Polyploidy in non-neoplastic tissues.

AIM To investigate the prevalence and amount of polyploidy in fine needle aspiration specimens of the liver, urinary cytospin preparations, and cytospin preparations from pleural and peritoneal fluid. METHODS Cells from 44 liver smears, 48 urine specimens, and 46 pleural and peritoneal aspirations were examined. After Feulgen restaining the DNA content of 100 randomly selected nuclei was determined using a TAS-plus image analysis system, combined with an automated microscope. RESULTS Polyploidy was observed up to 16c in the liver, and up to 8c in urothelium and mesothelium. Sixty eight per cent of the liver aspirates contained polyploid nuclei. The rate in urothelium was 20.8% and in mesothelium 6.5%. CONCLUSIONS Polyploidy in the liver may be interpreted as being associated with tissue differentiation, but the findings in urothelium and mesothelium remain of unknown importance.