Manual and automated AgNOR count in differentiating reactive mesothelial from metastatic malignant cells in serous effusions

OBJECTIVE: To distinguish reactive mesothelial cells from malignant cells in serous effusions using manual and automated methods of enumeration of argyrophilic nucleolar organizer regions (AgNORs). STUDY DESIGN: In this prospective study, 38 samples of benign (19 cases) and malignant (19 cases) serous effusions were included. AgNOR stain was used in each case along with routine Papanicolaou stain. The smears were examined under an oil immersion objective, and AgNOR dots were counted by direct observation independently by 2 observers. Automated AgNOR counting and morphometry were performed with a Quantimet 600 image cytometer (Leica, Cambridge, England). At least 100 cells were counted in each case. The number of AgNOR dots in individual cells, AgNOR area, nuclear area, AgNOR vs. nuclear area and nuclear perimeter were measured. Data on benign and malignant cells were compared. RESULTS: The AgNOR dots were discrete and smaller in benign effusion cases as compared to coarse and aggregated in malignant effusion cases. In benign reactive effusion cases the mean number of AgNOR dots per nucleus was 2.33 +/- 0.71 and 2.83 +/- 1.15 by the manual and automated method, respectively, whereas that for malignant effusion cases was 7.48 +/- 2.51 and 8.09 +/- 1.69 by the manual and automated method, respectively. Mean total AgNOR areas in benign and malignant groups were 4.77 +/- 2.66 microns 2 and 38.22 +/- 13.71 microns 2, respectively. Mean nuclear area, nuclear perimeter and ratio of AgNORs vs. nuclear area were 48.72 +/- 19.30 microns 2, 24.68 +/- 10.25 microns and .098 in benign effusion cases as compared to 174.25 +/- 82.36 microns 2, 69.03 +/- 27.23 microns and 0.22 in malignant effusion samples. All these values were significantly higher (P < .001, Student's t test) in malignant cells as compared to benign reactive cells. CONCLUSION: AgNOR dot enumeration, AgNOR area and ratio of AgNORs to nuclear area are valuable adjuncts to cytomorphology in differentiating reactive mesothelial cells from malignant cells in serous effusions. Automated AgNOR counting is rapid and less cumbersome.     

Diagnostic utility of GLUT-1 expression in the cytologic evaluation of serous fluids

OBJECTIVE: To evaluate the extent to which adenocarcinomas in body cavity fluids express GLUT-1 in comparison to currently available markers for adenocarcinomas. STUDY DESIGN: Archival paraffin-embedded cell blocks of serous fluids from 25 cases of benign effusions containing reactive mesothelial cells and 39 cases of malignant effusions with metastatic adenocarcinoma (11 ovarian, 11 pulmonary, 9 gastrointestinal and 8 breast) were retrieved from the surgical pathology files. All cases were stained with antibodies for GLUT-1, Ber-Ep4, B72.3 and CEA. Positive staining was defined as distinct linear membrane staining for GLUT-1 and Ber-EP4, cytoplasmic staining for CEA, and cytoplasmic or membrane staining for B72.3. Strong staining in at least 10% of the tumor cells was required in order to consider the case positive for the particular marker. RESULTS: GLUT-1 was expressed in 72% (28 of 39) of cases of malignant effusions: 100% (11 of 11) from the ovary, 91% (10 of 11) from the lung, 67% (6 of 9) from the gastrointestinal tract and 12% (1 of 8) from the breast. None (0 of 25) of the benign effusions expressed GLUT-1. Malignant effusions expressed CEA in 74% (29 of 39), Ber-Ep4 in 85% (33 of 39), and B72.3 in 62% (24 of 39). Benign effusions expressed CEA in 3 cases and B72.3 in 2 cases. CONCLUSION: GLUT-1 is a useful marker that can be applied to cytologic specimens. It can be used as a reliable component of an antibody panel to distinguish reactive mesothelial cells from metastatic adenocarcinoma in particular adenocarcinomas of body cavity effusions, in particular adenocarcinomas of ovarian and pulmonary origin.     

