Discrimination of various epithelia by simple morphometric evaluation of the basal cell layer. A light microscopic analysis of pseudostratified, metaplastic and dysplastic nasal epithelium in nickel workers

In-vivo nonlinear optical microscopy (NLOM) of epithelial-connective tissue interface (ECTI) reveals quantitative measures of neoplasia in hamster oral mucosa

The epithelial-connective tissue interface (ECTI) plays an integral role in epithelial neoplasia, including oral squamous cell carcinoma (OSCC). This interface undergoes significant alterations due to hyperproliferating epithelium that supports the transformation of normal epithelium to precancers and cancer. We present a method based on nonlinear optical microscopy to directly assess the ECTI and quantify dysplastic alterations using a hamster model for oral carcinogenesis. Neoplastic and non-neoplastic normal mucosa were imaged in-vivo by both multiphoton autofluorescence microscopy (MPAM) and second harmonic generation microscopy (SHGM) to obtain cross-sectional reconstructions of the oral epithelium and lamina propria. Imaged sites were biopsied and processed for histopathological grading and measurement of ECTI parameters. An ECTI shape parameter was calculated based on deviation from the linear geometry (ΔLinearity) seen in normal mucosa was measured using MPAM-SHGM and histology. The ECTI was readily visible in MPAM-SHGM and quantitative shape analysis showed ECTI deformation in dysplasia but not in normal mucosa. ΔLinearity was significantly (p < 0.01) higher in dysplasia (0.41±0.24) than normal (0.11±0.04) as measured in MPAM-SHGM and results were confirmed in histology which showed similar trends in ΔLinearity. Increase in ΔLinearity was also statistically significant for different grades of dysplasia. In-vivo ΔLinearity measurement alone from microscopy discriminated dysplasia from normal tissue with 87.9% sensitivity and 97.6% specificity, while calculations from histology provided 96.4% sensitivity and 85.7% specificity. Among other quantifiable architectural changes, a progressive statistically significant increase in epithelial thickness was seen with increasing grade of dysplasia. MPAM-SHGM provides new noninvasive ways for direct characterization of ECTI which may be used in preclinical studies to investigate the role of this interface in early transformation. Further development of the method may also lead to new diagnostic approaches to differentiate non-neoplastic tissue from precancers and neoplasia, possibly with other cellular and layer based indicators of abnormality.

Histomorphometric study to compare histological changes between oral squamous cell carcinoma and apparently normal adjacent oral mucosa

Despite the advances in surgery, radiotherapy and chemotherapy the annual death for oral squamous cell carcinoma (OSCC) is rising rapidly. The carcinoma has propensity to develop in a field of cancerization. Clinically may it be apparently normal mucosa (ANM) adjacent to squamous cell carcinoma which harbours certain discrete molecular alteration which ultimately reflects in cellular morphology. Hence the aim of the study is to assess histomorphometric changes in ANM adjacent to OSCC. A prospective study was done on 30 each of histologically diagnosed cases OSCC, ANM at least 1 cm away from OSCC, and normal oral mucosa (NOM). Cellular and nuclear morphometric measurements were assessed on hematoxylin and eosin sections using image analysis software. Statistical analysis was done using analysis of variance test and Tukey's post hoc test. The present study showed significant changes in cellular and nuclear area in superficial and invasive island of OSCC compared to ANM. The basal cells of ANM showed significant decrease in cellular and nuclear areas and nuclear cytoplasmic ratio when compared to NOM. Histomorphometry definitely can differentiate OSCC form ANM and NOM. The basal cells of ANM showed significant alterations in cellular area, nuclear area and nuclear cytoplasmic area when compared to NOM suggesting change in the field and have high risk of malignant transformation. These parameters can be used as indicator of field cancerization.

Factors in the pathogenesis of tumors of the sphenoid and maxillary sinuses: a comparative study

OBJECTIVES/HYPOTHESIS

To explain the processes that lead to the development of tumors in the maxillary and sphenoid sinuses.

