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

This study presents a simple morphometric method for objective classification of pseudostratified, various types of metaplastic, and dysplastic epithelium by evaluation of cellular features in the basal layer only. Fifty-four biopsy specimens were taken for diagnostic reasons from the nasal mucosa of nickel workers, and semithin toluidine-blue-stained sections were analysed. The most sensitive parameters in distinguishing between the various types of epithelium were: (i) the transverse nuclear diameter, (ii) the size of the nucleoli and (iii) the basal cell width expressed as an index weighted towards the cell profiles with the broadest attachment face on the basal lamina. A combination of these three parameters allows a clear separation between dysplastic, metaplastic and pseudostratified epithelium. The sequential increase in these parameters from pseudostratified epithelium through two histologically distinguishable stages of metaplasia (stratified cuboidal and mixed stratified cuboidal/stratified squamous epithelium) to fully developed squamous epithelium supports the concept that metaplasia develops gradually. The continuous increase in these parameters from metaplasia to dysplasia further suggests that metaplasia is a necessary step in the development of nasal epithelial dysplasia. This morphometric model appears especially useful in monitoring small sequential epithelial changes, and might also be used for evaluating other types of epithelia.     

How often is dysplasia diagnosed by biopsy or smear examination? Application of a maximum likelihood based method to the assessment of detection rates in the nasal mucosa of nickel workers.

In view of the known increased risk of nasal carcinoma and the high prevalence of dysplastic lesions of the nasal mucosa among nickel workers, regular screening for the existence of possibly precancerous dysplastic lesions is offered to workers in a Norwegian nickel refinery. Unfortunately, available sampling techniques do not allow the identification of all subjects in whom dysplastic changes are present. Independent histological and cytological (brush cytology) diagnoses, obtained for each of a group of 90 workers, have been used to estimate, by a maximum likelihood method, the probabilities that existing dysplastic lesions will be detected by each of these two screening methods. In the group studied, cytology performed rather less well than histology in unambiguously detecting dysplasia. However, when cytological specimens showing irregular (possibly dysplastic) epithelial cells were grouped with those showing clear dysplastic changes, detection probabilities were estimated at 0.52 by histology and 0.57 by cytology. Detection probabilities were estimated to be higher among subjects with a previously known history of dysplasia, particularly by histology (P < 0.01), probably due to larger dysplastic areas. In view of both its greater facility and speed of sampling, and its greater acceptability, brush cytology may be preferable to biopsy sampling for the screening of large numbers of workers at risk.     

Scanning electron microscopy in gastric adenocarcinoma and intestinal metaplasia

In recent years scanning electron microscopy has been used in gastric biopsy studies, contributing to better recognition of intestinal metaplasia and carcinoma, as a complement to light and transmission electron microscopy. During the second half of 1983, 53 cases of gastric carcinoma were diagnosed at the Department of Pathology of Hospital Mexico, of which six were studied ultrastructurally. A pattern similar to that of intestinal epithelium was found in cases of intestinal metaplasia. Well differentiated adenocarcinomas showed marked tumor cell proliferation with irregular "projections". In poorly differentiated carcinomas, changes were limited to areas where tumor cells invaded the epithelial surface. In summary, scanning electron microscopy is of great help in research and diagnosis of pathologic changes occurring in mucosal surfaces.     

The exfoliating cervical epithelial surface in dysplasia, carcinoma in situ and invasive squamous carcinoma. I. Scanning electron microscopic study.

The exfoliating epithelial surface in cone specimens of the human cervix with histologically normal epithelium, squamous metaplasia, dysplasia, carcinoma in situ and in cervical biopsies with invasive squamous carcinoma was studied by scanning electron-microscopy (SEM). A cobblestone-like surface with anisovillosis seems to herald the appearance of malignant cells on the exfoliating epithelial surface. Post-scanning histologic examination served as a diagnostic reference for the SEM findings.     

Marker features for malignancy in ectocervical cells. Statistical evaluation

Marker features for malignancy have recently been observed in ectocervical cells, even in cells that are visually normal in appearance. This study assessed the statistical significance of these marker features using a mixed-model nested-design analysis of variance (ANOVA). Features in blue intermediate cells from patients with normal cytology, moderate dysplasia, and severe dysplasia/carcinoma in situ, nonkeratinizing cells from patients with moderate dysplasia, severe dysplasia/carcinoma in situ, and invasive cancer, and dysplastic cells from areas of metaplasia from patients with moderate dysplasia, severe dysplasia/carcinoma in situ, and invasive cancer were tested. ANOVA clearly demonstrated that the marker features differentiate between cells of the same cell type originating from patients in different diagnostic categories. In every instance, the differences owing to the diagnostic category were statistically significantly greater than those caused by patient-to-patient variability. Although the discriminating marker features in the intermediate cells were almost exclusively spectral features reflecting staining differences, morphometric features were also marker features in the dysplastic cells.     

