Surgical strategy for intracranial dermoid and epidermoid tumors: An experience with 33 Patients

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.

Late-onset rupture of an intracranial dermoid cyst: a case report

BACKGROUND

Dermoid cysts are developmental abnormalities occurring between the third and fifth week of embryogenesis. These lesions can initially develop as intracranial or extracranial and persist throughout the patient's lifetime. While generally benign, their symptoms can be due to mass effect or local irritation secondary to rupture and release of contents, typically presenting as headaches and seizures. Intracranial dermoid cysts are rare and comprise less than 1% of all intracranial lesions, with rupture occurring approximately 0.18% of the time.

CASE PRESENTATION

Our case describes a 42-year-old Hispanic female with a late-onset rupture of an intracranial dermoid cyst with associated new onset seizures. She underwent uncomplicated neurosurgical resection with mesh placement and was scheduled to follow-up as an outpatient.

CONCLUSION

To avoid rupture and associated sequelae in future patients, we recommend considering a more invasive approach as the initial strategy if internal cysts are relatively accessible.

Endoscopically operated 15 ventral skull-base dermoid and epidermoid cysts: Outcomes of a case series and technical note

BACKGROUND

Epidermoid and dermoid tumors in the sellar region are rare. These cystic lesions are a surgical challenge, as the thin capsule adheres firmly to nearby structures. A case series of 15 patients is presented.

METHODS

The patients were operated on in our clinic between April 2009 and November 2021. The endoscopic transnasal approach (ETA) was used. Lesions were located in the ventral skull base. In addition, the literature was reviewed to compare clinical features and outcomes of ventral skull-base epidermoid/dermoid tumors operated on via ETA.

RESULTS

In our series, removal of cystic contents and tumor capsule (gross total resection: GTR) was achieved in 3 patients (20%). GTR was not possible for the others, because of adhesions to vital structures. Near total resection (NTR) was achieved in 11 patients (73.4%), and subtotal resection (STR) in 1 (6.6%). At a mean follow-up of 55±26.27 months, there were no cases of recurrence requiring surgery.

CONCLUSION

Our series demonstrates that ETA is suitable for resection of epidermoid and dermoid cysts in the ventral skull base. GTR cannot always be the absolute clinical aim, because of inherent risks. In patients with expected long-term survival, the aggressiveness of surgery should be weighed on an individual risk/benefit basis.

Surgical Presets of Ruptured Dermoid Cyst Resection: 2-Dimensional Operative Video

Intracranial dermoid cyst is a benign expansive lesion typically affecting children and young adults. They become symptomatic by progressive enlargement of the cyst and spilling of its content. In such cases, recurrent aseptic meningitis is observed. When located in the suprasellar area, optic pathways are usually displaced and compressed, and visual symptoms are common, as well as seizures. The tumor capsule can be thick and very adherent to the anterior cerebral arteries and the small arterial perforators. Radical surgical resection, including the capsule, is the current mainstay of treatment.1-5 The cranio-orbital approach is considered as an excellent surgical access option. Vascular adhesions are associated with a considerable surgical risk to the circle of Willis and its small branches. Residual cyst or perioperative spilling of its content produces severe aseptic meningitis and vasospasm associated with postoperative complications and long-term recurrences.4 This article demonstrates the details of the surgical management of a ruptured suprasellar dermoid cyst in a 22-year-old man. The patient consented to the procedure and publication of images. Image at 2:23 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas, Vol 1, ©LWW, 1998. Illustration at 2:47 reprinted from Surgical Neurology, 50(6), Arnautovic et al, "A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms," p 17, ©1998, with permission from Elsevier.

Asymptomatic rupture of an intracranial dermoid cyst: to intervene or not to intervene?

Dermoid cysts are an exceedingly rare phenomenon inside the cranial vault. These benign, slow-growing lesions can rupture, releasing cyst contents into the ventricular system and subarachnoid space causing pathology in the form of chemical meningitis and vasospasm. Here, we present the case of a 26-year-old man who was investigated for a facial nerve palsy and was incidentally found to have a ruptured dermoid cyst in the pineal region, with dissemination of cyst contents throughout the ventricular system.

Gamma knife radiosurgery of epidermoid tumors: an analysis of treatment results of eight patients

Background

Epidermoid tumors (ETs) of the central nervous system (CNS) are rare tumors that typically occur in the 4^th decade. They typically grow around vital neurovascular structures which makes surgical treatment difficult. The objective of this paper is to report on the effectiveness and safety in the management of epidermoid tumors with gamma knife surgery (GKS).

