A morphometric assessment of transitional mucosa in the colon

Expression of CD44s in human colorectal cancer

CD44s is a cell adhesion molecule, which belongs to the family of hyaluronan binding proteins. Anti-body to CD44s is used to establish the association of its expression with the clinicopathological characteristics of colorectal cancer using immunohistochemical methods. The aim of this study is to investigate the expression of the standard form of CD44 (CD44s) in colorectal cancer tissues as compared to adjacent normal colonic tissues. Furthermore, the level of expression of CD44s in colorectal cancer tissues was correlated with the degree of histological differentiation, Duke s classification, sex, size and site of the tumor. Immunohistochemical analysis for CD44s was carried out in 49 paraffin-fixed sections of neoplastic colorectal tissues and non-neoplastic ones adjacent to the lesion, by the standard peroxidase-antiperoxidase method. Expression of these antigens were compared in normal and malignant epithelium and stromal cells. The results show that the level of CD44s in the epithelial and stromal cells was significantly higher in the colorectal cancer tissues than the normal ones. However, there was no association between the percentages of expressions of CD44s and the degree of histological differentiation, Duke s classification, sex or size of the tumor. There was however, a significantly higher expression of CD44s in the epithelium of rectal cancer than that of colonic cancer. This study indicates that the expression of CD44s is significantly higher in colorectal cancer tissues. However, further studies are required to understand its role in tumor progression and metastasis of this disease.

An automated machine vision system for the histological grading of cervical intraepithelial neoplasia (CIN)

The histological grading of cervical intraepithelial neoplasia (CIN) remains subjective, resulting in inter- and intra-observer variation and poor reproducibility in the grading of cervical lesions. This study has attempted to develop an objective grading system using automated machine vision. The architectural features of cervical squamous epithelium are quantitatively analysed using a combination of computerized digital image processing and Delaunay triangulation analysis; 230 images digitally captured from cases previously classified by a gynaecological pathologist included normal cervical squamous epithelium (n=30), koilocytosis (n=46), CIN 1 (n=52), CIN 2 (n=56), and CIN 3 (n=46). Intra- and inter-observer variation had kappa values of 0.502 and 0.415, respectively. A machine vision system was developed in KS400 macro programming language to segment and mark the centres of all nuclei within the epithelium. By object-oriented analysis of image components, the positional information of nuclei was used to construct a Delaunay triangulation mesh. Each mesh was analysed to compute triangle dimensions including the mean triangle area, the mean triangle edge length, and the number of triangles per unit area, giving an individual quantitative profile of measurements for each case. Discriminant analysis of the geometric data revealed the significant discriminatory variables from which a classification score was derived. The scoring system distinguished between normal and CIN 3 in 98.7% of cases and between koilocytosis and CIN 1 in 76.5% of cases, but only 62.3% of the CIN cases were classified into the correct group, with the CIN 2 group showing the highest rate of misclassification. Graphical plots of triangulation data demonstrated the continuum of morphological change from normal squamous epithelium to the highest grade of CIN, with overlapping of the groups originally defined by the pathologists. This study shows that automated location of nuclei in cervical biopsies using computerized image analysis is possible. Analysis of positional information enables quantitative evaluation of architectural features in CIN using Delaunay triangulation meshes, which is effective in the objective classification of CIN. This demonstrates the future potential of automated machine vision systems in diagnostic histopathology.

A morphometrical analysis of minute depressed adenomas in familial polyposis coli

In a morphometrical study of minute adenomas in familial polyposis coli (FPC), ranging from 0.8 mm to 1.5 mm in diameter, five parameters of depressed adenomas were compared with those of ordinary polypoid adenomas. The density of glands (DG), an index of structural atypia, and the nuclear-cytoplasmic (N/C) ratio, an index of cellular atypia, were higher in depressed adenomas than in polypoid adenomas (74.8% vs 66.8% and 37.8% vs 32.7%, respectively). The cell area (C-area) of depressed adenomas was less than that of polypoid adenomas (107.3 microns 2 vs 121.1 microns 2), but there was no significant difference in values for the nuclear area (N-area) in the two types (40.0 microns 2 vs 39.2 microns 2). The higher N/C ratio of depressed adenomas was, therefore, not caused by enlargement of the nuclei but by reduction of the cell size. In addition, values of the sphericity of nuclei (SN) (3.14 vs 3.65) indicated rounder nuclei in depressed adenomas than in ordinary ones. The higher DG and N/C ratio of the depressed adenomas indicates their higher grade of atypia than that of ordinary polypoid adenomas.

