Intraluminal crystalloids in whole-organ sections of prostate

Mass Spectrometry-Based Assessment of Prostate Cancer-Associated Crystalloids Reveals Enrichment for Growth & Differentiation Factor 15 (GDF15)

Intraluminal crystalloids are a common finding within malignant prostatic acini and are infrequently identified within benign glands. The proteomic composition of these crystalloids remains poorly understood and may provide insight regarding prostate cancer pathogenesis. Laser microdissection assisted liquid chromatography tandem mass spectrometry (LMD-LC-MS/MS) was performed to compare proteomic composition of corpora amylacea within benign acini (n=9), prostatic adenocarcinoma-associated crystalloids (n=8), benign (n=8), and malignant prostatic acini (n=6). The expression of candidate biomarkers was then measured in urine specimens from patients with (n=8) and without prostate cancer (n=10) using ELISA; and immunohistochemistry-based expression in adjacent prostate cancer and benign glands was assessed in 56 whole-slide sections from radical prostatectomy specimens. LMD-LC-MS/MS revealed enrichment for the C-terminal portion of growth and differentiation factor 15 (GDF15) in prostatic crystalloids. Although urinary GDF15 levels were higher in patients with prostatic adenocarcinoma compared to those without (median: 1561.2 vs 1101.3, arbitrary units), this did not meet statistical significance (p=0.07). Immunohistochemistry for GDF15 revealed occasional positivity in benign glands (median H-score: 30, n=56), and diffuse positivity in prostatic adenocarcinoma (median H-score: 200, n=56, p<0.0001). No significant difference was identified within different prognostic grade groups of prostatic adenocarcinoma, or within malignant glands with large cribriform morphology. Our results show that the C-terminal portion of GDF15 is enriched in prostate cancer-associated crystalloids, and higher GDF15 expression is seen in malignant rather than benign prostatic acini. Improved understanding of the proteomic composition of prostate cancer-associated crystalloids provides the rationale for evaluating GDF15 as a urine-based biomarker of prostate cancer.

Prostate cancer: diagnostic criteria and role of immunohistochemistry

The diagnosis of prostate cancer is based on microscopic criteria. Presently, prostate needle biopsy interpretation can be a challenge for the pathologist due to the increased number of specimens with limited amount of suspicious glands and minimal atypia. It is critical for the pathologist to have an organized methodical approach when considering the morphological features enabling a definitive diagnosis of prostate cancer. Although several diagnostic criteria and supportive features have been advocated, only few findings are absolutely specific and diagnostic of prostate cancer. The diagnosis of prostate cancer relies on a combination of architectural and cytological features that are reviewed in detail herein. Infiltrative growth pattern, prominent nucleoli and lack of basal cells are the most useful diagnostic criteria. Perineural invasion, glomerulation and mucinous fibroplasia are pathognomonic features of prostate cancer, although uncommon on small prostate cancer foci. The role of immunohistochemistry in establishing a diagnosis of limited prostate is addressed.

Intraluminal crystalloids are highly associated with prostatic adenocarcinoma on concurrent biopsy specimens

Prostatic crystalloids are intraluminal eosinophilic structures with variable size and shape. Their presence has been described in conjunction with the occurrence of prostatic adenocarcinoma (pCA). We herein report the association of crystalloids and pCA in a prospective trial utilizing an extended multi-site transrectal ultrasound-guided (TRUS) prostate biopsy protocol. Three hundred and forty-four consecutive patients were prospectively enrolled at the Dallas Veterans Administration Hospital from November 2002 to September 2003. Indications for biopsy included a prostate-specific antigen (PSA) > or =4 ng/ml and/or abnormal digital rectal exam. A single pathologist evaluated all biopsy cores and documented the presence or absence of significant histopathologic features. Univariate and multivariate logistic regression analysis were applied to test the association of these features with the presence of pCA on concurrent biopsy. Median number of core biopsies per patient was 12 (range 3-36). Overall cancer detection rate was 42.7%. pCA was diagnosed in 66 (81.5%) of 81 patients with crystalloids, 70 (69.3%) of 101 patients with high-grade prostatic intraepithelial neoplasia (HGPIN), and 32 (84.2%) of 38 patients with both HGPIN and crystalloids on biopsy. Multivariate analysis identified crystalloids (RR 4.53, 95% CI 2.30-8.88) and HGPIN (RR 3.20, 95% CI 1.84-5.57) as independent predictors of the presence of cancer on concurrent biopsy (P<0.001). In this prospective analysis, crystalloids were significantly associated with pCA on concurrent biopsy and more predictive of the presence of pCA than HGPIN. These findings suggest that the presence of crystalloids alone or in combination with HGPIN in prostate biopsies may be a more compelling indication for repeat biopsy than HGPIN alone.

