Intracranial epidermoid cysts: benign entities with malignant behavior: experience with 36 cases

Abstract

Intracranial epidermoid cysts are benign slow-growing ectodermal inclusions that account for less than 1% of all intracranial tumors. We retrospectively reviewed 36 such cases to evaluate the demographic characteristics, clinical manifestations, anatomical distribution, surgical management, and treatment outcome of these tumors. Additionally, we sought to identify the relationship between median or paramedian cistern tumor localization and clinical parameters, such as recurrence risk, hospitalization duration, and postoperative complication rates. The most frequently observed neurological symptoms were transient headaches (77.8%), dizziness (36.1%), CN VII palsy (19.4%), CN VIII hearing difficulty (19.4%) and cerebellar signs (19.4%). The most common surgical approaches included retrosigmoid (36.1%), subfrontal (19.4%) and telovelar (19.4%) approaches; gross total resection was feasible in 83.3% of cases. The postoperative complication rate was 38.9%. Tumors were more frequently found in the paramedian cisterns (47.2%), followed by the median line cisterns (41.6%). Multivariate analysis revealed that postoperative hydrocephalus and age < 40 years were prognostic factors for tumor recurrence. Median-like tumor location was a risk factor for the presence of symptomatic hydrocephalus both preoperatively and postoperatively, increasing the likelihood of protracted hospitalization (> 10 days). Despite their benign histopathological nature, these tumors have an important clinical resonance, with a high rate of postoperative complications and a degree of recurrence amplified by younger age and hydrocephalus.

Figure 1

Distribution of the patients stratified by symptomatology.

Figure 2

Patient 1, IVth ventricle epidermoid cyst: images (a–c)—preoperative MRI (T1 DWI in sagittal, axial and coronal sequences) revealed a hypodense mass, respectively hyperdense in DWI, filling the fourth ventricle; 3-month follow-up MRI: images (d–f) (T1 and DWI sequences) demonstrate gross-total resection without remanence at the level of the fourth ventricle floor; images (g) and (h)—intraoperative aspect, median suboccipital approach.

Figure 3

Patient 2, recurrent cerebellopontine angle epidermoid cyst, preoperative MRI (performed in 2015). Images (a) and (b) T2 and T1 sequences, respectively, revealed an epidermoid cyst located in the right cerebellopontine angle. Three-month follow-up MRI (images c and d—DWI sequence and T2 sequences, respectively) demonstrated a subtotal resection with a small remnant deeply located in the right middle cerebellar peduncle. The patient was asymptomatic, so he was monitored periodically with MRI imaging at 6-month intervals. The last MRI performed in 2022 demonstrated a large recurrent tumoral mass, but the patient was neurologically stable and asked for delayed reintervention (image e—T2 sequence and image f—T1 sequence).