The morphology of gastritis.

Gastritis is a histopathologic diagnosis, which correlates poorly with both clinical symptoms of non-ulcer dyspepsia and endoscopic abnormalities. Worldwide, most cases of gastritis are due to Helicobacter pylori and are characterized by a diffuse superficial antral gastritis. Chronic inflammatory cells and lymphoid follicles are present in the lamina propria. Neutrophils are present in the surface and pit-lining epithelium. In North America and Western Europe, reactive gastropathy due to duodenal reflux or non-steroidal anti-inflammatory agents is also common. In this condition, there is no increase in inflammatory cells, but the pit-lining cells become hyperplastic, and the pits have a corkscrew appearance. Most examples of multifocal atrophic gastritis are the result of long standing Helicobacter gastritis, although there may be other causes as well. It is characterized by loss of glands in both pyloric and corpus mucosae with intestinal metaplasia of the surface epithelium. A subtype of intestinal metaplasia, in which sulphomucin (large bowel mucin) is present, has been associated with the development of distal gastric cancer. However, this association is relatively weak and is not considered useful for screening purposes. Gastric dysplasia may develop in areas of the stomach affected by intestinal metaplasia. High-grade dysplasia is a significant finding, with up to 60 percent of cases having coincident carcinoma and a further 25 percent of cases likely to develop an invasive malignancy within fifteen months.     

Amniotic membrane inhibits squamous metaplasia of human conjunctival epithelium

Squamous metaplasia is a common pathological process that occurs in the ocular surface epithelium. At present, there is no effective treatment for this abnormality. In the current study, we established an ex vivo conjunctival squamous metaplasia model by culturing human conjunctival tissues at an air-liquid interface for durations of up to 12 days. We then investigated the effects of amniotic membrane (AM) on squamous metaplasia through coculture of conjunctival tissues with AM or AM extract. We found that metaplasia features such as hyperproliferation and abnormal epidermal differentiation of conjunctival epithelium could be inhibited by AM or its extract. In addition, existing squamous metaplasia of conjunctival epithelium could be reversed to a nearly normal phenotype by AM. The mechanism by which AM prevents squamous metaplasia may involve downregulation of p38 mitogen-activated protein kinase and Wnt signaling pathways, which were activated in conjunctival explants cultured with an airlift technique. In conclusion, AM can inhibit and reverse squamous metaplasia of conjunctival epithelium. This finding may shed new light on prevention and treatment of diseases that involve epithelial squamous metaplasia.     

Differential glycosylation and cell surface expression of lysosomal membrane glycoproteins in sublines of a human colon cancer exhibiting distinct metastatic potentials.

Changes in the glycosylation of asparagine-linked oligosaccharides have been shown in various tumor cells, including human colon cancer. Attempts were made to elucidate the difference in Asn-linked oligo-saccharides attached to lysosomal membrane glycoproteins isolated from sublines of human colon carcinoma exhibiting high and low metastatic potentials in nude mice. Lysosomal membrane glycoproteins (lamp) 1 and 2 were immunoprecipitated from the cells after labeling with radioactive sugars, and the glycopeptides prepared were fractionated by serial lectin affinity chromatography employing immobilized concanavalin A, Datura stramonium agglutinin, and tomato lectin. Comparison of Asn-linked oligosaccharides from the different colonic carcinoma cells revealed the following features. First, the highly metastatic carcinoma cells express more poly-N-acetyllactosaminyl side chains with branched galactose residues than cells with low metastatic potential. Second, sialylation is more significant in the highly metastatic carcinoma cells than in the poorly metastatic ones. Conversely, N-acetyllactosamine units are less fucosylated in the highly metastatic cells than in poorly metastatic cells. These structural changes were apparently caused by the increase in sialyltransferase and the decrease in alpha 1----3 fucosyltransferase in the highly metastatic cells. The results also suggest that highly metastatic carcinoma cells express more sialyl Lex structures at the termini of poly-N-acetyllactosaminyl side chains than poorly metastatic carcinoma cells. Further, highly metastatic cells were found to express more lamp-1 and lamp-2 on the cell surface. These results were found to be correlated to the increased expression of sialyl Lex structures with high affinity binding of anti-sialyl Lex antibody on highly metastatic cells. Increased expression of sialyl Lex in the poly-N-acetyllactosamines of the cell surface may contribute to the metastatic behavior of the cells, assuming that this structure can serve as a better ligand for selectins present on endothelial cells and platelets.     

