Morphometrical analysis of urothelial cells in voided urine of patients with low grade and high grade bladder tumours.

Abstract

SUMMARY The morphometric differences between the urothelial cells (wet-fixed Papanicolaoustained) in the voided urine of 20 patients with low grade and high grade bladder tumours were measured. The morphometrical data of this learning set resulted in a cytomorphometrical classification rule, which was applied to a test set of 21 cases with low grade and high grade bladder tumours.The results of the cytomorphometrical classification rule correspond very well with the histomorphometrical classification and the histological grade of the parent tumours.The results indicate that it is feasible to classify bladder tumours using the cytomorphometrical data of the exfoliated urothelial cells alone.In a previous study' it was shown that cellular and nuclear dimensions of urothelial cells in the voided urine of patients with grade I and grade II tumours differ, and that normal urothelial cells cannot be distinguished from cells exfoliated from grade I tumours. However, it was not possible to separate all grade I tumours from all grade II tumours. For therapeutic reasons it is important to discriminate between these low grade bladder tumours (grade I and II) and high grade (grade III) tumours; it is clinically less important to separate grade I and II tumours.2 An objective method of distinguishing low grade from high grade tumours is desirable.For the classification rule (learning set) were used: mean nuclear area, mean nuclear diameter, standard deviation nuclear area, mean nuclear/cytoplasm (N/C) area ratio, mean N/C diameter ratio, standard deviation N/C area ratio and mean cytoplasmic area. Material and methods LEARNING SEITwenty cases of bladder tumour were selected for the learning set: 10 patients with a low grade tumour (grade I and II) and 10 cases with a high grade bladder tumour (grade III). The test set consisted of 21 cases, of which voided urine and the transurethrally resected bladder tumour were available for this study. HISTOMORPHOMETRYThe parent tumours of the test set were histomorphometrically classified using a classification rule. For this classification the nuclear areas of the superficial cells are measured.10 CYTOLOGICAL MATERIAL Voided urine was used for this study. Two consecutive samples were taken from each patient and the smears with the highest cytological grading were used. Wet-fixed Papanicolaou-stained smears were used for this study. The wet-fixation was achieved by spray-fixing (coating fixative 80 ml polyethylene glycol (MW 300), 690 ml isopropanol, 170 ml acetone, 60 ml distilled water).