An objective morphologic parameter to aid in the diagnosis of flat urothelial carcinoma in situ.

The diagnosis of carcinoma in situ (CIS) lacks objective criteria and is subject to misdiagnosis. We identified 20 bladder biopsy cases each of CIS, urothelial dysplasia, and normal urothelium according to the 1998 World Health Organization/International Society of Urological Pathology consensus classification of urothelial neoplasms. Lymphocytes from 10 bladder biopsy specimens were chosen as reference cells. Using an image analysis system, we measured the following nuclear features: area, diameter, roundness, ellipticity, and optical density (maximum, minimum, mean, median, standard deviation, and quartiles). We measured a mean of 75 urothelial nuclei/case and a total of 500 lymphocytes. Roundness and ellipticity were not useful in distinguishing among the 3 groups. The best discriminators were mean nuclear area and mean nuclear area of the 25% largest nuclei (upper quartile) of urothelial cells compared with lymphocytes. The mean nuclear area relative to lymphocytes was 1.8 times (1.2 to 2.5 times) in normal urothelium, 2.4 times (1.6 to 3.0 times) in urothelial dysplasia, and 3.6 times (2.8 to 5.7 times) in CIS. The mean upper quartile nuclear area relative to lymphocytes was 2.2 times (1.4 to 2.8 times) in normal urothelium (P <.0001), 2.9 times (1.8 to 3.6 times) in urothelial dysplasia (P <.0001), and 4.9 times (4.0 to 7.6 times) in CIS (P <.0001). The difference in optical density was statistically significant between CIS and the other 2 histologic categories (P <.0001). Nuclear area is an easy and objective morphologic parameter for the evaluation of bladder biopsy specimens. Pathologists can assess the size of urothelial nuclei without using an image analysis system and compare them with the size of nuclei of lymphocytes, which are almost always present in a bladder biopsy specimen. Dysplasia, which is a somewhat ambiguous lesion, overlaps in its measurements with those of benign urothelium. The most useful morphologic parameter is the mean nuclear area of the 25% largest nuclei; CIS nuclei are approximately 5 times the size of lymphocytes, whereas normal urothelial nuclei are only 2 times the size of lymphocytes.

Expression of metallothionein in seminal vesicles--an immunohistochemical study.

OBJECTIVE: The seminal vesicles and prostate share the same blood supply and exposure to carcinogens. Despite these similarities, fewer than 60 adenocarcinomas of the seminal vesicles have been described, whereas prostate cancer is the most common cancer in men today. Metallothionein plays a significant role in the detoxification of heavy metals. Thus, this study investigated the expression of metallothionein in seminal vesicle tissue. MATERIAL AND METHODS: Twenty individual tissue specimens each of normal seminal vesicle tissue and benign prostatic tissue underwent immunohistochemical staining with a monoclonal mouse anti-metallothionein antibody. RESULTS: Positive immunostaining for metallothionein was found in 8 of 20 (40%) of the seminal vesicle tissues, but in 14 of 20 (70%) of the prostate specimens. Seminal vesicle tissue stained only with weak intensity. CONCLUSION: Metallothionein expression is lower in seminal vesicles than in the prostate. The low cell turnover in seminal vesicle tissue may explain the lower staining activity of this tissue. These findings suggest that metallothionein expression cannot be regarded as the main reason for the vastly different cancer incidence in seminal vesicles and the prostate.

Correlation of Ki-67 and p53 with the new World Health Organization/International Society of Urological Pathology Classification System for Urothelial Neoplasia.

