Consensus development of a histopathological classification system for chronic prostatic inflammation.

OBJECTIVE: To develop a standardized histopathological classification system for chronic prostatitis (standardized description of prostatic inflammatory infiltrates) based on a literature review, extensive prospective evaluations in two recognized prostatitis research centres and widespread consensus of international urological centres identified as having major expertise or interest in chronic prostatitis. METHODS: Relevant articles for review were identified by a Medline search undertaken by the Cochrane Review Group in Prostate Diseases and Urologic Malignancies, and cross-checking bibliographies of retrieved studies, reviews, book chapters and abstracts of the American Urological Association and International Prostatitis Collaborative Network Annual Meetings. Initial drafts were based on classification systems independently developed by the Prostatitis Research Centers at Queen's University in Canada and University of Washington in the USA. A collaborative draft was distributed to 20 urological/pathological clinical centres who participated in the North American Chronic Prostatitis Collaborative Research Network and First International Prostatitis Collaborative Network. A consensus classification system was then distributed to the participating panel for acceptance. RESULTS: The literature review identified a reasonably consistent description of inflammatory infiltrate locations and patterns that were further incorporated into the draft based on the Queen's University and University of Washington proposals. Eighteen (90%) of the identified Prostatitis Centers participated in the revision of the draft and the final consensus process. The final consensus document classifies prostatic inflammation according to its extent and grade/severity in each tissue compartment (location). Conclusion The consensus of the expert panel was that this classification system can be used in the evaluation of prostatic inflammation in prostate biopsies, transurethral resected prostate chips or prostatectomy specimens. A standardized accepted framework to describe histopathological prostate inflammation will prove useful in evaluating prostate disease.

Three-dimensional microscopic image reconstruction of prostatic adenocarcinoma.

CONTEXT: Routine microscopy provides only a 2-dimensional view of the complex 3-dimensional structure that makes up human tissue. Three-dimensional microscopic image reconstruction has not been described previously for prostate cancer. OBJECTIVES: To develop a simple method of computerized 3-dimensional image reconstruction and to demonstrate its applicability to the study of prostatic adenocarcinoma. METHODS: Serial sections were cut from archival paraffin-embedded prostate specimens, immunostained using antikeratin CAM5.2, and digitally imaged. Computer image-rendering software was used to produce 3-dimensional image reconstructions of prostate cancer of varying Gleason grades, normal prostate, and prostatic intraepithelial neoplasia. RESULTS: The rendering system proved easy to use and provided good-quality 3-dimensional images of most specimens. Normal prostate glands formed irregular fusiform structures branching off central tubular ducts. Prostatic intraepithelial neoplasia showed external contours similar to those of normal glands, but with a markedly complex internal arrangement of branching lumens. Gleason grade 3 carcinoma was found to consist of a complex array of interconnecting tubules rather than the apparently separate glands seen in 2 dimensions on routine light microscopy. Gleason grade 4 carcinoma demonstrated a characteristic form of glandular fusion that was readily visualized by optically sectioning and rotating the reconstructed images. CONCLUSIONS: Computerized 3-dimensional microscopic imaging holds great promise as an investigational tool. By revealing the structural relationships of the various Gleason grades of prostate cancer, this method could be used to refine diagnostic and grading criteria for this common tumor.

The pathology of interstitial lung disease in nylon flock workers.

