Scanning electron microscopy of the upper urinary tract in transitional cell carcinoma of the renal pelvis.

Three nephrectomy specimens with transitional cell carcinoma (TCC) of the renal pelvis were thoroughly examined by both light and scanning electron microscopy. The tumours as well as the urothelium of the upper urinary tract were studied. In all three cases, extensive areas of the urothelium, even in places remote from the tumours, were found by scanning electron microscopy (SEM) to be covered by pleomorphic microvilli. This suggests that there is a widespread failure of differentiation of the urothelium to a much greater extent than can be appreciated by conventional light microscopy.     

Detection of neoplastic and preneoplastic urothelia by combined scanning and transmission electron microscopy of urinary surface of human and rat bladders

Scanning and transmission electron microscopy reveal distinct differences between the appearance of the luminal surface membrane of normal urothelium and those of transitional cell tumours of both human and rat bladder. The luminal surface membrane of the preneoplastic rat urothelium shows features similar to those seen in the fully developed tumour. In human tumour-bearing bladders the urothelium away from the transitional cell tumour is not recognizable as being preneoplastic by light microscopy. However, by scanning or transmission electron microscopy, the luminal membrane in some areas shows changes identical to those in the preneoplastic rat bladder. These observations are in accordance with in the clinical behaviour of the urothelium in patients with vesical transitional cell tumours which tend to recur in disparate sites. We suggest that scanning electron microscopy of the bladder urothelium away from the tumour may be of prognostic value for indicating the subsequent biological behaviour of the urothelium     

Scanning electron microscopy in early human bladder neoplasia

Biopsies of healthy looking urothelium from 61 patients with transitional cell carcinoma (TCC) of bladder were examined by scanning electron microscopy (SEM) and light microscopy. A proportion (40 %) showed abnormal features on SEM, in particular pleomorphic microvilli (PMV) in at least one area. SEM appearances were graded into four categories depending upon divergence from normal. Patients were followed up at cystoscopy and one year later a strong correlation was noted between original abnormal SEM appearances and subsequent tumour recurrence. These early results suggest that SEM could be helpful in the diagnosis, assessment, and clinical management of the unstable urothelium.     

Early cellular and ultrastructural response of the mouse urinary bladder urothelium to ischemia

An experimental ischemic model of mouse urinary bladder was developed to study urothelium permeability and changes in cell ultrastructure. The bladder permeability barrier response to experimental ischemia (30–120 min) was investigated by means of indigo carmine dye, trypan blue and lanthanum nitrate tracer, which were used as quantitative and qualitative indicators of urothelial integrity. Changes to the urothelium were studied by light microscopy, and by scanning and transmission electron microscopy. It was established that ischemia primarily induces breakdown of the blood– urine permeability barrier by disruption of the tight junctions. It causes focal interruption of the contacts between the cells, which is followed by detachment and desquamation of viable urothelial cells. Urothelial damage occurs as funnel-shaped wounds, which can extend into the lamina propria. They are proportional to the duration of ischemia and to the extent of reperfusion induced. Desquamated cells in the bladder lumen, when exposed to hypertonic and toxic urine, gradually become irreversibly changed. Received: 10 February 1999 / Accepted: 15 July 1999     

An ultrastructural and morphometric study of bladder tumours (I)

Summary The ultrastructure of urothelium from 4 patients with no evidence of tumour was compared with that taken from 22 patients with bladder neoplasms of different grade and stage. Two features were quantified: the percentage of reduplication of the basal lamina and the percentage of discontinuous basal lamina.Tumours showed a lower percentage of reduplicated basal laminae than normal tissues, the difference being significant in 3 out of 4 types of tumours. The difference in frequency between normal tissues and non-recurring tumours was not significant, but there was a significant difference between normals and recurring tumours.All types of tumours showed discontinuities in the basal lamina, including 80% of those staged non-invasive by light microscopy. None of the normal tissues showed these. The percentage of discontinuities seen in non-recurrent tumours was half that seen in recurrent ones, but both groups were significantly higher than normals.Loss of continuity of the basement membrane distinguishes invasive from non-invasive tumours. However, there is a high probability of these being missed by light microscopy alone. Therefore, electron microscopic studies on recurrent bladder tumours would increase the accuracy of staging and prognosis.     