Ultrastructure of pleural mesothelioma and pulmonary adenocarcinoma in malignant effusions as compared with reactive mesothelial cells.

OBJECTIVE: To determine the ultrastructural features of diffuse malignant pleural mesothelioma cells in cytologic specimens from pleural effusions. STUDY DESIGN: We retrospectively studied 35 pleural effusions: 12 diffuse malignant pleural mesotheliomas (8 epithelial type, 4 biphasic type), 12 pulmonary adenocarcinomas and 11 cases of reactive mesothelial cells. RESULTS: In the cytoplasm, reactive and malignant mesothelial cells had more-abundant intermediate filaments (P < .05, P < .01) and fewer free ribosomes (P < .001, P < .001) than adenocarcinoma cells. Reactive mesothelial cells had fewer mitochondria than mesothelioma cells (P < .05). Mesothelioma cells had longer, thinner microvilli on the cell surfaces (P < .001); length/diameter ratios of microvilli were 19.1 +/- 7.0 (mesothelioma) vs. 9.1 +/- 2.2 (adenocarcinoma) and 9.2 +/- 2.4 (mesothelial cells). Giant intercellular junctions (desmosomes or desmosomelike structures > 1 micron in length) were found in eight cases of mesothelioma. Core filaments or rootlets in microvilli were present in two cases of adenocarcinoma. CONCLUSION: Because cytologic specimens from pleural effusions were easy to obtain, we think ultrastructural cytology is useful in distinguishing mesothelioma from adenocarcinoma and benign effusions.     

Comparison of NCL-hTERT antibody reactivity and telomere repeat amplification protocol in situ in effusions

OBJECTIVE: To compare the performances of 2 methods, telomerase repeat amplification protocol (TRAP) in situ and antibodies to the hTERT protein, in assessing telomerase activity. STUDY DESIGN: TRAP in situ and immunohistochemistry with a commercial antibody (NCL-hTERT) was performed on 54 body cavity effusions. The results were compared and correlated to diagnosis. RESULTS: Thirty-four effusions from patients with verified malignant disease contained cytologically malignant cells. Both methods were positive in 33 of the cases, whereas only hTERT was positive in 1 case. Twenty effusions, all containing mesothelial cells, came from patients with benign conditions. In 2 fluids atypical, hyperplastic mesothelial cells were both TRAP in situ and hTERT positive. All remaining 18 fluids were TRAP in situ negative, whereas 12 of 18 were hTERT positive. Thus the results of TRAP in situ and hTERT immunohistochemistry disagreed in 1 of 34 (3%) malignant and 12 of 20 (60%) benign cases. CONCLUSION: The sensitivities for malignancy were similar for TRAP in situ and hTERT immunohistochemistry. The specificity of the applied hTERT antibody was significantly lower, due to hTERT reactivity in mesothelial cells.     

Monoclonal antibodies in the cytodiagnosis of serous effusions

In order to assess the value of immunocytochemical staining as a method of discriminating between benign reactive mesothelial cells and malignant epithelial cells in serous effusions, we have studied the reactions of a panel of commercially available antibodies on cells harvested from 83 pleural and peritoneal fluids and compared the results with the clinical and cytological diagnoses. The antibodies used were raised against cytokeratin (PKK1), epithelial membrane antigen (EMA), carcino-embryonic antigen (CEA), pregnancy specific B1-glycoprotein (SP1) and leucocyte common antigen (LCA). Anti-CEA was positive in 16 of 39 effusions (41%) containing carcinoma cells. Pregnancy specific B1-glycoprotein (SP1) was positive in 33% of the same samples. Mesothelial cells did not stain with these antibodies. Thus anti-CEA and SP1 can be used to discriminate between benign mesothelial and malignant epithelial cells in effusions. Anti-PKK1 stained both benign reactive mesothelial cells and malignant epithelial cells and cannot be used to discriminate between these two cell types. Strong positive staining of malignant cells was noted with anti-EMA. However, as occasional weak staining of mesothelial cells was also noted, strong staining with this antibody may be regarded as suspicious but not conclusive of malignancy.     

