Fourth ventricular epidermoid cyst – Case series, systematic review and analysis

Abstract

Background: Epidermoid cysts are extra-axial, pearly white avascular lesions mostly found in the cerebellopontine region. They are slow-growing and mostly become symptomatic when they attain significant size. They do occur at other anatomical locations, but fourth ventricle is a rare location. Three representative cases with their outcomes are described here. Methods: The systematic review was done with adherence to predefined criteria. The studied variables were age, gender, duration of symptoms (DOS), clinical features, hydrocephalus (HCP), extent of resection, postoperative complications, outcome, follow–up, and recurrence. Statistical analysis was done to identify predictive factors for outcome. Results: Final analysis included 58 studies containing 131 patients. The most common clinical feature was cerebellar dysfunction (93%). The most common cranial nerve involved was the abducens nerve ( n = 37, 28.46%). Preoperative HCP was present in nearly a third (35%) of patients. The outcomes were not different with age ( P = 0.23), gender ( P = 0.74), DOS ( P = 0.09), and HCP ( P = 0.50). Improved outcomes were associated with total resections ( P = 0.001), absence of preoperative cranial nerve dysfunctions ( P = 0.004), and presentation with features of raised intracranial pressure ( P = 0.005). Longer DOS (mean 76.74 months) was associated with significantly increased cranial nerve nuclei involvement ( P = 0.03). Aseptic meningitis was reported in 14.5% of cases. Recurrences were infrequently reported ( n = 9). Conclusions: Although the fourth ventricular epidermoid lesions are difficult to detect in an innocuous stage, when found, they should be extirpated early and totally, as a longer DOS leads to cranial nerve dysfunctions and suboptimal outcomes.

Epidermoid cyst of the cerebellar vermis: Case report of a rare medial topography

“…Intracranial epidermoid cysts are histologically benign, slowly growing, congenital neoplasms, that account for less than 2% of all intracranial tumors and 1%-5% of posterior cerebral fossa tumors [1 , 4] . Cerebellopontine angle (CPA) is the most common intracranial location for these pathologies constituting 40% of all cases [2 , 6] .…”

“…Epidermoid cysts are very rare benign tumors and represent less than 2% of all intracranial tumors [1] . They are slow growing, developed either from ectodermal inclusions at the time of neural tube closure between the third and fifth week of gestation, or less frequently secondary to post-traumatic or iatrogenic penetration of the epidermis at the level of the sub-arachnoid spaces [2 , 3] .…”

“…They are slow growing, developed either from ectodermal inclusions at the time of neural tube closure between the third and fifth week of gestation, or less frequently secondary to post-traumatic or iatrogenic penetration of the epidermis at the level of the sub-arachnoid spaces [2 , 3] . They are formed by the progressive accumulation of keratin debris from an epithelium of ectodermal origin “trapped” during embryogenesis, which is why they are sometimes compared to “skin in the wrong place” [1 , 2] . These tumors are ubiquitous and are located in the subarachnoid spaces, which they fill without destroying the nerve structures.…”

“…These tumors are ubiquitous and are located in the subarachnoid spaces, which they fill without destroying the nerve structures. They are usually located in the cerebellopontine angles as well as in the parasellar and temporal regions [1 , 4] . Medial forms are exceptional [3 , 5] .…”

Retroperitoneal congenital epidermoid cyst misdiagnosed as a solid pseudopapillary tumor of the pancreas: A case report

“…Acquired tumors are mostly caused by trauma and surgery wherein the epidermis is introduced into deep tissue. Epidermoid cysts are commonly found in the brain, trunk and neck and less commonly reported in the testis, penis, spleen and kidney[ 1 , 2 ].…”