Ductal carcinomas of the prostate: a clinicopathological and immunohistochemical study

Intraductal Adenocarcinoma of the Prostate With Cribriform or Papillary Ductal Morphology: Rare Biopsy Cases Lacking Associated Invasive High-grade Carcinoma

Prostatic duct adenocarcinoma, characterized by pseudostratified columnar epithelium, has historically been considered invasive carcinoma, although it may commonly have an intraductal component. Usual (acinar) intraductal carcinoma of the prostate (IDC-P) is a noninvasive high-risk lesion typically associated with high-grade, high-stage prostate cancer. Whereas there have been rare biopsy studies of pure acinar IDC-P or IDC-P associated with only low-grade carcinoma, there have been no analogous series of IDC-P with cribriform or papillary ductal morphology on biopsy unassociated with invasive high-grade carcinoma. We identified 14 patients with biopsies showing IDC-P with ductal morphology, defined as prostatic duct adenocarcinoma confined to glands/ducts with immunohistochemically proven retention of basal cells. Our series includes 12 patients with pure IDC-P and 2 patients with concurrent low-volume Grade Group 1 invasive cancer in unassociated cores. Three patients underwent radical prostatectomy: 2/3 had high-grade cancer in their resection specimen (Grade Group 3, Grade Group 5), including 1 with advanced stage and nodal metastases; 1/3 had Grade Group 1 organ-confined carcinoma and spatially distinct IDC-P with ductal morphology. Five men had only follow-up biopsies: 2/5 had cancer (Grade Group 2, Grade Group 4); 1/5 had IDC-P (on 2 repeat biopsies); and 2/5 had benign transurethral resection of the prostate. In all 5 cases with invasive cancer, the invasive portion was comprised purely of acinar morphology; no invasive ductal component was identified. Five patients did not have follow-up biopsies and were treated with radiation therapy±androgen deprivation. One patient had no follow-up information. In an analogous situation to acinar IDC-P, we propose that rarely there is a precursor form of ductal adenocarcinoma that can exist without concurrent invasive high-grade carcinoma and propose the term "IDC-P with ductal morphology," consistent with the terminology for acinar prostate adenocarcinoma. Until more evidence is accumulated, we recommend reporting and treating patients with IDC-P with ductal morphology in a manner analogous to those with acinar IDC-P. As with pure IDC-P with acinar morphology, we would also recommend not grading pure IDC-P with ductal morphology. Finally, we propose a new addition to the diagnostic criteria of IDC-P to include intraductal lesions with ductal morphology consisting of papillary fronds or cribriform lesions lined by cytologically atypical pseudostratified epithelium.

Diverse Immunoprofile of Ductal Adenocarcinoma of the Prostate with an Emphasis on the Prognostic Factors

BACKGROUND

Ductal adenocarcinoma (DAC) of the prostate is an uncommon histologic subtype whose prognostic factors and immunoprofile have not been fully defined.

METHODS

To define its prognostic factors and immunoprofile, the clinicopathological features, including biochemical recurrence (BCR), of 61 cases of DAC were analyzed. Immunohistochemistry was performed on tissue microarray constructs to assess the expression of prostate cancer-related and mammalian target of rapamycin (mTOR) signaling-related proteins.

RESULTS

During the median follow-up period of 19.3 months, BCR occurred in 26 cases (42.6%). DAC demonstrated a wide expression range of prostate cancer-related proteins, including nine cases (14.8%) that were totally negative for pan-cytokeratin (PanCK) immunostaining. The mTOR signaling-related proteins also showed diverse expression. On univariate analysis, BCR was associated with high preoperative serum levels of prostate-specific antigen (PSA), large tumor volume, predominant ductal component, high Gleason score (GS), comedo-necrosis, high tumor stage (pT), lymphovascular invasion, and positive surgical margin. High expressions of phospho-mTOR (p-mTOR) as well as low expressions of PSA, phospho-S6 ribosomal protein (pS6) and PanCK were associated with BCR. On multivariable analysis, GS, pT, and immunohistochemical expressions of PanCK and p-mTOR remained independent prognostic factors for BCR.