Spindle cell and cartilaginous metaplasia in a breast carcinoma with osteoclastlike stromal cells. A difficult fine needle aspiration diagnosis

The cytologic picture in fine needle aspirates from a unique type of breast tumor, with stromal proliferation of osteoclastlike giant cells, cartilaginous metaplasia and metaplastic spindle-shaped carcinomatous cells, is described. In this case, an erroneous cytologic diagnosis of fat necrosis associated with a rich component of reactive fibroblasts was made. This false-negative report, which was mainly due to lack of an obvious carcinomatous component in the aspirated material, is discussed with emphasis placed on the need to exclude spindle cell metaplasia in a breast carcinoma whose aspirates are characterized by a rich component of spindle-shaped cells.     

Histology of the adult mouse oviduct and endometrium following a single prenatal exposure to diethylstilbestrol

Light microscopy was used to examine the oviduct and endometrium of offspring from mice administered DES (10 micrograms/kg in 0.1 cc of corn oil, subcutaneously) or corn oil alone on Day 15 of gestation. Offspring were sacrificed at 5, 7 and 9 months of age. Oviduct changes in DES exposed offspring included numerous abnormal secretory cells which lined the mucosal folds of the isthmus. These cells contained a distinct granular cytoplasm which was eosinophilic and a nucleus displaced towards the apical surface. In addition both the ampulla and isthmus had mucosal folds which extended to the serosal surface and an accumulation of subepithelial fibrinoid material. Endometrial changes included squamous metaplasia of both the surface and glandular epithelial layer as well as extensive cystic glandular hyperplasia. In addition the endometrial connective tissue stroma exhibited fibrinoid accumulation. These changes may reflect an altered endocrine environment resulting from ovarian abnormalities during adulthood.     

Cytologic findings of atypical adenosis of the breast. A case report

BACKGROUND: Atypical apocrine adenosis, a well-described histopathologic entity, can sometimes be misdiagnosed as carcinoma. Apocrine cells can also appear atypical in cytopathology and be mistaken for carcinoma. Occasional case reports describe false positive cases due to the presence of apocrine cells in a few cases of radial scars and atypical apocrine metaplasia and in a degenerated cyst. CASE: A 37-year-old female underwent ultrasound-guided fine needle aspiration of an ill-defined breast nodule. The aspirate showed clusters and single cells containing abundant granular to focally vacuolated cytoplasm; enlarged, pleomorphic nuclei with irregular nuclear membranes; granular chromatin; and prominent nucleoli. These cells were distinct from and larger than the surrounding ductal and myoepithelial cells. Excision showed a nodular area of atypical apocrine adenosis adjacent to previous biopsy changes, correlating with the cytologic findings. CONCLUSION: Atypical apocrine adenosis can mimic carcinoma in histopathology and cytopathology. One should be cautious when reviewing apocrine cells in cytology, given their atypical features, especially their single, dispersed nature. However, the presence of accompanying benign cellular elements supports a benign diagnosis. Surgical biopsy should be recommended based on the cytologic findings.     

Pathophysiology and clinical relevance of Helicobacter pylori.

