normal hearing (pure-tone average < 25 db) was identified in three patients and serviceable hearing (pure-tone average 25-60 dB) in one patient. Three patients with nonserviceable hearing underwent a transcochlear or transotic approach. The remaining four patients underwent an attempted hearing preservation approach. Postoperatively, one patient developed delayed facial paralysis, improving within 3 months. Hearing was preserved in three patients. Two patients developed recurrence of disease within 4 and 7 years respectively.

CONCLUSIONS

Surgical management of aggressive petrous apex epidermoid is effective to preserve facial function and prevent recurrence. In our series different surgical approaches were used with variable outcomes.

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.

Intracranial epidermoid cyst with proliferative folliculosebaceous epithelium: Report of a rare case and discussion on pathogenesis

Intracranial epidermoid cysts are rarely known to increase in size over a brief period. While malignant transformations of epidermoid cyst have been previously described, no reports to date have described rapid proliferation accompanied by mature hair follicles and sebaceous glands without malignant transformations. The present case involved a 71-year-old man who visited a local physician with disturbance of equilibrium. A mass lesion was detected at the left cerebellopontine angle and was subsequently removed. Histopathological diagnosis of this lesion was as an epidermoid cyst. Seventeen years after this initial surgery, worsened left hypoacusis, disorientation, eating disorder and gait disturbance appeared, and the patient visited the physician again. Local recurrence of the lesion was observed, and the patient was referred to our hospital for its removal. Intraoperative findings revealed a pearly white tumor, histopathologically diagnosed as an epidermoid cyst. Three years later, local recurrence was observed, and the cyst was again removed. Intraoperative findings revealed a partially pearly white tumor similar to the tumor observed during the second surgery, but the majority of the tumor was non-shiny, ochre-colored and suckable. Histopathological diagnosis was an epidermoid cyst with an epidermis-like structure. Postoperative activities of daily living were independent thereafter, but from March of the following year, he began to experience increasing difficulty in walking and subsequently visited our hospital again. Tumor recurrence was observed and was removed again in November of the same year. Intraoperative findings revealed a tumor that was primarily ochre-colored, non-shiny, brittle and suckable. The histopathological diagnosis was folliculosebaceous epithelial proliferative lesion accompanied by an epidermis-like epithelium and a differentiation into hair follicles and sebaceous gland,s and the tumor was determined to be an epidermoid cyst with proliferative folliculosebaceous epithelium.

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.

Combined microsurgical and endoscopic technique for removal of extensive intracranial epidermoids

Background

Intracranial epidermoid tumors are challenging lesions because they grow along the subarachnoid spaces around delicate neurovascular structures and often extend from one compartment to another. The purpose of this study was to determine the usefulness of endoscopic assistance in the microsurgical resection of these lesions, in which total resection is therapy of choice.

Methods

A total of 48 cases of intracranial epidermoids were treated by combined microscopic and endoscopic techniques. Initially, the tumor was removed under the microscope and after ensuring maximum excision, the endoscope was used to find out and excise any residual tumor.

Results

Out of these 48 cases complete excision was achieved in 44 cases and subtotal excision in four patients. Postoperative complications were seen in 17 patients, but none of the complications was attributed to the use of endoscope. Overall use of endoscope benefited 79% of cases.

Conclusion

We recommend combined microsurgical and endoscopic approach to achieve complete/maximum resection of extensive intracranial epidermoid tumors.

Gamma knife radiosurgery for cerebellopontine angle epidermoid tumors

Background:

Intracranial epidermoid tumors are commonly found in the cerebellopontine angle where they usually present with either trigeminal neuralgia or hemifacial spasm. Radiosurgery for these tumors has rarely been reported. The purpose of this study is to assess the safety and clinical outcome of the treatment of cerebellopontine epidermoid tumors with gamma knife radiosurgery.

Methods:

This is a retrospective study involving 12 patients harboring cerebellopontine angle epidermoid tumors who underwent 15 sessions of gamma knife radiosurgery. Trigeminal pain was present in 8 patients and hemifacial spasm in 3 patients. All cases with trigeminal pain were receiving medication and still uncontrolled. One patient with hemifacial spasm was medically controlled before gamma knife and the other two were not. Two patients had undergone surgical resection prior to gamma knife treatment. The median prescription dose was 11 Gy (10–11 Gy). The tumor volumes ranged from 3.7 to 23.9 cc (median 10.5 cc).

Results:

The median radiological follow up was 2 years (1–5 years). All tumors were controlled and one tumor shrank. The median clinical follow-up was 5 years. The trigeminal pain improved or disappeared in 5 patients, and of these, 4 cases stopped their medication and one decreased it. The hemifacial spasm resolved in 2 patients who were able to stop their medication. Facial palsy developed in 1 patient and improved with conservative treatment. Transient diplopia was also reported in 2 cases.

Conclusion:

Gamma knife radiosurgery provides good clinical control for cerebellopontine angle epidermoid tumors.

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.