CONCLUSIONS

These results suggest GS, pT, and immunohistochemical expressions of PanCK and p-mTOR as independent prognostic factors for BCR in DAC. Since DAC showed diverse expression of prostate cancer-related proteins, this should be recognized in interpreting the immunoprofile of DAC. The diverse expression of mTOR-related proteins implicates their potential utility as predictive markers for mTOR targeted therapy.

Ductal and Acinar Adenocarcinoma of Prostate: Morphological and Immunohistochemical Characterization

OBJECTIVES

We sought to characterize the ductal and acinar subtype of prostate adenocarcinoma using hematoxylin and eosin (H&E) staining and an immunohistochemical antibody cocktail. We also investigated the clinical features, prostate-specific antigen (PSA) levels, and biological aggressiveness of these tumors.

METHODS

We utilized tumor bearing prostate biopsies, obtained between 2010 and 2014 from Dow Diagnostic Research and Reference Laboratory, to identify cases of prostatic ductal and acinar adenocarcinoma using routine H&E and immunohistochemical staining. The immunohistochemical antibody cocktail 34βE12/p63/AMACR was used for staining. The association of clinicopathological variables including patient's age at diagnosis, Gleason score, and PSA levels before surgery was retrospectively analyzed.

RESULTS

A total of 10 ductal and 140 non-ductal cases were identified. Ductal cases were predominantly high grade with advanced histopathological features (90%; p=0.030). Marked elevation in PSA level was also reported in most cases. No other significant statistical difference was observed.

CONCLUSIONS

Pathological and immunohistochemical examination could be used to characterize ductal and acinar adenocarcinoma of the prostate. Ductal adenocarcinoma of the prostate is a rare subtype of prostate carcinoma and is be more likely to present with advanced grade cancer suggesting that timely detection of the disease is vital.

Abiraterone acetate and castration resistant ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate is a rare histological variant that only represents <1% of prostate tumors. This histological variant has several important clinical implications with respect to their evolution, clinical prognosis, and treatment. We report the case of a 64-year-old patient with ductal adenocarcinoma of the prostate, which progresses to castration-resistant prostate cancer, that was treated with abiraterone acetate with good clinical response, to our knowledge, the first case of ductal adenocarcinoma of the prostate in treatment with abiraterone acetate.

Ductal adenocarcinoma of the prostate: immunohistochemical findings and clinical significance

INTRODUCTION

To investigate the clinical features, diagnosis, treatment, and prognosis of ductal adenocarcinoma of the prostate.

METHODS

The clinicopathological and immunohistochemical data of seven patients with ductal adenocarcinoma of the prostate were retrospectively analyzed. All patients underwent physical examination, magnetic resonance imaging (MRI), bone scan, cystoscopy, and computed tomography (CT) scan. The level of prostate-specific antigen (PSA) before and after surgery was assessed. Different prostate cancer markers were used for immunohistochemical staining.

RESULTS

The mean age of the seven patients diagnosed with prostatic ductal adenocarcinoma in this study was 76.2 years (range 57-88). Five patients presented with intermittent and painless gross hematuria, one patient with progressive dysuria, and one patient with elevated serum PSA on routine health examination. The level of PSA before surgery ranged from 1.3 to 45.0 ng/mL. Immunohistochemical staining results of the prostatic ductal adenocarcinoma confirmed positivity for PSA, prostatic acid phosphatase, androgen receptor, and alpha-methyacyl co-enzyme A (CoA)-reductase markers. Two of the patients underwent bilateral orchiectomy combined with anti-androgen therapy, three underwent transurethral resection of prostate, one received radical prostatectomy, and one received medical castration therapy. The clinical outcomes of all patients were satisfactory, based on follow-up data. The symptoms of hematuria and dysuria were ameliorated well, and the postoperative PSA level decreased below 4.0 ng/mL. Recurrence or metastasis of disease was not detected on MRI and bone scan.

CONCLUSION

Ductal adenocarcinoma of the prostate is a rare subtype of prostate carcinoma, the diagnosis of which could be based on pathological and immunohistochemical examination. Earlier management promises better prognosis.