STUDY DESIGN

A 32-year review of the world's literature on neoplasms of these two sinuses and a randomized case-controlled study comparing the normal mucosal architecture of the maxillary to the sphenoid sinus.

METHODS

Analysis of a 32-year world literature review reporting series of cases of maxillary and sphenoid sinus tumors. Tumors were classified by histological type and separated into subgroups if an individual incidence rate was reported. Histomorphometry of normal maxillary and sphenoid sinus mucosa was performed in 14 randomly selected patients (10 sphenoid and 4 maxillary specimens). Specimens were fixed in 10% formalin, embedded in paraffin, and stained with periodic acid-Schiff (PAS) and hematoxylin. Histomorphometric analysis was performed with a Zeiss Axioscope light microscope (Carl Zeiss Inc., Thornwood, NY) mounted with a Hamamatsu (Hamamatsu Photonics, Tokyo, Japan) color-chilled 3 charge coupled device digital camera. The images were captured on a 17-inch Sony (Sony Corp., Tokyo, Japan) multiscan monitor and analyzed with a Samba 4000 Image Analysis Program (Samba Corp., Los Angeles, CA). Five random areas were selected from strips of epithelium removed from each sinus, and goblet and basal cell measurements were made at magnifications x 100 and x 400.

RESULTS

The literature review revealed that the number and variety of tumors in the maxillary sinus are much greater than those in the sphenoid. The incidence of metastatic lesions to each sinus is approximately equal. No recognized pattern of spread from any particular organ system could be determined. On histomorphometric study there were no statistically significant differences between the sinuses in the concentration of goblet cells, basal cells, or seromucinous glands.

CONCLUSIONS

Factors involved in the pathogenesis of tumors of the maxillary and sphenoid sinuses include differences in nasal physiology, embryology, morphology, and topography. There are no significant histological differences in the epithelium and submucous glands between the two sinuses to explain the dissimilar formation of neoplasms.

Nuclear morphometry in experimental oral mucosal carcinogenesis

The area, perimeter and diameter of basal cell nuclei of rat palatal epithelium were measured and the deviation of the basal cell nuclear profile from the form of a sphere was assessed after the application of the carcinogen 4-nitroquinoline-1-oxide (4NQO). After a 24-week treatment-free period, designed to eliminate the irritant effect of the carcinogen, the rats were killed, the palatal mucosa was recovered and processed and the nuclear histometry was assessed with image analysis techniques. The basal cell nuclear area increased as the epithelium became dysplastic and then decreased as carcinoma developed, but there were significant variations in this parameter in the control groups. Basal cell nuclei from moderately or severely dysplastic epithelium, and from epithelium adjacent to areas of invasive carcinoma, were significantly less regular in profile by comparison with control nuclei. Variations in nuclear profile, but not nuclear area, perimeter or diameter, might reflect fundamental nuclear alterations of significance during the process of carcinogenesis.

Computer simulation modelling and visualization of 3D architecture of biological tissues. Simulation of the evolution of normal, metaplastic and dysplastic states of the nasal epithelium

Recent technical improvements, such as 3D microscopy imaging, have shown the necessity of studying 3D biological tissue architecture during carcinogenesis. In the present paper a computer simulation model is developed allowing the visualization of the microscopic biological tissue architecture during the development of metaplastic and dysplastic lesions. The static part of the model allows the simulation of the normal, metaplastic and dysplastic architecture of an external epithelium. This model is associated to a knowledge base which contains only data on the nasal epithelium. The latter has been well studied by numerous authors and its lesional states are well known. An inference engine allows the initialization of the static model parameters. A statistical comparison between simulated epithelia and real epithelia is achieved by adjusting the parameter values during the simulation. The dynamic part of the model allows the simulation of a growth process on a 3D representation based on the static model. The main hypothesis is that nasal epithelium is submitted to a continuous transformation from normal to cancer through metaplasia and dysplasia. The evolution of each cell (represented by its nucleus) depends on its local environment and also on its heritage from its mother-cell. Simulation of tissue renewal of the nasal pseudostratified epithelium has been achieved. The evolution from normal to hyperplasia has been simulated. After modification of the cell cycle modelling, the simulation of the development of metaplastic foci has been obtained.

