A combination of cytological and architectural morphometry in assessing regenerative hyperplasia and dysplasia in ulcerative colitis

Morphometry and stereology were used to assess the cytological and architectural characteristics of regenerative and dysplastic colorectal mucosal abnormalities in ulcerative colitis. Reproducibility of measurements was assessed and found to be good, confirming the objective and reproducible nature of morphometric analysis. Discriminant analysis between the morphometric features of regenerative mucosal change and low‐grade dysplasia revealed the significant cytological and architectural variables from which a cytological and architectural score were derived. The architectural score was capable of classifying all of the cases into their correct diagnostic category, although a combination of the two scores provided better separation of cases. Probability density analysis was carried out so that probabilities of group membership could be allocated to cases, given their cytological and architectural scores. Discriminant analysis was also applied to low‐ and high‐grade dysplasia. Important cytological and architectural variables were identified and used separately to derive scoring systems. In combination, the dual scoring of lesions was capable of separating low‐ from high‐grade dysplasia, although overlap was still evident. Again, probability density analysis allowed the allocation of cases into one or other category, although a closer examination showed that such a rule could not successfully classify a new set of low‐ and high‐grade dysplasia cases. Quantitative histological analysis of mucosal abnormalities is shown to be of use in the objective diagnosis of reactive and dysplastic change in patients with ulcerative colitis. The use of simple scoring systems and probability based allocation of cases promotes the future role of morphometric techniques in the diagnostic laboratory.