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Biomedical subjects

G Dhom

Publications and source records attributed to G Dhom.

At least 19 recordsLinked to original sources
PubMed1992

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.

Basement Membrane↗
PubMed1992

[Adrenal cortex carcinoma. A rare cause of a Conn syndrome in childhood].

A 2 1/3 year old girl presented classical Conn-Syndrome as diagnostic feature of an adrenocortical carcinoma. Sonographic diagnosis was confirmed by CT-scan, typical hormonal pattern and subsequent surgical procedure. Without further therapy there has been no relapse with a follow-up of 3 years.

Adrenal Cortex Hormones↗
PubMed1991

Relation of endocrine-paracrine cells to cell proliferation in normal, hyperplastic, and neoplastic human prostate.

The relative distribution pattern of the pan-endocrine marker Chromogranin A (Chr A) and the proliferation-associated Ki-67 antigen was investigated in 20 prospectively sampled prostatectomy specimens. In cryostat sections, the Chr A immunoreactivity showed evidence of endocrine differentiation in all 15 prostatic adenocarcinomas. Nine tumors displayed a weak, 5 a moderate, and 1 adenocarcinoma a strong endocrine differentiation. These findings highlight the importance of endocrine differentiation in prostate malignancy that histologically resembles ordinary adenocarcinomas. The simultaneous demonstration of Ki-67 and Chr A revealed that in normal, hyperplastic, and neoplastic prostate tissue Chr A-positive cells were preferentially situated in proximity to Ki-67-labeled cells. This relative distribution pattern of both markers may indicate that endocrine cells are involved in controlling cell proliferation through a paracrine hormonal mechanism. However, an obvious correlation was not found between the degree of endocrine differentiation and proliferative activity in prostatic adenocarcinomas. Furthermore, a coexpression of Ki-67 and Chr A in the same (tumor) cells was not observed suggesting that the endocrine phenotype is only expressed in the G0 phase of the cell cycle as well as in normal, hyperplastic, and neoplastic conditions.

Adenocarcinoma↗
PubMed1991

Basement membranes in fetal, adult normal, hyperplastic and neoplastic human prostate.

The distribution of the various basement membrane (BM) components (type IV collagen, laminin and heparan sulphate proteoglycan) was studied in fetal, adult normal, hyperplastic and neoplastic prostates in formalin- and ethanol-fixed paraffin-embedded specimens. Stromal, epithelial and neoplastic BMs expressed differential susceptibility to pepsin treatment, suggesting conformational differences in the expression of epitopes on BM proteins in distinct anatomical structures and various lesions of the human prostate. In fetal prostate the acinar BM was regular and continuous in contrast to normal adult prostate and various hyperplastic conditions where the acinar BM was locally thickened or unreactive to the anti-BM antibodies. The localization pattern of BM components in grade I and grade II phases of prostatic cancer did not differ essentially from those found in various hyperplastic lesions. Regardless of the histopathological grade of malignancy, prostatic carcinoma cells were surrounded by distinct pericellular and periacinar membranes which were present even at points of contact with the stroma. This suggests that stroma invasion is invariably associated with neoplastic BM formations. Immunohistochemical evidence of the stromal or epithelial origin of neoplastic BMs could not be found. However, the consistent extracellular distribution of neoplastic BM components in contact with the stroma indicates that the elaboration of BM material requires a stromal influence.

Adenocarcinoma↗
PubMed1990

Morphological and immunohistochemical investigations of the utriculus prostaticus from the fetal period up to adulthood.

We investigated the utriculus prostaticus from the fetal period up to adulthood in 148 prostates. During the second half of gestation the utriculus had a simple tubular or a cystic form and was lined with metaplastic squamous epithelium which showed immunohistochemical positivity for different keratins, carcinoembryonic antigen, and peanut agglutinin binding sites. After birth, alveolar outgrowths of the utriculus developed. After puberty, the utriculus had become a complicated and variable structure. The epithelium no longer differed from that of the prostate glands either morphologically or immunohistochemically. Within the epithelium numerous endocrine cells were found containing neuron-specific enolase, chromogranin, and serotonin. The utriculus and ejaculatory ducts were embedded in a fibrous stroma with, after birth, numerous plexus-like blood vessels. This fibrous zone was peripherally bordered by a layer of smooth muscle. There was no evidence for a function of the utriculus differing from that of the prostate glands. Since the epithelium of both structures is identical immunohistochemically, the epithelium of the sinus urogenitalis most likely particpates in the lining of the utriculus during embryogenesis.