Rates of regression and progression of dysplastic lesions in the nasal mucosa in nickel workers: a Markov model approach

Nasal epithelial dysplasia is considered a precancerous state. From 1976 through 1989, regular screening for such lesions has been performed among workers at the Falconbridge nickel refinery in Kristiansand. The longitudinal data thus obtained have been evaluated to ascertain to what extent, if any, pre-existing dysplasia can regress when exposure to nickel is reduced. A total of 418 pairs of observations were available from 243 workers. Interpretation of the data is complicated by the fact that dysplasia may remain undetected in small biopsies and the probability of detection of existing dysplasia was, therefore, incorporated into the two-state Markov model. Transition probability rates were estimated by maximum likelihood. The results suggest that regression of dysplasia has taken place and that regression rates increased with time. This finding probably reflects a decreased exposure resulting from a combination of a reduction in airborne nickel, improved personal hygiene and allocation of workers with dysplasia to work in areas with lower nickel exposure. Our results indicate that the chance of developing carcinomas related to nickel exposure is reduced. There are, however, indications that dysplasias continue to develop at a low rate.

Quantitative cellular and nuclear volumetric alterations in epithelium from lichen planus lesions of human buccal mucosa

Patients with oral lichen planus lesions may represent a relatively high risk population for subsequent development of oral cancer. Little is known of the relative effects of chronic inflammation and the process of malignant transformation itself on the histological structure of transforming epithelia. We have assessed cellular and nuclear volumes in defined basal and spinous cells from normal buccal mucosa epithelium, from epithelium associated with a non-specific chronic inflammatory infiltrate and from lichen planus lesions. Normal (N) tissues were obtained from the margins of non-neoplastic buccal mucosa lesions. Inflammatory (INF) lesions were from areas of the buccal mucosa diagnosed clinically as traumatic irritation without ulceration, and lichen planus (LI) lesions were biopsied from areas exhibiting Wickham's striae. Basal and spinous epithelial cells from normal and pathological human buccal mucosa were measured on haematoxylin and eosin-stained sections imaged through a video camera using a Zeiss VIDAS analyser and from these measurements, nuclear (VN) and cellular (VCELL) volumes were determined. VN and VCELL derived for both basal and spinous strata were similar in N and INF groups but were almost doubled in the LI group. Comparisons between LI and all other groups were significantly elevated. The effects of the inflammatory infiltrate on the oral epithelium in lichen planus and in non-specific inflammation thus differ significantly. VN and VCELL may serve as potential discriminators between benign lesions and premalignant lichen planus.

A histological morphometric study of nuclear size in benign and malignant neoplasms of the human cheek

This report describes the application of simple morphometric methods to generate quantitative data on nuclear size from tissue sections of normal, benign and malignant oral epithelium of the cheek. Measurements of nuclear areas of basal and spinous cells from cheek mucosa were made on haematoxylin and eosin-stained sections using a Zeiss VIDAS image analyser. The lesions examined comprised benign squamous cell papillomas and islands of cells from invasive squamous cell carcinomas. Normal control epithelium was obtained from the biopsy margins of non-neoplastic lesions. The nuclear areas (AN) were obtained by direct measurement whereas the nuclear diameters (DN) were determined automatically. In both basal and spinous strata, values for both these nuclear parameters were lowest in normal tissue and increased progressively through benign papillomas, with the highest values being found invariably in carcinomas. Statistically significant differences were detected between both normal and carcinoma and between papilloma and carcinoma. The morphometric parameters AN and DN are of value in distinguishing benign from malignant lesions of the human cheek.

