Large epidermoids of the quadrigeminal cistern: an experience of 15 consecutive cases and review of literature

Surgical Management of Temporal Lobe Epilepsy Secondary to Epidermoid Cysts: A Case Report With Review of the Literature

Epidermoid cysts represent roughly 1% of all intracranial tumors. They are frequently located in the cerebellopontine angle but rarely extend to the supratentorial brain. Epilepsy is an extremely uncommon manifestation of this neoplasm. We suggest the surgical management of a 35-year-old male who presented with a six-month history of intractable temporal lobe epilepsy. His seizures were characterized by a focal onset in the form of déjà vu experiences, followed by a secondarily generalized tonic-clonic seizure. Imaging revealed a heterogeneous cystic mass in the right cerebellopontine angle, extending supratentorially causing a mass effect on the mesial temporal region. Gross total resection was achieved through a combined subtemporal-retrosigmoid approach. Histopathology revealed an epidermoid cyst. The patient was entirely seizure-free at the three-month follow-up. Epidermoid cysts may present with epileptic seizures. Seizure freedom can be achieved with surgical management in most cases. The patient's symptoms, imaging findings, and epileptogenic focus must be considered to select the appropriate surgical strategy.

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.

Microscopic resection of a giant epidermoid tumor of the pineal region via supracerebellar infra and transtentorial approach with endoscope assistance

The authors present a case of a 22-year-old male who developed hydrocephalus symptoms related to a giant epidermoid tumor at the pineal region. The surgical approach and technique for a large epidermoid tumor in this area are extensively discussed. A paramedian contralateral supracerebellar infratentorial and transtentorial approach was performed, with the patient in a semisitting position. The tumor was removed using a microscopic technique, and endoscope assistance was used in order to reach the areas unable to be visualized under the microscope. The patient was neurologically intact at his 2-year follow-up, and postoperative MRI showed a significant decrease in the tumoral volume.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2128.

Endodermal Cyst with a Non-enhancing Nodule in the Quadrigeminal Cistern Developed in an Octogenarian

BACKGROUND

Intracranial endodermal cysts are congenital lesions that generally develop in the cerebellopontine angle and ventral brainstem of the posterior fossa, whereas endodermal cysts in the quadrigeminal cistern are very rare. We report a rare case of an endodermal cyst in the quadrigeminal cistern with a non-enhancing nodule that developed in patient over 80 years of age.

CASE DESCRIPTION

An 85-year-old man presented to our hospital with progressing gait disturbance and urinary incontinence. Preoperative images showed a cystic mass lesion with a nodule in the quadrigeminal cistern and hydrocephalus. There was no enhanced portion in the lesion, and the intensity of the cyst on magnetic resonance imaging revealed a high protein concentration. Subtotal resection was performed due to the adhesion of the cyst to the brainstem. It was diagnosed as an endodermal cyst. The postoperative course was uneventful, and hydrocephalus improved.

CONCLUSIONS

This is a rare case of an intracranial endodermal cyst in terms of location and age of onset compared with previous reports. This case demonstrates that endodermal cysts should be considered as a differential diagnosis for lesions in the quadrigeminal cistern with high protein concentration in the cyst and nodule representing chronic inflammation, regardless of enhancing effects.

A Single-Center Surgical Experience of Interhemispheric Epidermoids and Proposal of a New Radiological Classification

BACKGROUND

Epidermoids account for <1.5% of all intracranial tumors. Overall, the cerebellopontine angle has been the most commonly reported location. In the supratentorial compartment, epidermoids will usually be found in the suprasellar area, sylvian fissure, and intraventricular area. The interhemispheric fissure represents an extremely rare location for supratentorial epidermoids, with limited cases reported previously. Surgery of an interhemispheric epidermoid can be challenging because of its adherence to the anterior cerebral artery branches or the brain parenchyma itself. In the present study, we have reported the largest Series of interhemispheric epidermoid tumors to better understand the clinical behavior, radiological features, and surgical outcomes.

METHODS

In the present study, we retrospectively evaluated the data from 22 consecutive patients with interhemispheric epidermoids treated surgically during the past 10 years (2009-2019) at our center. During the same study period, we had treated 2355 patients with brain tumors (both primary and secondary), including 262 patients with intracranial epidermoids. Therefore, interhemispheric epidermoids comprised 0.009% of all brain tumors and 8.4% of all intracranial epidermoids in our experience. These patients all had newly diagnosed tumors and had undergone surgery for the first time at our center. All surgical specimens had been confirmed histopathologically.