Postatrophic hyperplasia of the prostate in Japan: histologic and immunohistochemical features and p53 gene mutation analysis

BACKGROUND

Postatrophic hyperplasia (PAH) is one of the patterns of prostatic atrophy but has been regarded as a precursor of prostatic cancer (PCA) because of its possible increase in proliferative activity compared with simple atrophy and morphologic mimicry of PCA.

METHODS

Radical prostatectomy specimens obtained from 28 patients with PCA were analyzed by histologic and immunohistochemical methods by using 34 beta E12 and Ki-67 as primary antibodies. Tissue from PAH, PCA, high-grade prostatic intraepithelial neoplasia (HGPIN), a possible precursor of PCA, and benign hyperplasia were microdissected and p53 gene mutations were examined by the polymerase chain reaction-single strand conformation polymorphism method followed by direct sequencing.

RESULTS

Histologically, PAH consists of compactly arranged small acini with irregular atrophic-appearing contours, mimicking PCA. PAH lesions were detected in 7 (25%) of 28 cases with PCA: multifocal in 6 of 7 (85.7%) cases, maximum size of lesions ranged from 0.3 to 2.3 mm. Mild nuclear enlargement and small nucleoli were observed in all cases. Capsular or perineural invasion, crystalloids, and mitotic figures were not found in any case. Inflammatory changes and fibrosis near PAH were found in 100% and 71% of cases, respectively. PAH involved non-transition zone in all cases and occasionally involved transition zone. Forty-three percent of PAH lesions were in proximity (<2 mm) to PCA. None of the clinical and pathologic factors examined were correlated with the presence of PAH. Immunohistochemical analysis by using 34 beta E12 revealed intact basal cells. Proliferative activity defined by positive rate for labeling with MIB-1 antibody was intermediate between benign prostatic hyperplasia and HGPIN. The frequency of p53 mutations in PAH lesions was 5.3%, which was similar to that in HGPIN lesions (4.2%). Benign glands never showed mutations.

CONCLUSION

These findings suggested that PAH might be a precursor for PCA.

Morphologic criteria for the diagnosis of prostatic adenocarcinoma in needle biopsy specimens. A study of 250 consecutive cases in a routine surgical pathology practice

CONTEXT

The diagnosis of prostate adenocarcinoma in needle core biopsy specimens is based on multiple diagnostic criteria and supportive features, most of which have been defined mainly from observations in transurethral resection and prostatectomy specimens. There is little information on the frequency with which diagnostic and supportive features of prostate cancer occur within benign glands. The few reports dealing with diagnostic criteria of cancer in needle biopsies have been largely confined to analysis of selected cases that posed particular diagnostic difficulty.

OBJECTIVE

To analyze the frequency with which numerous diagnostic or supportive features of prostate cancer occur in an unselected, consecutively performed series of 18-gauge prostate needle biopsy specimens.

DESIGN

Two hundred fifty consecutive 18-gauge prostate needle biopsy specimens (150 malignant and 100 benign) were evaluated, using hematoxylin-eosin-stained histologic sections.

RESULTS

The frequency of the histologic features in malignant and benign glands was as follows: prominent nucleoli (94% and 25% of malignant and benign specimens, respectively), marginated nucleoli (88% and 7%), multiple nucleoli (64% and 0%), blue-tinged mucinous secretions (52% and 0%), intraluminal crystalloids (40.6% and 1%), intraluminal amorphous eosinophilic material (86.7% and 2%), collagenous micronodules (2% and 0%), glomerulations (15.3% and 0%), perineural invasion (22% and 0%), retraction clefting (38.6% and 7%), and invasion of fat (0.7% and 0%).

CONCLUSIONS

Since not all diagnostic or supportive features of cancer are evident in any single case of cancer, particularly in needle biopsy specimens in which sampling is limited, awareness of these data would be helpful in the assessment of small foci of atypical glands being considered for cancer.

