Low-grade epilepsy-associated neuroepithelial tumors: Tumor spectrum and diagnosis based on genetic alterations

Brain tumors can always result in seizures when involving the cortical neurons or their circuits, and they were found to be one of the most common etiologies of intractable focal seizures. The low-grade epilepsy-associated neuroepithelial tumors (LEAT), as a special group of brain tumors associated with seizures, share common clinicopathological features, such as seizure onsets at a young age, a predilection for involving the temporal lobe, and an almost benign course, including a rather slow growth pattern and thus a long-term history of seizures. Ganglioglioma (GG) and dysembryoplastic neuroepithelial tumor (DNET) are the typical representatives of LEATs. Surgical treatments with complete resection of tumors and related epileptogenic zones are deemed the optimal way to achieve postoperative seizure control and lifetime recurrence-free survival in patients with LEATs. Although the term LEAT was originally introduced in 2003, debates on the tumor spectrum and the diagnosis or classification of LEAT entities are still confusing among epileptologists and neuropathologists. In this review, we would further discuss these questions, especially based on the updated classification of central nervous system tumors in the WHO fifth edition and the latest molecular genetic findings of tumor entities in LEAT entities.

Automated summary

Brain tumors involving cortical neurons can often lead to seizures, especially intractable focal seizures. Low-grade epilepsy-associated neuroepithelial tumors (LEATs), such as ganglioglioma (GG) and dysembryoplastic neuroepithelial tumor (DNET), have common clinicopathological features including seizure onsets at a young age, involvement of the temporal lobe, and a slow growth pattern. Surgical treatments with complete resection of tumors and epileptogenic zones offer the best chance for seizure control and recurrence-free survival in patients with LEATs. However, there is ongoing debate among experts regarding the classification and diagnosis of LEAT entities.