OBJECTIVE: The present study examines p53 and Ki-67 staining patterns of the diagnostic entities included within the new World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification of urothelial neoplasms. DESIGN: We retrospectively studied 151 bladder biopsies from 81 patients with the following neoplasms: normal urothelium (n = 34 biopsies); low-grade intraurothelial neoplasia (LGIUN; n = 19); high-grade intraurothelial neoplasia (HGIUN; n = 20); papillary hyperplasia (n = 4); papilloma (n = 3); papillary neoplasm of low malignant potential (LMP; n = 12); low-grade papillary carcinoma (n = 28); and high-grade papillary carcinoma (n = 31). Sections were labeled immunohistochemically with antibodies to p53 and Ki-67 (MIB-1). Two hundred cells from each lesion were visually counted, and the percentage of positive cells was tabulated without knowledge of the WHO/ISUP diagnosis. RESULTS: In flat lesions, p53 positivity was of limited diagnostic utility; the marker was present in 6 of 34 benign biopsies, 6 of 19 LGIUNs, and 10 of 20 HGIUNs. In one case in which HGIUN was present elsewhere in the bladder, 29% of the benign urothelial cells were p53 positive. In papillary lesions, p53 positivity was not seen in 4 of 4 cases of papillary hyperplasia, 3 of 3 papillomas, and 8 of 12 LMP tumors. In contrast, p53 was detected in 18 of 28 low-grade and 26 of 31 high-grade papillary urothelial carcinomas. A p53 labeling index (LI) greater than 30% was only seen in HGIUNs and high-grade papillary carcinomas. In flat lesions, an increased Ki-67 LI separated out benign urothelium (mean LI, 0.62%) from dysplasia (mean LI, 3.3%) and HGIUN (mean LI, 11.6%). In papillary lesions, Ki-67 positivity was as follows: papillary hyperplasia (mean LI, 1.1%); papilloma (mean LI, 4.3%); LMP tumors (mean LI, 2.5%), low-grade papillary carcinoma (mean LI, 7.3%); and high-grade carcinoma (mean LI, 15.7%). A Ki-67 LI greater than 10% was seen only in low- and high-grade papillary carcinomas, HGIUN, and single cases of LGIUN and papillary neoplasm of LMP. CONCLUSIONS: An increased proliferative index as demonstrated by immunohistochemical staining for Ki-67 (MIB-1) is most often seen in papillary carcinoma and HGIUN. Marked p53 positivity is also characteristic of carcinoma but may be seen in benign-appearing urothelium, suggesting a "field effect" with occult molecular aberration.

Molecular and immunohistochemical staging of men with seminal vesicle invasion and negative pelvic lymph nodes at radical prostatectomy.

BACKGROUND: Patients with seminal vesicle invasion (SVI) at radical retropubic prostatectomy (RRP) have a poor prognosis. Routine microscopic examination of pelvic lymph nodes (LNs) can miss small metastases and, thereby, confuse tumor staging and clinical decision-making. The authors used immunohistochemical and molecular methods to examine archival paraffin-embedded LNs of men who had undergone RRP for clinically localized prostate carcinoma and who had tumors demonstrating SVI and negative LNs at surgery. METHODS: Between June 1982 and June 1997, 2151 consecutive men underwent RRP for clinically localized prostate carcinoma. Of these, 109 (5.1%) tumors had SVI with negative LNs. The actuarial likelihood of having a tumor that was undetectable by testing prostate-specific antigen (PSA) 5 and 10 years after surgery was 45% and 29%, respectively, for men with isolated SVI. Archival LN specimens were available for 102 men who had isolated SVI. Reverse transcription polymerase chain reaction (RT-PCR) was performed for PSA and prostate-specific membrane antigen (PSMA). All specimens were examined concurrently by immunohistochemistry (IHC). RESULTS: Careful reevaluation of pelvic LNs demonstrated metastases in 9 (8.8%) men originally classified as metastasis-free. Reevaluation by hematoxylin and eosin (H&E) staining identified three previously unrecognized cases of LN metastases. IHC identified six cases, three of which were missed by H&E. RT-PCR identified four cases, three of which were not revealed by other methods. CONCLUSIONS: The poor prognosis of patients with SVI does not seem due to occult LN metastases. The low yield of unsuspected foci of prostate carcinoma in the LNs of men with SVI and negative LNs by routine staging does not justify IHC or molecular examination to find occult carcinoma.

Can immunohistochemistry enhance the detection of micrometastases in pelvic lymph nodes from patients with high-grade urothelial carcinoma of the bladder?

Immunohistochemistry for keratin has enhanced our ability to detect micrometastases in certain cancer patients with negative lymph nodes by routine histologic examination of H&E-stained sections. However, there is no information about micrometastasis of bladder cancer. We performed immunohistochemistry for keratins on 159 pelvic lymph nodes, which were negative for metastatic tumors on routine H&E-stained sections, from 19 patients with high-grade muscle invasive urothelial bladder cancer. In 1 man, 1 lymph node contained a keratin-positive micrometastasis that was not present on the original H&E-stained slide. However, the metastasis was seen readily on a new H&E-stained section prepared from the paraffin block adjacent to the keratin-stained section. Immunohistochemical analysis for keratins revealed no additional case of micrometastasis of urothelial carcinoma of the bladder. The perinodal fibroadipose tissue of a lymph node from a woman contained a few keratin-positive benign glands of endosalpingiosis. A thorough examination of the H&E-stained sections is the best method for detecting lymph node metastases of urothelial carcinoma from the bladder. There is a potential risk for misdiagnosis of metastases by using immunohistochemistry or polymerase chain reactions for keratins because of the occasional presence of benign epithelial cells in pelvic lymph nodes and associated connective tissue.

