Occurrence of cell death (apoptosis) in prostatic intra-epithelial neoplasia

The aim of our study was to assess the frequency and location of apoptotic bodies (ABs) in haematoxylin and eosin-stained sections of prostatic intraepithelial neoplasia (PIN) and then to compare the patterns with those in benign prostatic hyperplasia (BPH) and prostatic invasive adenocarcinoma (PAC). ABs were identified in all epithelial cell layers of the ducts, acini and tumour islands, as well as in the lumina contained in such structures. In the epithelial cell layers, ABs were found in general in the intercellular space and occasionally in the cytoplasm of epithelial cells. The frequency of ABs increased from BPH through PIN up to PAC. The proportions of ABs in PIN lesions of low grade (PINlow) and high grade (PINhigh) were greater than in BPH, the values decreasing from the nuclei in the basal position towards those in the luminal layer. In PINlow, the mean category values were 0.85% (standard error, SE, 0.311%) in the basal, 0.623% (SE 0.065%) in the intermediate and 0.474% (SE 0.138%) in the luminal position. In PINhigh, the mean category values were 1.006% (SE 0.16%) in the basal position, 0.713% (SE 0.182%) in the intermediate and 0.618% (SE 0.172%) in the luminal position. The proportions of ABs in adenocarcinoma with cribriform pattern decreased from the basal towards the luminal layer, as for PIN: 1.806% (SE 0.346%) in the basal position, 1.15% (SE 0.172%) in the intermediate and 0.886% (SE 0.137%) in the luminal position. In the solid/trabecular adenocarcinomas, the mean category value in the cell layer adjacent to the stroma was 2.154% (SE 0.203%), whereas in the other cell layers it was 2.052% (SE 0.239%). In small and large acinar adenocarcinomas, the proportions of positive nuclei were 1.022% (SE 0.1%) and 0.922% (SE 0.163%), respectively. The evaluation of the frequency and location of ABs gives accurate information on cell death in PIN in comparison with BPH and PAC.