Scanning electron microscopy of normal and malignant human urothelium

Structure of the pelvic and penile urethra--relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus)

The urethra is the main place of entry for sexually transmitted pathogens. However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands. The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s. Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies. Conventional techniques of light and scanning electron microscopy were utilized. The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse. However, there is variation in drainage type among accessory sex glands for the inner urethra. The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra. The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra.

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.

Selected ultrastructural aspects of urothelial and prostatic tumors

Ultrastructural techniques have been widely applied in the study of urothelial and prostatic tumors. In the common proliferative diseases affecting the lower urogenital tract, electron microscopy has provided us with a greater understanding of the pathobiology and morphology of these disease processes. Specific diagnostic application, however, has been limited. In the unusual tumors affecting urothelium and prostate such as neuroendocrine carcinoma, carcinosarcoma, and sarcomas, electron microscopy has provided some practical diagnostic information of value in patient management. This paper provides a survey of the fundamental and practical contributions of ultrastructural studies in the prostatic and urothelial areas.

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.

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 epithelium, 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.

Collection and evaluation of normal exfoliated urinary bladder cells in man using scanning electron microscopy

Normal exfoliated urinary bladder cells were collected from midstream urine samples from 21 male patients. Procedures for urine filtration using Millipore filters of Nucleopore filters, cell fixation and preparation for scanning electron microscopy investigation were developed. Correlations were made between the surface morphology of exfoliated cells and that of biopsies from different anatomical regions of the urinary bladder. Scanning electron microsocopy (SEM) of exfoliated normal urinary bladder cells proved to be a more sensitive method for discovering cellular surface details than light microscopy. This information forms the basis for further SEM studies of cell surface alterations due to urothelial diseases.

Surface characteristics of malignant human urinary bladder epithelium studied with scanning electron microscopy

Biopsies were obtained from 28 male and seven female patients with cystoscopically and histologically confirmed urinary bladder carcionoma. Tissue specimens for light microscopy and scanning electron microscopy (SEM) were obtained from the tumours as well as from cystoscopically tumour-free mucosa of the dome, the lateral walls and the trigone of the urinary bladder and also from the proximal urethra. Certain surface structural changes, which seem to represent malignancy, present in different regions of the urinary bladder were detected by SEM, although not visible by light microscopy.

Scanning electron microscopy of exfoliated malignant and non-malignant human urothelial cells

Midstream urine samples were taken from 35 patients with histologically diagnosed urinary bladder carcinoma, from 27 patients without history or sign of malignancy or infection in the urinary tract, and from eight patiens with cystitis. The urine was filtered through Millipore filters, or Nuclepore filters, pore size 5.0 microns, on which the cells were caught. From the same patients biopsies were obtained from different anatomic regions of the urinary bladders as well as from the carcinomas that were present. The filters and the biopsies were examined with scanning electron microscopy (SEM). The exfoliated cells trapped on the filters were in good morphological condition. Idential characteristics of the cell surface morphology were recognized in the biopsies and the exfoliated cells from each patient. In non-malignant cases the cells displayed the regional morphological charcteristics of the urinary bladder. Bacteria and an increased number of red and white blood cells were attached to the cell surface of numerous exfoliated cells in patients with cystitis, but no pleomorphic microvilli were detected in these patients. In cases of malignancy exfoliated cells with pleomorphic microvilli on their surface were detected. A large majority of the exfoliated cells shed in the urine with pleomorphic microvilli on their surfaces still retained enough regional surface characteristics to determine their origin. Some of the cells were completely covered with pleomorphic microvilli and it was impossible to determine their origin.