Significance of small foci of Gleason score 7 or greater prostate cancer on needle biopsy.

OBJECTIVES: With increased screening for prostate cancer, we have noted a greater number of patients with small foci of Gleason score 7 or greater prostate cancer on needle biopsy. The significance of these findings is unknown. METHODS: We studied 57 men with small foci of Gleason score 7 or greater on needle biopsy. Tumor length was less than 1.5 mm in all but 2 cases. In those 2 cases, there were two minute (less than 0.5 mm) foci of cancer separated by 1.8 mm. The length of cancer ranged from 0.2 to 1.8 mm (mean 0.63 mm). In all cases, only one core was involved. RESULTS: Thirty-three men underwent radical prostatectomy (RP), 14 received radiation, 8 underwent surveillance, and 2 received hormonal therapy. Men who underwent RP were younger (62 years) than those who had radiotherapy (69.1 years), who were younger than those who underwent surveillance (74.5 years). The mean prostate-specific antigen (PSA) for men undergoing RP was 8.0 ng/mL (range 1.4 to 22). Preoperative serum PSA values did not predict organ-confined status. Needle biopsy grades were as follows: 3 + 4 = 7 (n = 30); 4 + 3 = 7 (n = 17); 4 + 4 = 8 (n = 7); 5 + 4 = 9 (n = 1); and 5 + 5 = 10 (n = 2). We were able to review slides in 27 of the RP specimens, of which 24 were well sampled. Of these 24 cases, 33% had positive margins and 33% were not organ confined; the median tumor volume was 0.5 cc (mean 1.04). No difference in RP tumor volume was found between tumors with needle biopsy Gleason primary grade 3 and those with 4 or greater. The percentage of Gleason pattern 4 on needle biopsy weakly correlated with the percentage of Gleason pattern 4 in the RP specimen (P = 0.04). However, the percentage of Gleason pattern 4 only in the RP specimen, but not in the biopsy, correlated with whether the tumor was organ confined. CONCLUSIONS: The likelihood of having organ-confined disease with small foci of Gleason score 7 or greater on needle biopsy appears to be equivalent to that calculated from the Partin Tables for greater amounts of Gleason score 6 cancer on needle biopsy. In men who are considering RP, small foci of Gleason score 7 or greater adenocarcinoma on needle biopsy should not necessarily be considered an adverse finding.

Prostate cancer sampled on sextant needle biopsy: significance of cancer on multiple cores from different areas of the prostate.

OBJECTIVES: To determine the relationship between the location of positive sites, when more than one sextant site shows prostate cancer in a given patient, and pathologic stage, tumor volume, and margin status if radical prostatectomy is performed. METHODS: We performed biopsies using a spring-loaded biopsy gun on 343 Stage T1c (nonpalpable) radical prostatectomy specimens from each sextant site. RESULTS: In 56 cases, carcinoma was identified in two separate sextant sites. In 38 cases, the sites were vertical to each other (ie, left apex, left mid); in 8 cases, the sites were diagonal (ie, left apex, right mid); in 5 cases, the sites were horizontal (ie, left apex, right apex); and in 5 cases, they were not contiguous but were separated by an uninvolved sextant site (ie, left apex, left base). Tumors were more likely to be multifocal in cases with diagonally positive biopsies (P <0.0001) and horizontally positive biopsies (P <0.0001) than in those with vertically positive biopsies. No significant differences were found in organ-confined status and margin positivity among cases with different positive biopsy locations. The dominant tumor nodule was larger (mean 2.76 cc) in cases with noncontiguously positive biopsies than in all other groups combined (mean 1.44 cc) (P = 0.017). CONCLUSIONS: When more than one sextant site shows cancer, there are differences in terms of whether the tumors sampled are multifocal versus solitary depending on which sites are positive. However, no significant differences were found in predicting pathologic stage and margin positivity.

Bioimpedance: novel use of a minimally invasive technique for cancer localization in the intact prostate.