Adolescent↗
PubMed1990

Unusual prostatic carcinomas.

Over 90% of malignant epithelial tumors of the prostate are common carcinomas. Uncommon or rare prostate carcinomas can histogenetically be related to 4 epithelial types of the prostate: the secretory epithelium, the basal cells, the endocrine cells and the transitional epithelium. The rare, purely mucinous carcinoma and the ductal papillary carcinoma belong to the type of secretory epithelium. The latter is rarely seen in the large central prostatic ducts, it develops more frequently in peripheral ducts and is combined with common prostate carcinoma. The so-called endometrioid carcinomas of the utriculus described in the literature are probably ductal prostate carcinomas. To date no carcinoma has been found in the utriculus. The adenoid cystic carcinoma of the prostate is a basal cell tumor with preponderantly good prognosis. Endocrine cells are disseminated in most common prostate carcinomas. Thereby mixed forms showing both portions of a common adenocarcinoma and of a carcinoid may occur. Pure carcinoids of prostate are rare findings. The small cell carcinoma of the prostate is the highly malignant variant of the endocrine cell type. Immunohistochemically, a multitude of proteohormones are demonstrable in endocrine tumor cells. The ectopic ACTH production with Cushing's syndrome is of particular clinical significance.

Adenocarcinoma↗
PubMed1990

Squamous cell carcinoma of the prostate.

Eleven case of squamous cell carcinoma of the prostate have been divided into four groups according to their histological features and natural history: a pure squamous cell carcinoma of the prostate (one case); b common prostatic adenocarcinoma with malignant squamous component after oestrogen treatment (two); c urothelial carcinoma of the prostate with malignant squamous cell metaplasia (four); and d urothelial carcinoma of the urinary bladder with squamous cell metaplasia growing into the prostate (four). The squamous portions may spread to invade the fibromuscular stroma and grow in prostatic ducts. Necrosis of comedo type and inflammatory infiltrates appeared in a number of cases. The survival times of nine patients ranged from 1 to 17 months. Squamous components were shown by immunohistochemistry to contain various keratin types, carcino-embryonic antigen and peanut agglutinin binding sites. Whenever a squamous cell carcinoma in the prostate is diagnosed histologically various possibilities as to its origin should be considered.

Aged↗
PubMed1989

Current status of cancer registration in the Federal Republic of Germany and prospects for further development.

There is a network of hospital registries at cancer centers in the Federal Republic of Germany which, by 1985, had registered about 200,000 patients. Although the hospital registries do not have a strict population basis, the data obtained could be used for analytic epidemiological studies. The hospital registries are hindered from doing their own epidemiological cancer research mainly by their shortage of personnel. A particular organization - a pediatric cancer registry in Mainz - has registered about 95% of all childhood neoplasias and leukemias since 1980. Of the population-based registries of the Saarland, Hamburg, and Münster, only the Saarland Cancer Registry can at present provide actual incidence rates. In the three federal states of Saarland, Hamburg, and North Rhine-Westphalia, laws concerning cancer registries were enacted with different regulations regarding registration. In Hamburg and North Rhine-Westphalia the patient has to approve forwarding of his personal data to the registry. Exceptions are permitted under special conditions. Pathology institutes cannot report directly. In the Saarland, research institutes are not allowed to be given personal data. The position of the epidemiological cancer registries is actually threatened by the official application of restrictive data-protection laws.

Female↗
PubMed1988

Investigations of the estrogen (ER-ICA-test) and the progesterone receptor in the prostate and prostatic carcinoma on immunohistochemical basis.

