Morphometrical analysis in ulcerative colitis with dysplasia and carcinoma

Semi-automatic image analysis was used to assess the epithelium in ulcerative colitis with dysplasia and carcinoma. There were three main sources of variation within the dataset: (1) nuclear size, nuclear cytoplasmic ratio and nuclear stratification; (2) the variation of nuclear size; and (3) nuclear shape and polarity. Discriminant analysis chose the mean nuclear cytoplasmic ratio % and the coefficient of variation of nucleus to cell apex distance to derive a scoring system which completely separated normal mucosa (n = 20) and carcinoma (n = 30). The classification rule allocated all high grade dysplasia to the tumour category. Scores for regeneration and low grade dysplasia overlapped with each other and the normal and tumour groups. Scatter plots of the two discriminating variables showed good separation of regeneration and high grade dysplasia, and a degree of overlap with low grade dysplasia. The scatter plots allowed identification of overlapping and misallocated cases, requiring review of their histology and redesignation of the diagnosis in five cases. This study confirms quantitatively the visual criteria used in grading mucosal changes and their trend from regeneration through dysplasia to carcinoma. It underlines the necessity of assessing not only cytological but also architectural and inflammatory components when diagnosing regeneration and low grade dysplasia. Mucosal morphometry may be of use in confirming high grade dysplasia which is an indication for colectomy.