Morphometrical analysis of nuclear abnormality of tubular tumors of the stomach with image processing

Nuclear size and shape on histological specimens were used to quantify nuclear abnormality in gastric tubular tumors. A valid technique for this morphometrical analysis by image processing was developed. Furthermore, the present study examined the nuclear size and shape to determine if they were reliable criteria to be used for differential diagnosis. Nuclear area, maximum diameter and maximum width on the histological specimens were defined as factors to represent nuclear size. Nuclear aspect ratio represented nuclear shape. Histological features revealed varied degrees of condensation of nuclei; this was due to different protocols for preparing the histological specimens. This finding indicated that the size of intermediate lymphocytes on the same specimens should be measured as a control in order to estimate the degree of nuclear condensation. The present study also demonstrated that at least 200 nuclei should be measured on the histological specimens to obtain accurate nuclear size and shape. Histologically, the nuclei in benign tubular adenoma and borderline lesions tended to be spindle-shaped, while those in well-differentiated type tubular adenocarcinoma tended to be round and swollen. The nuclei in borderline lesions were larger than those in benign tubular adenoma and smaller than those in well-differentiated type tubular adenocarcinoma. Our results for the above 4 factors corresponded well with these histological findings. The nuclear size and shape on histological specimens were concluded to be reliable criteria for assessing nuclear abnormality in gastric tubular tumors and useful ones for differential diagnosis.

Changes in cytokeratin expression accompany squamous metaplasia of the human respiratory epithelium

To determine the characteristics of metaplastic changes of the nasal respiratory epithelium, the distribution of individual cytokeratins (CKs) was studied immunohistochemically and by two-dimensional gel electrophoresis. The authors define four types of changes of the normal pseudostratified columnar epithelium: (1) transitional pseudostratified epithelium (first unusual CK.: no. 13); (2) stratified columnar epithelium (increased expression of CKs 4 and 13; CKs 7, 8, 18 and 19 reduced); (3) stratified squamous epithelium, nonkeratinized (appearance of CK 16); and (4) stratified squamous epithelium, keratinized (expression of CKs 1 and 10, variable CK5 and 14 patterns in basal cells). These phenotypes were found simultaneously within single specimens, resulting in apparent overall variability in the immunohistochemical staining patterns. Spatially, changes in CK expression towards "normal" parts were not abrupt but rather gradual. Biochemical data confirmed the immunohistochemical findings and added CK 6 to the pattern of altered nasal mucosa. The findings of this study suggest a stem cell metaplasia in the nasal epithelium which is based on its inherent bimodal developmental programme. A gradual loss of normal respiratory epithelial differentiation, as seen by the loss of CKs 7, 8, and 18, was paralleled by the appearance of squamous epithelial type CKs, e.g. the expression of CKs 1, 10 and 13. Basal cell types CKs 5, 14, 17 and 19 were maintained during this process. Implications of these results for general concepts of CK expression in the metaplastic process are discussed.

Morphometrical analysis of structural abnormality of tubular tumors of the stomach with image processing

Four indices, index of tubular density, index of dispersion of tubular size, degree of complexity of tubular shape and frequency of complex-shaped tubuli, were defined to quantify the structural abnormalities of gastric tumors in morphometrical analysis by image processing. The values of each index corresponded well with the degree of each structural abnormality found pathologically. These indices were considered to be valid for representing their respective structural factors. There were significant differences among the mean values of the scores calculated by a formula using all 4 indices of benign tubular adenoma, borderline lesion and well-differentiated type tubular adenocarcinoma (P less than 0.05). Therefore, the discriminant formula was considered to be valid for integrating these indices and for representing structural abnormality of gastric tubular tumors.

Basal cell nuclear size in experimental oral mucosal carcinogenesis

It has been suggested that the size of the nuclei of epithelial basal cells can be used in predicting the likelihood of malignant transformation of epithelium. This proposition was assessed in rat palatal epithelium after the carcinogen 4-nitroquinoline-1-oxide had been applied to the epithelium for varying periods of time. No consistent alterations in basal cell nuclear size, including area, perimeter, diameter and regularity of form were found with routine light microscopy as the epithelium passed through various stages of dysplasia to carcinoma. This finding casts doubt on the value of using a variation of basal cell nuclear size as a predictor of malignant transformation.