Flocking is a widely used industrial process in which short lengths of synthetic fibers are applied to backing fabric to produce plush material. In response to an apparent outbreak of interstitial lung disease in flock workers, the Centers for Disease Control hosted a clinical-pathological workshop to identify the defining characteristics of the disease and possible etiologic agents. Six pathologists reviewed 15 biopsies of 15 cases (out of a clinical caseload of 20 patients) and assessed the pattern, extent and degree of pulmonary inflammation, fibrosis, and other changes. A consensus clinical-pathologic diagnosis was reached for each patient and correlated with clinical and radiologic findings. Four of eight open lung biopsies and one of seven closed (transbronchial) lung biopsies demonstrated a characteristic pattern to which the descriptive terminology lymphocytic bronchiolitis and peribronchiolitis with lymphoid hyperplasia was applied. The other biopsies showed nonspecific inflammatory changes, airspace organization, and diffuse alveolar damage. One open lung biopsy demonstrated respiratory bronchiolitis with lymphoid hyperplasia. None of the lung biopsies showed more than mild interstitial fibrosis and no granulomas were identified. The consensus of the workshop was that lymphocytic bronchiolitis and peribronchiolitis with lymphoid hyperplasia was a characteristic and distinctive pattern of injury in the flock workers' lung biopsies. Although the etiology of this disease remains undefined at present, the injury pattern and environmental studies suggest a chronic immunologic response to inhaled material.

Immunohistochemical evidence of loss of PTEN expression in primary ductal adenocarcinomas of the breast.

Germline mutations in PTEN, encoding a dual-specificity phosphatase on 10q23.3, cause Cowden syndrome (CS), which is characterized by a high risk of breast and thyroid cancers. Loss of heterozygosity of 10q22-24 markers and somatic PTEN mutations have been found to a greater or lesser extent in a variety of sporadic component and noncomponent cancers of CS. Among several series of sporadic breast carcinomas, the frequency of loss of flanking markers around PTEN is approximately 30 to 40%, and the somatic intragenic PTEN mutation frequency is <5%. In this study, we analyzed PTEN expression in 33 sporadic primary breast carcinoma samples using immunohistochemistry and correlated this to structural studies at the molecular level. Normal mammary tissue had a distinctive pattern of expression: myoepithelial cells uniformly showed strong PTEN expression. The PTEN protein level in mammary epithelial cells was variable. Ductal hyperplasia with and without atypia exhibited higher PTEN protein levels than normal mammary epithelial cells. Among the 33 carcinoma samples, 5 (15%) were immunohistochemically PTEN-negative; 6 (18%) had reduced staining, and the rest were PTEN-positive. In the PTEN-positive tumors as well as in normal epithelium, the protein was localized in the cytoplasm and in the nucleus (or nuclear membrane). Among the immunostain negative group, all had hemizygous PTEN deletion but no structural alteration of the remaining allele. Thus, in these cases, an epigenetic phenomenon such as hypermethylation, -ecreased protein synthesis or increased protein degradation may be involved. In the cases with reduced staining, 5 of 6 had hemizygous PTEN deletion and 1 did not have any structural abnormality. Finally, clinicopathological features were analyzed against PTEN protein expression. Three of the 5 PTEN immunostain-negative carcinomas were also both estrogen and progesterone receptor-negative, whereas only 5 of 22 of the PTEN-positive group were double receptor-negative. The significance of this last observation requires further study.

Analysis of the 10q23 chromosomal region and the PTEN gene in human sporadic breast carcinoma.

We examined a panel of sporadic breast carcinomas for loss of heterozygosity (LOH) in a 10-cM interval on chromosome 10 known to encompass the PTEN gene. We detected allele loss in 27 of 70 breast tumour DNAs. Fifteen of these showed loss limited to a subregion of the area studied. The most commonly deleted region was flanked by D10S215 and D10S541 and encompasses the PTEN locus. We used a combination of denaturing gradient gel electrophoresis and single-strand conformation polymorphism analyses to investigate the presence of PTEN mutations in tumours with LOH in this region. We did not detect mutations of PTEN in any of these tumours. Our data show that, in sporadic breast carcinoma, loss of heterozygosity of the PTEN locus is frequent, but mutation of PTEN is not. These results are consistent with loss of another unidentified tumour suppressor in this region in sporadic breast carcinoma.

Immunohistochemical detection of multidrug resistance protein in human lung cancer and normal lung.