Morphometric analysis of colorectal cancer

Thirteen nuclear and cellular morphometric variables were measured in 312 cases of colorectal adenocarcinoma. All variables, except nuclear shape factors, differed significantly (P < 0.001) between normal colorectal and tumor tissue. In adenocarcinomas, epithelial nuclei in well-differentiated mucosa tended to be elliptic, while those in poorly differentiated mucosa were more spheric. Increasing values of maximum nuclear and elliptic diameter were associated with progression from none to simple tubule configuration (P < 0.001), none to easily discerned nuclear polarity (P < 0.001), and expanding growth pattern (P < 0.001). Univariate survival analysis revealed that none of the morphometric variables was significantly related to patient survival. Multivariate regression analysis showed that no morphometric variable could add significantly to a model containing the variables of patient age, Dukes stage, and tumor differentiation. Morphometry may be useful in distinguishing malignant from normal tissue and degrees of differentiation, but it is of little prognostic value in colorectal adenocarcinoma.

Differentiation-associated changes in mucin glycoprotein antigenicity in mucosa adjacent to rare gastrointestinal tract tumours of non-mucosal origin

We have investigated changes in mucin antigenicity and morphology in the perineoplastic mucosa adjacent to rare, predominantly non-mucosal gastrointestinal (GI) tumours. Twenty-nine tumours of small and large intestine, including primary mesenchymal and ectodermal tumours, were examined immunohistochemically using 11 monoclonal antibodies (MAbs) raised against SIMA and LIMA (small and large intestinal mucin antigens). Non-epithelial GI tumours were essentially non-reactive, while adjacent mucosa showed altered mucin expression and morphology, in particular, features of transitional mucosa (TM). Combinations of different SIMA epitopes were detected adjacent to all colorectal tumours, and, similarly, LIMA epitopes adjacent to small intestinal tumours. Specific patterns adjacent to certain tumours may reflect influences of factors produced by individual tumours on mucin composition. Altered antigenicity and morphology in TM thus appear to be reactive changes in response to a wide range of GI tumours, presumably as a consequence of factors secreted by the tumour and/or a host response to the tumour.

Biopathologic characteristics of DNA content in crypt cells of transitional mucosa adjacent to carcinomas of the rectum and rectosigmoid

The transitional mucosa (TM) adjacent to carcinomas of the large bowel shows histologic and mucin histochemical changes that may indicate premalignant change and may be of prognostic value after radical resection. In this study, 10 anterior resection specimens from patients with carcinomas of the rectum and rectosigmoid were used to compare the nuclear DNA content in TM with those in cancer tissue and with those in nontransitional mucosa (N-TM; i.e., uninvolved mucosa remote from tumors showing normal histologic and mucin histochemical features). The nuclear DNA content was assessed using DNA image cytometry on Feulgen-stained sections. As compared with N-TM, crypts in TM contained greater numbers of cells, were elongated, and were more likely to be branched with marked sialomucin secretion, accompanied by a marked reduction in the normal sulfomucin content. The mean nuclear DNA content in the upper, middle, and lower thirds of crypts was significantly higher in TM than in N-TM, and the nuclear DNA content in TM exhibited no correlation to that in tumors. The results suggest that TM adjacent to carcinomas of the rectum and rectosigmoid has higher proliferative activity, providing further evidence that TM may be an unstable premalignant change.

The clinical and biological significance of the transitional mucosa adjacent to colorectal cancer

The underlying nature of the transitional mucosa adjacent to colorectal cancer is defined and the evidence for and against the statement that this transitional mucosa involves primary premalignant change presented in this article. An association between mucin histochemical changes at the margins of resection and a poorer clinical outcome of patients has been recognized in patients with colorectal cancer after surgery. The retained transitional mucosa at the margins of resection appears to correlate with tumor recurrence and a poorer survival in patients who have undergone radical resection. It is considered that the transitional mucosa adjacent to colorectal cancer and its presence at the margins of resection may be an important prognostic marker for patients with large bowel cancer following radical resection.

Characterization of human colorectal mucosa, polyps, and cancers by means of computerized morphonuclear image analyses

Fifty-eight Feulgen-stained imprint smears from freshly resected colorectal tissue were analyzed by means of a SAMBA 200 cell image processor to establish a quantitative grading of their evolution from normal to malignant mucosa on the basis of 15 morphonuclear parameters relative to morphometry (nuclear size), densitometry (DNA content), and texture (chromatin pattern). The colorectal samples belonged to six groups: normal mucosa from patients without (Group 1) or with (Group 2) colorectal cancer, adenomas (Group 3), and cancers corresponding to the three stages of the Dukes' classification (Groups 4 to 6). Results indicated that analysis of the morphonuclear parameters computed on 250 to 300 nuclei/cases objectively and quantitatively showed the adenoma-cancer sequence. This need for only a small number of nuclei to assess a highly efficient analysis created a preoperative investigative tool using cytologic smears during endoscopy. The authors also made preliminary data banks for objective and reproducible grading of unknown cases by comparisons (discriminant analyses) with their contents. This approach must be validated prospectively on a large series of cases to furnish a system for colorectal malignancy diagnosis.