Melatonin prevents the development of hyperplastic urothelium induced by repeated doses of cyclophosphamide

Repeated cyclophosphamide (CP) chemotherapy increases the risk of developing bladder cancer, which could be due to the extremely rapid proliferation of urothelial cells observed in hyperplastic urothelium induced by CP treatment. We investigated the effect of melatonin on the development of urothelial hyperplasia induced by repeated CP treatment. Male ICR mice were injected with CP (150 mg/kg) or melatonin (10 mg/kg) with CP once a week for 3, 4 and 5 weeks. Transmission and scanning electron microscopy, immunohistochemistry and Western blot analysis were used to study the ultrastructure, apoptosis, proliferation and differentiation of urothelial cells. Repeated doses of CP caused the development of hyperplastic urothelium with up to ten cell layers and increased proliferation and apoptotic indices regarding Ki-67 and active caspase-3 immunohistochemistry, respectively. Scanning electron microscopy observations, cytokeratin and asymmetrical unit membrane immunohistochemistry and Western blot analysis showed a lower differentiation state of superficial urothelial cells. Melatonin co-treatment prevented the development of hyperplastic urothelium, statistically significantly decreased proliferation and apoptotic indices after four and five doses of CP and caused higher differentiation state of superficial urothelial cells.     

Light and electron microscopy in determining the histogenesis of vascular tumors

Six human vascular neoplasms were studied in light and electron microscopes. Electron microscopic examinations revealed specific ultrastructural features of tumour pericytes, cells of smooth-muscle tumours and tumour endothelium. Some tumours were found to be polymorphic in their cellular composition. The electron microscopy method revealed polymorphism of the tumour with diffuse distribution of cell elements (the presence of endothelial strata in hemangiopericytoma or the presence of the pericytic component in an endothelioma) but proved to be of low effectiveness in focal distribution of cell elements. It is concluded from the foregoing that simultaneous utilization of light and electron microscopy is necessary for vertification of such complicated neoplasms as vascular tumours of man.     

Ciliated epithelia in the urethra: case report and literature review

The presence of ciliated epithelial cells in the urethra has not been well recognized. Only two reports in the literature, both of which used scanning microscopy studies, have described this phenomenon. In this report, we illustrate the presence of scattered, ciliated epithelial cells in penile urethral biopsy specimens from a 38-year-old man with a history of bladder calculi and hematuria, by both light and transmission electron microscopy studies. The cilia in the urethra showed typical light microscopic and ultrastructural features of those seen in other organs. These ciliated cells are present in association with urothelial papilloma, condyloma acuminatum and acute inflammation of the urethra. These findings suggest that ciliated cells in the penile 0 urethra might be a consequence of metaplastic change of the urothelium, secondary to local stimulation or irritation.     

Loss of heterozygosity at 9q32-33 (DBC1 locus) in primary non-invasive papillary urothelial neoplasm of low malignant potential and low-grade urothelial carcinoma of the bladder and their associated normal urothelium

Tumour recurrence has a major impact on patients with non-invasive papillary urothelial tumours of the bladder. To explore the role of DBC1 (deleted in bladder cancer 1 locus), a candidate tumour suppressor gene located at 9q32-33, as prognostic marker we have performed loss of heterozygosity (LOH) testing in 49 patients with primary papillary urothelial tumours and associated normal urothelium. Data from the 38 tumours and 11 specimens of normal urothelium that were informative in the LOH study (D9S195 marker) showed that LOH in urothelium (45.4%) but not in non-invasive tumours (60.5%) was associated with tumour recurrence (p = 0.026) but not to grade or progression. Also, tumours whose normal urothelium had LOH were larger (p = 0.020) and showed cyclin D1 over-expression (p = 0.032). Non-significant increased expression of p53, p21Waf1, apoptotic index and tumour proliferation, and decreased expression of p27Kip1 or cyclin D3 also characterized tumours whose normal urothelium had LOH. The expression of these G1-S modulators, apoptotic index and tumour proliferation was more heterogeneous in papillary urothelial tumours, irrespective of having retained heterozygosity or LOH. Also, Bax expression decreased in papillary urothelial tumours having LOH (p = 0.0473), but Bcl-2 was unrelated to LOH status. In addition, FGFR3 protein expression decreased in LOH tumours (p = 0.036) and in those having LOH in their normal urothelium (p = 0.022). FGFR3 immunohistochemical expression was validated by western blot in selected cases. The survival analysis selected LOH in normal urothelium as a marker of disease-free survival (log-rank 5.32, p = 0.021), progression-free survival (log-rank 3.97, p = 0.046) and overall survival (log-rank 4.26, p = 0.038); LOH in tumours was significant in progression-free survival (log-rank 3.83, p = 0.042). It is concluded that LOH at the DBC1 locus in normal urothelium seems to be relevant in the prognosis of non-invasive papillary tumours of the bladder via selecting cases with increased proliferation, frequent alterations of the G1-S phase modulators, and decreased FGFR3 protein expression.     