Materials and methods

This is a retrospective study of the medical records of 8 patients treated with GKS for epidermoid tumors between July 2010 to June 2019. The median prescription dose was 11 Gy, ranging from 10 to 12 Gy, 5 patients received the total dose target to the 50% line and 3 to the 55% isodose line. The mean tumor volume was 12.4 cc ranging from 4.4 to 24.8cc. The median follow-up time was 33.7 months and ranged from 0.9 to 58.8 months. At follow-up, patients were evaluated for neurological signs and symptoms and radiographic evidence of progression of disease. Two patients were treated after failure of linac stereotactic radiosurgery. One patient underwent stereotactic radiosurgery prior to GKS, and the other had failed surgical resection prior to GKS.

Results

The median age was 33 years old. There were two males and six females. The most common presenting manifestation was headaches followed by vision and hearing problems. Symptoms were resolved in all cases, except for one who had partial control of trigeminal neuralgia. All patients were locally controlled by imaging and neurological examination at first follow-up.

Conclusion

Gamma knife surgery is a safe and effective alternative treatment in patients with CNS epidermoid tumors and should be included in the initial recommendation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Resection of an Isolated Pituitary Stalk Epidermoid Cyst Through a Pretemporal Approach: Case Report and Review of the Literature

BACKGROUND

Intracranial epidermoid cysts are congenital epidermal inclusion cysts derived from ectodermal origin with desquamated skin. The majority of these cysts occur in the cerebellopontine angle cistern. Epidermoid cyst of the pituitary stalk, however, is a rare location. To date, only 4 previous cases have been reported.

CASE DESCRIPTION

A 63-year-old male presented to our clinic with migraine headaches, dizziness, increased thirst, increased urinary frequency, and impotence. Magnetic resonance imaging of the brain demonstrated a rim-enhancing cystic mass with diffusion restriction on diffusion-weighted imaging located within the pituitary stalk. The patient underwent a pretemporal approach with gross total resection of the cyst. The patient's postoperative course was uneventful with no new deficits and/or endocrinopathies.

CONCLUSION

Epidermoid cyst of the pituitary stalk is an unusual and rare presentation. Four other cases treated via endoscopic approaches have been previously reported in the neurosurgical literature. To our knowledge this is the first case description of an infundibular epidermoid cyst pressing with isolated diabetes insipidus surgically treated via a transcranial pretemporal approach with gross total resection. The patient had a smooth and uneventful postoperative course with persistent diabetes insipidus.

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.

Surgical Management of Intracranial Giant Epidermoid Cysts in Adult: A Case-Based Update

Epidermoid cysts (ECs) are benign and slow-growing lesions that account for about 0.2%-2% of all intracranial tumors. Symptoms appear slowly and tumors may have already grown to giant proportions when patients receive their first diagnosis. The optimal treatment for ECs is surgical removal, which includes the total resection of the entire capsule of the lesion in order to minimize the risk of malignant transformation associated with partial removal. However, considering the giant size that the ECs can reach at the time of the diagnosis, and their adherence to the surrounding structures, the risks and benefits of total versus subtotal resections in the short- and long-term patients' outcome are still under debate. Here, we report a case of an extensive giant EC and offer a discussion of its characteristics, surgical management, and postoperative outcome, taking a cue to argue about the recent literature based in the latest case studies.

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.

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.

Cerebellar Vermian Epidermoid Tumor: A Report of 2 Cases

BACKGROUND

Epidermoid tumors are rare, benign slow-growing congenital tumors, most frequently located in the cerebellopontine angle of the intracranial cavity. They usually grow to a large size before patients become symptomatic. Although these tumors are amenable to surgery, their adherence to neurovascular structures poses a surgical challenge that results in subtotal resection, thus increasing the risk of recurrence.

CASE DESCRIPTION

We report 2 adult patients whose imaging studies revealed epidermoid tumors located in the cerebellar vermis, an uncommon site for such tumors. The patients presented with variable symptomatology. We highlight the imaging features and challenges of surgery. Both patients had good outcomes, with resolution of symptoms and neurologic deficits.

CONCLUSIONS

A safe complete excision of epidermoid tumor and its capsule is possible with a good understanding of their clinical and radiologic features and a high index of suspicion. To the best of our knowledge, this is the first report of cerebellar vermian epidermoid tumors from sub-Saharan Africa.

Suprasellar keratinous cyst: A case report and review on its radiological features and treatment outcome

BACKGROUND

Keratinous or epidermoid cysts (ECs) are encapsulated lesions lined by squamous cell epithelium. They comprise approximately 1% of intracranial lesions. Contrary to dermoid cysts, they lack dermal elements such as sebaceous or apocrine glands and hair follicles. The sellar region is the second most common intracranial site following the cerebellopontine angle. Here, we report a case of EC in a patient who complained of endocrine disturbances. We also performed a systematic review on previously published cases to analyze clinical and radiological characteristics and report the treatment outcomes of suprasellar ECs.