Use of desmin immunohistochemistry to distinguish between mesothelial cells and carcinoma in serous fluid cell block preparations

OBJECTIVE: To evaluate the utility of immunohistochemical stains for desmin in discriminating mesothelial cells from adenocarcinoma in serous fluid cell block preparations. STUDY DESIGN: Cell block preparations from 22 cases (representing 18 patients) that were positive for carcinoma and 5 cases that were negative for malignancy were immunostained with an antibody to desmin. Positive staining was evaluated and scored semiquantitatively in both tumor cells and background mesothelial cells in the malignant cases and mesothelial cells in the negative controls. Staining was evaluated with a score of 0-3 for intensity and 0-5 for distribution. The sum of the two scores was recorded as the total score (TS). RESULTS: Mesothelial cells from all the carcinoma and benign cases stained with desmin (median TS = 5.5, range 4-8), typically strong in intensity and widespread in distribution. Positivity was observed in carcinoma cells in all cases, typically weak and focal (range 2-4). Using a total score of 4 as a cutoff for definitively positive staining, desmin staining was positive in mesothelial cells in 25/25 cases and carcinoma cells in 1/22 cases (P < .0001, Fisher's exact test). Additionally, using the Mann-Whitney ranked sum test on the 20 cases with evaluable mesothelial cells, the medians of the total scores for mesothelial cells (5.5) and carcinoma cells (2.5) were significantly different (P < .0001). CONCLUSION: A total score of > or = 4 was significantly associated with mesothelial cell staining. Use of desmin immunohistochemical staining in cell block preparations may be helpful in distinguishing between mesothelial cells and carcinoma.     

Proliferation and apoptosis in solid tumors. Analysis by laser scanning cytometry

OBJECTIVE: To examine the relationship between apoptosis and proliferation in a series of human solid malignant tumors, making use of objective, reproducible techniques newly developed for laser scanning cytometry (LSC). STUDY DESIGN: Apoptosis was detected by in situ end labeling of DNA strand breaks with FITC-conjugated nucleotide. Proliferation was detected by Ki-67 antibody. Two parameters were detected independently and simultaneously with DNA measurement on aliquots of cell suspensions obtained by mechanical dissociation of fresh tumors and placed on microscope slides. RESULTS: The number of cells undergoing apoptosis varied from 0.5% to 28.1% (average, 5.4 +/- 6.0). Aneuploid tumors showed a higher percentage of apoptotic cells (7.9 +/- 7.2) as compared to diploid tumors (3.4 +/- 4.0). Tumors with the greatest number of apoptotic cells on LSC also had the largest number of apoptotic cells on light microscopic examination. The number of cells labeled by Ki-67 ranged from 1.7% to 56.7% (average, 20.0 +/- 15.5). Aneuploid tumors were characterized by a higher Ki-67 index (average, 28.3 +/- 14.3%) than the diploid tumors (13.2 +/- 13.3%). CONCLUSION: Overall, there was a very weak or no correlation between apoptosis and proliferation. However, a subset of aneuploid tumors had a high percentage of cells positive for Ki-67 and low percentage of apoptotic cells. Diploid tumors did not show any correlation between apoptosis and proliferation, although many of those tumors had both low apoptotic and proliferative indices. Whether those differences are of prognostic significance remains to be determined in follow-up studies that include more cases and clinical data. Here we have shown that LSC is a powerful new tool of potential clinical value for fast, objective analysis of apoptosis, proliferation and DNA ploidy in solid malignant tumors.     