Considerable knowledge has recently accumulated on the mechanism by which Helicobacter pylori (H. pylori) induces chronic gastritis. Although H. pylori is not an invasive bacterium, soluble surface constituents can provoke pepsinogen release from gastric chief cells or trigger local inflammation in the underlying tissue. Urease appears to be one of the prime chemoattractants for recruitment and activation of inflammatory cells. Release of cytokines, such as tumor necrosis factor alpha, interleukin 1 and 6, and oxygen radicals, leads to a further tissue inflammation accompanied by a potent systemic IgA and IgG type of immune response. Chronic inflammation and antigens on glandular epithelial cells lead to a progressive destruction with loss of the epithelial barrier function. Within the gastric mucosa, patches of intestinal metaplasia develop, which may be a risk factor for subsequent development of gastric carcinoma. Hyperacidity in duodenal ulcer patients induces gastric metaplasia in the duodenal bulb, which represents a target for H. pylori colonization and ulcer formation. H. pylori can be detected in the majority of patients with peptic ulcers and, compared to age-matched healthy people, it is also found more often in patients with dyspepsia and gastric carcinoma. Although H. pylori can be detected in healthy people, the marked reduction of the ulcer recurrence rate by eradication of H. pylori (80 percent versus 20 percent relapse within one year) suggests that H. pylori is a major risk factor for duodenal ulcer formation. The potential role of H. pylori in non-ulcer dyspepsia and carcinogenesis is under investigation. Current regimens aimed at eradicating H. pylori use a combination of several drugs that are potentially toxic. Since the risk of complications may exceed the potential benefit in most patients, eradication treatment should be limited to clinical trials and to patients with aggressive ulcer disease. New drug regimens, e.g., the combination of proton pump inhibitors with one antibiotic, may provide less toxic alternatives. Beyond ulcer treatment, effective and well-tolerated eradication regimens may have a place in prophylaxis of gastric carcinoma.     

Retinoid X receptor alpha and retinoic acid receptor gamma mediate expression of genes encoding tight-junction proteins and barrier function in F9 cells during visceral endodermal differentiation

Retinoids are critical for differentiation of columnar epithelial cells and for preventing metaplasia of these cells into stratified squamous epithelial cells, in which tight junctions (TJs) are essentially absent. This implies that retinoids might play important roles in regulating the structures and functions of TJs of columnar epithelium. F9 murine embryonal carcinoma cells differentiate into epithelial cells resembling visceral endoderm bearing TJs, when grown in suspension as aggregates in the presence of retinoic acid (RA). We show that RA induces the TJ structure and expression of several TJ-associated molecules, such as ZO-1, occludin, claudin-6, and claudin-7, as well as a barrier function in the genetically engineered cell line F9:rtTA:Cre-ER(T) L32T2, which allows sophisticated genetic manipulations simply by addition of ligands (H. Chiba et al., 2000, Exp. Cell Res. 260, 334-339). Interestingly, our data indicate that a barrier for small substances is generated after that for large ones during de novo formation of TJs. We also compared the RA-induced expression of TJ components and barrier function in RXRalpha(-/-)-RARgamma(-/-) F9 cells with those in wild-type cells and show that the retinoid signals for transduction of these events are mediated by specific RXR-RAR pairs.     

Differences in lectin binding in squamous metaplasia induced by benzo(a)pyrene and vitamin A deficiency in hamster tracheal explants

Summary Epidermoid metaplasia in the hamster trachea can be produced by treatment with benzo(a)pyrene (BP) or vitamin A deficiency. To elucidate distinguishing features of the two types of lesions, lectin binding to tissue sections of tracheal explants exhibiting metaplastic lesions was assessed. In squamous metaplasia induced by vitamin A deficiency, Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), and peanut agglutinin (PNA) showed faint (+) to moderate (++) binding in both basal and suprabasal cells; Concanavalin A (Con A) showed moderate binding (++) to suprabasal cells and no binding in basal cells. In the BP-induced lesions, PNA and WGA bound intensely (++++, +++, respectively) in basal cells and faintly (+) to moderately (++) in suprabasal cells. The staining seemed to be predominant at the periphery of the cells. Further, the intensity of PNA and WGA staining increased significantly after the neuraminidase treatment. DBA and Con A showed faint (+) to moderate (++) binding in the BP-induced metaplasia. The results show that in BP-induced metaplasia, cells in the basal region show preferential binding of PNA and WGA. This research was supported by grant RO1-HL32308 from the National Heart, Lung and Blood Institute, Bethesda, MD.     

Cytological Changes Associated With Tubo-Endometrioid Metaplasia of the Uterine Cervix

Two women who had undergone previous cervical surgery for the treatment of glandular intraepithelial neoplasia (GIN) and cervical intraepithelial neoplasia (CIN), were found to have severely dyskaryotic cells of glandular and metaplastic type in follow-up cervical smears. A third patient was found to have similar abnormal cells in a routine screening smear. All of the patients were subjected to either hysterectomy or cervical conization and in all cases histological examination showed tubo-endometrioid glands in the endocervix, well away from the uterine isthmus, with no associated endometrial stromal tissue. All of the cervical smears were reviewed and cytological features that facilitate the distinction between tubo-endometrioid metaplasia and squamous or glandular dyskaryosis were identified. These features include the smaller size of affected cells, more marked nuclear hyperchromasia, inconspicuous nucleoli, the formation of glandular structures, the lack of discrete squamous dyskaryosis and the absence of the typical 'feathering' noted with GIN. the possibility of tubo-endometrioid metaplasia should be considered when atypical glandular or metaplastic cells are noted in cervical smears, particularly, but not exclusively, in women who have been treated for CIN or GIN. In the presence of these changes clinicians should rebiopsy the cervix before embarking on further unnecessary surgery which may adversely affect fertility and pregnancy, particularly in younger patients.     

