Epidermoid and dermoid cysts. Clinical evaluation and late surgical results

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.

Tubular retractor-assisted minimally invasive parafascicular approach for dermoid cyst

Intracranial dermoid cysts are benign lesions that may be diagnosed incidentally or present symptomatically due to mass effect-focal neurological deficits, seizures and/or hydrocephalus-or chemical meningitis secondary to spontaneous rupture. The use of tubular retractors in minimally invasive parafascicular surgery (tsMIPS) has been described extensively as a technique to preserve neurological function whilst safely maximizing the extent of resection. The authors present the first use of the tsMIPS approach for removal of a dermoid cyst in a 68-year-old female who presented with abulia and seizures due to a large Sylvian fissure dermoid cyst. This approach minimized trauma to surrounding cortical-subcortical structures, as supported by connectome analyses, without sacrificing visualization of the operative field. Additionally, itavoided manipulation of the lenticulostriate arteries attached to the walls of the dermoid cyst. The use of an endoscope ensured complete drainage of the cyst components and therefore the effectiveness of the procedure.

Ultrasound as a standalone tool for the management of pediatric calvarial dermoid cysts

PURPOSE

Calvarial dermoid and epidermoid cysts are benign lesions common in pediatric neurosurgery. Diagnosis is primarily clinical, with frequent but inconsistent use of imaging. Dermoids have been shown to possess distinct sonographic features, but ultrasound (US) remains underutilized in their management. The purpose of this study is to investigate the independent reliability of US in managing pediatric calvarial dermoids and distinguishing them from other calvarial lesions.

METHODS

A retrospective review of consecutive patients ≤ 21 years of age with surgically resected calvarial masses between 2017-2024 was performed. Demographic, clinical, and imaging data were analyzed. Pearson chi-squared tests were used for comparison of categorical variables and a binomial linear model was generated controlling for age, lesion tenderness, growth, and suture location.

RESULTS

Fifty-nine patients with 61 lesions (31 in females; median age 13 months) were included. Dermoids were more common in younger patients (median age 12 months), along suture lines, and were less likely to present with tenderness (p < 0.001) or rapid growth (p = 0.003). Ultrasound was used in 83% of cases and was the sole imaging modality in 33%. On multivariate analysis, suture location was a significant positive predictor of a dermoid diagnosis (OR = 8.08, 95% CI = 1.67-44.18), while rapid growth was a significant negative predictor (OR = 0.08, 95% CI = 0.003-0.80).

CONCLUSION

Ultrasound presents a sensitive and reliable method for the evaluation of most pediatric calvarial lesions, especially dermoid cysts, and warrants being part of standard workup. With appropriate patient selection, US obviates the need for additional imaging in pediatric patients.

An infected intradural dermoid cyst associated with a complete dermal sinus of the posterior cranial fossa: A case report and literature review

Posterior fossa dermoid cysts are uncommon benign congenital abnormalities. Meningitis is seen as a primary symptom in these situations, more rarely we can find cerebral abscesses. In this case, we describe a 4-year-old Syrian boy who presented with headaches and frequent vomiting as his major complaints. No indication of cerebellar injury was present. He had signs of hydrocephalus like grade III bilateral papilledema but did not develop meningitis. The patient was diagnosed with a complete dermal sinus of the posterior cranial fossa in combination with an infected intradural dermoid cyst and a secondary abscess formation. In Conclusion, the preoperative diagnosis of infected dermoid cysts and dermal sinus tracts lacking signs of infection or meningitis poses challenges, particularly when accompanied by hydrocephalus that can resemble cerebellar tumors. Thorough preoperative assessment is vital for these complex cases.

Postoperative Symptomatic Cerebral Vasospasm: Requiring Attention Following an Uneventful Resection of an Epidermoid Cyst - A Case Report and Literature Review

Cerebral vasospasm associated with epidermoid cyst can be caused by tumor content spillage, such as spontaneous rupture and postsurgical resection. Symptomatic cerebral vasospasm following the resection of an intracranial epidermoid cyst is a rare but serious complication that lacks a consensus on treatment. Case presentation: A 10-year-old girl underwent an uneventful complete resection of a left cerebellopontine angle epidermoid cyst. On the second postoperative day (POD 2), she exhibited reduced speech, confusion, and hyperventilation followed by hypocapnia. On POD 4, she developed right hemiparesis and dysphasia. Cerebral magnetic resonance imaging showed restricted diffusion areas in her left temporal and parietal lobes and the dorsal thalamus. Magnetic resonance angiograms confirmed narrowing of the proximal middle cerebral arteries, consistent with vasospasm. Conservative management, consisting of intravenous hydration and corticosteroid administration, proved effective in resolving her symptoms and radiologic vasospasm. On POD 8, the extensive restricted diffusion areas notably decreased in size. Her right hemiparesis was completely resolved, and her dysphasia gradually improved over time. At the 1-year follow-up, she exhibited moderate transcortical sensory dysphasia. To our knowledge, this study is the first to report on a pediatric case of symptomatic cerebral vasospasm following an epidermoid cyst resection. The combination of tumor content spillage and hyperventilation may contribute to the occurrence of cerebral vasospasm and subsequent ischemia. This complication should be acknowledged after a complete and uneventful resection.