Preneoplasia in the prostate gland with emphasis on high grade prostatic intraepithelial neoplasia

There are a variety of morphological patterns and processes that have been implicated in the pathogenesis of prostate cancer. Prostatic intraepithelial neoplasia (PIN), inflammation with or without atrophy, and adenosis (atypical adenomatous hyperplasia) have all been given candidate status as precursor lesions of prostatic adenocarcinoma. Based on decades of research, high grade prostatic intraepithelial neoplasia (HPIN), a proliferative lesion of prostatic secretory cells, has emerged as the most likely morphological pre-invasive lesion involved in the evolution of many but not all prostatic adenocarcinomas. In this manuscript, we briefly discuss other proposed precursors of prostatic adenocarcinoma and then focus on the history, diagnostic criteria and morphology of HPIN. The incidence of HPIN and its relationship to prostate cancer is reviewed. The differential diagnosis of large glandular patterns in the prostate is discussed in depth. Finally, we summarise the recent clinicopathological studies evaluating the clinical significance of HPIN and discuss follow-up strategies in men diagnosed with HPIN.

Intraductal carcinoma of the prostate without invasive carcinoma on needle biopsy: emphasis on radical prostatectomy findings

PURPOSE

Limited information is available on radical prostatectomy findings in men with intraductal carcinoma of the prostate on needle core biopsy in the absence of invasive prostate cancer.

MATERIALS AND METHODS

From the consulting files of one of us we identified 83 men in whom biopsy showed only intraductal prostate cancer. Followup was available in 66 cases. We reviewed slides in 21 radical prostatectomy cases.

RESULTS

Treatment was radical prostatectomy in 23 men, radiation therapy in 15, hormone therapy in 8 and radiation plus hormone therapy in 15 while 5 underwent no treatment or repeat biopsy. Of the 21 radical prostatectomies available for review findings revealed pathological stage pT3a in 8 (38%), pT3b in 3 (13%), pT2 in 8 (38%) and intraductal carcinoma without identifiable invasive cancer in 2 (10%). One patient with pT3a had a positive lymph node at surgery. Average Gleason score was 7.9. Three patients (14%) experienced post-prostatectomy biochemical failure and another (5%) had bone metastases 2.5 years after prostatectomy. In 15 prostatectomies (71%) there was extensive intraductal carcinoma, defined as greater than 10% of tumor being intraductal, including the 2 cases of intraductal carcinoma only. Of the 19 prostatectomies with invasive adenocarcinoma 16 (84%) were conventional acinar adenocarcinoma, 2 (11%) ductal adenocarcinoma, and 1 (5%) mixed ductal and acinar adenocarcinoma.

CONCLUSIONS

At radical prostatectomy men in whom prior biopsies showed only intraductal carcinoma of the prostate typically have high grade (Gleason score 7 or greater) invasive adenocarcinoma and most have advanced stage disease (pT3). Definitive therapy is recommended in men with intraductal carcinoma of the prostate on needle biopsy even in the absence of pathologically documented invasive prostate cancer.