Prostate Cancer - Old Problems and New Approaches. (Part II. Diagnostic and Prognostic Markers, Pathology and Biological Aspects)

Diagnostic and prognostic markers for prostatic cancer (PCa) include conventional protein markers (e.g., PAP, PSA, PSMA, PIP, OA-519, Ki-67, PCNA, TF, collagenase, and TIMP 1), angiogenesis indicator (e.g., factor VIII), neuroendocrine differentiation status, adhesion molecules (E-cadherin, integrin), bone matrix degrading products (e.g., ICPT), as well as molecular markers (e.g., PSA, PSMA, p53, 12-LOX, and MSI). Currently, only PSA is used clinically for early diagnosis and monitoring of PCa. The histological differential diagnosis of prostatic adenocarcinoma includes normal tissues such as Cowper's gland, paraganglion tissue and seminal vesicle or ejaculatory duct as well as pathological conditions such as atypical adenomatous hyperplasia, atrophy, basal cell hyperplasia and sclerosing adenosis. A common PCa is characterized by a remarkable heterogeneity in terms of its differentiation, microscopic growth patterns and biological aggressiveness. Most PCa are multifocal with signi ficant variations in tumor grade between anatomically separated tumor foci. The Gleason grading system which recognizes five major grades defined by patterns of neoplastic growth has gained almost uniform acceptance. In predicting the biologic behavior of PCa clinical and pathological stages are used as the major prognostic indicators. Among the cell proliferation and death regulators androgens are critical survival factors for normal prostate epithelial cells as well as for the androgen-dependent human prostatic cancer cells. The androgen ablation has been shown to increase the apoptotic index in prostatic cancer patients and castration also promotes apoptotic death of human prostate carcinoma grown in mice. The progression of PCa, similarly to other malignancies, is a multistep process, accompanied by genetic and epigenetic changes, involving phenomenons as adhesion, invasion and angiogenesis (without prostate specific features).

Histologic and histochemical characterization of seminal vesicle intraluminal secretions

CONTEXT

We have observed intraluminal crystalloid morphology in seminal vesicles that is superficially similar to that seen in prostate neoplasia, but found little information on such morphology in the literature.

DESIGN

Two hundred fifty-three prostate specimens (163 needle biopsies, 75 radical prostatectomies with prostate carcinoma, 11 prostates from autopsy, and 4 cystoprostatectomies without prostate carcinoma) were examined for seminal vesicle secretions, which were categorized as (a) dense platelike inspissated, (b) fluidlike, (c) crystalloid morphology, and (d) absent. Histochemical stains (periodic acid-Schiff with and without diastase, Alcian blue at pH 2.5, and mucicarmine) were performed to characterize the nature of secretions.

RESULTS

Proteinaceous secretions were identified in 82% of seminal vesicles examined. Of these, 61% had predominantly dense, platelike, inspissated secretions, 15% had predominantly fluidlike secretions, and 24% had predominantly crystalloid morphology. Although in some cases the crystalloid morphology resembled that of prostatic intraluminal crystalloids, the seminal vesicle crystalloids differed in that they were invariably multiple, had curved edges, and had varied forms (elliptical, cylindrical, rodlike, and rectangular). Seventy-one percent of seminal vesicle crystalloids were associated with dense, platelike, inspissated secretions and appeared to be created by fracturing within platelike secretions. There was no relationship between seminal vesicle crystalloid morphology and associated malignancy in the prostate gland, as it was seen in 24% of cases with prostate carcinoma and 25% of cases without prostate carcinoma (P = 1.0000). Fluidlike secretions were positive for Alcian blue (pH 2.5) and mucicarmine, whereas dense platelike secretions and crystalloid morphology were negative for Alcian blue (pH 2.5) and mucicarmine.

CONCLUSIONS

Seminal vesicle secretions are fairly common and, when fluidlike, are composed of acid mucopolysaccharides. Inspissation of secretions appears to be associated with loss of acidity, presumably resulting in dense platelike secretions and crystallization. Awareness of both the crystalloid morphology in seminal vesicle tissue and the distinguishing features from prostatic crystalloids may be important while interpreting prostate needle biopsies in which seminal vesicle epithelium may be confused for prostate carcinoma because of a small acinar morphology with accompanying cytologic atypia and crystalloid morphology.

