Cytonuclear morphometry in the assessment of dysplasia in colorectal adenomatous polyps. A pilot study

Analysis of images for detection of oral epithelial dysplasia: A review

This paper provides a review of various image analysis approaches that have been previously used for recognition of dysplasia in images of the epithelium of the oral cavity. This domain has become especially admissible with the uncovering of the importance of image analysis which can probably be an aid to subjective diagnosis by histopathologists. Oral malignancy is a rampant form of cancer found among people of the Indian subcontinent due to various deleterious habits like consumption of tobacco, areca nut, betel leaf etc. Oral Submucous Fibrosis, a precancer, whose pathological category falls between normal epithelium and epithelial dysplasia, is caused because of these habits and can ultimately lead to oral cancer. Hence early detection of this condition is necessary. Image analysis methods for this purpose have an enormous potential which can also reduce the heavy workload of pathologists and to refine the criterion of interpretation. This paper starts with a critique of statistics of oral carcinoma in India and distribution of cancer in intra-oral sites and moves on to its causes and diagnostic approaches including causative agents, problems in curative approach and importance of image analysis in cancer detection. The various image analysis methods to appraise the cytological and architectural changes accompanied by Oral Epithelial Dysplasia in the images of the oral epithelial region have been described in relation to 2005 WHO Classification System and it was found that in future, analysis of images based on the mentioned methods has the potential in better interpretation and diagnosis of oral carcinoma.

Disordered arrangements of basal cells as a prognostic factor for oral epithelial dysplasia: a morphometric study of 96 cases

OBJECTIVE

The aim of this study was to assess objectively the predictive value of the atypical appearance of the basal layer of oral epithelial dysplasia (OED) for development into invasive carcinoma.

STUDY DESIGN

Ninety-six OED cases were examined. These cases were divided into 2 groups: 38 cases that developed into invasive carcinoma and 58 cases that did not. Furthermore, 12 histopathological factors were quantified morphometrically in each case and assessed by Cox's proportional hazards model.

RESULTS

The standard deviation of the length between the apical membrane of the basal cells and the basement membrane was significantly associated with development of OED into invasive carcinoma (P < .001; hazard ratio, 3.124).

CONCLUSION

We provided novel, objective data demonstrating that an atypical appearance, especially the disordered arrangement of the basal cells representing loss of polarity, may be useful for predicting the development of OED into invasive carcinoma of the tongue.

Endoscopy, morphology, morphometry and molecular markers: predicting cancer risk in colorectal adenoma

The evaluation of short- and long-term risk for developing cancer in patients with colorectal adenomas is controversial. Good, reliable predictors of cancer risk in any adenoma are currently lacking and are limited to adenoma size, number and histologic type. In fact, the evaluation of any adenoma or precancer lesion (e.g., hyperplastic polyps, serrated adenoma or aberrant crypt foci) within the colorectum may be assessed by a number of techniques ranging from direct visualization through the endoscope, to microscopic assessment, and to evaluation at the molecular level. Emerging techniques may yield improved methods of adenoma risk-assessment in the near future. For one, newer endoscopy technologies include chromoendoscopy or endocytoscopy, which now render endoscopists able to resolve the surface and subsurface mucosa at cellular resolution in vivo and in real time - thus, bringing the microscope to the patient's bedside. This new era in endoscopic imaging is dubbed 'histoendoscopy'. Further, while traditional views of classifying protruding and sessile lesions include those of Haggitt, the sm-classification, the Japanese and the so-called Vienna classifications to evaluate neoplasia, the development of new molecular techniques may give way to new methods of classifying preneoplasia and precancerous lesions. This review discusses some pros and cons of risk evaluation technologies in the colorectal tract by endoscopy, microscopy, and quantitative and molecular features. The morphometry-based studies performed over the past decades for the quantitative assessment of cellular and nuclear features within adenomas have failed to yield results amenable for clinical translation and are unlikely to improve further and gain widespread use with current technology. Rather, emerging knowledge of pathway-specific markers through the outlining of a molecular classification will likely be the basis for improved detection and diagnosis. The emerging genomic and proteomic technologies allowing for noninvasive tests to detect (asymptomatic) cancer and neoplasia are discussed. Lastly, the importance of recognizing bias and pitfalls and the adherence to guidelines for biomarker research are addressed.