Nuclear shape as a prognostic discriminant in colorectal carcinoma

In search for a more reliable prognostic discriminant, a retrospective analysis of 100 cases of colorectal carcinoma having undergone curative resection and followed for at least 5 years were assessed by nuclear morphometry. Each case was staged according to the Dukes' classification as well as graded histologically. For all patients in this series, the perimeter, area, and nuclear shape factor of 50 interphase nuclei were determined for each carcinoma. The information was obtained through the use of an image analysis system by tracing the nuclear profiles (magnification 1000x) as digitized on a video screen. The nuclear shape factor was defined as the degree of circularity of the nucleus, a perfect circle recorded as 1.0. A nuclear shape factor greater than 0.84 was associated with poor outcome. Multiple regression models showed that the single nuclear parameter of the shape factor was the most highly significant predictor of survival (P less than 0.0001). This variable remained highly significant even when corrected for sex, age, histologic grade, and Dukes' classification. These findings indicate that a nuclear shape factor greater than or equal to 0.84 as determined by nuclear morphometry is an independent morphometric nuclear variable of great importance in the prognosis of large bowel carcinoma.

Morphometric evaluation of dark and clear epidermal basal cells during early 2-stage chemical skin carcinogenesis in the hairless mouse using two different fixation methods

Ultrastructural morphometric characteristics of basal keratinocytes in hairless mouse epidermis were analyzed statistically. The following variables were assessed: (i) low versus physiological osmolality during fixation, (ii) alterations induced by a 2-stage carcinogenesis regimen using DMBA and TPA, (iii) criteria for a cell being dark versus being clear, (iv) inter-observer variation. The results show that with low fixation osmolality most basal cells swell and become electron lucent. The few cells which apparently do not swell stand out as shrunken electron dense dark cells. Morphometrically they are more differentiated than clear cells, but do share many features with the basal cell type which appears after fixation in a buffer of physiological osmolality. Iso-osmolality during fixation seems to induce a homogeneous basal cell population of relatively electron dense cells without typical dark and clear elements. Treatment with DMBA/TPA induces not only intercellular edema and reduced desmosomal contacts, but causes injury to the plasma membrane leading to hydropic changes in the cells. This general intra- and intercellular DMBA/TPA induced hydration might induce secondary compression of some of the cells, leading to an increased number of compressed dark cells. It is, however, only after fixation in low buffer osmolality that these effects of DMBA/TPA are statistically significant and clearly observable. The inter-person variation was, apart from a few instances, either not statistically significant or did not interfere with the other effects. We did not find clear arguments in favor of the view that dark cells are primitive epidermal stem cells. They seem only to reflect non-specific toxic effects of tumor promoters, which appear only under certain fixation conditions, that have been used by most authors. The results suggest that dark and clear cells are mainly a consequence of the degree of cellular hydration.

Silver impregnation of membranes on undeplasticized semi-thin sections for morphometry

Biomembranes can be stained on large semi-thin sections of epoxy embedded tissue with silver nitrate after iodine impregnation and without resin removal.

Morphometric analysis of gallbladder adenocarcinoma: discrimination between carcinoma and dysplasia

To characterize the cytological features of well differentiated adenocarcinoma of the gallbladder, a comparative morphometric analysis was made using 35 histologically classified cases of invasive well differentiated adenocarcinoma, 13 cases of mild dysplasia, 19 cases of severe dysplasia, and 22 control gallbladders. The variables analyzed were nucleocytoplasmic (N/C) ratio and nuclear area (N.A.). Both the mean values of N/C ratio and N.A. demonstrated a progressive increase from control to mild dysplasia, to severe dysplasia and to carcinoma. The differences were statistically significantly different. Discriminant analysis was made with a set for learning and a set for testing, selected from the 89 lesions with random numbers. Using this discriminant function, all the cases except one carcinoma were discriminated as carcinoma, and all the cases of control, adenoma, and mild dysplasia were discriminated as benign lesions. However, cases of severe dysplasia were subdivided into benign or malignant. These results indicate that morphometric analysis clearly differentiates carcinomas from benign lesions, and that the dysplastic mucosal lesions can be divided into benign and malignant, although some difficult borderline lesions exist.

