Dual Pathology in Chronic Epilepsy Patients with Neoplasms
RA Prayson. Cleveland Clinic Foundation, Cleveland, OH
Background: Neoplasms are a well established cause of medically intractable or chronic epilepsy. Certain tumors, including gangliogliomas (GG) and dysembryoplastic neuroepithelial tumors (DNT), are well known to be associated with cortical dysplasia. This study retrospectively examines the incidence of dual pathology in patients with tumors and chronic epilepsy.
Design: Retrospective view of 270 tumors arising in patients with medically intractable epilepsy encountered during a 20 year period (1989 to 2009). Dual pathology was noted in 50/270 (17.8%) patients, including 27 males (54%) with a mean age at surgery of 17.7 years (range 1-52 years).
Results: The vast majority of lesions n=40 (80%) were located in the temporal lobe and less commonly parietal lobe (n=4) and occipital lobe (n=3). Tumor diagnoses included GG (n=29), DNT (n=10), low grade glial/glioneuronal neoplasm (n=5), low grade astrocytoma (n=2), angiocentric glioma (n=1), low grade mixed glioma (n=1), DNT/GG mixed tumor (n=1), and meningioangiomatosis (n=1). Forty-one (82%) tumors represented WHO grade I neoplasms. Concomitant pathology included malformation of cortical development (cortical dysplasia) in 40 patients (80%) (Palmini et al type I: n=37; Palmini et al type II: n=3). Hamartias were identified in 10 patients (20%), hippocampal sclerosis in 4 patients (8%), and nodular heterotopia in 1 patient (2%).
Conclusions: Dual pathology was observed in a significant subset of chronic epilepsy patients with neoplasm (17.8% in this study). Most tumors were WHO grade I neoplasms and represented GG or DNET. The true incidence of dual pathology was likely underrepresented, given the limited extent of adjacent nontumoral tissue sampling in cases of resected tumor. Coexistent pathology may account for the incidence of recurrent or residual epilepsy in patients who undergo tumor resection.
Tuesday, March 23, 2010 1:00 PM
Poster Session IV # 242, Tuesday Afternoon