Monoclonal antibody QCRL-1 is highly specific for a defined linear epitope in a relatively poorly conserved region of the human multidrug resistance protein (MRP). We have used QCRL-1 to examine MRP expression in archival and fresh snap-frozen samples of untreated small cell (SC) and non-small cell (NSC) lung cancers (LCs), as well as normal lung. We found that the majority (87%) of all histological subtypes of NSCLC had detectable levels of MRP in most of the tumor mass. In a substantial proportion of adenocarcinomas (55%) and squamous cell carcinomas (28%), immunoreactivity approached that obtained with the highly multidrug resistant cell line H69AR from which the MRP was originally cloned. Both the level and frequency of MRP expression in untreated SCLC was significantly lower than in NSCLC. The MRP was detectable in only 56% of SCLC tumors and, in most cases, was expressed in small focal clusters of cells. Immunofluorescence studies of tumor tissue and normal lung confirmed the plasma membrane location of the MRP. However, in normal bronchial epithelium and seromucous glands, unlike in tumor cells, the MRP was detected only on basolateral membranes. In addition, strong MRP immunoreactivity was detected in reactive type II pneumocytes present in hyperplastic alveoli, but not in normal type I and type II pneumocytes. No potentially confounding correlation independent of its possible role in drug resistance was observed between MRP expression in untreated NSCLC and any clinicopathological parameter examined, including overall survival.

Primary adenocarcinoma in an enterocutaneous fistula associated with Crohn's disease.

Increasing numbers of intestinal adenocarcinomas in patients with Crohn's disease have been reported, but the strength of this association still needs to be elucidated. Adenocarcinoma has also been documented in different types of fistulous tracts associated with Crohn's disease. The first case of well-differentiated mucinous adenocarcinoma involving only enterocutaneous fistulae is reported in a patient with long-standing Crohn's disease complicated by persistent abdominal wall fistulous tracts. The malignant lesion arose from neoplastic transformation of columnar epithelium lining portions of the fistulae occurring as a result of either re-epithelialization of these inflammatory tracts or mural implantation of mucosal tissue secondary to prior ulceration. The patient has remained disease-free eight years after surgical resection of the tumour. Even though intestinal carcinoma is not as strongly associated with Crohn's disease as with ulcerative colitis, intestinal carcinoma should be considered in the setting of long-standing disease, previous intestinal exclusion surgeries and complications such as enterocutaneous or other types of fistulous tracts. The prognosis of such patients may be excellent with early diagnosis and treatment.

Analysis of PTEN and the 10q23 region in primary prostate carcinomas.

Deletions involving chromosome 10q23 occur frequently in prostatic carcinomas. Recently, a novel tumour suppressor gene, PTEN, mapping to this interval, has been identified. Mutation or deletion of PTEN has been observed in a proportion of prostate cancer cell lines; however, primary prostate carcinomas have not been studied. We have investigated the involvement of PTEN in primary prostatic adenocarcinomas using a panel of 51 matched normal and prostate tumour DNAs. We first determined the proportion of tumours with allele loss at loci in 10q23 which span the region containing the PTEN gene. Our results show that LOH involving 10q23 is common in primary prostate carcinomas. Twenty-five of 51 (49%) tumours showed loss of heterozygosity (LOH) over the region spanning the PTEN locus. We next directly analysed the PTEN gene for mutations of the coding region using single strand conformation polymorphism (SSCP) and sequence analyses. Of those tumours with LOH, only a single tumour was found to carry a missense mutation in PTEN. No mutations in PTEN were identified in tumours without LOH. Our results suggest either that mutation of PTEN is a late event in prostate tumorigenesis, or that another tumour suppressor gene important in prostate cancer may lie close to PTEN in 10q23.

Increased expression of the 72-kd type IV collagenase in prostatic adenocarcinoma. Demonstration by immunohistochemistry and in situ hybridization.

