Cavernous sinus epidermoid cyst
A “Cavernous Sinus Epidermoid Cyst” refers to the presence of an epidermoid cyst within the cavernous sinus. This condition is extremely rare, and the cavernous sinus is not a typical location for epidermoid cysts.
According to their location, epidermoid cysts of the CS can be divided into 3 different categories: the first group is composed of cysts that present an extracavernous origin and invade or compress the CS. The second group of cysts originates in the lateral wall of the CS. They are located between the 2 cavernous dural layers (interdural cysts). The third group consists of the true intracavernous epidermoid tumors, which tend to encase the internal carotid artery, encircling and displacing the cranial nerves laterally 1)
The presence of an epidermoid cyst within the cavernous sinus could potentially lead to various neurological symptoms or complications due to the compression of vital structures. This is a very uncommon condition, and diagnosis and management would require a multidisciplinary approach involving neurologists, neurosurgeons, and radiologists, among others.
Systematic reviews
In 2022 a systematic review of related literature using PubMed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Various combinations of the following terms were used to search the literature: epidermoid cyst, cavernous sinus, intracranial, central nervous system, endoscopy, endoscopic, endonasal, and transsphenoidal. Our search strategy initially identified 62 articles. After screening titles and abstracts, a second filter of the collected literature according to the tumor location and surgical method was performed. Finally, it included 13 English literature, a total of 48 cases of intracranial cavernous sinus epidermoid cyst. We summarized the clinical symptoms, surgical approach, operation time, degree of resection, postoperative complications, and long-term prognosis of these cases. Through a search of previous literature, they found that 48 cases were reported in detail. All these patients were treated with microneurosurgery, including simple microsurgery and endoscopic-assisted surgery, and total or subtotal resection was achieved 2)
In 2018 related literature from the past 40 years (18 articles, 20 patients) was evaluated.
The most common chief complaints were facial numbness or hypesthesia (64.5%), absent corneal reflex (45.2%), and abducens or oculomotor nerve deficit (35.5%). On MRI, 51.6% of the epidermoid cysts showed low T1 signals and equal or high T2 signals. In the other lesions, the radiological findings varied considerably given differences in the composition of the cysts. Surgery was performed via the extradural approach (58.1%), intradural approach (32.3%), or a combined approach (9.7%). After the operation, symptoms remained similar or improved in 90.3% of patients, and new oculomotor paralysis developed after the operation in 9.7% of patients. Seven patients (22.6%) developed meningitis postoperatively (5 aseptic and 2 septic), and all of them recovered. All patients achieved good recovery before discharge (Karnofsky Performance Status score ≥ 70). Over an average follow-up of 4.6 ± 3.0 years in 25 patients (80.6%), no recurrence or reoperation occurred, regardless of whether total or subtotal resection of the capsule had been achieved.
Both the extradural and intradural approaches can enable satisfactory lesion resection. A favorable prognosis and symptomatic improvement can be expected after both total and subtotal capsule resections. Total capsule resection is encouraged to minimize the possibility of recurrence provided that the resection can be safely performed 3).
Case reports
A 54-year-old woman presented with chronic persistent headaches and occasional syncope. Brain MRI demonstrated a space-occupying lesion of the left CS, and digital substruction angiography (DSA) showed a small aneurysm at the beginning of the left ophthalmic artery. Thrombotic therapy for carotid-ophthalmic aneurysms was performed first, and the patient underwent resection of the CS lesion secondary. Considering the location of the lesion the neuroendoscopy technology and the experience of the doctor, we made bold innovations and used an EET approach to achieve complete resection of the lesion. The postoperative pathological results were consistent with the characteristics of the epidermoid cyst. During the 1-year follow-up, the patient showed no apparent signs of recurrence on the head MRI.
Epidermoid cyst of the cavernous sinus is a rare benign occupying lesion in the cavernous sinus. Reviewing the previous literature, the main treatment is microneurosurgery, and neuroendoscopy is only used as auxiliary equipment. We present the first case of complete endoscopic resection of CS epidermoid cyst by EET approach according to CARE guidelines, aiming to share the new surgical plan for CS epidermoid cyst and provide more surgical options for this disease for neurosurgery colleagues 4).
A 22-year-old female patient, who suffered a right-sided headache for 5 years. The video demonstrates main steps and surgical nuances of resection of a right interdural cavernous sinus epidermoid cyst, measuring 22 × 19 × 21 mm (4.3 cc) ( Fig. 1A ). On initial physical examination, the patient had a right partial third nerve palsy (mild ptosis with minimal diplopia), without any other cranial nerve deficit. A right no-keyhole pterional craniotomy was performed, followed by extradural anterior clinoidectomy and peeling of the outer dural layer of the lateral wall of the cavernous sinus. The dura matter was also detached from the distal carotid dural ring, which was exposed by the clinoidectomy ( Fig. 2A ). This maneuver provided excellent exposure of the interdural epidermoid cyst, which severely compressed the oculomotor nerve against the posterior petroclinoid dural fold ( Fig. 2B ). Gross total resection of the epidermoid cyst was achieved ( Fig. 1B and C ). The patient developed a transient worsening of the third nerve palsy, which recovered completely 3 months after the surgery. Postoperative magnetic resonance imaging revealed no signs of residual tumor. The link to the video can be found at: https://youtu.be/pobhYb5ZNig 5)
Large epidermoid cyst of the cavernous sinus: Case report
Author: Yuanyuan Hu,Xianzeng Hou,Zhenpeng Liu,Guangcun Liu Publication: Interdisciplinary Neurosurgery Publisher: Elsevier Date: June 2017