Differential distribution of pepsinogen II between the zones of the human prostate and the seminal vesicle

Pepsinogen II (PG II) is a gastric proenzyme which has previously been found in both human seminal fluid and the prostate gland. However, no regional distribution of PG II has been noted within the prostate nor has it been found in the seminal vesicle. Bouins-fixed sections of central zone, peripheral zone and seminal vesicle, taken from 10 prostates removed at radical prostatectomy or cystectomy, were exposed to antibody against PG II and stained using the A-B-C immunoperoxidase technique. Formalin-fixed tissue from autopsy prostates of four men in the third decade, and six cases with BPH nodules, were also examined for PG II activity. In nine of 10 seminal vesicles, and seven of 10 central zone samples, more than 50 per cent of the cells stained positive for PG II. By contrast, in nine of 10 peripheral zone samples staining was present in five per cent or less of the epithelial cells. Similarly, PG II activity in the four autopsy prostates occurred almost entirely within the central zone and ended abruptly at the boundary between the peripheral and central zones. BPH nodules contained no PG II activity. These findings provide the first evidence that the central and peripheral zones may serve different biological functions. Embryologically it is currently thought that the prostate is of endodermal origin and the seminal vesicle of mesodermal origin. The presence of large amounts of PG II in both the seminal vesicle and central zone lends support to the hypothesis of a common mesodermal origin for these two structures.     

Pathogenesis and biological significance of seminal vesicle invasion in prostatic adenocarcinoma

Seminal vesicle invasion and the percentage involvement by cancer of each seminal vesicle were related to cancer volume, quantitative histological grade and presence or absence of lymph node metastases in 243 radical prostatectomy specimens. There were 47 prostates with seminal vesicle invasion. Frequency and extent of seminal vesicle invasion were strongly correlated with cancer volume, with minimal invasion noted in only 6% of the cases less than 4 cc. The relationship of seminal vesicle invasion to lymph node metastasis was statistically significant but cancer volume and histological grade were much stronger predictors of lymph node metastasis. The route of invasion from the prostate in 46 cases involved direct tumor spread into the midbase region near the ejaculatory ducts. Seminal vesicle invasion often may not be identified if the tissue nearest the ejaculatory ducts at the prostate base is not sampled.     

Pathology of benign prostatic hyperplasia. Insight into etiology.

Morphometric studies of prostates with benign hyperplasia (BPH) have revealed features that may help clarify the disease's natural history and biologic behavior. Hyperplasia arises within a small anatomic region having precise boundaries and containing an unusual juxtaposition of glandular and stromal elements. Diffuse non-nodular enlargement of the transition zone is the commonest morphologic feature of BPH, but nodules show a greater potential for growth and comprise most of the tissue in large (more than 50-gm) resection specimens. Most nodules are predominantly glandular, with features that suggest a pathogenetic role of induction of embryonic-type stroma.     

Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk

Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.      

Differential cytokeratin expression in normal, hyperplastic and malignant epithelial cells from human prostate.

Studies were undertaken to define the expression of cytokeratins in normal, hyperplastic and malignant epithelial cells from human prostate. Cytokeratin (CK) polypeptides, separated by two-dimensional electrophoresis, were identified by immunoblotting with CK-specific monoclonal antibodies. CK polypeptides 5, 7, 8, 15, 18 and 19 were identified in fresh normal and hyperplastic prostate. Expression of CK 15 has not been previously reported in human prostate. Analysis of central and peripheral zone tissues from human prostate did not reveal qualitative differences in CK expression between these areas. Epithelial cells harvested from fresh BPH tissue by percoll gradient centrifugation and propagated in vitro using selective culture techniques showed alterations in CK expression compared to intact human prostate. Specifically, CKs 6, 14, 16 and 17 were noted in cultured BPH epithelial cells but not fresh normal prostate or BPH tissue. Immunoblot analysis of the established prostate cancer cell lines PC3, DU145 and LNCAP showed expression of CKs 8 and 18 but not CKs 5, 7 and 15 which were observed in benign prostate. These studies further characterize CK expression in benign and malignant human prostate and provide insights which may be useful in differentiating normal, hyperplastic and malignant epithelial cells in the human prostate gland.     

Multiple cancers in the prostate. Morphologic features of clinically recognized versus incidental tumors.

Multiple independent tumors were identified in specimens from 117 of 234 prostatectomies for clinical adenocarcinoma; there were 266 incidental cancers in these 117 prostates. The clinically detected carcinoma was the largest (or only) tumor in all 202 Stage B cases. However, among 32 Stage A cases (detection by transurethral resection), there were 8 prostates in which an incidental tumor was larger than the clinically manifest cancer. These were all small tumors except for two incidental cancers with a volume greater than 2cm3; roughly 80% of incidental carcinomas were smaller than 0.5 cm3, whereas fewer than 20% of manifest tumors were smaller than 0.5 cm3. Comparison with a series of cancers found incidentally at cystoprostatectomy for bladder cancer showed the same volume distribution as incidental (smaller) carcinomas in patients with prostate cancer. This distribution was thought to reflect the volume distribution of prostate cancer in the general population older than 50 years of age. It was concluded that additional incidental tumors are common in patients with prostate cancer, but their sum of volumes is seldom as large as the clinical cancer volume.     

Hodgkin disease: CT of the thymus

The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement.     

Solitary bronchioloalveolar carcinoma: CT criteria

The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.