Gene expression profiles of ductal versus acinar adenocarcinoma of the prostate

Ductal adenocarcinoma is an uncommon variant of prostatic adenocarcinoma with a generally more aggressive clinical course than usual acinar adenocarcinoma. However, the molecular distinction between ductal and acinar adenocarcinomas is not well characterized. The aim of this investigation was to evaluate the relatedness of ductal versus acinar prostatic adenocarcinoma by comparative gene expression profiling. Archived, de-identified, snap frozen tumor tissue from 5 ductal adenocarcinomas, 3 mixed ductal-acinar adenocarcinomas, and 11 acinar adenocarcinomas cases were analyzed. All cases of acinar and ductal adenocarcinomas were matched by Gleason grade. RNA from whole tissue sections of the 5 ductal and 11 acinar adenocarcinomas cases were subjected to gene expression profiling on Affymetrix U133Plus2 microarrays. Independently, laser-capture microdissection was also performed on the three mixed ductal-acinar cases and five pure acinar cases to isolate homogeneous populations of ductal and acinar carcinoma cells from the same tumor. Seven of these laser-capture microdissected samples (three ductal and four acinar cell populations) were similarly analyzed on U133Plus2 arrays. Analysis of data from whole sections of ductal and acinar carcinomas identified only 25 gene transcripts whose expression was significantly and at least two-fold different between ductal and acinar adenocarcinomas. A similar analysis of microdissected cell populations identified 10 transcripts, including the prolactin receptor, with more significant differences in expression of 5- to 27-fold between ductal and acinar adenocarcinomas cells. Overexpression of prolactin receptor protein in ductal versus acinar adenocarcinoma was confirmed by immunohistochemistry in an independent set of tumors. We conclude that ductal and acinar adenocarcinomas of the prostate are strikingly similar at the level of gene expression. However, several of the genes identified in this study, including the prolactin receptor, represent targets for further investigations on the molecular basis for histomorphological and clinical behavioral differences between acinar and ductal adenocarcinomas.

Role of radiotherapy in ductal (endometrioid) carcinoma of the prostate

BACKGROUND

Ductal carcinoma of the prostate is a rare variant of prostate cancer that presents most commonly with obstructive urinary symptoms or hematuria. This case series of 6 patients is the first to report the outcome of ductal carcinoma treated with external beam radiotherapy.

METHODS

A retrospective review was performed of patients treated between 1980 and 2006 at Fox Chase Cancer Center, Philadelphia, Penn. Six patients were identified with ductal carcinoma.

RESULTS

Five of the 6 patients were treated definitively and the sixth patient was treated at recurrence 3 years after a radical prostatectomy. Patient ages ranged from 66-80 years and the initial prostate-specific antigen (iPSA) ranged from 1.69-100.3 ng/mL. Three patients had a mixed acinar and ductal carcinoma, 2 with a Gleason score (GS) of 8 and 1 with a GS of 7. Of the patients treated definitively, 4 had clinical stage T2A-T2C and 1 had clinical stage T1B. Definitive radiotherapy was delivered to the prostate with doses between 72 Gy and 78 Gy. Pelvic lymph nodes were treated in all patients. One patient was treated postradical prostatectomy to the prostate bed to a dose of 60 Gy. Adjuvant androgen deprivation was given in 5 of the patients. Two of the patients died from metastatic disease at 1.4 and 7.1 years after treatment. The remaining 4 patients remain alive between 3.2 and 4.8 years from treatment, with 3 patients biochemically without evidence of disease. No patients have developed a local recurrence.

CONCLUSIONS

Ductal carcinoma of the prostate may be treated effectively with external beam radiotherapy. Aggressive management is indicated, even with low-volume metastatic disease.

Computational Modeling and Experimental Evaluation of a Novel Prodrug for Targeting the Extracellular Space of Prostate Tumors

We are developing a noninvasive approach for targeting imaging and therapeutic radionuclides to prostate cancer. Our method, Enzyme-Mediated Cancer Imaging and Therapy (EMCIT), aims to use enzyme-dependent, site-specific, in vivo precipitation of a radioactive molecule within the extracellular space of solid tumors. Advanced methods for data mining of the literature, protein databases, and knowledge bases (IT. Omics LSGraph and Ingenuity Systems) identified prostatic acid phosphatase (PAP) as an enzyme overexpressed in prostate cancer and secreted in the extracellular space. Using AutoDock 3.0 software, the prodrug ammonium 2-(2'-phosphoryloxyphenyl)-6-iodo-4-(3H)-quinazolinone (IQ(2-P)) was docked in silico into the X-ray structure of PAP. The data indicate that IQ(2-P) docked into the PAP active site with a calculated inhibition constant (K(i)) more favorable than that of the PAP inhibitor alpha-benzylaminobenzylphosphonic acid. When (125)IQ(2-P), the radioiodinated form of the water-soluble prodrug, was incubated with PAP, rapid hydrolysis of the compound was observed as exemplified by formation of the water-insoluble 2-(2'-hydroxyphenyl)-6-[(125)I]iodo-4-(3H)-quinazolinone ((125)IQ(2-OH)). Similarly, the incubation of IQ(2-P) with human LNCaP, PC-3, and 22Rv1 prostate tumor cells resulted in the formation of large fluorescent IQ(2-OH) crystals. No hydrolysis was seen in the presence of normal human cells. Autoradiography of tumor cells incubated with (125)IQ(2-P) showed accumulation of radioactive grains ((125)IQ(2-OH)) around the cells. We anticipate that the EMCIT approach will enable the active in vivo entrapment of radioimaging and radiotherapeutic compounds within the extracellular spaces of primary prostate tumors and their metastases.