Low-temperature and conventional scanning electron microscopy of human urothelial neoplasms

The appearance of neoplastic human urothelium viewed by low-temperature scanning electron microscopy (LTSEM) and conventional scanning electron microscopy (CSEM) was compared. Fixed, dehydrated neoplastic cells viewed by CSEM had well-defined, often raised cell junctions; no intercellular gaps; and varying degrees of pleomorphic surface microvilli. The frozen hydrated material viewed by LTSEM, however, was quite different. The cells had a flat or dimpled surface, but no microvilli. There were labyrinthine lateral processes which interdigitated with those of adjacent cells and outlined large intercellular gaps. The process of fixation and dehydration will inevitably distort cell contours and on theoretical grounds, the images of frozen hydrated material should more closely resemble the in vivo appearance.     

Morphological analysis of the acute effects of overdistension on the extracellular matrix of the rat urinary bladder wall.

PURPOSE: To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats. MATERIALS AND METHODS: The bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). RESULTS: LM--The control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. The overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM--The cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM--A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces. CONCLUSIONS: Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.     

The Anal Transitional Zone: A Scanning and Transmission Electron Microscopic Investigation of the Surface Epithelium

The ultrastructure of the anal transitional zone (ATZ) is described by means of scanning and transmission electron microscopy. The technique used permits histologic reexamination of the scanning electron microscopic biopsies. The surface of the ATZ shows, in addition to areas of normal colorectal mucosa and squamous epithelium, a characteristic picture: there are cells of varying size, arranged in a cobblestone pattern, and a surface covered with short microvilli that tend to form rows, indicating beginning microridge formation. This corresponds histologically to the so-called ATZ epithellum, and it is suggested that this might be metaplastic squamous epithelium rather than urothelium. The deepest part of the epithelium contains endocrinelike cells with granules of at least two types.     

The Anal Transitional Zone: A Scanning and Transmission Electron Microscopic Investigation of the Surface Epithelium

The ultrastructure of the anal transitional zone (ATZ) is described by means of scanning and transmission electron microscopy. The technique used permits histologic reexamination of the scanning electron microscopic biopsies. The surface of the ATZ shows, in addition to areas of normal colorectal mucosa and squamous epithelium, a characteristic picture: there are cells of varying size, arranged in a cobblestone pattern, and a surface covered with short microvilli that tend to form rows, indicating beginning microridge formation. This corresponds histologically to the so-called ATZ epithellum, and it is suggested that this might be metaplastic squamous epithelium rather than urothelium. The deepest part of the epithelium contains endocrinelike cells with granules of at least two types.     

Detection of squamous cell differentiation in experimental tumors of urothelium by using epidermal G2 chalone

The presence of epidermal G2 chalone was investigated by different immunochemical methods in normal urothelium and in tumors of the urinary bladder induced in rats with N-butyl-N-butanol-(4)-nitrosamine. This chalone was not revealed in normal urothelium but found in 37 out of 56 tumors examined. In all these 37 tumors, squamous urothelial metaplasia was detected by electron or even light microscopy. The extent of morphological manifestations of squamous metaplasia showed a definite correlation with the concentration of chalone in tissue extracts. The method used may be applied as a subsidiary test for the determination of focal squamous metaplasia in biopsy material of human urothelial tumors which is of importance for prognosis of the disease.     

An assessment of the value of electron microscopy in tumour diagnosis.