Acute headache and seizures in psychiatric patient revealing atypical location of a ruptured dermoid cyst

Intracranial dermoid cysts are rare slow-growing cystic lesions. They are frequently extra-axial, intra-axial localization is very rare. These benign congenital ectodermal inclusions cysts have a rare risk of rupture. Ruptured dermoid cysts can manifest with headache, epilepsy seizure, cerebral infarction, meningitis, and hydrocephaly. Neuroimaging features are quite characteristic. We report a case of a 30-year-old male who presented to the emergency room with subacute-onset headaches. CT scan and MRI show a ruptured intracranial dermoid cyst.

Intracranial Dermoid in Patients With Fibrous Dysplasia

OBJECTIVES

Intracranial epidermoid cyst (EC) and craniofacial fibrous dysplasia (CFD) were histogenetically different rare congenital benign diseases. The coexistence of intracranial EC and CFD was extremely rare and had not been reported yet.

MATERIALS AND METHODS

We retrospectively reviewed the clinical and radiologic information of 3 patients diagnosed with concomitant EC and CFD at Beijing Tiantan Hospital from January 2003 to January 2021 and summarized their clinicopathological features, treatment modalities, and outcomes. In addition, we performed a systematic review of cases of the coexisting intracranial EC and other intracranial abnormalities to explore the potential connections.

RESULTS

There were 2 women and 1 man with the mean age of 31 years old. Satisfactory resection was fulfilled for all the 3 ECs. CFD, however, was managed with watchful waiting. During the mean follow-up time of 58 months, all the ECs showed no sign of recurrence, and all the CFD lesions remained stable. Two EC specimens underwent genetic study, showing no GNAS mutations and negative G s α protein expression. In the literature review of concomitant intracranial EC and other intracranial abnormalities, 23 studies were included. With 5 reported cases, the intracranial aneurysm was found to be the most common intracranial disease that coexisted with EC.

CONCLUSIONS

The coexistence of intracranial EC and CFD was extremely rare. However, no convincing mechanism and evidence underlying such coexistence had been found. To provide more profound understanding about these 2 diseases and improve diagnosis and treatment strategy, further research and verification should be considered.

An Atypical Case of Intracranial Dermoid Cyst in an Adult Female: A Case Report and Literature Review

Intracranial dermoid cysts are unusual cystic tumors that are often benign, develop slowly, and are present from birth. They are made up of mature squamous epithelium and may house ectodermal features such as glands (apocrine, eccrine, and sebaceous). Dermoid cysts may be asymptomatic and can be detected incidentally during brain imaging for unrelated causes. Dermoid cysts tend to grow gradually and may eventually exert pressure on the brain and surrounding areas. Unfortunately, they can seldom burst, resulting in an unfavorable prognosis for the patient depending on the size, location, and clinical presentation. Headache, convulsions, cerebral ischemia, and aseptic meningitis are the most frequent symptoms. Magnetic resonance imaging (MRI) and computed tomography (CT) of the brain aid in accurate diagnosis and therapy planning. In some cases, the treatment consists of surgical monitoring with regular surveillance imaging. In other cases, surgery is needed, depending on the symptoms and the location of the cyst in the brain.

Intracranial epidermoid cysts: benign entities with malignant behavior: experience with 36 cases

Intracranial epidermoid cysts are benign slow-growing ectodermal inclusions that account for less than 1% of all intracranial tumors. We retrospectively reviewed 36 such cases to evaluate the demographic characteristics, clinical manifestations, anatomical distribution, surgical management, and treatment outcome of these tumors. Additionally, we sought to identify the relationship between median or paramedian cistern tumor localization and clinical parameters, such as recurrence risk, hospitalization duration, and postoperative complication rates. The most frequently observed neurological symptoms were transient headaches (77.8%), dizziness (36.1%), CN VII palsy (19.4%), CN VIII hearing difficulty (19.4%) and cerebellar signs (19.4%). The most common surgical approaches included retrosigmoid (36.1%), subfrontal (19.4%) and telovelar (19.4%) approaches; gross total resection was feasible in 83.3% of cases. The postoperative complication rate was 38.9%. Tumors were more frequently found in the paramedian cisterns (47.2%), followed by the median line cisterns (41.6%). Multivariate analysis revealed that postoperative hydrocephalus and age < 40 years were prognostic factors for tumor recurrence. Median-like tumor location was a risk factor for the presence of symptomatic hydrocephalus both preoperatively and postoperatively, increasing the likelihood of protracted hospitalization (> 10 days). Despite their benign histopathological nature, these tumors have an important clinical resonance, with a high rate of postoperative complications and a degree of recurrence amplified by younger age and hydrocephalus.

Endoscopic Endonasal Surgery for Dermoid Cysts Arising From the Middle Cranial Fossa Floor: A Rare Case Series

OBJECTIVE

Dermoid cysts (DCs) are congenital, slowly growing, and may cause nervous system symptoms. Related literature is limited and mainly includes case reports. We report a case series of DCs originating from the middle cranial fossa floor (MCFF) and investigate their demographic information, clinical characteristics, imaging findings, surgical procedures, and prognostic outcomes.

METHODS

We reviewed the patients with DCs arising from the MCFF undergoing endoscopic endonasal surgery (EES) in our center between 2012 and 2022.

