A morphometric method to discriminate normal from dysplastic/carcinoma in situ squamous epithelium in the human esophagus

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.

Analysis of nuclear DNA and morphometry, and proliferating cell nuclear antigen in primary and metastatic malignant melanoma

Sections from 23 primary malignant melanomas and 39 corresponding metastases were analysed for DNA content, nuclear morphometry, and proliferating cell nuclear antigen (PCNA). In 15 of 23 patients (65%) both primary and secondary tumours showed similar DNA patterns, whereas a disparity was found in the remaining eight patients (35%). The 23 primary tumours and groups of metastases (from different patients) located in skin, lymph nodes, and brain did not differ significantly in any of the variables investigated. Cox stepwise regression analysis indicated that a large variability (CV) of nuclear area in the first metastasis correlated with increased survival after recurrence (p = 0.039) as well as with survival (p = 0.031).

Grading of precancerous laryngeal lesions by multiparameter image analysis at separate epithelial layers

In order to detect early precancerous changes which do not involve the whole thickness of the epithelium, we used a novel image analysing program based on an IBAS system (Kontron, Germany) to determine nuclear DNA content (NC) as well as average nuclear area (NA) and variation of nuclear area (VA), in the entire epithelium and in three sublayers, parabasal, intermediate, and superficial. DNA aneuploidy was found in only half of the cases classified as 'high-grade' (HG) lesions, comprising carcinoma in situ (CIS) and severe epithelial dysplasias (EDIII), and was chiefly demonstrable in the parabasal third of the epithelium. The other lesions were DNA euploid. HG lesions showed highly significant increases of NA and VA at the lower levels of the epithelium when compared with 'low-grade' (LG) lesions comprising moderate and mild epithelial dysplasias (EDII and EDI). Our data show that the combination of multiparameter image analysis with conventional morphology assists in the objective grading of precancerous lesions and permits the reliable detection of high-grade lesions.

Morphometric characteristics in adenocarcinoma of the pancreas and chronic pancreatitis

BACKGROUND

Morphometric analysis whereby size and form of cellular nuclei are transformed into quantities has previously been shown to be a valuable adjunct to the histopathologic differential diagnosis between chronic pancreatitis and pancreatic carcinoma. The present study aims to assess the clinical value of morphometry performed on cytologic material from benign and malignant pancreatic lesions.

METHODS

Cytologic specimens from 100 patients with the diagnosis of pancreatic carcinoma and 15 patients with chronic pancreatitis were evaluated by interactive morphometry using a digital image analyzer system.

RESULTS

There were significant differences (p < 0.001) for all morphometric variables between the malignant and benign groups (mean area p 50, 135.41 microns 2 versus 69.66 microns 2; anisokaryosis, 0.74 versus 0.41; and polymorphism, 0.13 versus 0.09).

CONCLUSIONS

Morphometry may be used as a complementary tool in the cytologic diagnosis of pancreatic carcinoma.

Morphometric, DNA and PCNA in thin malignant melanomas

Morphometric assessment of nuclear area, shape and density, nucleolar area, analysis of DNA content and expression of proliferating cell nuclear antigen (PCNA) was performed in a case control study of 72 malignant melanomas, thickness < or = 0.8 mm and Clark level II-III. Twenty-four thin metastasizing melanomas (TMM) were individually compared to two thin non-metastasizing melanomas (TNM) after individual matching for site of primary tumor, tumor thickness, level of invasion, tumor regression and duration of follow-up. Conditional logistic regression analysis with maximum likelihood estimates showed significant differences between TMM and TNM with regard to the nuclear correlation coefficient (p = 0.005), standard deviation of nuclear shape NCI (p = 0.017), and nuclear density (p = 0.030), indicating that thin melanomas with pleomorphic and possibly densely packed nuclei are associated with recurrence. No significant differences were found regarding nuclear or nucleolar area, mean nuclear shape NCI, nuclear DNA content or expression of PCNA.

Quantitative histopathological evaluation of vocal cord dysplasia with particular emphasis on nuclear orientation

We have applied morphometry on formaldehyde-fixed, H & E-stained diagnostic laryngeal biopsies from 7 patients with mild dysplasia and 7 with severe dysplasia/carcinoma in situ, in search of objective parameters required for reproducible histopathological grading of epithelial dysplasias. Special emphasis has been put upon the individual nuclear polarity as a spatial variable. Also included were 4 specimens with normal epithelium. By means of a semiautomatic digitizing tablet, the nuclear and epithelial area, formfactor and the polarity variation between the longitudinal axes of adjacent nuclei were measured in the basal, parabasal, middle and luminal layers of the epithelium. N:C-ratio, mean values of nuclear area, formfactor or their coefficient of variation could not distinguish between mild and severe dysplasia. The variations in neighboring nuclear polarity, however, revealed a highly significant distinction between mild and severe dysplasia (p less than 0.001). This parameter may therefore have diagnostic potential.