Distinguishing benign from malignant pleural effusions by lectin immunocytochemistry

Since distinguishing malignant from benign cells in pleural effusions can be difficult, with reactive mesothelial cells simulating adenocarcinoma cells, the binding patterns of a battery of lectins on cells in eight benign and eight malignant effusions were studied using the avidin-biotin peroxidase complex method. The following lectins were used: concanavalin A, Dolichos biflorus agglutinin, peanut agglutinin, Phaseolus vulgaris agglutinin, Ricinus communis germ agglutinin, soybean agglutinin, Ulex europeaus agglutinin (UEA) and wheat germ agglutinin. Several patterns of staining were seen with the lectins, but only UEA was helpful in distinguishing between benign and malignant effusions. Sixty percent of the adenocarcinomas stained with UEA, whereas none of the cells in the benign effusions did. These results imply that UEA positivity is indicative of carcinoma and can be useful in separating reactive or atypical mesothelial cells from adenocarcinoma cells.     

Immunocytochemical Staining of Serous Effusions With the Monoclonal Antibody Ber-Ep4

Cytospin preparations were made from 102 serous effusions for immunocytochemical staining using a panel of monoclonal antibodies including a new monoclonal antibody Ber-EP4. On cytological examination, 32 fluids were reported to contain tumour cells consistent with metastatic adenocarcinoma; 66 contained benign cells only and three were reported to contain cells suspicious of malignancy. One effusion contained tumour cells consistent with malignant mesothelioma. Positive staining of the tumour cells with Ber-EP4 was observed in the 32 effusions (100%) which contained adenocarcinoma cells. No staining of the mesothelial cells in these 32 specimens was observed. Carcinoembryonic antigen, epithelial membrane antigen Ca2 and CD15 staining of tumour cells was noted in 53%, 50%, 50% and 9% of these cases, respectively. None of the mesothelial cells in the benign effusions stained with Ber-EP4. Nor did the malignant mesothelial cells in the only case of malignant mesothelioma. These findings suggest that Ber-EP4 is a valuable addition to antibodies available for the differential diagnosis of mesothelial cells and adenocarcinoma cells in serous effusions.     

Diagnostic interest of the monoclonal antibody CA1 in malignant pleural effusion

The Ca1 antibody was used in an immunohistochemical procedure on smears of cells from 40 patients with malignant pleural effusion. The control group consisted of 25 benign pleural effusions with a high percentage of reactive mesothelial cells. The Ca1 Mc Ab was positive in 19 (79%) of the 24 pleural effusions with positive malignant cytology. In all the benign cases the Ca1 Mc Ab was negative (100% specificity). The Ca1 Mc Ab detected malignant mesothelial cells in two cases and was negative with reactive mesothelial cells and other nucleated cells present in the pleural effusion. We conclude that the Ca1 antibody offers a useful diagnostic method for malignant pleural effusions, when the morphological interpretation is doubtful.     

Characterizing subpopulations of neoplastic cells in serous effusions. The role of immunocytochemistry

OBJECTIVE: To analyze the role of immunochemistry in serous effusions. STUDY DESIGN: We analyzed cell blocks of 18 pleural and 18 peritoneal effusions diagnosed as malignant (18), benign (14) and suspicious (4). They were immunostained by the avidin-biotin complex method with a panel of four monoclonal antibodies--CEA, Ber-EP4, LeuM1 (CD15) and p53--and, for lectins (Ulex europaeus) UEA-l, ConA and ConBr. RESULTS: Seventeen of the 18 cases of adenocarcinoma were positive for CEA (95%), 12 (66.6%) for Ber-EP4, 11 (61%) for CD15 and 11 (61%) for p53. Twelve of the 18 (66.6%) were positive for UEA-1, CEA, Ber-EP4 and CD15. UEA-1 did not react with mesothelial cells. p53 Gave a positive reaction in only one case, reactive mesothelial cells. ConA and ConBr reacted indiscriminately with benign and malignant cells; thus, it was not useful in distinguishing between these cells. CONCLUSION: In this context no antibody used alone is reliable for corroborating a diagnosis, but the selective use of a small panel of three markers (CEA, Ber-EP4 and LeuM1) can be very useful in solving diagnostic difficulties in the cytodiagnosis of serous effusions.     