RESULTS

A total of 5 patients with DCs were enrolled (2 males and 3 females), with a mean age of 46.2 years at the onset. All DCs originated from the MCFF with 1 case involving the middle cranial fossa bone and another 1 case affecting the dura mater. One (20.0%) patient had neurological involvement. After admission, all patients received EES with a total resection rate of 100.0% (5 of 5). After a median follow-up of 73.2 months, all patients achieved complete clinical and radiological improvements. No surgical-related complications or relapses were observed during the long-term follow-up.

CONCLUSION

Endoscopic endonasal surgery is considered a safe and effective approach for the treatment of DCs in the MCFF. A larger sample size and longer follow-up time are needed.

Concurrent occurrence of squamous cell carcinoma in a cerebellopontine angle epidermoid cyst: A case report and review of the literature

Background:

Intracranial epidermoid cysts are rare benign lesions. Cases of malignant transformation (MT) into squamous cell carcinoma (SCC) have rarely been reported. We present a case of concurrent occurrence of SCC diagnosed during primary resection of epidermoid cyst (EC) and a relevant literature review.

Case Description:

A 61-year-old patient was diagnosed with a right cerebellopontine angle (CPA) lesion after suffering from vertigo, diplopia, and right trigeminal (V2) hypoesthesia. Brain magnetic resonance imaging (MRI) showed a lesion consistent with an EC, demonstrating restricted diffusion with rim-enhancing area on the medial side of the cyst. During resection, two different tissue pathologies were observed, one consistent with an epidermoid (which was completely removed) and an additional firm tissue adherent to the brainstem, preventing gross total resection. Pathological evaluation confirmed two separate histologies – epidermoid and SCC. The patient never recurred to complete the recommended radiotherapy. Eleven months following surgical resection, a follow-up MRI showed local massive recurrence of the enhancing lesion. He was, further, treated with radiotherapy and is currently being followed up.

Conclusion:

MT of an intracranial EC to SCC is rare and associated with poor prognosis. SCC may be found incidentally at time of primary resection or arise from a remnant of previously operated EC. Thus, aggressive complete resection should be intended, and separate pathological specimens should be sent from any abnormal region of the tumor.

Malignant transformation of a cerebral dermoid cyst into a squamous cell carcinoma with malignant intraperitoneal spreading along a ventriculoperitoneal shunt: illustrative case

BACKGROUND

Malignant progression of intracranial dermoid cysts into squamous cell carcinoma is extremely rare with only three reports published so far. Intracranial dermoid cysts are uncommon benign tumors lined by stratified squamous epithelium of embryonic ectodermal origin.

OBSERVATIONS

Here, the authors present the case of a 64-year-old female with a recurrent temporal dermoid cyst. After surgery for the recurrent dermoid cyst, once in the early 1990s and another 16 years later, the patient presented with headache and nausea due to hydrocephalus. After implantation of a ventriculoperitoneal shunt, she deteriorated rapidly and died only 60 days after admission. Autopsy revealed malignant transformation of the epithelial lining of the dermoid cyst into a squamous cell carcinoma resulting in neoplastic meningiosis and intraperitoneal tumor spread along a previously implanted ventriculoperitoneal shunt.

LESSONS

Malignant transformation should be considered in patients with dermoid cyst who show new leptomeningeal contrast enhancement. In the case of hydrocephalus, alternatives to peritoneal shunting should be considered.

Intradural dermoid cyst with complete dermal sinus of the posterior fossa: Contribution of 3D imaging with histopathological correlation

A 5-year-old girl who presented with two episodes of meningitis, had a patchy red area and a small skin dimple in the midline of the occiput on physical examination. Imaging revealed a well-demarcated oval intradural lesion of the posterior fossa with restricted diffusion and peripheral enhancement, raising the possibility of an abscess. The 3D volume rendering of CT images of the inner surface of bone showed chronic bone remodeling and a tiny bone defect of the outer table. This detailed anatomical evaluation has an added value to MRI characteristics to orient for a preoperative diagnosis of an intradural dermoid cyst with a dermal sinus, that was confirmed by histopathological analysis after surgical excision.

An Unusual Presentation of Spontaneous Rupture of Dermoid Cyst

Intracranial dermoid cysts are exceptionally rare tumors. Interestingly, this condition has a low mortality rate but a high morbidity rate due to its numerous complications. We report a case of a 62-year-old man who presented with a headache and was found to have a ruptured dermoid cyst, complicated with the dissemination of lipid droplets within the subarachnoid space.

A Rare Third Ventricular Dermoid Cyst in an Adult With Imaging Characteristics Consistent With a Colloid Cyst

A 64-year-old male presented with spontaneous intracerebral hemorrhage and obstructive hydrocephalus without evidence of a third ventricular mass in 2019. The patient was lost to follow-up and re-admitted one year later for hydrocephalus secondary to a third ventricular mass. Imaging characteristics were consistent with a colloid cyst, which was the presumptive diagnosis. A transcallosal transchoroidal approach was utilized for cyst resection. The cyst wall was carefully incised, releasing flakey, partially solid contents which were grossly inconsistent with a colloid cyst. Due to the concern of iatrogenic cyst rupture in the setting of unknown diagnosis, the patient was placed on steroids post-operatively. Surgical specimens sent at the time of surgery were consistent with dermoid cyst. We present the first reported case of a third ventricular dermoid cyst in an adult initially misdiagnosed as a colloid cyst based on imaging characteristics.