BACKGROUND: Prostate cancer is presently diagnosed by transrectal ultrasound (TRUS)-guided sextant needle biopsy. While echo texture of the tissue can prompt localization of tumor, it is presently imprecise. From 50-75% of men biopsied, based on an abnormal digital rectal examination (DRE) or elevated prostate-specific antigen (PSA) level, have negative biopsy results. Improvements in tumor localization during TRUS-guided prostate biopsy are greatly needed. Bioimpedance is an electrical property of biologic tissue. Electric current is limited in living tissue by highly insulating cell membranes; however, different tissue architecture such as cancer may impede current differently and allow detection of differences between normal and abnormal or malignant prostate tissue. Our goal was to assess the utility of bioimpedance measurements in differentiating tumor from normal prostatic tissue in an ex vivo model. METHODS: Bioimpedance was measured in six ex vivo prostates, which were removed for clinically localized prostate cancer. Two bioimpedance needles, 1 mm apart, were inserted 3 mm into the posterior surface of the prostate an average of 16 times per gland. Frequencies ranging from 100 kHz-4 MHz were used to obtain 594 bioimpedance measurements from the six glands. These measurements were then correlated with histology to determine the presence or absence of prostate cancer. RESULTS: Prostate cancer was found to have a higher impedance, of 932+/-170 ohms, compared to areas of no cancer within the same prostate, 751+/-151 ohms, P < 0.0001, at 2 MHz. This phenomenon was observed across all frequencies tested. CONCLUSIONS: This study demonstrates for the first time application of bioimpedance to distinguish areas of prostate cancer from areas of normal prostate. This technology may improve identification and localization of cancer within the prostate. Moreover, bioimpedance can potentially guide needle placement during prostate biopsy and thus improve sampling of tumors. Currently, our ex vivo model is limited by variables such as temperature and lack of blood flow. Further studies in an in vivo model will be needed to assess their effect.

Does long-term finasteride therapy affect the histologic features of benign prostatic tissue and prostate cancer on needle biopsy? PLESS Study Group. Proscar Long-Term Efficacy and Safety Study.

OBJECTIVES: Finasteride, a common agent used to treat benign prostatic hyperplasia (BPH), inhibits 5-alpha-reductase. Testosterone is converted by 5-alpha-reductase to the more potent dihydrotestosterone, which is the primary androgen in the prostate. Leuprolide is a stronger antiandrogen that is used to downstage prostate cancer before radical prostatectomy. Leuprolide induces marked atrophy of prostate carcinoma cells, which sometimes makes pathologic diagnosis of cancer difficult, although evaluation at radical prostatectomy is easier than at biopsy. It is unknown whether finasteride produces similar changes, which would result in greater diagnostic difficulty because such changes would be seen on biopsy to rule out cancer in men with suspicious clinical findings treated for BPH. The current study investigated the histologic effects of finasteride therapy on human prostate cancer and benign prostatic tissue on needle biopsy. METHODS: In blinded manner, we reviewed 53 needle biopsy specimens showing prostate carcinoma (35 treated with finasteride, 18 with placebo). Also reviewed in blinded manner were 50 benign needle biopsy specimens (25 treated with finasteride, 25 with placebo). The Gleason score, number of cores involved, percentage cancer involvement in a core, percentage of atrophic changes in cancer cells, presence of mitoses, blue-tinged mucinous secretions, prominent nucleoli, and high-grade prostatic intraepithelial neoplasia were documented for each case in the cancer group. The percentage of atrophy, basal cell hyperplasia, transitional metaplasia, chronic inflammation, and stromal proliferation was documented for each case in the benign group. RESULTS: No significant histologic differences were present in either the benign or cancer group between cases treated with finasteride and placebo. CONCLUSIONS: We conclude that finasteride treatment for BPH does not cause difficulty in the diagnosis of cancer in prostate needle specimens. It is possible that there are severely atrophic areas resulting from finasteride treatment that are undersampled. However, the conclusion that cancer seen on needle biopsy in men treated with finasteride is unaltered and readily identified as cancer remains valid.

How often are diagnostic features missed with less extensive histologic sampling of prostate needle biopsy specimens?