The expression of the 72-kd type IV collagenase has been implicated as an important factor in determining the invasive potential of malignant tumors. Using immunohistochemistry and nonisotopic in situ hybridization, type IV collagenase expression was assessed in benign and malignant prostatic tissue obtained from 117 surgical and autopsy specimens. Diffuse strong staining for type IV collagenase mRNA and protein was identified in the malignant cells of more than 85% of prostatic adenocarcinomas and the dysplastic cells of high grade prostatic intraepithelial neoplasia. Benign hyperplastic epithelium showed moderate expression in basal cells and mild expression in secretory cells. The qualitative patterns of type IV collagenase expression in prostatic epithelium at the protein and mRNA levels in individual cases were identical. There was no correlation between the level of type IV collagenase expression and either tumor grade or stage. In 10% of adenocarcinomas, focal mild to moderate stromal cell immunoreactivity was present but mRNA was not detectable in the stromal compartment in any case. The enhanced expression of type IV collagenase in dysplastic epithelium and prostatic adenocarcinoma suggests it contributes to the development of the invasive phenotype. The vast majority of the enzyme present in these tumors is synthesized by malignant cells and its production by stromal cells is negligible.

Immunohistochemical analysis of type IV collagenase expression in prostatic hyperplasia and adenocarcinoma.

The 72-kDa Type IV collagenase (T4C) is a matrix metalloproteinase, the expression of which may be important in normal basement membrane metabolism. The production of T4C by malignant cells has been linked to their invasive and metastatic potential in several tumor systems. The pattern of T4C immunoreactivity was assessed in formalin-fixed, paraffin-embedded prostatic tissue using polyclonal, monospecific antibodies. Basal cells in normal and hyperplastic epithelium demonstrated slight to moderate cytoplasmic immunoreactivity, while secretory epithelial cells showed generally weaker immunostaining. In 35 of 35 cases of primary adenocarcinoma and five of five cases of metastatic adenocarcinoma in lymph nodes, the majority of malignant cells showed strong immunoreactivity. Similar strong immunostaining was also seen in foci of prostatic intraepithelial neoplasia. The high level of expression of T4C in prostatic adenocarcinoma and its metastases suggests this metalloproteinase may play a role in determining the invasive and metastatic properties of this tumor. The enhanced immunoreactivity in prostatic intraepithelial neoplasia suggests the induction of T4C may be an early event in the development of the invasive phenotype. The expression of T4C in benign epithelial cells may be a manifestation of its putative physiological role in basement membrane metabolism.

Microencapsulation of human fibroblasts in a water-insoluble polyacrylate.

Viable human diploid fibroblasts have been micro-encapsulated in EUDRAGIT RL, a commercially available water-insoluble polyacrylate, by an interfacial precipitation technique. Cells in medium and polymer solution (in diethyl phthalate) were coextruded and formed into droplets by a coaxial air stream. The droplets fell into a corn-oil/mineral-oil mixture to extract the solvent to precipitate the polymer around the cells. Capsules were ca. 500 mum in diameter depending on the air flowrate with a ca. 10-mum thick wall. When collagen (1 mg/mL) was added to the cell suspension prior to encapsulation and base-washed corn oil was used, cell growth occurred with one doubling achieved after five to six days as the collagen gel contracted inside the capsule. In the absence of collagen, cells spread on the inner wall of the capsule but did not grow, presumably because the surface charge on the capsule was inadequate. In similar fashion fibroblasts spread but did not grow on films of EUDRAGIT RL but did grow on blends of EUDRAGIT RL and EUDRAGIT E containing 10-30% of the latter more highly aminated polyacrylate. Although not suitable for anchorage-dependent cell growth by itself, EUDRAGIT RL has been suitable as a model polymer to demonstrate the feasibility of using water insoluble polyacrylates and organic solvents and nonsolvents for the micro-encapsulation of fibroblasts. Such microcapsules are of potential interest as a mode of large scale tissue culture for the production of novel therapeutic agents.