[The usefulness of Ki67 expression in the biopsy specimens, to predict the biochemical progresion of the prostate cancer after radical prostatectomy]

OBJECTIVE

To evaluate the usefulness of Ki67 expression in the biopsy specimens, to predict the biochemical progression of the prostate cancer after radical prostatectomy.

MATERIAL AND METHODS

We analyse the Ki67 expression in the biopsy specimens of 103 patients treated with radical prostatectomy. The mean follow up is 3.4 years (1.3-8.8 years). We correlate the biochemical progression with traditional prognostic factors as the PSA (> 10/< or = 10), Gleason (> or = 7/< 7), pT classification (pT3/pTO-2) and immunohistochemical factor Ki67 (> 3%/< or = 3%).

RESULTS

Of all 103 patients, in 71 (69%) biochemical progression was not detected and in 32 (31%) biochemical progression was detected. The mean of preoperative PSA is 10.07 ng/ml in the patients without progression and 20.90 ng/ml in the patients with biochemical progression (p=0.0001). The mean of Gleason score in 6.03 in the patients without progression and 6.75 in the patients with biochemical progression (p=0.0001). The percentage of Ki67 expression is 3.95% in the patients without progression and 5.05% in the patients with biochemical progression (p=0.030). The tumors pT0-2 progressed 12/67 (17.9%) and the tumors pT3 progressed 20/36 (55.6%) (p=0.0001). Multivariant regression analysis indicate that it does not exist a statistically significant relation between Ki67 (> 3%/< or = 3%) expression in the biopsy specimens and the biochemical progression of the prostate cancer after radical prostatectomy (p=0.204).

CONCLUSIONS

The immunohistochemical factor Ki67 (> 3%/< or = 3%) in the biopsy specimens, is less effective than the classic factors, PSA (> 10/< or = 10), Gleason (> or = 7/< 7) and pT classification (pT3/pT0-2), to predict the biochemical progression of the prostate cancer after radical prostatectomy.

The utility of Ki-67 expression in the differential diagnosis of prostatic intraepithelial neoplasia and ductal adenocarcinoma

Cribriform and/or papillary prostatic lesions observed on limited tissue, such as needle biopsy, can pose diagnostic dilemmas. One such area of difficulty is the distinction between papillary and/or cribriform prostatic high-grade prostatic intraepithelial neoplasia (HG-PIN) and ductal adenocarcinoma. Over 48 months, we identified 17 cases of ductal adenocarcinoma and 17 cases of HG-PIN from radical retropubic prostatectomy specimens. The HG-PIN lesions were in all cases associated with an acinar prostatic adenocarcinoma component. For each case, we evaluated the proliferative activity, assessed by Ki-67 immunohistochemistry. The majority (82%) of ductal adenocarcinomas were composed of mixed papillary and cribriform patterns, with the remaining demonstrating pure papillary or cribriform patterns. The HG-PIN lesions showed a papillary, cribriform, or mixed papillary/cribriform architecture. The proliferative activity, defined as Ki-67 labeling index, was statistically higher in ductal adenocarcinoma (mean 33%, range 21%-66%) as compared with HG-PIN (mean 6%, range 2%-15%), with no overlap in the Ki-67 indices (P = 0001). A combination of histological features and measurements of cellular proliferation may be helpful to distinguish HG-PIN from ductal adenocarcinoma in limited prostatic tissue samples.