A morphometrical analysis of dysplasia in small adenomas of the large intestine

In a morphometrical study of 40 colorectal adenomas less than 10 mm in diameter and of 10 specimens of normal mucosa, it was found that nuclear size, perimeter and shape-factor of the epithelial cells were significantly different in neoplastic when compared with normal tissues. The same was found for the volume fraction of stroma, gland spaces, goblet and non-goblet epithelium, for the gland diameter, nuclear stratification height and stratification index, but not for the epithelial height nor the total volume fraction of the epithelium. In a multivariate analysis, stratification index and nuclear size of the epithelial cells contributed most significantly to determination of the histological grade of dysplasia in adenomas. By the combination of these two morphometric variables 75% of all adenomas could be correctly allocated to the grade of dysplasia.

The prognostic significance of morphometry for squamous cell hyperplasia of the laryngeal epithelium

Laryngeal biopsies of squamous cell hyperplasia with atypia were graded by means of morphometry, using five non-correlated nuclear parameters preselected with linear discriminant analysis, and were tested for their prognostic significance, in a follow-up study. Fifty-two biopsy specimens were obtained from 18 patients who were merely followed and if necessary underwent a repeated biopsy examination. The lesions of 10 patients progressed to invasive carcinoma. In 8 patients the second or further biopsies were again classified as squamous cell hyperplasia with atypia. For both groups the mean follow-up period was 7.2 years (range: 3 1/2-11). In the progressive group 73% of the biopsies were morphometrically classified as prognostically unfavourable, whereas the clinical outcome on the basis of the last biopsy was correctly predicted for 6 out of the 10 cases (mean probability: 94%), the other 4 cases were 'mis-classified', although for 3 cases with a low probability (mean: 60%). For a valuable morphometrical classification of lesions of individual patients, the results as presented are still insufficient. Morphometrical classification probabilities may be improved when the numbers of untreated patients with squamous cell hyperplasia with atypia do increase.

The nasal mucosa in softwood exposed furniture workers

Recent reports suggest that softwood exposed woodworkers may have an increased incidence of sinonasal carcinoma. The present study was undertaken in order to evaluate the histological changes, especially the presence of possible precancerous lesions, in the nasal mucosa of furniture workers exclusively exposed to softwood. Histological examination of nasal biopsies from 44 furniture workers and 37 controls revealed a higher degree of metaplastic changes in the former group. In addition we observed four cases (9%) of dysplasia among softwood exposed workers. Nasal epithelial dysplasia is morphologically similar to dysplasia in other organs where the precancerous state of this lesion has been proved. Acceptance of nasal dysplasia as a precancerous lesion means that histological examination of biopsies is an appropriate tool in identifying occupational groups with an increased incidence of sinonasal carcinoma.

The karyological basis of atypia

There is no distinct DNA-pattern correlating with the degree of dysplasia. Atypical DNA-histograms can be found in morphologically normal smears especially when earlier smears had been suspicious. They can also persist after hysterectomy. In cases of progression aneuploidy and large scatter dominate while in cases of regression the DNA values are concentrated in the polyploid classes. Therefore, persisting atypical histograms signalize an increased risk in cases of dysplasia.