Predictive variables for the biological behaviour of basal cell carcinoma of the face: relevance of morphometry of the nuclei

We did a morphometric analysis of 130 histological sections of basal cell carcinoma (BCC) of the face to find out whether morphometric variables in the structure of the nuclei of BCC cells could serve as predictors of the biological behaviour. We considered the following variables: maximum and minimum diameters, perimeter, nuclear area and five form factors that characterise and quantify the shape of a structure (axis ratio, shape factor, nuclear contour index, nuclear roundness and circumference ratio). We did a statistical analysis of primary and recurring tumours and four histology-based groups (multifocal superficial BCCs, nodular BCCs, sclerosing BCCs and miscellaneous forms) using a two-sided t test for independent samples. Multifocal superficial BCCs showed significantly smaller values for the directly measured variables (maximum and minimum diameters, perimeter and nuclear area). Morphometry could not distinguish between primary and recurring tumours.

Computerized quantitative pathology for the grading of dysplasia in surveillance biopsies of Barrett's oesophagus

Decision models for surveillance of Barrett's oesophagus (BO) are governed by the grade of dysplasia on endoscopic biopsy, but subjective grading is prone to observer variation. Computerized morphometry and immunoquantitation can objectively discriminate between different grades of dysplasia in oesophagectomy specimens with BO. The present study evaluated the feasibility of such quantitative analysis on surveillance biopsies of BO. Biopsy criteria for quantitative analysis were defined, excluding 101 (21%) of 472 archival BO surveillance biopsies. In the remaining haematoxylin and eosin (H&E) sections, 105 areas that distinctively displayed no dysplasia (ND), low-grade dysplasia (LGD) or high-grade dysplasia (HGD) were demarcated. Agreement on double-blind examination by two experienced pathologists was reached in 66 areas (63%; kappa: 0.44). For 21 ND/LGD and 11 LGD/HGD disagreement areas, corresponding sections for p53 and Ki67 immunohistochemistry were available. The best combination of two discriminating features was stratification index (SI) with p53 area % for ND versus LGD (89% correct classification), and SI with Ki67 area % for LGD versus HGD (91% correct classification). Fifteen of the 21 ND/LGD disagreement areas could be classified uniquely as either ND or LGD by SI and p53, and eight of the 11 LGD/HGD disagreement areas as either LGD or HGD by SI and Ki67. Correlation coefficients for repeated measurements of SI, Ki67, and p53 by the same observer were 0.94, 0.92, and 0.86, and by two independent observers 0.86, 0.93, and 0.92, respectively. Computerized quantitative pathology on BO surveillance biopsies is feasible provided that well-defined biopsy criteria are used. Using a combination of features associated with cellular differentiation and proliferation, such as SI, p53, and Ki67, quantitative pathological analysis assists in reducing diagnostic variability in the grading of dysplasia during surveillance of BO.

Computerized quantitative pathology for the grading of dysplasia in surveillance biopsies of Barrett's oesophagus

Decision models for surveillance of Barrett's oesophagus (BO) are governed by the grade of dysplasia on endoscopic biopsy, but subjective grading is prone to observer variation. Computerized morphometry and immunoquantitation can objectively discriminate between different grades of dysplasia in oesophagectomy specimens with BO. The present study evaluated the feasibility of such quantitative analysis on surveillance biopsies of BO. Biopsy criteria for quantitative analysis were defined, excluding 101 (21%) of 472 archival BO surveillance biopsies. In the remaining haematoxylin and eosin (H&E) sections, 105 areas that distinctively displayed no dysplasia (ND), low-grade dysplasia (LGD) or high-grade dysplasia (HGD) were demarcated. Agreement on double-blind examination by two experienced pathologists was reached in 66 areas (63%; kappa: 0.44). For 21 ND/LGD and 11 LGD/HGD disagreement areas, corresponding sections for p53 and Ki67 immunohistochemistry were available. The best combination of two discriminating features was stratification index (SI) with p53 area % for ND versus LGD (89% correct classification), and SI with Ki67 area % for LGD versus HGD (91% correct classification). Fifteen of the 21 ND/LGD disagreement areas could be classified uniquely as either ND or LGD by SI and p53, and eight of the 11 LGD/HGD disagreement areas as either LGD or HGD by SI and Ki67. Correlation coefficients for repeated measurements of SI, Ki67, and p53 by the same observer were 0.94, 0.92, and 0.86, and by two independent observers 0.86, 0.93, and 0.92, respectively. Computerized quantitative pathology on BO surveillance biopsies is feasible provided that well-defined biopsy criteria are used. Using a combination of features associated with cellular differentiation and proliferation, such as SI, p53, and Ki67, quantitative pathological analysis assists in reducing diagnostic variability in the grading of dysplasia during surveillance of BO.

