✓ The histological grade and the bromodeoxyuridine (BUdR) labeling index of 60 astrocytomas of “ordinary” cell types (fibrillary, protoplasmic, gemistocytic, and anaplastic astrocytomas and glioblastomas) were compared to determine whether the grading system reflects the proliferative potential of the tumors. The tumor grade was based on the presence or absence of four criteria (nuclear abnormalities, mitosis, necrosis, and vascular endothelial proliferation): Grade 1, no criterion, Grade 2, one criterion, Grade 3, two criteria; and Grade 4, three or four criteria. The BUdR labeling index, or percentage of S-phase cells, was calculated in paraffinembedded tumor sections after in situ labeling by intraoperative intravenous infusion of BUdR, 200 mg/sq m. Exponential regression analyses showed a positive correlation between the histological grade and labeling index (r = 0.88, p < 0.001) that was stronger than the correlations between log labeling index and age (r = 0.55, p < 0.001) and between grade and age (r = 0.55, p < 0.001). These results indicate that the histological grading system reflects the proliferative potential of “ordinary” astrocytomas.
Comparative study in a series of 60 cases
François Labrousse, Catherine Daumas-Duport, Leszek Batorski and Takao Hoshino
Paul Hallacq, François Labrousse, Nathalie Streichenberger, Dan Lisii and Georges Fischer
✓ Myxopapillary ependymomas represent the most frequent type of ependymomas found at the conus medullaris—cauda equina-terminal filum level. They are neuroectodermal tumors mainly observed during the fourth decade of life. Pediatric cases have been rarely described at an age range of 10 to 13 years. Myxopapillary ependymomas are typically solitary tumors involving the terminal filum. Simultaneous discovery of two tumors located both on the terminal filum has been reported once. The pathogenesis of this focal ependymoma located at the same embryological level, on the terminal filum, is uncertain; it may represent one end of a spectrum, the other end being the giant ependymoma of the terminal filum.