Freiburg Neuropathology Case Conference. A Mass Lesion of the Fourth Ventricle

Fourth Ventricular Epidermoid Cyst - Case Series, Systematic Review and Analysis

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.

Predictors of Outcomes in Fourth Ventricular Epidermoid Cysts: A Case Report and a Review of Literature

OBJECTIVE

To present an illustrative case of fourth ventricular epidermoid cyst and review the literature to identify predictors of surgical outcomes.

METHODS

A case of fourth ventricular epidermoid cyst is presented and a systematic review of 5 popular databases was performed by independent authors. Stepwise logistic regression was performed to identify clinical predictors of outcomes.

RESULTS

A 21-year-old woman presented with 3 months of headaches and visual obscurations and was diagnosed with a multilobulated mass in the fourth ventricle. The patient underwent suboccipital craniotomy. Complete removal of the mass was achieved and the final diagnosis was consistent with an epidermoid cyst. The systematic review identified 23 studies that reported 37 patients. Mean age was 42.8 years. Mean length of time between symptom onset and diagnosis was 4.43 years. Age (P = 0.049) and duration of symptoms (P < 0.001) were significantly different between patients who experienced symptom improvement and those who did not. Duration of symptom onset to diagnosis was a significant predictor of poor outcomes (odds ratio, 1.19, 95% confidence interval, 1.003-4.785).

CONCLUSIONS

Our review found that in patients with fourth ventricular epidermoid cysts, unfavorable outcomes were predicted by older age and by longer intervals from symptom onset to diagnosis. Clinicians should maintain a high index of suspicion for fourth ventricular epidermoid cysts in patients presenting with cerebellar signs and visual disturbances.