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.

Infratentorial abscess secondary to dermal sinus associated with dermoid cyst in children: Review of the literature and report of a rare case

Background:

Dermal sinus is usually located at either end of neural tube but most commonly lumbosacral. When occipital, it extends caudally and is mostly localized in the midline position or in the cavity of the fourth ventricle. It could communicate with the skin through a fistula with potential risk of deeper abscesses. Posterior fossa abscess secondary to dermal sinus associated with intracranial dermal cyst is an uncommon pathology.

Case Description:

A 24-month-old girl was admitted to our institution with a cutaneous fistula in the midline of the occipital region. Brain imaging showed an infratentorial intradiploic cyst with peripheral enhancement to contrast medium. The mass showed hyperintensity on T1-weighted sequences, with the lower signal on T2-weighted images. A suboccipital craniotomy was performed with evacuation of the abscess and excision of the capsule. Contextually a 3 cm whitish and encapsulated cystic mass with hair component was extracted. Histology confirmed the diagnosis of abscess associated with dermal cyst and dermal sinus. The patient condition improved and 15 days after excision, was discharged. The postoperative MRI showed total removal of the lesion. A 36-month follow-up highlighted no evidence of recurrence.

Conclusion:

Posterior fossa dermoid cyst should be considered in all children with a cutaneous fistula. Early neurosurgical treatment of these benign tumors should be performed to prevent the development of severe intracranial infection. Best results are associated with early diagnosis and complete removal of the abscess. The present work further reviews the few similar cases that have been reported in the literature confirming the need for future research.

Spinal Dermoid and Epidermoid Cyst: An Institutional Experience and Clinical Insight into the Neural Tube Closure Models

Objectives  The spinal dermoid and epidermoid cysts (SDECs) are rare entities comprising less than 1% of pediatric intraspinal tumors. The present study aims to extrapolate the clinicoradiological data, in order to identify the most plausible neural tube closure model in human and provide a retrospective representation from our clinical experience.

Materials and Methods  We collected the details of all histologically proven, newly diagnosed primary SDECs who underwent excision over the past 20 years. Secondary or recurrent lesions and other spinal cord tumors were excluded. Surgical and follow-up details of these patients as well as those with associated spinal dysraphism were reviewed. Clinical and radiological follow-up revealed the recurrence in these inborn spinal cord disorders.

Results  A total of 73 patients were included retrospectively, having a mean age of 22.4 ± 13.3 years, and 41 (56.2%) cases fell in the first two decades of life. Twenty-four (32.9%) dermoid and 49 (67.1%) epidermoid cysts comprised the study population and 20 of them had associated spinal dysraphism. The distribution of SDECs was the most common in lumbosacral region ( n = 30) which was 10 times more common than in the sacral region ( n = 3). Bladder dysfunction 50 (68.5%) and pain 48 (65.7%) were the most common presenting complaints. During follow-up visits, 40/48 (83.3%) cases showed sensory improvement while 11/16 (68.7%) regained normal bowel function. There was no surgical mortality with recurrence seen in eight till the last follow-up.

Conclusions  The protracted clinical course of the spinal inclusion cysts mandates a long-term follow-up. The results of our study support the multisite closure model and attempt to provide a retrospective reflection of neural tube closure model in humans by using SDECs as the surrogate marker of neural tube closure defect.

Intradiploic epidermoid cyst in a dog

CASE DESCRIPTION

A 10-year-old 7-kg (15.4-lb) neutered male Shih Tzu was referred for evaluation because of a sudden onset of dullness and intermittent vomiting of 1 to 2 weeks' duration. Two days prior to evaluation, clinical signs had worsened and 1 seizure was reported.

CLINICAL FINDINGS

A 3.5 × 2.5-cm soft, dome-shaped mass of the right occipital region of the head was noted on physical examination. Radiography and CT confirmed the presence of the mass and indicated its intra- and extracranial expansion. The MRI images showed compression of the cerebellum by the mass, with distinct margins of hypointensity on both T1- and T2-weighted images.

TREATMENT AND OUTCOME

Surgery was performed, and the mass was completely excised. The dog had mild ataxia, hypermetria, and head tremors after surgery. Histologic examination of the mass yielded a diagnosis of intradiploic epidermoid cyst. On examination 3 weeks after surgery, the previous neurologic signs had resolved. On examination 25 months after surgery, the dog remained free of clinical signs.

CLINICAL RELEVANCE

The present report described the clinical signs, diagnostic imaging results, and successful surgical removal of an intradiploic epidermoid cyst in a dog. Long-term prognosis may be good with complete removal of intradiploic epidermoid cysts in dogs.

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.

Intraspinal epidermoid and dermoid cysts-tumor resection with multimodal intraoperative neurophysiological monitoring and long-term outcome

BACKGROUND

Intraspinal epidermoid/dermoid cysts are very rare, benign tumors arising from pathological displacement of epidermal cells into the spinal canal. Literature data about the long-term outcome after microsurgical resection with multimodal intraoperative neurophysiological monitoring (IONM) are lacking. We analyzed one of the largest case series with special regard to intraoperative characteristics and long-term outcome after IONM-aided surgery.