Spread of prostate carcinoma to the perirectal lymph node basin: analysis of 112 rectal resections over a 10-year span for primary rectal adenocarcinoma

We recently identified metastatic prostate carcinoma (PCA) within perirectal lymph nodes (PLNs) from 2 patients undergoing abdominoperineal resection (APR) for rectal adenocarcinoma (RA). As this phenomenon has not been addressed by any studies in the literature and because these positive PLNs had the potential to be mistakenly diagnosed as metastatic RA, we were prompted to undertake a retrospective study of rectal resections for RA to determine the frequency of PCA metastasizing to the PLNs in this patient population. The laboratory information system of the Department of Pathology, Capital Health, Halifax, Nova Scotia was searched for lymph node (LN)-positive RAs resected by low anterior resection or APR in male patients between January 1, 1992 and December 31, 2002. The hematoxylin and eosin slides were retrieved and reviewed, comparing the histology of the primary rectal tumor with that of the LN metastases in each case. Metastases having a different histologic appearance than the primary rectal tumor or having a pattern suggestive of metastatic PCA were analyzed by immunohistochemistry to detect prostate specific antigen (PSA), prostatic acid phosphatase (PAP), cytokeratin 7 (CK7), cytokeratin 20 (CK20), and carcinoembryonic antigen in LN metastases and in each RA. The presence or absence of mucin in the tumors was assessed by staining with Alcian blue, periodic acid-Schiff (PAS) +/- diastase, and modified PANFOPAS (2-hydroxy-3-naphthoic acid hydrazide/fast black B/saponification/periodic acid-Schiff). The study identified 112 cases of RA with positive LNs. Of those, 5 of 112 (4.5%) were identified as having metastatic PCA within the PLNs. All five were positive for PSA and PAP and only one case had rare CK20-positive tumor cells. The primary RAs were all diffusely positive for CK20 and carcinoembryonic antigen. Two cases of metastatic PCA expressed colonic type/acetylsialomucin, which was also seen in well-differentiated primary RAs. These 5 patients had a mean age of 76.8 years (range, 68-82 years). Four (80%) underwent APR while one (20%) underwent a low anterior resection. The mean number of LNs identified per case was 14 (range, 5-26). The mean number of LNs per case with metastatic PCA was 7.6 (range, 1-18). The majority of the LNs were under 1.0 cm in diameter. Two cases (40%) were associated with significant extranodal extension of PCA. The PLNs were mistakenly diagnosed as being involved by RA 40% of the time. On follow-up, 2 patients (40%) had died with progressive pelvic tumor, while 3 patients (60%) were alive, including 2 who, as a result of the study, were referred to the urology service for management. Both of these patients were subsequently started on medical (anti-androgen) therapy and 1 additionally had bilateral orchiectomy. In 4 of the patients, the serum PSA after the rectal resection ranged from 2.5 to 13.5 ng/mL. In 1 patient, the serum PSA was markedly elevated (5961 ng/mL), and this patient was subsequently identified on bone scan as having extensive skeletal metastases. This study identified a subset (4.5%) of patients with RA and PLNs positive for PCA. PCA may extend to the PLN basin and therefore influence the management of patients with rectal tumors and the staging, LN dissection, and management of patients with PCA. Moreover, the LNs were incorrectly diagnosed as metastatic RA 40% of the time, emphasizing the need to consider the differential diagnosis of metastatic PCA when evaluating PLNs. The diagnosis of metastatic PCA can be confirmed using an immunohistochemical panel consisting of PSA, PAP, CK20, and carcinoembryonic antigen along with mucin stains in some cases. In patients undergoing APR for RA, there should be preoperative screening for PCA as it will not be possible to do a digital rectal examination or transrectal ultrasound post-APR, and a prostate biopsy, if necessary, would have to be done via the more difficult transperineal approach.