Immunohistochemical study of lysozyme, alpha 1-anti-chymotrypsin, tissue polypeptide antigen, keratin and carcinoembryonic antigen in effusion sediments

The cellular sediments of 42 malignant and 16 benign effusions (58 cases) were studied using the immunoperoxidase technique. Serial sections of formalin-fixed, paraffin-embedded residual sediments of effusions, sent for routine cytologic examination, were studied by commercially available polyclonal antisera against lysozyme, alpha 1-anti-trypsin, alpha 1-anti-chymotrypsin, tissue polypeptide antigen (TPA), a wide-spectrum anti-keratin, carcinoembryonic antigen (CEA) and, in single cases, thyroglobulin and prostate-specific antigen. A final definite diagnosis from histologic study of biopsy or autopsy specimens was known in all cases. All carcinomas, the mesotheliomas and the reactive mesothelial cells showed a positive reaction for TPA and, partly, the wide-spectrum keratin. Lysozyme could be demonstrated in the cells of the one proven malignant fibrous histiocytoma; all malignant epithelial cells were negative. Alpha 1-anti-chymotrypsin and alpha 1-anti-trypsin showed similar reactions: they were often positive in carcinoma cells of the breast, the bronchial system and the pancreas, in contrast to a mostly negative reaction in carcinomas of the stomach and ovary. CEA showed considerable differences; it was always negative in benign and malignant mesothelial proliferations but mostly positive in carcinomas of the stomach, pancreas and bronchial system. It was only positive in less than 20% of the carcinomas of the breast and always negative in the proven malignant effusions of primary carcinomas of the ovary and prostate. Studying a combination of several tumor markers is possible in serial paraffin-embedded sections and may be a valuable criterion in the cytologic diagnosis of effusions.     

Diagnostic utility of BCA-225 in detecting adenocarcinoma in serous effusions

OBJECTIVE: To determine the diagnostic value of the BCA-225 antibody in discriminating adenocarcinoma from benign mesothelium in body cavity effusions. STUDY DESIGN: One hundred four cases of unequivocally benign (34 cases) and malignant (70 cases) serous effusions with cell block material were immunostained for BCA-225 using the ABC method without antigen retrieval. The percentage of positively staining cells in each case was estimated in a blind fashion. RESULTS: BCA-225 stained at least 10% of morphologically malignant cells in 28 of 32 (88%) breast carcinomas and 58 of 67 (87%) adenocarcinomas overall. Neuroendocrine carcinomas (two cases) and one mesothelioma were positive in < or = 5% of their respective tumor cells. Of 34 benign cases, 6 (18%) exhibited positive staining, albeit in rare, morphologically benign cells. CONCLUSION: BCA-225 is able to discriminate adenocarcinoma from reactive mesothelium in cell block preparations and may prove useful as part of an antibody panel.     

Ki-67 and AgNOR proliferative markers as diagnostic adjuncts to fine needle aspiration cytology of thyroid follicular lesions

