We aimed to identify whether there is any correlation between chromosomal/genetic changes, nuclear morphology and the histological grade of urothelial carcinomas of the urinary bladder. Morphometry and multicolour fluorescence in situ hybridisation (FISH) techniques were applied to 250 cells in five low-grade cases and 350 cells in seven high-grade cases of urothelial carcinoma. Compared with low-grade carcinomas, most high-grade cases showed larger and more variable nuclear size, more frequent polysomy of centromere enumeration probes (CEPs) 3, 7 and 17, and the loss of the 9p21 locus. The number of CEP signals in cells was increased as the nuclear area of the cells became larger. Cells with gains in two or more types of CEP had significantly larger nuclei than cells with normal FISH signal patterns. In conclusion, the present study indicates that there was a correlation between nuclear morphology and chromosomal/genetic changes which were related to histological grading. Thus, we show that differences in the chromosomal/genetic aberrations present in low- and high-grade tumours can affect not only nuclear morphology but also the histopathological and clinical behaviour of urothelial carcinomas.
Keywords: UroVysion; chromosome; nuclear morphology; urinary bladder; urothelial carcinoma.