The contribution of electron microscopy to the diagnosis of tumours in a general hospital has been investigated. During a three year period 235 cases were examined, of which 66 (28%) were diagnostic problems by light microscopy. In 42 (64%) of the problem cases a contribution towards diagnosis was made by ultrastructural examination, which was most useful for anaplastic polygonal cell tumours, of some value for spindle cell neoplasms, and least helpful in the further categorisation of metastatic carcinoma.     

The three-dimensional ultrastructure of the pancreatic acinar cell (authors transl)]

The pancreatic acinar cells of normal rats were studied by scanning electron microscope. A three-dimensional image is presented of the structure and arrangement of the zymogen granules as well as of the apical microvilli and the zymogen discharge in the pancreatic acinar cell. The study of these structures in physiologic and pathologic conditions by scanning electron microscopy can be recommended to support the understanding of findings obtained by light and transmission electron microscopy.     

Granular cell tumour of the mammary gland simulating malignancy

Summary Primary granular cell tumours of the breast in 35 2and 55 year old women were studied by light microscopy, transmission electron microscopy and immunohistochemistry. Light and electron microscopy revealed a neural origin of the tumours and this was further substantiated by immunohistochemical studies, with positive S-100 protein reaction and negative reactions for surface heavy and light chains, CEA, alfa-1-antitrypsin, muramidase and GFA-protein. Granular cell tumour of the mammary gland is a very rare tumour. Clinically it sometimes simulates carcinoma because of its fibrous consistency, fixation to pectoral fascia and skin retraction. The diagnosis of granular cell tumour should be included in the differential diagnosis of carcinoma of the breast.The granular cell tumour is derived from neuro-ectodermal tissue. Whether it represents a neurogenic cell-confined metabolic disturbance with lysosomal activation, or a true neoplasm remains to be elucidated.     

Scanning electron microscopy of normal, neoplastic and inflamed human bladder

Scanning electron microscopy (SEM) was used to compare the topographic fine structure of urothelium from normal, neoplastic and inflamed human bladders. The three groups of patients show different patterns. The normal bladder lining is characterized by regularly arranged large superficial cells with ridged surfaces. By contrast, the surface cells of a transitional cell carcinoma are rounded up and covered with microvilli. In some patients with cystitis or post inflammatory hyperplasia SEM appearances intermediate between normal and neoplastic patterns are encountered. However, except in extremely severe cystitis it is possible on SEM to differentiate between inflamed and neoplastic urothelium. Surface microvilli provide a useful malignant marker for transitional cell carcinoma. However, severe inflammation of the bladder, when diagnosed on cystoscopic examination, can and must be excluded by light microscopy before this marker is considered diagnostic for neoplasia.     

Ochronotic arthropathy. A comparative scanning electron microscopic and light microscopic study of the synovium in ochronosis

The synovium in two cases of ochronosis was studied by scanning electron microscopy and light microscopy. Several features not yet described were seen by scanning electron microscopic examination and correlated with the light microscopic findings. This is the first report in the English language literature comparing scanning electron microscopic findings with the light microscopic findings in ochronosis.     

Patterns of chromosomal aberrations in urinary bladder tumours and adjacent urothelium

Bladder cancer is often characterized by recurrent and multifocal growth, and tumours are frequently accompanied by precancerous alterations of the surrounding urothelium. These findings have led to the hypothesis that cells from areas of genetically aberrant but morphologically non-cancerous or even unremarkable mucosa may be the source of bladder carcinomas. Fluorescence in situ hybridization (FISH) was performed using ten probes targeting five different chromosomes that are known to be frequently altered in bladder cancer (centromere 1, 8, 9, 11, 17 and 1p36, 8p23, 9p21, 11q13, 17p13) on paraffin-embedded tissue sections of 11 superficial bladder cancers. Copy number changes of the tumours were compared to those in the urothelium adjacent to the tumour. Eleven of 11 (100%) tumours and eight of 11 (73%) samples of adjacent urothelium showed copy number changes of at least one chromosome. The occurrence of similar patterns of chromosomal aberrations in the tumours and their associated urothelium supports the hypothesis of a clonal relationship. It is concluded that FISH analysis targeting five different chromosomes is more sensitive than conventional histology for distinguishing between neoplastic and normal cells of the urothelium.