METHOD

All 12 patients (m:f = 1.4:1) who underwent microsurgical tumor resection with multimodal IONM for intraspinal epidermoid/dermoid tumors between 1998 and 2019 in our university hospital were included. We retrospectively investigated the patients' characteristics, imaging/surgical parameters, and postoperative long-term outcomes.

RESULTS

Symptomatic tumor manifestation was seen during adulthood in 4 patients (median age 33.0 years) and during childhood in 8 patients (median age 4.3 years). Spinal dysraphism was the most often comorbidity (75%). The most frequent symptoms at diagnosis were spastic pareses (75%), ataxia (58%), and vegetative disorders (42%). Tumors were most often lumbosacral (L1-L5 42%, L5-S3 50%) and intradural-extramedullary (92%). For microsurgical resection, IONM with EMG, SSEPs, and TcMEPs of the limbs and pudendal nerve/anal sphincter was always applied and feasible; intraoperative corrective actions were initiated in three cases due to transient IONM deterioration. None of the patients showed a postoperative deterioration of the neurological status with a gross total resection rate of 92%. Pain situation, McCormick grade, and mJOA Score were improved at long-term follow-up (median 4.8 years).

CONCLUSIONS

IONM-aided resection of intraspinal epidermoid/dermoid tumors is feasible both in adult and pediatric cases and enables a satisfying clinical and surgical outcome.

Mastoid Dermoid Cyst

A case of mastoid dermoid cyst (DC) was presented, and differences with cases of other temporal bone DCs were analyzed. The mastoid DC was also compared with mastoid congenital cholesteatoma. We reported a case of a patient with mastoid DC, evaluating her clinical, radiological, and surgical findings. A review of the literature was performed to compare our findings with those reported. The preoperative radiological evaluation prompted us to plan a surgical approach to the lesion, suspecting the presence of a mastoid congenital cholesteatoma. The surgical findings were in line with the presence of a mastoid DC. Only two cases reported in the literature presented features that fulfilled the criteria of a true mastoid DC. A DC confined to the mastoid region is an extremely rare clinical entity, with asymptomatic and slow growth. Preoperative radiological differentiation between congenital cholesteatoma and DCs with atypical features can be difficult. However, surgical excision is the treatment of choice in both cases. Diagnosis is confirmed by the histological evaluation.

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.

A Rare Case of Infected Cervicodorsal Intramedullary Epidermoid Cyst

Introduction  Intramedullary spinal epidermoid cysts have a reported incidence of less than 1% of intramedullary spinal cord tumors; and out of these, intramedullary epidermoid lesions within the cervical spinal cord are even rarer. Here, we present the case of an adult patient with an infected intramedullary epidermoid cyst, identified on magnetic resonance imaging (MRI) at the C7–D1 level that was successfully excised without any worsening of neurological status.

Case Presentation A 23-year-old female patient presented with history of moderate degree intermittent fever followed by gradually progressive right-sided weakness. She had paresthesia below C5 dermatome on the right side. On close inspection of 
the back, a tiny sinus opening was noted at the D2 level near the midline. MRI of the spine showed an intramedullary lesion at the C6–D1 level with the tract connecting to the subcutaneous lesion. Somatosensory evoked potential (SSEP) monitoring was done during the surgery with near total excision of the lesion.

Conclusion Even though the location is rare, a differential diagnosis of the epidermoid should always be considered. A tiny dermal sinus opening helped us in proper diagnosis, along with surgical excision, by providing us a direct path to the intramedullary lesion. An early diagnosis and treatment with neurophysiological monitoring helped us in the maximum safe resection of the lesion without developing any new deficit.

Intratumoral Rathke's Cleft Cyst Remnants Within Craniopharyngioma, Pituitary Adenoma, Suprasellar Dermoid, and Epidermoid Cysts: A Ubiquitous Signature of Ectodermal Lineage or a Transitional Entity?

BACKGROUND

The authors present cystic epithelial masses in the suprasellar region which on histopathology revealed 4 mixed tumors having simple cuboidal epithelium of Rathke's Cleft Cyst (RCC) elements trapped within pituitary adenoma, epidermoid cyst, dermoid cyst, and papillary craniopharyngioma respectively.

OBJECTIVE

To highlight the developmental theory of ectodermal continuum in the realm of suprasellar epithelial cystic lesions and examines the cardinal aspects that distinguish RCC from its confounder, ciliary craniopharyngioma.

METHODS

The authors performed a medical chart review on 4 patients who had coexisting RCC with craniopharyngioma, pituitary adenoma, suprasellar dermoid, and epidermoid cysts.

RESULTS

This series of unique suprasellar lesions elucidate the spectrum of cases from Rathke's cyst to other suprasellar epithelial cysts including a recently identified clinical entity called ciliary craniopharyngioma, which authors feel is a misnomer. The authors also report the first case of ruptured dermoid cyst admixed with elements of Rathke's cyst elements and xanthogranuloma in neurosurgical literature.

CONCLUSION

We propose that the new entity of ciliary craniopharyngioma could be just another variant of RCC elements nested within a typical papillary or adamantinomatous lesion. Further study is warranted to understand the implications of natural history with tumors containing RCC elements.

Meet in the middle: a technique for resecting nasocranial dermoids-technical note and review of the literature

INTRODUCTION

Nasal dermoids with intracranial extension are benign lesions that can have life-threatening consequences, as a nasal punctum may serve as a portal of entry for infection into the central nervous system. The surgical management of these lesions can be challenging, as the extracranial and intracranial cysts and sinus tract must be resected to prevent recurrence, and the surgery must be carried out with an acceptable esthetic result.