The significance of intraluminal prostatic crystalloids in benign needle biopsies

Intraluminal prostatic crystalloids (IPC) are more common in prostate cancer acini than in benign acini. This study was undertaken to evaluate the hypothesis that crystalloids seen in a benign biopsy may indicate an increased risk of a concomitant prostatic carcinoma. A total of 600 patients underwent more than one prostate biopsy. For 394 patients the results of the biopsy were either negative or positive for prostate cancer. After exclusion of patients whose biopsy results were considered negative but coded as high-grade prostatic intraepithelial neoplasia or were suspicious for cancer or whose slides were unavailable for review, 331 patients remained. Biopsy results for these patients were evaluated for the presence of IPC. Also, 18 completely-embedded benign prostates from cystoprostatectomy specimens from patients with bladder cancer were evaluated for the presence of IPC. Seven hundred twenty-five biopsy specimens were reviewed; 51 (7%) contained crystalloids. Thirty-two of 634 (5%) benign biopsy specimens and 19 of 91 (21%) prostatic carcinoma biopsy specimens contained crystalloids. Sixteen of 331 patients (5%) had crystalloids in the initial benign biopsy specimen; 6 patients subsequently were determined to have carcinoma (38%), and 10 continued to have negative results (62%). Three hundred fifteen initial benign biopsies did not show crystalloids; 83 (26%) patients were subsequently diagnosed as having prostatic carcinoma (p = 0.238, Fisher's Exact Test, chi-square test). The IPC were found in 5 of 18 cystoprostatectomy prostates (28%). In this study, the presence of IPC on the initial biopsy specimens was not a significant risk factor for a subsequent diagnosis of prostate cancer. The IPC were not uncommon in prostates without cancer.

The significance of intraluminal crystalloids in benign prostatic glands on needle biopsy

Based on data from autopsy, radical prostatectomy, and cystoprostatectomy specimens, it has been suggested that the finding of intraluminal crystalloids in benign glands on needle biopsy may indicate a concurrent carcinoma; therefore, repeat biopsy is recommended. We studied data from 56 consecutive needle biopsies from the Johns Hopkins Hospital and Dianon Systems in which the diagnosis of intraluminal crystalloids in benign glands was rendered and follow-up data were subsequently obtained. Cases in which crystalloids were present in glands suspicious for cancer, in glands of high-grade prostatic intraepithelial neoplasia, or in adenosis were excluded from the study. Follow-up data included repeat biopsy results and serum prostatic specific antigen levels. Of the 56 men, 31 (55%) had repeat biopsy (two underwent transurethral resection of the prostate [TURP]); the remaining men were either noncompliant or had medical conditions precluding subsequent biopsy. Of the 31 men who underwent repeat biopsies, 23 (74%) had benign diagnoses, one (3%) had high-grade prostatic intraepithelial neoplasia, and seven (23%) had adenocarcinoma. There was no difference in serum prostate-specific antigen values between those with and without cancer on repeat biopsy. In a control population of men with a benign first biopsy not showing crystalloids, the incidence of cancer on repeat biopsy was 16.2%, which was not statistically significantly different from the incidence found in our study group. We conclude that men with prostate biopsy results showing benign glands with crystalloids are at no significantly higher risk of having cancer on repeat biopsy than if crystalloids were not present.

Neutral and acid mucins and eosinophil and argyrophil crystalloids in carcinoma and atypical adenomatous hyperplasia of the prostate

Neutral and acid mucins and eosinophil and argyrophil crystalloids were studied in the glandular intraluminal contents of 130 prostatic carcinomas (PCa) and 22 atypical adenomatous hyperplasias (AAH). Specimens were studied in the usual extension for diagnostic purposes and considered positive when minimal amounts of mucin or any crystalloid were present. Some amount of altered secretion was seen in 110 PCa (84.6%) and in 17 AAH (77.3%); the similarity of the figures speaks for the close relationship of these lesions. The relative incidences in PCa/AAH were 61.5%/77.3% for neutral mucin, 80%/54.5% for acid mucin (p < 0.01), 25.4%/50% for eosinophil crystalloids (p < 0.02), 44.6%/9.1% for argyrophil crystalloids (p < 0.01) and 57%/36% for a compound secretion. The incidence of eosinophil crystalloids was greater in AAH and inversely proportional to the Gleason grade in PCa. The incidence of acid mucins and argyrophil crystalloids was higher in PCa and directly proportional to the tumour grade in all but the poorly differentiated ones. It is therefore suggested that AAH positive for acid mucins or argyrophil crystalloids be classified in the high grade AAH group.

