gms | German Medical Science

Objective: Long-term epilepsy associated tumors (LEATs) are usually well-circumscribed, mostly benign tumors associated with drug-resistant epilepsy. However, some LEATs can recur and eventually become malignant. The aim of the present study was to analyse the reoperation rate of LEATs with a particular focus on both epileptological and oncological aspects.

Methods: This retrospective single-center study includes a total of 43 patients, who underwent reoperation for LEAT. The reasons (tumor recurrence versus tumor rest) and indications for reoperation (oncological, epileptological both) were evaluated. Epileptological data, histopathological results and oncological outcome concerning tumor recurrence, malignisation rate and overall survival were analyzed.

Results: A total of 186 patients underwent neurosurgical resection for LEAT. Of those, 43 patients (23%) needed second surgical intervention because of tumor recurrence or on-going seizures. The duration between first surgery and reoperation was 92 months (+/-72). The histopathological examination revealed 10 (23.3%) dysembryoplastic neuroepithelial tumors (DNET), 27 (62%) gangliogliomas (GG), 3 (7%) pilocytic astrocytomas, and 3 (7%) pleomorphic xanthoastrocytomas (PXA). The first treatment included surgical resection in 37 and SEED implantation in 6 patients. After the first surgical intervention 39 patients did not become seizure free. Of those, 20 patients (51%) showed tumor rest, 15 (39%) had tumor recurrence and in 4 (10%) patients no morphological reason for the on-going epilepsy could be found. Tumor progression without seizures was observed in 4 patients. Thus, the indication for reoperation was epileptological in 24, oncological in 11 and combination of both in 8 patients. DNET were re-operated significantly more often because of tumor rest (p=0.02). At last available outcome 33 patients (76.7%) were completely seizure free. Tumor malignisation occurred in 8 patients. All of them underwent adjuvant radiotherapy and in 6 patients additional chemotherapy was performed. 5 patients died during the follow-up period (4 GG and 1 PXA).

Conclusion: Reoperation for LEAT provides satisfying epileptological and oncological results in most of the cases. Although LEATs showed low malignisation rate, tumour recurrence occurred in almost half of the re-operated cases, implying that not only the epileptological but also the oncological aspect should be taken into consideration.