OBJECTIVE: To differentiate hyperplastic nodules (HPN), follicular adenoma (FA) and follicular carcinoma (FCA) of the thyroid by cytomorphologic features combined with argyrophilic nucleolar organizer regions (AgNORs) and Ki-67 proliferative markers on fine needle aspiration cytology. STUDY DESIGN: Cytomorphologic patterns, along with two proliferation markers, Ki-67 and AgNORs, in fine needle aspirates of 123 histologically confirmed cases of thyroid follicular lesions, including 39 hyperplastic nodules, 70 follicular adenomas and 14 cases of follicular carcinomas, were recorded. RESULTS: Mean AgNOR (mAgNOR) counts and Ki-67 labelling index (LI) were consistently higher in FCA in comparison to FA and HPN irrespective of the cytologic patterns in fine needle aspiration smears. Between benign and malignant lesions, an overlap of 1.83% at the cutoff point of 4.0 was observed in cases of mAgNORs, whereas it was 11.09% at a cutoff of 5.0 in cases of Ki-67 LI. CONCLUSION: mAgNOR counting in fine needle aspiration smears is more sensitive, simple and cost effective as compared to Ki-67 LI for differentiating between benign and malignant thyroid follicular neoplasms.     

Cytophotometric determination of DNA in mesotheliomas and reactive mesothelial cells

Cytophotometry was used to study the nuclear DNA content of cells in Feulgen-stained effusion specimens from 18 patients with mesothelioma and 14 patients with reactive mesothelial proliferations. The mean DNA content (MDNA) of mesothelioma cells was significantly higher than that of reactive mesothelial cells (P less than .001). Other parameters reflecting the DNA content also differed significantly between the two kinds of cells, including (1) the ratio of mean mesothelial DNA to mean lymphocyte DNA, (2) the percentage of mesothelial cells with DNA content exceeding three times the lymphocyte MDNA and (3) the coefficient of variation of the DNA content. Since these parameters were highly correlated, only one was accepted in a stepwise linear discriminant model for distinguishing reactive from mesotheliomatous effusions. The model correctly classified all of the reactive effusions studied and 89% of the mesotheliomatous effusions. These results indicate that DNA analysis, using the Feulgen stain and cytophotometry, yields criteria that may be useful in distinguishing benign reactive mesothelial cells from malignant mesothelioma in effusions when used in conjunction with other traditional parameters.     

Specific tumor markers in diagnostic cytology. Immunoperoxidase studies of carcinoembryonic antigen, lysozyme and other tissue antigens in effusions, washes and aspirates

The immunoperoxidase technique was used to identify specific tumor markers in exfoliated cells in fine needle aspirates and body fluids. Carcinoembryonic antigen (CEA) and lysozyme staining was evaluated in cytocentrifuge preparations from 42 malignant effusions and aspirates and 16 benign effusions. Reactive mesothelial cells were negative for CEA and lysozyme or showed faint peripheral cytoplasmic staining. Malignant cells from 50% of the adenocarcinomas studied were positive for CEA. All tumors studied were negative for lysozyme. These staining patterns are helpful in the differential diagnosis of reactive mesothelial and adenocarcinoma cells, a frequent diagnostic dilemma. Moreover, demonstration of specific tumor antigens (e.g., prostatic acid phosphatase, calcitonin and immunoglobulin) helped define the origin of metastatic malignancy in selected cases. Estrogen receptor activity was also identified in tumor cells using this technique. Immunoperoxidase was helpful in the evaluation of malignant cytologic specimens from patients with more than one tumor. Interpretation of staining patterns is discussed, with reference to the limitations of the technique. Immunoperoxidase methods maintain cytologic detail, are readily adaptable to diagnostic cytology and increase the specificity of cytologic diagnosis.     

Significance of immunocytochemical expression of E-cadherin, N-cadherin and CD44 in serous effusions using liquid-based cytology

