DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOR - MORPHOLOGICAL, IMMUNOCYTOCHEMICAL, AND DEOXYRIBONUCLEIC-ACID ANALYSES IN A PEDIATRIC SERIES

OVERTREATMENT BY RADIOTHERAPY and/or chemotherapy for central nervous system tumors in infancy and childhood may be deleterious, so the recognition of surgically curable clinicopathological entities is mandatory. The dysembryoplastic neuroepithelial tumor is a complex multinodular lesion consisting of glial nodules, associated with a specific glioneuronal element and/or with focal cortical dysplasia, and occurring in young patients presenting with intractable, mostly complex partial, seizures without neurological deterioration. We report on 14 patients; 9 were from a series of 600 pediatric patients with intracranial central nervous system tumors studied at a single institution from 1988 to 1993, and 5 were referred from other pediatric hospitals. Six tumors were frontal, six were temporal, one was parietal, and one was occipitoparietal. Computed tomographic scans disclosed hypodense lesions with cystic appearances in 4 patients and slight focal postcontrast enhancements in only 2 patients, whereas magnetic resonance imaging, available for 7 of 14 patients, showed hypointense lesions in T1-weighted images and hyperintense lesions in T2-weighted images. Defonnities of the overlying cranium were also observed in five patients. The age range at the time of surgery (excluding a 20-year-old male patient who underwent surgery at the main pediatric hospital) was 2.6 to 13 years, with a mean of 6.68 years. The male to female patient ratio was 10:4, and the duration of symptoms was 0.2 to 6 years. Monoclonal antibody immunostaining with neuronal specific enolase, neurofilament, microtubule-associated protein MAP2 (clone AP20; Sigma Chemical Co., St. Louis, MO), synaptophysin (Biogenex, San Ramon, CA), and beta-tubulin confirmed the obvious neuronal component, whereas immunostaining with glial fibrillary acidic protein and S-100 confirmed the glial component. The proliferative cell nuclear antigen labeling index range was 0.38 to 7.65%, with a mean of 2.1% +/- a standard deviation of 1.96, whereas MIB1 (Immunotech, Marseille, France) (a clone recently developed from Ki-67) immunostained only sporadic nuclei. The deoxyribonucleic acid ploidy in 11 of 14 patients (static cytometry) was diploid in all (deoxyribonucleic acid index range, 0.92 to 1.08) except one, in whom it was aneuploid-triploid (deoxyribonucleic acid index, 1.52). In two patients, follow-up computed tomography failed to disclose significant growth, and the remaining patients have had no recurrence to date. Awareness of this clinicopathological entity is essential for therapeutic and prognostic purposes.