In this paper we study the feasibility of measuring the diverse biological parameters in stereotaxic biopsies from human brain lesions. These biological parameters are the nuclear area (NA), the proliferation index (PI) and the ploidy level, the latter of which was evaluated by means of the DNA index (DI) and histogram type (DHT). These parameters were assessed by means of the digital cell image analysis of Feulgen-stained nuclei. This analysis was performed on 124 samples from 22 computed tomography (CT)-guided stereotaxic biopsies. The data show that the methodology used here enables the above parameters to be assessed on small samples without limiting the classical anatomopathological diagnosis. The data also reveal that the DHT corresponded more accurately to the ploidy level in the sample analysed than the DI. Lastly, it appears that supratentorial astrocytic tumours of the adult, which constituted the majority of the cases analysed here, are strongly heterogeneous at a biological level.