OBJECTIVE: To assess the diagnostic utility of E-cadherin (E-cad), N-cadherin (N-cad) and CD44 to discriminate adenocarcinoma cells from benign and malignant mesothelial cells in body cavity fluids and to clarify the origin of cancer cells. STUDY DESIGN: A total of 120 ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) cytologic specimens of serous effusions, which included 22 cases of reactive mesothelium, 6 cases of malignant mesothelioma and 92 cases of metastatic adenocarcinoma from various sites, were immunostained for E-cad, N-cad and CD44. RESULTS: Eighty-three of 92 metastatic adenocarcinomas (90.21%) expressed E-cad, while 1 of 6 malignant mesotheliomas and 1 of 22 cases of reactive mesothelium were positive for E-cad. All 6 cases of mesothelioma expressed N-cad, whereas most cases of metastatic adenocarcinomas were negative. CD44 immunoreactivity was seen in 18 of 22 (81.81%) benign effusions and in 21 of 92 (22.82%) metastatic adenocarcinomas. CONCLUSION: The combination of E-cad, N-cad and CD44 appears to be a useful panel for distinguishing metastatic adenocarcinoma, mesothelioma and reactive mesothelium and also for clarifying the exact histogenetic origin of cancer cells. This is of great importance in a few otherwise-insoluble cases because of differences in tumor treatment and prognosis.     

Macrophage size determinations in the diagnosis of tuberculous effusions

This study investigated the usefulness of macrophage size determinations in lymphocyte-rich pleural effusions to improve the cytologic diagnosis of tuberculous pleurisy. The size of pleural macrophages was analyzed by quantitative morphometric planimetry in 18 effusions due to tuberculosis, 21 effusions following radiotherapy for malignant disease and 10 effusions due to congestive heart failure. Macrophages were identified and clearly separated from mesothelial cells by latex phagocytosis and immunostaining with the monoclonal antibody My4 (CD14). The mean macrophage area (+/- standard deviation) in tuberculous effusions (92 +/- 14 sq micron) was significantly smaller than in postradiation (141 +/- 28 sq micron) and heart-failure effusions (154 +/- 22 sq micron) (P less than .0001). There was also a smaller ratio of mesothelial cells in tuberculous effusions (0.5 +/- 0.9%) in comparison with effusions following radiotherapy (4 +/- 5%) or congestive heart failure (10 +/- 12%). In summary, this study demonstrated some cytomorphologic parameters that may be helpful in the differential diagnosis of tuberculous effusions.     

Ki-67 antibody immunostaining in benign and malignant human prostatic disease.

Indices of mitotic potential may improve prognostic discrimination in patients with malignant disease. Ki-67 is a monoclonal antibody directed against an unknown proliferation antigen which has been shown to be a measure of mitotic potential. Sixty-four benign and eighty malignant prostatic biopsies were stained with the Ki-67 antibody. Nuclear and cytoplasmic staining was identified in benign and malignant biopsies using immunoalkaline phosphatase and immunoperoxidase staining reactions. Nuclear staining was identified in 14 benign and 44 malignant biopsies. Nuclear staining for Ki-67 was seen in 36% of biopsies with Gleason histological score (GHS) 2-4, 71% with GHS 5-7 and 62% with GHS 8-10. Nuclear staining was associated with advanced local disease stage, but not with metastatic disease stage. Clinical follow-up is required to establish the value of Ki-67 immunostaining as a prognostic determinant in prostatic cancer.     

Heparanase expression: a potential ancillary diagnostic tool for distinguishing between malignant cells and reactive mesothelium in body cavity effusions

OBJECTIVE: Heparanase, an endoglycosidase that cleaves heparan sulphate, is frequently expressed in carcinomas and was suggested to play a role in cell invasion and metastasis. We investigated whether heparanase expression may serve as a reliable marker to discriminate benign mesothelial cells from malignant cells shed into body cavities. METHODS AND RESULTS: Cytological smears of effusions from 51 hospitalized patients were immunostained for heparanase. Strong immunoreactivity was noted in 35 of 40 (88%) carcinoma samples and in all three malignant mesothelioma cases. Only rare (<3%) reactive mesothelial cells were noted showing a faint negligible staining. Specificity was 100%, sensitivity 88%, and positive and negative predictive values were 100% and 89% respectively. CONCLUSIONS: Our results suggest that heparanase may be of value as a complementary component in a diagnostic panel of markers, contributing to its reliability and accuracy.