Estrogen (ER) and Progesterone receptors (PR) were demonstrated immunohistochemically on frozen sections from 11 prostatectomy and 7 cystoprostatectomy specimens in the nuclei of various cell types. The periglandular fibrocytes and smooth muscle cells were extensively positive, the interglandular stromal cells were only partly so. Normal basal cells stained focally positive, hyperplastic basal cells stained extensively. The glandular secretory epithelium and atrophic glands were negative. The same findings were obtained in hyperplastic nodules. Both ER and PR also occurred in the urothelium of central prostatic ducts and of the prostatic urethra. The fibrous stroma around the ejaculatory ducts and seminal vesicles was extensively positive while the epithelium was negative. The smooth musculature of the seminal vesicles was only partly positive. On large field sections, the ER as well as the PR were numerically equally distributed throughout the inner zone of the prostate and the prostate proper. 12 prostatic carcinomas (G I-G III) were ER- and PR-negative. Estrogens may contribute to nodular hyperplasia by triggering a stromal proliferation with a secondary inductive epithelial growth. Obviously they do not act directly on prostatic carcinoma but inhibit growth via the hypophyseal-testicular axis. The biological significance of the PR in the prostate is unknown.

Humans↗
PubMed1988

Histology and immunohistochemistry studies in prostate cancer.

Histopathologic diagnosis of prostate carcinoma is not yet free of problems. There are particular difficulties in demarcating atypical forms of hyperplasia from well-differentiated carcinomas and in diagnosing and classifying incidental carcinomas. With the aid of conventional histology, however, nearly all diagnostic problems relevant for the patient can be solved. In routine diagnostics, modern immunohistochemical techniques are particularly helpful in assessing metastases of an undetected primary tumor. New immunohistochemical techniques provide insight into the receptor content of the prostate and show the histogenesis of prostate carcinoma in a new light. The estrogen receptor (modified ER-ICA test) is present in the nuclei of stromal cells and of basal cells within the glands, but not in the secretory epithelium. The receptor-associated protein--ER-D5--is found in the cytoplasm of stromal and basal cells. In basal cells and secretory epithelium, keratins show a different pattern. Immunohistochemically common adenocarcinomas display the pattern of secretory epithelium; urothelial and squamous cell carcinomas, on the contrary, display the pattern of basal cells. This finding does not support the opinion that the basal cell is the stem cell of secretory epithelium and the precursor cell of prostate carcinoma.

Carcinoma↗
PubMed1987

Papillary carcinoma of the prostate, location, morphology, and immunohistochemistry: the histogenesis and entity of so-called endometrioid carcinoma.

Fifty carcinomas that were partially to completely papillary in nature were examined. According to urethroscopic and rectal palpation findings, six of the carcinomas were located centrally, 40 tumors were in the prostate proper, and four were clinical stage T0. The epithelium of the papillary portions of the tumors was dark in some instances, light in others. Immunohistochemistry revealed that 20 of 22 tumors were positive for prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA). In no case was a topical relationship to the utriculus prostaticus demonstrable. The epithelium of the utriculus in seven additional patients who were not involved in this series also stained positively for PAP and PSA. Usual carcinomas of the prostate proper can develop endometrioid structures that do not differ immunohistochemically from ordinary portions of the carcinoma. Tumors located in central portions of the prostate are, in our opinion, morphologic variants of usual prostatic carcinomas, and apparently arise in prostatic ducts. We conclude that a distinction between endometrioid carcinomas and tumors of prostatic ducts does not seem justified and that papillary prostatic carcinomas should be treated like common prostatic cancer.

Acid Phosphatase↗
PubMed1987

Assessment of depth of invasion in rectal cancer by endosonography.

Pre-operative staging of rectal cancer could be significantly improved by the imaging method of endorectal ultrasound. Using high-frequency transducers a complex rectal wall pattern was demonstrated. Depending on in vitro or in vivo examinations and on US probes of different frequency the current interpretation is not uniform. Agreement exists on the interpretation of the muscularis propria which is of clinical importance. Objective and precise criteria for lymph node differentiation have yet to be worked out.

Humans↗