RESULTS

The mean age of the patients was 31 years (range, 17-61 years), with a male predilection. Seizures and headache were the most common mode of presentation. The average tumor size was 5.2 cm (range, 3.5-10 cm). Of the 22 tumors, 21 were in the anterior two thirds of the fissure. Anatomical distortion of the corpus callosum was seen in 13 patients (59%). The extent of excision was total in 17 (77.3%), near total in 3 (13.6%), and subtotal in 2 (9%) patients. The near or subtotal excisions had been necessary because of either tumor adherence to the pericallosal artery (n = 3) or a missed tumor lobule (n = 2). The mean follow-up time was 32 months, with no tumor recurrence.

CONCLUSION

Interhemispheric epidermoids can often reach a large size with substantial lateral extension found at diagnosis. The position of the anterior cerebral Artery branches can help to differentiate interhemispheric epidermoids from radiologically similar corpus callosum, velum interpositum, and cavum septum pellucidum epidermoids. Complete surgical excision with minimal complications is feasible, with good long-term outcomes.

What is the risk of venous cerebellar infarction in the supracerebellar infratentorial approach?

The supracerebellar infratentorial approach (SCITA) is a standard approach used in a neurosurgical practice. It carries some risk of associated complications including cerebellar venous infarction with possible serious sequelae. The objective of this study is to address the incidence of cerebellar venous infarction in SCITA. A search through the currently available literature was performed in September 2019 from the year 2000 until September 2019 dealing with 'supracerebellar infratentorial approach'. Out of the 578 patients found in thirteen case series, two venous infarctions were present; the remaining four patients were published as case reports. By analysing the case series, we calculated the risk of such a complication to be 0.345% (95% CI [0.061%, 1.248%]). Case reports were not included. The real risk is estimated to be higher. The risk of cerebellar venous infarction is an unpredictable, infrequent but real complication with potentially dreadful sequelae. Each neurosurgeon using this approach should be aware of this event when employing this approach. The avoidance of cerebellar venous infarction can be lowered by leaving as many bridging veins intact as possible.

Giant Epidermoid Cyst: A Rare Cause of Temporal Lobe Epilepsy

Introduction  Epidermoid tumors represent approximately 0.3 to 1.8% of all intracranial brain tumors. Only 1.5% of all intracranial epidermoid cysts (ECs) invade the brain and secondary epilepsy is extremely rare. Since August 2014, a 59-year-old male smoker had been presenting bad smell feelings, totaling four episodes with sudden onset and duration of 2 minutes. On September 2014, after a sense of smell episode, it evolved into loss of contact and automatic movements followed by generalized tonic–clonic movements. The brain magnetic resonance imaging revealed an extensive subtemporal lesion affecting anterior, middle, and posterior fossa with invasion of the choroidal fissure and projection to the temporal horn of the lateral ventricle. Pretemporal craniotomy with combined approaches, transsylvian and subtemporal, allowed for the excision of a white keratinized and softened lesion suggestive of EC.

Discussion  The optimal surgical strategy in individuals with ECs and seizures is not established. The evaluation of the cause and risk–benefit must be held to choose the appropriate surgical strategy: lesionectomy, lobectomy, or amygdalohippocampectomy. In this case, a lesionectomy was performed due to an absence of evidence of involvement of hippocampus and amygdala.

Conclusion  Epilepsy secondary to ECs is a rare association. Lesionectomy can be an option with good results without increasing the morbidity.

Mood Disorder as an Early Presentation of Epidermoid of Quadrigeminal Cistern

Intracranial epidermoids are space-occupying lesions of rare variant. Although cerebropontine angle and parasellar region are common sites of occurrence, it has been reported in various other parts of the intracranial cavity. Headache and features of increased intracranial tension are the common clinical manifestation. Report of psychiatric symptoms as the initial presentation of epidermoid is not known in literature except a single case report, which describes mutism to be the manifestation of intracranial epidermoid. We present here the case of a young male, who presented with long depressive episode persisting for 3 years with subsequent switch to mania, which persisted for more than 3 years. An episode of unconsciousness warranted neuroimaging, which revealed a large epidermoid of the quadrigeminal cistern. Surgical resection of the epidermoid was done. Persisting mood symptoms had responded to mood stabilizer and antipsychotic treatment.