Exploring the scope of redox-triggered chiroptical switches: syntheses, X-ray structures, and circular dichroism of cobalt and nickel complexes of N,N-bis(arylmethyl)methionine derivatives

N,N-Bis(arylmethyl)methionine derivatives are chiral ligands whose complexes with metal ions may show molecular helicity that can be modulated by defined structural processes. It was shown previously that exciton-coupled circular dichroism (ECCD) spectral amplitude could be modulated by one-electron copper redox chemistry in copper complexes of these ligands. Here we describe the further development of novel systems that show conformational changes resulting in the inversion of exciton chirality. The phenomenon was probed in a N,N-bis(arylmethyl)methionine derivative containing quinoline/pyridine moieties and a methionine carboxylate moiety. The sign of the ECCD of the complex formed between this ligand and CoCl2 is negative, which suggests that the deprotonated carboxylate oxygen coordinates to the metal, but the sulfur atom does not. The sign of the ECCD inverts to positive upon addition of ascorbic acid, which can be turned back to negative upon further treatment with persulfate. X-ray quality crystals of three cobalt complexes and one nickel complex were obtained. The ascorbate-treated cobalt complex of the ligand and the same ligand with nickel, however, vary from the behavior expected from their X-ray crystal structures. It is clear that the solution and crystallographic structures of these complexes differ in several cases.     

Multidrug resistance gene and P-glycoprotein expression in gastric adenocarcinoma and precursor lesions.

Overexpression of the Multiple Drug Resistance gene (MDR1) has been proposed as a major mechanism related to both intrinsic and acquired resistance to chemotherapeutic agents. The gene product is a membrane protein (P-glycoprotein), that acts as an energy-dependent drug efflux pump decreasing drug accumulation in resistant tumor cells. We have characterized MDR1 and P-Glycoprotein expression in human gastric adenocarcinoma and in precursor lesions. MDR1 mRNAs, analyzed by dot-blot technique, were detected in 9 of 10 non-tumoral gastric mucosae and in 8 of 10 gastric adenocarcinomas. Immunohistochemical analysis, using the MRK16 monoclonal antibody, revealed heterogeneous expression of P-Glycoprotein in individual cells. The P-Glycoprotein was found on the surface of cells of gastric areas with intestinal metaplasia subtype III. This type of intestinal metaplasia, also called "colonic metaplasia", has been strongly associated with a high risk for the development of gastric cancer. The fact that the P-Glycoprotein was detected in this precursor lesion is consistent with the intestinal metaplasia-dysplasia and carcinoma sequence proposed in the histogenesis of this tumour. The finding that P-Glycoprotein was heterogeneously expressed in malignant cells of some gastric adenocarcinomas also suggests that this transporter system probably contributes to primary and secondary multidrug resistance in this neoplasm.     

Aspiration cytology of the conjunctival surface

OBJECTIVE: To evaluate a method of obtaining conjunctival cells that utilizes aspiration of the conjunctival surface. STUDY DESIGN: Eighteen eyes from 16 patients with epibulbar lesions underwent aspiration of the conjunctival surface using a tuberculin syringe without a needle. The aspirated cells were prepared by the cytocentrifuge or Millipore filter technique. The lesions were subsequently biopsied, and the cytologic and histologic diagnoses were compared. RESULTS: Diagnoses of the conjunctival lesions, in decreasing order of frequency, were conjunctival intraepithelial neoplasia (dysplasia, carcinoma in situ), squamous cell carcinoma, squamous metaplasia, nevus, lymphoma and inflammation. In this feasibility study, the cytologic diagnosis accurately correlated with the histologic diagnosis in most cases. There were two cases in which the cytologic diagnosis led to the correct histologic diagnosis. CONCLUSION: Aspiration cytology of the conjunctival surface is useful in obtaining diagnostic material and may be used as a guide to where a biopsy should be performed. Limitations include inadequate samples and lack of observer experience.