Prostatic ductal adenocarcinoma showing Bcl-2 expression

Prostatic ductal adenocarcinoma represents a rare histological variant of prostatic carcinoma with features of a papillary lesion at cystoscopy. There are conflicts regarding the existence, origin, staging, grading, treatment and clinical behavior of this tumor. The aim of the present study is to examine the expression of Bcl-2 and p53 in prostatic ductal adenocarcinoma and to evaluate its origin by analyzing prostate specific antigen, prostate specific acid phosphatase, cytokeratins, epithelial membrane antigen and carcinoembryonic antigen expressions. The results confirmed the expression of prostate specific antigen and prostate specific acid phosphatase in prostatic ductal adenocarcinoma. The demonstrated expression of Bcl-2 was predominant in the better-differentiated tumor. Bcl-2 expression appears not to be associated with neuroendocrine differentiation as assessed by chromogranin A reactivity. Thus, the first case of a prostatic ductal adenocarcinoma showing Bcl-2 expression is presented. The tumor was negative for p53.

Unusual subtypes of prostate cancer

The vast majority of prostatic tumors developing in adult males are adenocarcinomas. For the most part, variations in histology have not received specific designations and, from a practical approach, have had any specific prognostic implications handled through application of the Gleason grading system. Nonetheless, some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some controversy regarding the appropriate application of the Gleason grading scheme in these tumors. In addition, there are carcinomas that are in fact not adenocarcinomas and that should be kept as distinct entities. In this paper, the histologic variants of adenocarcinoma are reviewed with emphasis on clinicopathologic features and the clinical relevance of these subtypes. Other carcinomas that occur in the prostate gland are also discussed again with a focus on the clinicopathologic characteristics.

Prostate biopsy interpretation. Current concepts, 1999

Needle biopsy of the prostate has a pivotal role in the diagnosis of prostate cancer and the prediction of outcome. Strategies for sampling the prostate are being refined, which will increase the diagnostic yield. In combination with other clinical factors, the pathologic findings obtained from the biopsy specimen provide enhanced predictive accuracy for stage and individual outcome.

Does prostatic ductal adenocarcinoma exist?

Prostatic ductal (endometrioid) adenocarcinoma has been considered a distinct pathologic and clinical entity since it was first described more than 30 years ago. Its current status as a unique neoplasm is controversial, however, because it has considerable histologic overlap with typical acinar adenocarcinoma, particularly in small specimens such as needle biopsies. There are also conflicting views regarding its clinical behavior. We recently encountered a series of typical peripheral zone cancers of the prostate gland with prominent papillary or cribriform pattern that apparently did not involve the large periurethral prostatic ducts or verumontanum. To determine the incidence of these "ductal features" in nonductal carcinoma, we reviewed the findings in 338 consecutive totally embedded whole-mount prostatectomy specimens with typical clinical and pathologic features of acinar carcinoma. We defined carcinoma with significant "ductal features" as one that displayed papillary or cribriform pattern involving an arbitrarily defined aggregate focus at least 5 mm in diameter. Anti-keratin 34beta-E12 immunohistochemical staining for basal cells allowed exclusion of areas of papillary or cribriform pattern of high-grade prostatic intraepithelial neoplasia. We identified carcinoma with ductal features (papillary or cribriform growth) in 17 prostatectomy specimens (5% of cases) exclusively in the peripheral zone without involving the periurethral region. Papillary pattern was present in 11 of these cases (65%) and cribriform pattern in 10 (59%), including 4 cases (24%) with both patterns. Of 11 needle biopsy specimens available for examination from these 17 cases, 4 (36%) contained at least focal papillary or cribriform pattern of carcinoma. We conclude that adenocarcinoma arising in the peripheral zone of the prostate gland may display ductal carcinoma features (papillary or cribriform growth) classically associated with ductal adenocarcinoma. These findings, together with the recognized near-constant association of prostatic ductal adenocarcinoma and typical prostate cancer, suggest that ductal adenocarcinoma results from spread of typical prostatic acinar carcinoma into the large accommodating periurethral ducts and stroma, and that there are no unique histologic features other than site of growth. Identification of papillary or cribriform growth of cancer in prostate needle biopsies usually results from peripheral zone adenocarcinoma and not ductal adenocarcinoma.