[Ultrastructural relationships between tumour and stroma in the prostatic carcinoma (author's transl)]

Distribution of basement membranes in primary and metastatic carcinomas of the prostate

The presence of periacinar and pericellular basement membranes (BMs) has been reported recently in common prostatic adenocarcinomas. In this study we extended our investigations of BMs on lymph node and hematogenous metastases, primary prostatic cancer with unusual histologic features, and posttreatment tumors. In contrast to prostatic malignancies that derive from the transitional epithelium (squamous cell carcinoma, prostatic transitional cell carcinoma) and prostatic involvement by bladder cancer, inconspicuous stromal changes and distinct BM formations at the site of tumor invasion were observed in carcinomas deriving from the secretory epithelium (papillary ductal carcinoma) and from the basal cell (basal cell carcinoma). Even highly malignant anaplastic and small cell carcinomas, as well as irradiated and/or hormonally treated tumors, showed distinct BM formations in contact with the stroma. The same observations could be made in lymphatic and hematogenous metastases of different anatomic sites. These findings indicate that prostatic malignancies may retain BMs even in high-grade lesions, metastases, posttreatment tumors, and variants of prostatic adenocarcinoma.

Electron microscopic results on the ventral prostate of the rat after CdCl2 administration. A contribution towards etiology of the cancer of the prostate

The prostate epithelium of rats which received repeated cadmium chloride (CdCl2) injections showed a gradual disruption of structural differentiation. Electron microscopy studies revealed severe changes in the ultrastructure affecting all epithelial cell organelles, particularly the nuclei, rough endoplasmatic reticulum, the golgi apparatus, and mitochondria. The cells infiltrating the stroma contained secretory vacuoles and their nuclear evaginations on the invasion front showed similarities to ultrastructural pathological changes in man. Examinations of the ventral prostate following oral CdCl2 administration revealed changes ranging in severity up to dysplasia, but there was no evidence of carcinoma.

Ductal spread in prostatic carcinoma

The histologic appearances of ductal invasion were studied in 139 cases of prostatic adenocarcinoma diagnosed in the Department of Pathology, Howard University Hospital, during the period January 1980 through October 1983. Intraductal spread was found in almost half (48%) of the prostatic glands examined. Ductal spread was associated with the local extent (P less than 0.001) rather than with the grade of the tumor (P less than 0.01). Three distinct patterns of ductal penetration were recognized. The duct wall was completely destroyed in microinvasion. In foci of ductal permeation the integrity of the basement membrane was generally preserved, and the duct wall was infiltrated mainly by solitary tumor cells. When the tumor spread was by extension in continuity within the duct wall, the neoplastic cells appeared to grow between the pre-existing epithelial layers. It was concluded that prostatic carcinoma cells have the ability to penetrate the wall of benign ducts and progressively replace the normal epithelial elements. In this process the general framework of the affected duct appears to be preserved.

On the histology of human seminoma: development of the solid tumor from intratubular seminoma cells

Intratubular seminomas of the testis associated with solid tumors were studied by light and electron microscopy in order to obtain information about the earliest stage of emigration from the tubules and invasion of the interstitial space. Careful examination of numerous sections reveals that at this stage neoplastic cells protrude into evaginations of the tubule covered by basement membrance or directly invade that membrane. At the site of tumor cell emigration, the basement membrane is thickened and multilayered. Tumor cells devoid of basement membrane were found in the interstitium. Their transmigration through the basement membrane was never observed. Subsequent to the migration of seminoma cells the tubules are smaller in diameter and contain only Sertoli cells. From the observations described it is inferred that tumor cells in the interstitial tissue increase in number, form strands and lobules, and finally build up the solid tumor.

Cyto- and histomorphogenesis of the prostate carcinoma. A comparative light- and electron-microscopic study

The fundamental histologic proliferation patterns of the prostate carcinoma are presented by the glandular and solid and/or cribriform structures. These were ultrastructurally analyzed from 28 carcinomas based on the cell forms in prostate carcinomas, which were already defined by electron microscope. These are characterized by their different cytoplasmic differentiation, whereby the singular cell types each represent a different functional state of a common tumor cell. The results indicate that the prostatic carcinoma develops morphologically in phases. The well-known growth patterns of the tumor are equivalent to its different states of development. In the first phase, a pattern develops out of a tumor stem cell (perhaps "primary atypical reserve cell"), which is either glandular or solid/cribriform, whereas this depends on the trend of the tumor cells to differentiate. The glandular structure possesses centrifugally proliferated glandular, often functionally deranged tumor cells, and shows signs of early stromal infiltration. The solid/cribriform pattern consists of centripetal proliferated, often less-differentiated tumor cells with or without lumen formation, and a peripheral layer of basal cells, whereby the idiopathic stroma architecture remains as it is. In the successive phase, stroma infiltration and destruction is distinctly marked durinaplastic" during tumor growth. Histologically, one often sees at this stage an "anaplastic" pattern; however, ultrastructurally its orign can be recognized as being glandular or solid/cribriform. The advanced stages of the tumor are furthermore characterized by a mixed cell pattern with all states of differentiation and by progressing tumor cell degeneration.