TECHNIQUE

The authors present a technique for the resection of nasocranial dermoids that eliminates the need to remove and replace the frontonasal segment. Working through a small frontal craniotomy enables the surgeon to drill out the sinus tract through the foramen cecum and inferiorly into the nose. This exposure eliminates the need to enter the frontal sinus, if it is present.

CONCLUSION

The extracranial punctum and tract are resected from below in a minimally invasive fashion that permits removal of the lesion without a disfiguring scar.

Surgical management of spinal intramedullary tumors: Ten-year experience in a single institution

Despite their rare occurrence, intramedullary spinal cord tumors can cause considerable morbidity and mortality without treatment. Timing of surgery, extent of resection and selection of favorable treatment option are important considerations for a good surgical outcome. In this clinical study, we report our patient series and convey our treatment strategy. We retrospectively reviewed 91 patients with primary intramedullary spinal cord tumors who underwent microsurgical resection at our institution between 2008 and 2018. Data were collected consisting of age, sex, location and histology of tumor, extent of resection, presenting symptoms and neurological outcomes. Modified McCormick Scale was used to assess neurological status of patients. 47 female and 44 male patients were followed-up for a mean period of 35.7 months. The most frequent pathological diagnosis was ependymoma in 56 patients, followed by astrocytoma in 21 and hemangioblastoma in 5 patients. The rest of the tumors consisted of 3 cavernomas, 3 mature cystic teratomas, 2 PNET, one epidermoid tumor. Gross total resection was achieved in 67 patients, while subtotal resection and biopsy was performed in 15 and 9 respectively. The most commonly involved localization was cervical (n = 39), followed by thoracic region (n = 24). Despite immediate postoperative worsening of neurological status, a great number of patients improved at the last follow-up. Gross total resection remains the primary goal of treatment while adjuvant radiation and/or chemotherapy may be alternative options for high grade tumors. Preoperative neurological status was the most important and the strongest predictor of functional outcome.

Cervical intradural extramedullary epidermoid cyst at the background of congenital scoliosis with a semi-segmented C6 hemivertebra

In the present case study, we present a female adolescent patient harboring a rare clinical presentation of spinal intradural extramedullary epidermoid cyst concomitant with congenital scoliosis. A 17-year-old female patient was admitted to the clinic with long-lasting neck pain. She was neurologically intact yet had cervicothoracic scoliosis. Cervical MRI and CT depicted a right C6 hemivertebra, fused to the lower endplate of the C5 vertebra. At the same vertebra level, she had an intradural extramedullary mass lesion anterior to the spinal cord. We planned to excise the mass lesion first. We used neuromonitoring during the surgery and made the surgery via posterior approach. We observed a pearl-like mass lesion anterolateral to the spinal cord. We excised the mass lesion with its capsule microsurgically via peace-meal route. She was neurologically stable following the surgery. Histopathological diagnosis was epidermoid cyst. Most of spinal inclusion cysts occur secondary to spinal dysraphism or iatrogenic inoculation. Isolated spinal inclusion cyst located anterior to the spinal cord concomitant with vertebral anomalies should be kept in mind before making proper surgical planning. Surgery is the modality of choice for spinal inclusion cyst and should be performed under the guidance of neuromonitoring, especially in cases with lesions located at higher spinal levels.

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.

Endoscopic endonasal resection of epidermoid cysts involving the ventral cranial base

OBJECTIVE

Epidermoid cysts (ECs) commonly extend to involve the ventral cisterns of the cranial base. When present, symptoms arise due to progressive mass effect on the brainstem and adjacent cranial nerves. Historically, a variety of open microsurgical approaches have been used for resection of ECs in this intricate region. In recent years, the endoscopic endonasal approach (EEA) has been proposed as an alternative corridor that avoids crossing the plane of the cranial nerves. To date, there is a paucity of data in the literature regarding the safety and efficacy of the EEA in the treatment of ECs of the ventral cranial base.

METHODS

The authors reviewed a prospectively acquired database of EEAs for resection of ECs over 8 years at Weill Cornell, NewYork-Presbyterian Hospital. All procedures were performed by the senior authors. Standardized clinical and radiological parameters were assessed before and after surgery. Statistical tests were used to determine the impact of previous surgery and tumor volume on extent of resection and recurrence as well as the method of closure on rate of CSF leak.

RESULTS

Between January 2009 and February 2017, 7 patients (4 males and 3 females; age range 16-70 years) underwent a total of 8 surgeries for EC resection utilizing the EEA. Transplanum and transclival extensions were performed in 3 and 5 patients, respectively. Methods of closure incorporated a gasket seal in 6 of 8 procedures and a nasoseptal flap in 7 of 8 procedures. Gross-total resection (GTR) was achieved in 43% of patients, and near-total resection (> 95%) was obtained in another 43%. Complications included diabetes insipidus (n = 2), postoperative CSF leak (n = 2), transient third cranial nerve palsy (n = 1), and epistaxis (n = 1). With a mean follow-up of 43.5 months, recurrence has been observed in 2 of 7 patients. In 1 case, reoperation for recurrence was required 71 months following the initial surgery. Use of the gasket-seal technique with nasoseptal flap coverage significantly correlated with the absence of postoperative CSF leakage (p = 0.018). GTR was achieved in 25% of the patients who had prior surgeries and in 50% of patients without previous resections. The mean volume of cysts in which GTR was achieved (4.3 ± 1.8 cm3) was smaller than that in which subtotal or near-total resection was achieved (12.2 ± 11 cm3, p = 0.134).