Effect of neoadjuvant endocrine therapy (combined androgen blockade) on normal prostate and prostatic carcinoma. A randomized study

The morphologic changes induced by neoadjuvant combination endocrine therapy were evaluated in prostatectomy specimens from patients diagnosed with localized prostate cancer. These patients participated in a prospective, randomized clinical trial investigating the effect of 3 months of combination therapy with flutamide and an LHRH agonist prior to radical prostatectomy versus radical prostatectomy alone. Ninety-six radical prostatectomy specimens processed according to the same protocol were evaluated without knowledge of prior treatment. Forty-seven patients were randomly assigned to the neoadjuvant combination therapy group and 49 to the control arm. Compared with the control group, several changes were strongly and significantly associated with exposure to neoadjuvant combination therapy. The nonmalignant prostatic tissue showed strong prominence and hyperplasia of the basal cell layer, accompanied by epithelial cell vacuolization and markedly reduced occurrence of prostatic intraepithelial neoplasia (p < 0.001) after combination therapy. Prostate cancer tissue, on the other hand, showed smaller nucleoli (p < 0.001), cell vacuolization (p < 0.001), rare intraluminal crystalloids (p < 0.001), higher Gleason grade (p < 0.001), lower prevalence of capsular penetration (p < 0.001), and less frequent invasion of the perineural spaces (p < 0.001) and surgical margins (p = 0.002). Tumor volume, was also reduced by more than 40% in the treated group (p = 0.007). The present findings show that preoperative endocrine combination therapy induces highly characteristic changes in both nonmalignant and cancerous prostatic tissue. Furthermore, following endocrine treatment, the surgical margins are less likely to be involved by cancer and capsular penetration is reduced.

Acid mucin and high molecular weight cytokeratin in prostatic lesions: evaluation of a combined histochemical and immunohistochemical stain

OBJECTIVE

To evaluate the presence of acid mucins and high molecular weight cytokeratin (KER) in prostatic lesions using a combined histochemical and immunohistochemical stain consisting of Alcian blue at pH 2.5(AB) with a strept-avidin-biotin complex (SAB) staining for KER (SAB-KER).

MATERIALS AND METHODS

Sections were obtained from archival paraffin blocks which included 20 cases of prostatic carcinoma, 30 cases of benign hyperplasia, and five cases of basal cell hyperplasia. Sections were stained for mucosubstances using the AB stain, for KER using SAB-KER and by both AB and SAB-KER, the combined stain (CS).

RESULTS

With the CS stain KER, which is present in the prostatic basal cells, was not detected in malignant glands and in 60% of these cases intraluminal blue-stained acidic mucin was seen. On the other hand, all benign hyperplastic prostatic glands were devoid of intraluminal acidic mucin and showed staining for KER of their basal cells. Areas of basal cell hyperplasia were strongly positive for KER and intraluminal acidic mucin was seen in one case. Each of the stains separately gave similar results to the CS method but the contrast between the areas of carcinoma and hyperplasia was accentuated by the CS, and small foci of carcinoma were easily detected.

CONCLUSION

The combined AB+SAB-KER stain is quicker to perform and allows the simultaneous appraisal of acid mucin and KER.

Diagnostic criteria of limited adenocarcinoma of the prostate on needle biopsy

Over a period of 25 weeks 434 needle biopsy specimens of the prostate were sent to the author for consultation because of diagnostic concerns. The final diagnoses were cancer (69%), benign (13%), atypical but not diagnostic (10%), high grade prostatic intraepithelial neoplasia (PIN) (5%), and miscellaneous (3%). The most common benign entities mimicking cancer were atrophy (29 specimens) and adenosis (19 specimens). The 300 cancer specimens were analyzed further. Architecturally, the presence of small glands between larger benign glands was the most common pattern seen in 80% of carcinomas; haphazard growth patterns, single cells, and cribriform glands were seen less frequently. The following diagnostic features were helpful: nuclear enlargement (77% of specimens); prominent nucleoli (76%); pink acellular intraluminal secretions (53%); amphophilic cytoplasm (39%); blue-tinged mucinous secretions (34%); crystalloids (25%); PIN (13%); mitotic figures (11%); and perineural invasion (3%). The mean and median numbers of malignant glands in this series were 31 and 20, respectively (range, two to 300). Tumors with a Gleason score lower than 6 caused greater diagnostic problems for referring physicians because these tumors had a greater number of malignant glands, yet were still sent in for consultation (P = .0018). Gleason score was positively correlated with prominent nucleoli and amphophilic cytoplasm and inversely correlated with the presence of crystalloids. Prominent nucleoli, which often are quoted as being essential for the diagnosis of prostate cancer, were not seen in 24% of the specimens and seen only rarely in another 25%. The diagnosis of prostate cancer is based on a constellation of features. Even in this series with a limited number of malignant glands, 85% of specimens contained three or more of the above-listed diagnostic features in addition to architectural atypia.

