Stereotactic biopsies from astrocytic tumors. Diagnostic information contributed by the quantitative chromatin pattern description.

OBJECTIVE

To reduce the problem of heterogeneity in astrocytic tumors by means of computer-assisted microscope analysis of Feulgen-stained nuclei.

STUDY

DESIGN

Thirty-eight glial tumors for which we obtained 227 stereotactic biopsies were subjected to digital cell image analysis of Feulgen-stained nuclei. This series of 38 glial tumors included 36 supratentorial astrocytic tumors (13 astrocytomas, 7 anaplastic astrocytomas and 16 glioblastoma multiformes) and 2 grade 3 astrocytic tumors of the cerebellum.

RESULTS

The results suggest a new methodology, enabling the biologic characteristics of the brain parenchymal area surrounding a given glial tumor to be characterized. This methodology relies on the performance of three successive steps. The first is quantitative characterization of nuclear morphology and its chromatin pattern by means of 15 morphonuclear variables. This characterization is carried out by means of the computer-assisted microscope analysis of Feulgen-stained nuclei. The second step consists of setting up morphonuclear data banks, with each process giving the precise portrait of a given cell nuclear population. This process is carried out by means of multivariate analysis, taking into account the 15 variables mentioned above. Multivariate analysis includes principal components analysis followed by the canonical transformation of the data. The third step consists of testing unknown cases against these morphonuclear data banks. This is carried out by means of linear discriminant analysis, which enables the various cell nuclear types in the stereotactic biopsy to be quantified.

CONCLUSION

The present methodology makes it possible to investigate whether infiltrating tumor cells are present in or absent from the parenchymal brain area surrounding a glial tumor. It can therefore contribute additional information to that contributed by computed tomography and/or magnetic resonance imaging with respect to the precise delineation of the volume of a brain tumor. This delineation must be as precise as possible to allow total surgical resection of the tumor and prevention of its recurrence.