Morphological, immunohistochemical, stereological and nuclear shape characteristics of proliferative Leydig cell alterations in rats

Proliferative Leydig cell (LC) alterations (hyperplasia, adenoma) of laboratory rats often pose diagnostic problems because the progression from normal to hyperplasia to neoplasia is continuous. The LC compartments of 130 Wistar rats (kfm: WIST strain) of approximately 2 years of age were examined. Ten typical cases conventionally classified as being normal or as showing diffuse or focal hyperplasia or small or large adenomata were investigated in more detail. In large adenomata, areas with large and small LC nuclei were identified. Immunohistochemical characterization, EM examination, as well as stereologic and planimetric investigations were performed. Hyperplastic and neoplastic LC essentially retained their normal appearance and immunohistochemical characteristics, but were found to contain more lipid droplets, fibroblast-like cells and patches of collagen than normal LC at the EM level. LC proliferation was accompanied by significant LC hypertrophy. LC nuclei of hyperplastic LC compartments were slightly larger while those of LC adenoma were markedly larger than nuclei of normal LC. The values for circle-related and ellipticity factors indicated that the nuclei of normal and hyperplastic LC were more markedly oval than nuclei of neoplastic LC. Concavity factor and bending energy measurements revealed that the small and oval nuclei of normal and hyperplastic LC had significantly more and deeper indentations than the larger and somewhat rounder nuclei of neoplastic LC. It is concluded that LC proliferations conventionally diagnosed as hyperplasia or adenoma on the basis of their size were composed of cytologically different LC populations.

Image analysis in the discrimination of verrucous carcinoma and squamous papilloma

Verrucous carcinoma is a differentiated variant of squamous cell carcinoma and may present diagnostic difficulties as it may be erroneously diagnosed as squamous papilloma. In this study, the sizes of the intermediate cells in these two conditions were measured by means of morphometric analysis. Biopsies from 28 patients with verrucous carcinoma, 25 patients with squamous papilloma, and ten squamous cell carcinomas were analysed. A significant difference was shown (P less than 0.001) by an uncorrelated t-test between verrucous carcinoma and squamous papilloma. The former had a mean cell area of 373 microns 2 and the latter 184 microns 2. Squamous cell carcinomas differed from the other two neoplasms by their large range of cell areas both within and between cases. Thus, image analysis can be of diagnostic help in cases where no firm initial histopathological diagnosis can be obtained. The diagnosis should be made on morphological grounds, but a mean cell area greater than 300 microns 2 supports a diagnosis of verrucous carcinoma whereas an area less than 250 microns 2 supports a diagnosis of squamous papilloma.

Discrimination of pancreatic adenocarcinomas from chronic pancreatitis by morphometric analysis

Chronic pancreatitis and pancreatic ductal adenocarcinoma show similar gross and microscopic anatomical features. Morphological examination alone is not always sufficient in diagnostic practice to make the clinically important discrimination between these two entities. Cases of pancreatic tumors were analysed in a morphometric study to evaluate the discriminatory value of nuclear and nucleolar features. Histologic sections of pancreas from 18 cases of chronic pancreatitis and 33 cases of ductal adenocarcinoma were included either into a learning or a test set. A multivariable discriminatory rule was derived from the learning set of 23 cases including nuclear polymorphism and nucleolar density. When applied to the test set, all 28 cases of adenocarcinomas and chronic pancreatitis were correctly classified. Distributional features describing nucleolar density and variation in nuclear size and shape were the most efficient discriminatory variables. Morphometry is shown to be a simple and fast cell analytical method which can support clinical judgement in distinguishing between chronic pancreatitis and pancreatic ductal adenocarcinoma.

Planimetry in pathology--a method in its own right besides stereology and automatic image analysis

Under the term planimetry all possibilities of quantitative morphological description of structures at the two-dimensional level which do not require densitometry and do not consider the 3rd spatial dimension are subsumed. Because planimetry has several advantages with respect to preparation techniques and structure recognition compared to stereology and expensive densitometric image analysis systems, it seems necessary to give a synoptic description of planimetry as a morphometric method in its own right in pathology. This should lead to a clinically orientated development in parallel to stereology and densitometry. The recent status and advances with regard to the methods of measuring and evaluation are discussed.