The interrelationship between tubular and papillary sectors of tubulo-villous colorectal adenomas: comparative morphometric analysis and evaluation of cell proliferation

In a series of 100 colorectal adenomas, 23 tubulo-villous adenomas were individualized through the identification of papillae as structures persisting for more than 100 microm in serial sections with a connective axis lined with epithelial cells. In these adenomas, the tubular and villous areas with the highest dysplasia were selected, and a morphometric analysis was undertaken to assess the Index of Structural Atypia, the Nucleo-Glandular Index, and the Nuclear Stratification Index. The AgNor count and the proliferating cell nuclear antigen (PCNA) Label Index (LI) also were performed. The overall mean of each of these indexes was significantly higher in the villous sector than in the tubular one (P < .001). In 16 cases, the semi-objective method of dysplasia gradation showed a superior degree in the papillary sector, whereas it showed an equal degree in the remaining seven lesions. The AgNOR count was significantly different in all cases, with higher values in villous sectors (P < .05). With the exception of one case, this was confirmed by the PCNA LI. The Stratification Index showed significantly different values in 20 cases, whereas the other morphometric indexes showed a less discriminatory result. Our findings objectively show that the degree of dysplasia in tubulo-villous adenomas should be analyzed in the villous sector. The existence of heterogeneous cellular populations has been confirmed both in the structural organization of cells and in some basic parameters such as the cell proliferation rate in colorectal adenomas. Our findings suggest that the occurrence of villous architectural growth is a secondary event in a tubular adenoma. Enhanced cellular proliferation of the villous area allows the progressive substitution of tubular structures.

Clinical decision making in Barrett's oesophagus can be supported by computerized immunoquantitation and morphometry of features associated with proliferation and differentiation

Grading of dysplasia in Barrett's oesophagus has a therapeutic impact, but subjective grading is associated with substantial observer variation. Quantitative pathological methods could help to achieve a more accurate and reproducible diagnosis. In the present study, the immunoquantitation of p53 and Ki67 and the morphometric analysis of features associated with proliferation and differentiation were evaluated for this purpose. In slides of 35 oesophagectomy specimens, 73 areas that displayed either no dysplasia (ND), low-grade dysplasia (LGD), high-grade dysplasia (HGD), or intramucosal carcinoma (ImCa) were initially considered. Agreement on double blind examination by two experienced pathologists was reached in 58 areas, which were used as the 'learning set'. The 15 areas of disagreement were used as a second set. In the univariate analysis, the most significant differences in the learning set were found for Ki67, p53, stratification index (SI), mean nuclear area, and volume. Further multivariate analysis showed that for discrimination between ND and LGD, the combination of Ki67 and SI resulted in 94 per cent correctly classified areas. Likewise, for the discrimination between LGD and HGD, Ki67 and SI were the most powerful combination (again, 94 per cent of areas classified correctly). The discrimination between HGD and ImCa with any combination of the quantitative parameters never exceeded 80 per cent correct classification. The addition of p53 was of no value in improving the discrimination of ND vs. LGD, or of LGD vs. HGD. In the 15 original disagreement areas of the initial set of 73, three of the five ND/LGD areas could be uniquely classified as either ND or LGD by Ki67 and SI. Moreover, three of the four LGD/HGD disagreement areas could be uniquely classified with the combination of Ki67 and SI as either LGD or HGD. We conclude that the quantitative assessment of cytometric and morphometric features associated with proliferation and differentiation (especially Ki67 and SI) can be a valuable adjunct tool for clinical decision making in Barrett's oesophagus.

Predicting the risk of metachronous colorectal cancer in patients with rectosigmoid adenoma using quantitative pathological features. A case-control study

The prognostic value of quantitative pathological features in rectosigmoid adenomas was investigated, in search of more precise identifiers of adenoma-bearing patients at high risk of metachronous colorectal cancer. In a "nested case-control study" design, 21 cases with metachronous colon cancer during an average follow-up time of 16 years (range 3-30 years) after polypectomy and 67 controls were selected from a cohort of 1618 patients. The most advanced adenoma of each patient was analysed. Cases were matched with up to three controls simultaneously for size, grade of dysplasia, histological type, and number of adenomas, as well as for duration of follow-up. The patients did not undergo any post-polypectomy surveillance. Geometric characteristics of tumour nuclei, the arrangement of nuclei in the epithelium, and glandular changes were measured, and mitoses were counted. Several quantitative features measuring nuclear polymorphism and crowding showed significant prognostic value, while those measuring glandular changes and mitotic activity did not. A multivariate combination of the average distance between nuclei and the standard deviation of nuclear area discriminated an unfavourable group (n = 44) with 17 metachronous cancers from a favourable group (n = 44) with four metachronous cancers (P = 0*001, RR = 6*3). With the optimum cut-off, 28 patients without any metachronous cancer were discriminated from a group of 60 patients with 21 metachronous cancers. In conclusion, in the present study, quantitative pathological features assessed in rectosigmoid adenomas showed prognostic value additional to traditional measures. These features may therefore be useful in guiding post-polypectomy surveillance.