CONCLUSIONS

The EEA for resection of ECs of the ventral cranial base is a safe and effective operative strategy that avoids crossing the plane of the cranial nerves. In the authors' experience, gasket-seal closure with nasoseptal flap coverage has been associated with a decreased risk of postoperative CSF leakage.

Suprasellar Epidermoid Cyst Originating from the Infundibulum: Case Report and Literature Review

Epidermoid cysts account for a small fraction of intracranial brain tumors, most commonly found in the cerebellopontine angle and parasellar cisterns. Here we present a rare case of an epidermoid cyst located in the suprasellar region, specifically originating from the infundibulum. Only one additional case with an epidermoid cyst originating within the pituitary stalk has been previously reported in the literature. The patient in this case presented with headaches, diplopia and blurred vision without any endocrinopathy. The patient's pre-operative evaluation was significant for pseudotumor cerebri, hyponatremia, obesity, and a history of smoking; post-operative course was significant for neurogenic diabetes insipidus.

[Dermoid cysts of the posterior cerebral fossa in children revealed by recurrent aseptic meningitis: Report of two cases and a review of the literature]

INTRODUCTION

Dermoid cysts of central nervous system are very rare. The usual clinical presentation is dominated by intracranial hypertension, epilepsy and cranial palsy. The revelation mode could be recurrent aseptic meningitis.

AIM

The aim of this case report is to consider the dermoid cyst as regards the differential diagnosis in children treated for recurrent aseptic meningitis to avoid misdiagnosis and ice qui a orienté le diagnostic à une méningitnadequate treatment.

METHODS

Two children were admitted in the pediatric department for recurrent aseptic meningitis. The MRI confirmed the presence of a posterior fossa dermoid cyst.

RESULTS

Loss of meningitis after microsurgical resection.

CONCLUSION

The diagnosis of dermoid cyst is performed and reconsidered at an early stage in aseptic meningitis in order to establish an adequate therapy, which is surgery.

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.

Massive Intradural Dermoid Cyst Without Sinus Tract

Dermoid cysts can present as a rare, benign, congenital intracranial tumor of neuroectoderm origin trapped during embryogenesis. Past clinical reports have reported lesions in the posterior fossa, at the midline, and in the intradural region all in conjunction with a superficial sinus tract. The authors present a unique patient of a completely intracranial, intradural, dermoid tumor of the midline cerebellum devoid of any evidence of sinus tract. The histological characteristics, radiological features, and management of this unusual patient are described.

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.

[Fourth ventricule epidermoid cyst: about a case]

Les kystes épidermoïdes sont des tumeurs bénignes rares développées à partir d'inclusions ectodermiques. Ils siègent habituellement au niveau de l'angle ponto-cérébelleux, la région para-sellaire et la fosse temporale. Leur siège au niveau du quatrième ventricule est exceptionnel. Nous rapportons le cas d'une patiente de 47 ans admise pour un syndrome d'hypertension intracrânienne associé à des troubles de la marche. Le diagnostic de kyste épidermoïde du V4 fut évoqué sur les données de l'IRM en séquences de diffusion puis confirmé en per opératoire et en histologie. L'exérèse chirurgicale a été subtotale en raison d'une adhérence de la capsule à la partie supérieure du plancher du V4. Après un recul de 36 mois, la patiente ne manifeste aucun signe de ré-évolution tumorale.

Large intraventricular epidermoid with bobble head doll syndrome in an adult

Intracranial epidermoid tumors are rare (0.2-1.8%), histologically benign, slow-growing, congenital neoplasms of the central nervous system arising from the retained ectodermal implants. We report an unusual case of intra third ventricular epidermoid in an adult presenting with the Bobble-head doll syndrome and review the relevant literature.

Interdural cavernous sinus dermoid cyst in a child: case report

Interdural dermoid cysts (DCs) of the cavernous sinus (CS), located between the outer (dural) and inner layer (membranous) of the CS lateral wall, are rare lesions in children. The authors report on a 5-year-old boy with third cranial nerve palsy and exophthalmos who underwent gross-total removal of an interdural DC of the right CS via a frontotemporal approach. The patient had a good outcome and no recurrence at the 12-month follow-up. To the best of the authors' knowledge this is the second pediatric case of interdural DC described in the literature.

Brainstem epidermoid cyst: An update

The incidence of epidermoid tumors is between 1% and 2% of all intracranial tumors. The usual locations of epidermoid tumor are the parasellar region and cerebellopontine angle, and it is less commonly located in sylvian fissure, suprasellar region, cerebral and cerebellar hemispheres, and lateral and fourth ventricles. Epidermoid cysts located in the posterior fossa usually arise in the lateral subarachnoid cisterns, and those located in the brain stem are rare. These epidermoids contain cheesy and flaky white soft putty like contents. Epidermoid cysts are very slow growing tumors having a similar growth pattern of the epidermal cells of the skin and develop from remnants of epidermal elements during closure of the neural groove and disjunction of the surface ectoderm with neural ectoderm between the third and fifth weeks of embryonic life. We are presenting an interesting case of intrinsic brainstem epidermoid cyst containing milky white liquefied material with flakes in a 5-year-old girl. Diffusion-weighted imaging is definitive for the diagnosis. Ideal treatment of choice is removal of cystic components with complete resection of capsule. Although radical resection will prevent recurrence, in view of very thin firmly adherent capsule to brainstem, it is not always possible to do complete resection of capsule without any neurological deficits.