Karyometry of pseudostratified, metaplastic and dysplastic nasal epithelium by morphometry and stereology. 2. Automated image analysis (IBAS) of the basal layer of nickel workers

A mathematical model for the stereological analysis of parallel-oriented, spheroidal nuclei has been applied to the basal layers of respiratory, metaplastic and dysplastic nasal epithelia. Nuclear profiles seen on tissue sections were measured with an automatic image analyser (IBAS). Nuclear profile area distributions were used to assess possible polyploidies. The result are compared to the histopathological grading, consisting of pseudostratified (respiratory), cuboidal, mixed cuboidal/squamous, squamous, and dysplastic epithelia. The estimated nuclear axis lengths, volumes, surface areas and volume/surface ratios are, in the great majority of cases, significantly smaller in pseudostratified or cuboidal epithelium than in squamous metaplasia and dysplasia. Correspondingly, the numerical density of the nuclei is lower in the latter cases, in which is also noted a smaller nuclear eccentricity. No significant difference is found between the nuclei of squamous and dysplastic epithelia. There is a clear correlation between the mean profile areas and the stereologically estimated volumes of the nuclei. When classifying the mean profile areas into four classes, a progressive shift from the smaller towards the larger size classes is observed when passing from pseudostratified to dysplastic epithelia, through the different metaplastic stages. The nuclear profile area plots often show several peaks, even in some pseudostratified and cuboidal epithelia, probably reflecting polyploidy. There is a marked tendency towards larger profile areas in squamous metaplasia and dysplasia. One histopathologically typical dysplasia showed only small-sized nuclei and another had a notable contribution of those in its profile area plot, in contrast with all the other dysplasias and squamous metaplasias, which displayed practically no small nuclei. The possible implications of the existence of "small-sized-nuclei-dysplasias" are discussed. The literature dealing with nuclear volumes or DNA quantities in putative preneoplastic situations in reviewed. Our method adds some valuable objective criteria to those used in classical histopathological grading. It should be possible to apply this method to other epithelial tissues.

A general model for the light and electron microscopic morphometry/stereology (M & S) of precancerous epithelial transformation using clinical biopsies

A morphometric model is presented which has proved valuable in the analysis of precancerous lesions at the light and electron microscopic level. The material consisted of biopsies of nasal mucosa embedded in plastic and sectioned perpendicular to the luminal surface. Sampling was restricted to the basal layer in order to compare in the different metaplastic and dysplastic stages a common cell type which is easy to identify in all stages and to reduce the workload. The application of digitizers, classical point counting procedures and linear parameters all allow a good separation between the different types of epithelium. The latter method is especially advisable in diagnostic pathology since the workload becomes drastically reduced as a consequence of linear instead of area parameters (e.g. cell width, i.e. contract zone with basement membrane, instead of cell size) and classifying instead of counting points. A 3-class ruler served for the estimation of the transverse diameters of nuclei, cell width and the sum of the longitudinal and transverse nucleolar axes. The use of a weighted index is more sensitive than simple measurements. The reliability of the method was also tested in a prospective study in which the biopsies were first analyzed by morphometry. The agreement between the prior morphometric classification and the subsequent histologic classification was 91%. The results demonstrate that basal cells alone carry the information for grading metaplastic and dysplastic changes in epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple and efficient method for objective discrimination between pseudostratified, metaplastic and dysplastic nasal epithelium

Morphologic features may sometimes be interpreted differently by different pathologists. By introducing objective methods in the histological evaluation the subjectivity of the judgement is reduced and a higher degree of consistency achieved. In the present study three linear parameters of nasal epithelial basal cells: the largest transversal nuclear diameter, the sum of the longitudinal and transversal nucleolar axes and the basal cell width, i.e. the width of the attachment face to the basement membrane, were classified by means of three-class rulers. From this classification weighted indices were made which were then given equal weight and transformed, so that when added up their sum, the joint index (Q) to the largest possible extent was consistent with pseudostratified/stratified cuboidal, stratified squamous and dysplastic epithelium when Q less than or equal to 1, 1 less than Q less than or equal to 2 and Q greater than 2 respectively. Tested prospectively we found 91% agreement between the morphometric and histological classification. The method presented is extremely simple and rapid to perform, and appears to have diagnostic potential in distinguishing various types of epithelial alterations of the nasal mucosa. The method may also be useful in approaching similar problems in other epithelia.