New classification of epilepsy-related neoplasms: The clinical perspective

Neoplastic CNS lesions are a common cause of focal epilepsy refractory to anticonvulsant treatment, i.e. long-term epilepsy-associated tumors (LEATs). Epileptogenic tumors encompass a variety of intriguing lesions, e.g. dysembryoplastic neuroepithelial tumors or gangliogliomas, which differ from more common CNS neoplasms in their clinical context as well as on histopathology. Long-term epilepsy-associated tumor classification is a rapidly evolving issue in surgical neuropathology, with new entities still being elucidated. One major issue to be resolved is the inconsistent tissue criteria applied to LEAT accounting for high diagnostic variability between individual centers and studies, a problem recently leading to a proposal for a new histopathological classification by Blümcke et al. in Acta Neuropathol. 2014; 128: 39-54. While a new approach to tissue diagnosis is appreciated and needed, histomorphological criteria alone will not suffice and we here approach the situation of encountering a neoplastic lesion in an epilepsy patient from a clinical perspective. Clinical scenarios to be supported by an advanced LEAT classification will be illustrated and discussed.