CASE DESCRIPTION

A 42-year-old woman presented with a one-year history of amenorrhea, weight gain, severe headache, and visual disturbances for 6 months. Work-up identified an elevated prolactin level and a temporal field defect of the right eye. Magnetic resonance imaging (MRI) showed a cystic suprasellar lesion pushing on the optic chiasm. She underwent endoscopic trans-sphenoidal surgery, which confirmed a keratinous cyst on histology. Postoperatively, complete resection was confirmed on imaging. She did well although her hospital stay was prolonged due to diabetes insipidus and hypocortisolism.

CONCLUSION

Chronic endocrine disturbances can be the presenting complaints of a suprasellar EC, whose T1-weighted MRI appearance can be non-specific, mimicking other differential diagnoses, such as a Rathke's cleft cyst. However, the T2-weighted MRI appearances of ECs are generally hyper-intense and lesions show diffusion restriction. Treatment is surgical and yields good outcomes in most cases reported.

Sparing a Craniotomy: The Role of Intraoperative Methylene Blue in Management of Midline Dermoid Cysts

BACKGROUND

Midline nasal dermoid cysts are rare congenital anomalies that extend intracranially in approximately 10 percent of cases. Cysts with intracranial extension require a craniotomy to avoid long-term complications, including meningitis, abscesses, and cavernous sinus thrombosis. Current guidelines recommend preoperative imaging with either magnetic resonance imaging or computed tomography to determine appropriate management.

METHODS

Patients who underwent excision of a midline nasal dermoid cyst between January 1995 and September 2016 were identified using Current Procedural Terminology codes. In cases with equivocal imaging findings or uncertain stalk extent during surgical dissection, methylene blue was used intraoperatively. Demographics, preoperative imaging findings, intraoperative dye findings, surgical approach, and complications were collected.

RESULTS

A total of 66 midline dermoid cyst excisions were identified; 17 (25.8 percent) had intracranial extension requiring craniotomy. Preoperative imaging showed a subcutaneous cyst in 41 (62.1 percent), intraosseous tracking in three (4.5 percent), and intracranial extension in 15 (22.7 percent). Twelve patients (18.2 percent) had preoperative imaging that was inconsistent with intraoperative findings. Methylene blue was used in 17 cases and indigo carmine was used in one case. Intraoperative dye findings changed management in five cases, and in three cases a craniotomy was avoided without evidence of cyst recurrence.

CONCLUSIONS

This report is the largest published series of midline dermoid cysts with intracranial extension. In almost 20 percent of cases, preoperative imaging was not consistent with intraoperative findings. Given disparate radiographic and intraoperative findings, methylene blue is a valuable tool that can facilitate appropriate, morbidity-sparing management of midline dermoid cysts.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms: A case report and literature review

RATIONALE

There were a few case reports concerning epidermoid tumor coexisted with multiple cerebral aneurysms. Here, we present one case of coexistence of intracranial epidermoid tumor and multiple cerebral aneurysms and performed a literature review.

PATIENT CONCERNS

A 42 years old male patient was admitted to our institution with complaints of headache and dizziness.

INTERVENTIONS

The radiological examinations showed a hypointense lesion in the right parasellar and petrous apex region and an ipsilateral saccular aneurysm originated from the M2-M3 junction of the right middle cerebral artery (MCA) and a saccular aneurysm of the clinoid segment of right internal carotid artery (ICA).

INTERVENTIONS

The patients underwent a right frontotemporal approach for removal of the epidermoid tumor and clipping of the MCA aneurysm in one stage. The aneurysm located at the clinoid segment of ICA was invisible and untreated during operation.

OUTCOMES

No postoperative complications were found in the patient. The patient's follow up after 5 years of surgical treatment was uneventful, and the untreated aneurysm remains stable.

LESSONS

The coexistence of intracranial epidermoid tumor and cerebral aneurysm is a rare event. The secondly inflammation in cerebral arterial wall may be responsible for the aneurysm formation. Surgical treatment of the intracranial epidermoid tumor and cerebral aneurysm repair may be an optimal scheme in one stage.

Endoscopic endonasal resection of a giant middle fossa epidermoid cyst

Intracranial epidermoid cysts are rare. We report a case of a 55-year-old man who presented with trigeminal neuralgia and was found, on imaging, to have an epidermoid cyst located in the right middle fossa. He was managed via an entirely endoscopic endonasal approach. Postoperative magnetic resonance imaging confirmed complete removal of the mass, and the patient continued to have complete resolution of symptoms at a 1-year follow-up.

Intracranial Intra-arachnoid Diverticula and Cyst-like Abnormalities of the Brain

Primary intracranial cystic or cyst-like lesions include intra-arachnoid, epidermoid, dermoid, and choroid plexus cysts. Differentiation of these cystic lesions can usually be accomplished by imaging studies alone; however, some cysts are similar in appearance and require histopathology for definitive diagnosis. Clinical signs often reflect the location of the cysts within the intracranial cavity rather than the type of cyst. If clinical signs are significant and progressive, surgical removal is warranted and may be successful, although cystic contents could be harmful if allowed to contact surrounding brain parenchyma or meninges.