Quantification of proliferative activity in colorectal adenomas by mitotic counts: relationship to degree of dysplasia and histological type

AIM

Proliferative activity of tumours reflects their malignant potential. In colorectal adenomas, a subjective impression of the number of mitoses is a criterion often used to assess the degree of dysplasia. Since these subjective impressions of mitotic activity may lack reproducibility, the aim of this study was to perform an objective analysis.

METHODS

Mitotic counts were conducted in tissue sections of 59 colorectal adenomas. Of these, 20 showed mild, 20 moderate, and 19 severe dysplasia, according to blind duplicate assessments by two pathologists. Forty three were classified as tubular adenomas and 16 as "villous" adenomas (tubulo-villous and villous). The number of mitoses, both per unit area of epithelium (area weighted mitotic counts, AWMC) and per colonic crypt (mitotic counts per colonic crypt MCCC), was scored in the most dysplastic area within the adenoma. Mitotic figures were counted using a light microscope (ocular x 10, objective x 40, NA 0.75), and the area of the glandular epithelium was measured using an interactive video overlay measurement system. Twenty glands per specimen were assessed. In the intra-observer reproducibility tests, the coefficients of error for the AWMC and MCCC were 4.5% and 7.4% respectively.

RESULTS

For the AWMC a significant difference was found between mild and moderate as well as between mild and severe dysplasia, but not between moderate and severe dysplasia. The results of the MCCC showed the same trend, but the differences did not reach a significant level. Furthermore, cases classified as mild dysplasia were found that showed numerous mitoses, while cases classified as severe dysplasia were found with only very few mitoses. No significant difference in AWMC was found between tubular and villous adenomas. Thus the different malignant potential of tubular and villous adenomas was not reflected by a difference in AWMC. A seemingly strong difference for MCCC between tubular and "villous" adenomas appeared to depend completely on the difference in crypt size between these two groups.

CONCLUSIONS

The area weighted mitotic count, rather than the mitotic count per colonic crypt, may be useful for assessing the proliferation rate in colorectal adenomas.

Dysplasia and early carcinoma in inflammatory bowel disease and colorectal adenomas

The control of colorectal cancer is currently dependent on early detection, and its prevention requires the recognition and treatment of its precursor lesions. The adenoma has been established as the precursor of colorectal carcinoma in the general population. Among patients with inflammatory bowel disease (IBD), dysplasia is associated with, and precedes, invasive carcinoma. In this section criteria are described for the histological detection of preinvasive and early invasive neoplasia in the large intestine of patients with and without IBD. The therapeutic implications of these diagnoses are stressed. A brief review of subcellular changes, including genetic alterations, in colorectal neoplasia is included.

Stereological assessment of architectural changes in dysplastic epithelium of colorectal adenomas

BACKGROUND

Against the background of developing quantitative prognostic indicators for the future risk of colorectal cancer in adenoma bearing-patients, the possibilities of stereological measuring techniques for providing objective measures of architectural changes in colorectal adenomas were examined.

MATERIAL AND METHODS

The haematoxylin-eosin stained tissue sections of 59 adenomas, of which 20 showed mild dysplasia, 20 moderate dysplasis, and 19 severe dysplasia, were assessed. Using a projection microscope equipped with a coherent test system that was specifically designed to analyze anisotropic tissue, the volume density of stroma, epithelium and lumen, the outer and the inner gland surface density, and the length density lumen were determined.

RESULTS

With respect to grading, significant differences in the means of the inner gland surface density and the length density lumen were found mainly between mild and severe dysplasia as well as between moderate and severe dysplasia. This was especially evident when considering the subgroup of tubular adenomas. Stepwise discriminant analysis resulted in an overall correct jackknifed classification of 81.3% when mild and moderate dysplasia cases were taken as one group, and were compared with the group of severe dysplasia cases. With respect to histological type, the volume density lumen and the outer surface density glands, were most favourable. These two features allowed for an 87.5% overall correct jackknifed classification of tubular adenomas, versus adenomas with villous components. The analysis time was roughly 30 minutes per polyp. Intra-observer reproducibility was satisfying, with CE-values < or = 5% for all variables. Inter-observer reproducibility tests were encouraging.

CONCLUSIONS

The application of stereological techniques can be worthwhile in assisting in the classification of colorectal adenomatous polyps. Such techniques could therefore be a useful tool to estimate the prognostic value of adenoma morphology with respect to the development of metachronous colorectal tumours.

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.