DNA INDEX AND S-PHASE IN PRIMARY BRAIN-TUMORS - A COMPARISON BETWEEN FRESH AND DEPARAFFINIZED SPECIMENS STUDIED BY FLOW-CYTOMETRY

Forty-nine primary intracranial tumors (33 astrocytomas, eight acousti c schwannomas, five oligodendrogliomas, and three miscellaneous tumors ) were studied by flow cytometry. Each tumor specimen was divided into two portions: one was studied as an unfixed suspension stained with p ropidium iodide and the other after formalin fixation and paraffin emb edding. The 50-mu m sections from the paraffin blocks were deparaffini zed, rehydrated, and enzymatically disintegrated, and the cells in sus pension were stained with propidium iodide. Flow cytometry of the two portions showed a significant correlation between fresh and fixed spec imens regarding the S-phase (r = 0.87) and a very close correlation of the deoxyribonucleic acid (DNA) index (r = 0.95). When the 33 astrocy tomas were analyzed separately, similar results were obtained (r = 0.8 6 for S-phase and r = 0.93 for DNA index, respectively). This study de monstrated a high correlation between fresh and fixed specimens for DN A ploidy and S-phase both in primary intracranial tumors in general an d also in the selected subgroup of astrocytomas.