Mucinous adenocarcinoma of the prostate and hormone sensitivity

We report a case of mucinous adenocarcinoma of the prostate treated successfully with androgen ablation followed by laparoscopic lymphadenectomy and total perineal prostatectomy. This case demonstrates that mucinous adenocarcinoma of the prostate may be hormonally sensitive.

Sulfur-rich prostatic intraluminal crystalloids: a surgical pathologic and electron probe x-ray microanalytic study

Prostatic intraluminal crystalloids are irregular eosinophilic, non-birefringent structures increasingly recognized as potential indicators of prostatic malignancy. In a study of 250 randomly selected surgical pathology cases of prostatic tissues none of 50 cases of benign glandular hyperplasia (0%), one of 50 cases of atypical adenomatous hyperplasia, 18 of 50 cases of well-differentiated adenocarcinoma (36%), seven of 50 cases of moderately differentiated adenocarcinoma (14%), and none of 50 cases of poorly differentiated adenocarcinoma (0%) revealed intraluminal crystalloids. A histochemical and immunohistochemical staining panel indicated that the crystalloids were nonproteinaceous. Crystalloids were stained intensely with phosphotungstic acid hematoxylin and did not stain for prostatic-specific antigen or hemoglobin. Crystalloids were clearly differentiated from prostatic corpora amylacea on light microscopy, histochemistry, scanning, and transmission electron microscopy. Electron probe x-ray microanalysis of 10 cases of crystalloids revealed uniform high sulfur peaks and small sodium peaks. We conclude that intraluminal crystalloids are associated more frequently with low-grade prostatic adenocarcinoma, may occur in benign tissue bordering adenocarcinoma, are predominantly composed of inorganic sulfur, and their presence in benign and atypical prostate biopsies may be of pathologic significance and should warrant further clinical investigation and possibly repeat biopsy.

Argyrophil crystalloids in adenocarcinoma of the prostate

Considering the advantages provided by the study of glandular secretions in proliferative diseases of the prostate, we carried out a study of 100 consecutive cases of benign hyperplasia (68), glandular dysplasia (12), and carcinoma (20). Samples were predominantly obtained by transurethral resection from patients whose mean ages were 64, 67, and 73.5 years, respectively. The paraffin embedded material was sectioned and stained with hematoxylin-eosin, PAS-diastase, PAS-Alcian blue, methenamine silver, and Masson trichrome. Intraglandular secretion in normal, hyperplastic, and even neoplastic samples was predominantly neutral mucin, but in 2 cases of atypical adenomatous hyperplasia, and in all the carcinomas, we found acid mucin secretion. Holmes crystalloids were present in one case of nodular hyperplasia (1.4%), 2 cases of dysplasia (16.6%), and in 5 carcinomas (25%). As another manifestation of altered secretion, we also saw numerous needle-shaped argyrophilic and isotropic crystalloids, not previously described, in 12 of the 20 carcinomas (60%). These crystalloids were exclusively found in the carcinomas, reached a size of 50 mu, and were completely differentiated from the Holmes crystalloids by their odd needleshape and their staining characteristics.

Immunohistochemical and ultrastructural studies of intraluminal crystalloids in human prostatic carcinomas

Intraluminal crystalloids (ICr) observed in 19 cases of incidental or invasive human prostatic carcinoma (PCa) and in a case of benign prostatic hyperplasia were examined extensively by immunohistochemistry and electron microscopy. They were brilliantly eosinophilic with haematoxylin and eosin, manifesting needle-like, triangular, rectangular, hexagonal and irregular lump-like in shape. They were strongly positive, dark blue, with phosphotungstic acid -haematoxylin (PTAH) stain in all cases examined. Among the human antibodies tested, epithelial membrane antigen (EMA) gave specifically positive immunostainability with ICr in all cases. Annual ring-like lamellar or concentric structures were detected by electron microscopy. Positive staining of ICr with PTAH and anti-EMA antibody is very useful as a diagnostic marker for PCa in human prostatic tissues.

Crystalloids in latent prostatic carcinoma

Intraglandular crystalloids have been studied in 108 cases of latent prostatic carcinoma collected at autopsy. The morphological features of these crystalloids are essentially the same as reported by previous authors. The crystalloids were identified in 62.0% of cases over age 50 years. They were present in 76.9% of cases in the seventh decade, the highest prevalence among the decades. The number of crystalloids relative to the number of malignant glands tended to be inversely proportional to the size of the carcinoma. We conclude that crystalloids are related to the early development of prostatic carcinoma.