Ultrastructural studies of human prostatic neoplasia

Forty-two specimens of human prostatic neoplasia (32 carcinomas, eight benign hyperplasia, two bladder tumors infiltrating prostatic tissue, and 15 tissue cultures derived from prostatic neoplasia) were examined by electron microscopy. Intracisternal viruslike particles, 150-200 nm in diameter and budding, were found in epithelial cells of four carcinomas. In some of these particles, an electron-dense central core or two concentric layers were discernible. In addition, particles resembling type C virus particles, 90-130 nm in diameter, were observed in intracytoplasmic vacuoles in five cases of carcinomas and in one case of benign prostate hyperplasia. Thus, viruslike particles were found in 9 of 32 cases of prostate carcinoma and in one of eight cases of benign prostate hyperplasia. Virus particles have, so far, not been found in any of the tissue culture specimens. Further studies are required to determine the nature of these particles and their relationship to the origin of human prostatic neoplasia. Additional observations in both benign hyperplasia and carcinoma include intranuclear mitochondria, multilayered nuclear inclusions, bundles of intranuclear fibrils, intracytoplasmic tubules, extracellular tubulo-filamentous structures, and cilia.ltilayered nuclear inclusions, bundles of ilo-filamentous structures, and cilia.

[Colonization of the mouse liver by transplanted virogenic leukemia cells. Electron microscopic investigations (author's transl)]

Cells of a virogenic, immature myelogenic leukemia were injected in i.p. in one week old mice, strain NMRI, each animal receiving 10(5), 10(6) or 13(7) cells respectively in 0.2 ml Hanks' BSS. Mice were sacrificed at different times between 10 hrs and 21 days p.i. and liver specimens were prepared for electronmicroscopic studies. 10 hrs p.i. the leukemic cells are found in the sinusoids of the liver and after 30 hrs in the periportal fields. The leukemia cells migrate into the Disse spaces from the sinusoids. The leukemic cells penetrate with cytoplasmic digitations between connected endothelial cells. There is no lytic disintegration of the endothelial cells. The leukemic cells multiply by mitotic division of the Disse spaces, thereby compressing the liver cells. The cell membranes of both cell-types remain intact. Electronmicroscopically no evidence is found of a secretion of enzymes from the leukemia cells that destroy liver cells. Destruction of the liver cells is the consequence of the growth-pressure exerted by the dividing leukemic cells. Within the liver of the recipients the leukemic cells produce RNA-viruses. In the cytoplasm - frequently in the area of the Golgi-field - groups of immature A-particles are formed. In the virus fields the ribosomes disappear. The immature A-particles consist of two concentric electron dense shells. On the surface of the liver cells budding particles and immature C-particles develop. Extracellular mature C-particles with a homogeneous nucleoid and an irregular outer shell may be seen. The formation of viruses is found to be independent of the stage of the leukemia.

Microfilaments in human epithelial cancer cells

The occurence, distribution, and ultrastructural morphology of microfilaments in malignant epithelial cells of invasive squamous cell carcinoma of human oral cavity were studied by electron microscopy. The findings are compared with those in malignant oral epithelial cells of carcinoma-in-situ. In the malignant cells of invasive carcinoma, microfilaments 50-70 A in diameter are prominent in the cortical cytoplasm of the lateral and basal cell surfaces, adjacent and parallel to the plasma membrane, and extending into cell processes and microvillous extensions. Additional microfilaments are found to run from the peripheral cytoplasm to the perinuclear region. The microfilaments are aggregated into bundles aligned parallel to the long axis of the cell and display foci of increased electron density. They also tend to be aggregated into complex polygonal arrays. These microfilaments are similar in organization, concentration and ultrastructural architecture to those of various other nonmuscle cells, where they are thought to be capable of contraction and associated with cell motility. The presence of a microfilament system believed to be associated with contractile and motile cell processes may be an important characteristic of malignant cells of invasive tumors. The lack of abundant organized microfilaments in malignant cells in the absence of tumor invasion, and the presence of a prominent microfilament system in cells of invasive tumors, suggest that the microfilaments are related to the invasive properties of malignant tumor cells.

[Ultrastructural findings in carcinoma of the prostate after combined endocrine and radiation treatment]

Carcinomas of the prostate treated by orchiectomy, 60Co-radiation, and hormonal drugs a relatively short time prior to the time of biopsy were studied with the electron microscope. The following degenerative changes of tumor cells and fibromuscular stroma were found: The nuclei of the tumor cells were intensely heterochromatic, irregularly shaped, and the perinuclear rim dilated; large atypical sizes, multiple segmentations and "nuclear invaginations" were observed. The tumor cell cytoplasm showed vacuolar degeneration, and the limiting membranes of the tumor cells were extensively destroyed. Remarkable changes were also found in the fibromuscular stroma: There was a proliferation of collagenous fibers as well as degenerative transformations ending in hyalinization. The smooth muscle cells were dissociated and fragmented, sometimes showing vacuolar degeneration of the cytoplasm. The endothelium of the blood vessels was swollen, and the vessel walls were thickened. In spite of these radiation-induced lesions it remains undecided as to what degree the other therapeutic measures take part in the total therapeutic effects as seen in the ultrastructural findings. However, these regressive changes are much more pronounced than those seen after orchiectomy alone and partly resemble the findings which are characteristic of radiation induced structural lesions. The morphological changes are not uniform throughout the tumor. It is not unusual to find intact tumor cells next to totally degenerated cells. They represent poorly differentiated tumor cells. It is discussed whether these "embryonic" tumor cell types are and remain resistant to treatment and if a tumor recurrance may originate in them later on.