CONGENITAL OLIGODENDROGLIOMA - A CASE-REPORT OF A 34TH-GESTATIONAL WEEK FETUS WITH IMMUNOHISTOCHEMICAL STUDY AND REVIEW OF THE LITERATURE

A case of congenital oligodendroglioma occurring in a 34th-gestational week fetus is reported. The tumor was necrotic, hemorrhagic, and gela tinous. It covered the basal part of the brain, and almost the entire cerebellum was replaced by the tumor, The tumor cells had small, round , hyperchromatic nuclei and watery clear cytoplasm, and were arranged in a paved or alveolar pattern, Immunohistochemically, S100 protein, m yelin-basic protein, neuron-specific enolase and Leu 7 were weakly pos itive for the cytoplasm, but glial fibrilliary acidic protein, synapto physin, neurofilament, desmin, and vimentin were negative. Many tumor cell nuclei were positive for mutant p53 protein, and the labeling ind ex was 85%., But there was no genetic alteration in exons 4 to 9 of p5 3 gene from the peripheral blood. The apoptosis index was 1.5%. Consid ering the p53 labeling index and the apoptosis index together, this co ngenital oligodendroglioma may be regarded as potentially malignant de spite the benign morphological features, Copyright (C) 1997 by W.B., S aunders Company.