The authors determined whether clinically relevant diagnostic information would be lost by examination of <3 levels per tissue core in prostate needle biopsy specimens. They evaluated 439 consecutive sextant biopsy specimens for the following three histopathologic features: presence of adenocarcinoma involving one core, Gleason pattern 4 in cases of grade 3 + 4 = 7 adenocarcinoma, and perineural invasion (PNI) by carcinoma. For all cases, 3 levels from each involved core were reviewed for the presence or absence of these three features. In 50 cases with adenocarcinoma involving only 1 core, diagnostic carcinoma was present on all 3 levels in 43 cores (86%). Carcinoma was present on only 2 levels in 3 cores (6%), present only on 1 level in 3 cores (6%), and present only on additional cut-downs, not on the original 3 levels in 1 core (2%). Among 32 cases, 51 cores were identified that contained Gleason grade 3 + 4 = 7 adenocarcinoma. In 41 cores (80%), pattern 4 was identified in all 3 levels. In 5 cores (10%), pattern 4 was identified on only 2 levels, and in another 5 cores (10%), pattern 4 was present on only 1 level. Among 36 cases, 69 tissue cores were identified that contained perineural invasion (PNI). In 54 cores (78%), PNI was present on all 3 levels. In 7 cores (10%), PNI was present on only 2 of 3 levels, while in 7 other cores (10%), PNI was present on only 1 of 3 levels. In 1 core (1.5%), PNI was noted only on additional cutdowns, not on the original 3 levels. We estimated that reducing the number of levels to 1 per core could result in the misdiagnosis of PNI, grading, or carcinoma in approximately 8-11% of cores with these features and could have changed the case diagnosis in 9 of 439 cases. If only 2 levels were reviewed, we predict misdiagnosis in 5% to 6% of cores with these features and a change in the case diagnosis in 5 of 439 cases. Misdiagnosis of clinically relevant features on prostate biopsy specimens can be minimized with histologic review of 3 levels per tissue core.

Rare expression of high-molecular-weight cytokeratin in adenocarcinoma of the prostate gland: a study of 100 cases of metastatic and locally advanced prostate cancer.

Immunohistochemistry with antibodies for high-molecular-weight cytokeratin labels basal cells and is used as an ancillary study in diagnosing prostate carcinoma, which reportedly lacks expression of high-molecular-weight cytokeratin. A recent report questioned the specificity of this marker, describing immunopositivity for high-molecular-weight cytokeratin in a small series of metastatic prostate cancer. We have also noted rare cases of prostate lesions on biopsy with typical histological features of adenocarcinoma showing immunopositivity for high-molecular-weight cytokeratin, either in tumor cells or in patchy cells with the morphology of basal cells. In some of these cases, it was difficult to distinguish cancer from out-pouching of high-grade prostatic intraepithelial neoplasia. To investigate whether prostate cancer cells express high-molecular-weight cytokeratin, we studied 100 cases of metastatic prostate carcinoma and 10 cases of prostate cancer invading the seminal vesicles from surgical specimens. Metastatic sites included regional lymph nodes (n = 67), bone (n = 19), and miscellaneous (n = 14). Cases with any positivity for high-molecular-weight cytokeratin antibody (34betaE12) were verified as being of prostatic origin with immunohistochemistry for prostate-specific antigen and prostate-specific acid phosphatase. Only four cases were detected positive for high-molecular-weight cytokeratin. In two cases (one metastasis, one seminal vesicle invasion) there was weakly diffuse positivity above background level. Two metastases in lymph nodes showed scattered strong staining of clusters of tumor cells, which represented <0.2% of tumor cells in the metastatic deposits. These positive cells did not have the morphology of basal cells. We conclude that prostate cancer, even high grade, only rarely expresses high-molecular-weight cytokeratin. This marker remains a very useful adjunct in the diagnosis of prostate cancer.

Cell turnover in human seminal vesicles and the prostate: an immunohistochemical study.

The human prostate and seminal vesicles are both androgen-dependent sex accessory organs. Their growth behavior, response to hormone manipulation, susceptibility to benign and malignant processes and sex accessory functions, however, differ greatly. The growth behavior of most tissues correlates well with the cell turnover rate of that tissue. Therefore, we compared the cell turnover of normal human prostate and seminal vesicles. Immunohistochemical expression of MIB-1 (proliferation), bcl-2 and transforming growth factor (TGF beta) were examined in 20 different samples taken from histologically normal human prostatic and seminal vesicle tissue. For the quantification of apoptosis, the TUNEL technique was used. The apoptosis rates in normal prostatic tissue (0.73+/-0.60) were significantly greater (P=0.003) than those seen in seminal vesicles (0.02+/-0.01). The proliferation rates also differed significantly (P=0.002) between these tissues (prostate: 0.77+/-0.78; seminal vesicles: 0.02+/-0.02). Eighty percent of the prostate tissue stained for bcl-2, whereas only 55% of the seminal vesicle tissue showed staining for bcl-2. All seminal vesicles and 75% of the prostate samples stained for TGF beta. For both androgen-dependent tissues, apoptotic rates closely equaled proliferation rates. The cell turnover, however, was much higher in the prostate than in the seminal vesicles. TGF beta seems to be more important for the regulation of cell turnover in the seminal vesicles than bcl-2. These differences in the proliferative behavior may explain why disturbances of apoptotic regulation lead to a more extensive net cell gain in prostatic tissue compared to the seminal vesicles. This might help explain the vastly different incidence of benign and malignant tumors in these organs.