History of Management of Supratentorial Dysembryoplastic Neuroepithelial Tumors in Children

Understanding of Disease

• First described in 1988: DNET is a relatively “new” tumor type, first identified in 1988 (11) and described in the WHO classification only in 1993. Nonetheless, DNETs are not rare; in unselected series they make up approximately 1% of brain tumors, while in epilepsy surgery centers they account for 5–20 % of resective epilepsy surgeries.
• Misidentified as other low-grade gliomas: Before the entity was described, these lesions were probably diagnosed as low-grade astrocytomas, oligodendrogliomas, oligoastrocytomas, or gangliogliomas.
• Some classify DNET as neurodevelopmental tumor: Together with gangliogliomas, DNETs are classified by some authors as neurodevelopmental tumors, believed to have developed during embryogenesis (2).

Technological Development

• MRI scan: The preoperative diagnosis of a DNET depends heavily on MRI. Indeed, the entity was not described until 1988, a few years after the widespread introduction of MRI for the evaluation of patients with epilepsy.
• Advancement in surgical technology:  The surgical treatment of DNET borrows both from glioma surgery and from nonlesional epilepsy surgery. Technological advances in glioma surgery such as ultrasound aspirators (CUSA), awake surgery, image-guided surgery, and interventional MRI have played important roles. All investigations performed in epilepsy surgery to detect the surgical focus that has to be resected have also improved the results.

Surgical Technique

• Intraoperative MRI: The role of interventional MRI in low-grade glioma surgery is increasing, both to enhance safety and to maximize tumor removal. It can be expected that interventional MRI will also become more important for surgery of DNETs.