Langzeit-Management intrakranieller Epidermoidzysten - die Balance zwischen Resektionsausmaß und Funktionserhalt

Epidermoid cysts represent about 1% of all intracranial neoplasms. Surgical treatment of these rare benign lesions can be challenging due to capsular membranes adhering to critical neurovascular structures, particularly as they are frequently widespread and deep-seated. Their tendency for recurrence necessitates meticulous surgical intervention, balancing radicality and the risk of neurological morbidity. The current study focuses on correlating surgical outcomes with the extent of resection and recurrence rates during long-term follow-up.

The monocenter retrospective study involved patients being operated for epidermoid cysts between 2000 and 2021. A detailed analysis of their clinical, surgical, and neuroradiological data was performed, with special interest on long-term symptom development and changes in imaging.

The study included 55 patients (56.4% male) with epidermoid cysts located predominantly in the cerebellopontine angle/prepontine cistern (75.3%), beside supratentorial and fourth ventricular lesions. The mean age at surgery was 44.3 years. The most common symptoms were dizziness and trigeminal nerve affection (29% each), followed by hearing difficulties/loss, headaches, and gait disturbances (27% each). Postoperative MR imaging showed remnants of restricted diffusion < 10 mm in 28%, and remnants > 10 mm in 7% of cases (non-total removal). Progression on imaging after non-total removal was found in 64.0%, whereas recurrence after total removal was detected in 20.5%. The rate of immediate postoperative symptom improvement was similar after total and non-total removal (12.6% vs. 10.5%), and after one year, the rate of symptom improvement was higher after total removal (41.7% vs. 28.0%). The rate of new, though mostly transient, cranial nerve deficits after surgery was similar in both groups (total vs. non-total removal: CN III, VI or VI: 15.4 vs. 20%, CN VII: 15.4 vs. 8%, CN VIII: 5.1 vs. 0%, CN IX, X, XI or XII: 10.2 vs. 16%), as were general, usually minor surgical complications (total vs. non-total removal: 20.5 vs. 16%).

A more radical resection without remnants of restricted diffusion on postoperative imaging was associated with a higher rate of long-term symptom improvement and less recurrence. However, functional preservation should remain priority in the surgical management of epidermoid cysts. Long-term follow-up is always mandatory, as recurrences were regularly observed even after total removal.