Isolated thoracic intramedullary epidermoid cyst - a rare entity

Intramedullary epidermoid cysts of the spinal cord are rare tumours, especially those not associated with spinal dysraphism. Around 60 cases have been reported in the literature. Of these, only 10 cases have had magnetic resonance imaging (MRI) studies. Here, we report a case of isolated intramedullary epidermoid tumour at D2-D3 level. The etiology, pathology, clinical features, MRI characteristics and surgical treatment of such rare intramedullary tumours are discussed.

Primary intradural sacral epidermoid in a nondysraphic spine: Case report and review of literature

The occurrence of epidermoids within the spinal canal is uncommon. Most of the reported spinal epidermoids (SEs) have been described in the thoracic or lumbar regions. They occur either following trauma or in the setting of coexistent spinal dysraphism. The authors describe an unusual case of a 28-year-old lady who presented with long-standing back pain and urinary incontinence. Magnetic resonance imaging (MRI) of her spine demonstrated a sacral SE without any coexistent spinal dysraphism. The diagnosis of an epidermoid was confirmed by histopathological examination following laminectomy and excision. To the authors’ best knowledge, this is the third case of a sacral SE occurring in a non-dysraphic spine. The case is discussed in the light of a relevant literature review.

Rapid-onset paraparesis and quadriparesis in patients with intramedullary spinal dermoid cysts: report of 10 cases

OBJECT Intramedullary dermoid cysts are rare tumors of the spinal cord. Presentation with rapid onset of paraparesis or quadriparesis (onset within 2 weeks) is rarer still. The authors present their experience in the management and outcome of patients with such a presentation. METHODS Patient records between 2000 and 2014 were retrospectively reviewed to identify those with intraspinal dermoid cysts who presented with rapid-onset paraparesis or quadriparesis. Their clinical, radiological, operative, and follow-up data were analyzed. RESULTS Of a total of 50 patients with intraspinal dermoid cysts managed during the study period, 10 (20%) presented with rapid-onset paraparesis or quadriparesis; 9 patients ranged in age from 8 months to 2 years, and 1 patient was 25 years old. A dermal sinus was seen in the lumbar region of 4 patients, the sacral region of 3, and the thoracic region of 1, and in 1 patient no sinus was found. All except 1 patient presented with rapid-onset paraparesis secondary to infection of the intramedullary dermoid cyst. One patient presented with rupture of a dermoid cyst with extension into the central canal up to the medulla. Early surgery was done soon after presentation in all except 2 patients. Among the 9 patients who underwent surgery (1 patient did not undergo surgery), total excision of the intramedullary dermoid cyst was done in 3 patients, near-total excision in 4 patients, and partial excision in 2 patients. Of the 9 patients who underwent surgery, 8 showed significant improvement in their neurological status, and 1 patient remained stable. The 1 patient who did not undergo surgery died as a result of an uncontrolled infection after being discharged to a local facility for management of wound infection. CONCLUSIONS Early recognition of a dermal sinus and the associated intraspinal dermoid cyst and timely surgical intervention can eliminate the chances of acute deterioration of neurological function. Even after an acute onset of paraparesis or quadriparesis, appropriate antibiotic therapy and prompt surgery can provide reasonably good outcomes in these patients.

Cerebellopontine angle epidermoid cysts: clinical presentations and surgical outcome

Epidermoid cysts constitute less than 1% of intracranial tumors with the majority of them involving cerebellopontine angle (CPA). Although several mechanisms for cranial nerve dysfunction due to these tumors have been proposed, no direct evaluation for hyper- or hypoactive dysfunction has been done. In this case series, pathophysiology of cranial nerve dysfunction in CPA epidermoid cysts was evaluated with special attention to a new mechanism of capsule strangulation caused by stratified tumor capsule. Twenty-two cases with epidermoid cysts of CPA micro-neurosurgically treated in our departments since 2005 were reviewed. Clinical status of the patients before the surgery and post-operative functional outcome were recorded. Available data from the English literature were summarized for comparison. Mass reduction of cyst contents in most cases was usually associated with prompt and marked improvement of the symptoms suggesting neuroapraxia caused by compression of the tumor content and/or mild ischemia. Among them, two cases showed strangulation of the affected nerves by the tumor capsule whose preoperative dysfunction did not improve after surgery in spite of meticulous microsurgical removal of the lesion. Involved facial and abducent nerves in these two cases showed distortion of nerve axis and nerve atrophy distal to the strangulation site. We report the first direct evidence of etiology of cranial nerve dysfunction caused by cerebellopontine angle epidermoid tumors. Young age and rapidly progressive neurological deficit might be the characteristics for strangulation of the affected nerves by the cyst capsule. Even though the number of cases might be limited, immediate decompression and release of the strangulating band might be urged in such patients to prevent irreversible deficits.