Ductal (endometrioid) adenocarcinoma of the prostate: a clinicopathological study of 16 cases

Recent insights on the clinical, pathological, and molecular features of intraductal carcinoma of the prostate

Intraductal carcinoma of the prostate, a unique histopathologic entity that is often observed (especially in advanced prostate cancer), is characterized by the proliferation of malignant cells within normal acini or ducts surrounded by a basement membrane. Intraductal carcinoma of the prostate is almost invariably associated with an adjacent high-grade carcinoma and is occasionally observed as an isolated subtype. Intraductal carcinoma of the prostate has been demonstrated to be an independent poor prognostic factor for all stages of cancer, whether localized, de novo metastatic, or castration-resistant. It also has a characteristic genetic profile, including high genomic instability. Recognizing and differentiating it from other pathologies is therefore important in patient management, and morphological diagnostic criteria for intraductal carcinoma of the prostate have been established. This review summarizes and outlines the clinical and pathological features, differential diagnosis, molecular aspects, and management of intraductal carcinoma of the prostate, as described in previous studies. We also present a discussion and future perspectives regarding intraductal carcinoma of the prostate.

Prevalence of prostate cancer in men with haematuria: a systematic review and meta-analysis

OBJECTIVES

To investigate the prevalence of prostate cancer in men attending evaluation for haematuria, as this could help healthcare providers to determine whether men with haematuria should have prostate examinations performed.

METHODS

The study was performed according to a pre-specified protocol uploaded to the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022299383). A systematic search of MEDLINE, Ovid and Google Scholar was performed in December 2021. Two independent researchers evaluated all titles, available abstracts, and full texts. We included studies on adult men (aged ≥18 years) describing haematuria and prostate cancer.

RESULTS

We screened 4252 titles and abstracts when available and assessed 350 studies in full text. In total, 65 studies were included and 42 was summarised in a meta-analysis. In total, 18 752 men with haematuria were included, and the pooled prevalence (95% confidence interval [CI]) of prostate cancer was 3.0% (2.0-4.1%). In men with macroscopic haematuria, the pooled prevalence (95% CI) of prostate cancer was 5.9% (2.9-9.9%; n = 265/5373). In men with microscopic haematuria, the pooled prevalence (95% CI) of prostate cancer was 1.4% (0.8-2.2%; n = 71/6642).

CONCLUSION

Our findings indicate that the prevalence of prostate cancer is considerable in men attending evaluation for haematuria. Therefore, digital rectal examination and prostate-specific antigen measurement should become a standard procedure for all men with haematuria, especially for men with macroscopic haematuria.

Magnetic resonance imaging findings of pure prostatic ductal adenocarcinomas: a case series

PURPOSE

This study aimed to investigate the characteristics of magnetic resonance imaging (MRI) findings in pure prostatic ductal adenocarcinoma.

METHODS

From January 2009 to February 2020, seven patients who were diagnosed with pure prostatic ductal adenocarcinoma and had a referable preoperative MRI scan were included in the study. We evaluated the following MRI findings for each tumor: size, location, presence of multi-cystic component, and apparent diffusion coefficient (ADC) value.

RESULTS

The median maximum diameter of the tumors was 22 mm (range 19-70 mm). Regarding transverse distribution, five tumors were located in the periurethral area and two were located peripherally apart from the urethra. Two of the seven tumors had cystic components. The median ADC value of the tumors was 0.754 × 10^-3 mm²/s (range 0.570-0.963 × 10^-3 mm²/s). Based on the transverse distribution and components of the tumors on MRI, ductal adenocarcinomas were classified into three types: type I as a non-cystic tumor located peripherally apart from the urethra (29%, two cases); type II as a non-cystic tumor located in the periurethral area (43%, three cases); and type III as a tumor with a multi-cystic component (29%, two cases).

CONCLUSION

The non-cystic mass with periurethral distribution (type II) and multi-cystic mass (type III) may be characteristic features that differentiate pure ductal adenocarcinoma from ordinary acinar adenocarcinoma on MRI.

Optimizing the diagnosis and management of ductal prostate cancer

Ductal adenocarcinoma (DAC) is the most common variant histological subtype of prostate carcinoma and has an aggressive clinical course. DAC is usually characterized and treated as high-risk prostatic acinar adenocarcinoma (PAC). However, DAC has a different biology to that of acinar disease, which often poses a challenge for both diagnosis and management. DAC can be difficult to identify using conventional diagnostic modalities such as serum PSA levels and multiparametric MRI, and the optimal management for localized DAC is unknown owing to the rarity of the disease. Following definitive therapy for localized disease with radical prostatectomy or radiotherapy, the majority of DACs recur with visceral metastases at low PSA levels. Various systemic therapies that have been shown to be effective in high-risk PAC have limited use in treating DAC. Although current understanding of the biology of DAC is limited, genomic analyses have provided insights into the pathology behind its aggressive behaviour and potential future therapeutic targets.

Ductal Prostate Cancers Demonstrate Poor Outcomes with Conventional Therapies

BACKGROUND

Ductal prostate adenocarcinoma (DAC) is a rare, aggressive, histologic variant of prostate cancer that is treated with conventional therapies, similar to high-risk prostate adenocarcinoma (PAC).

OBJECTIVE

To assess the outcomes of men undergoing definitive therapy for DAC or high-risk PAC and to explore the effects of androgen deprivation therapy (ADT) in improving the outcomes of DAC.

DESIGN, SETTING, AND PARTICIPANTS

A single-center retrospective review of all patients with cT1-4/N0-1 DAC from 2005 to 2018 was performed. Those undergoing radical prostatectomy (RP) or radiotherapy (RTx) for DAC were compared with cohorts of high-risk PAC patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Metastasis-free survival (MFS) and overall survival (OS) rates were analyzed using Kaplan-Meier and Cox regression models.

RESULTS AND LIMITATIONS

A total of 228 men with DAC were identified; 163 underwent RP, 34 underwent RTx, and 31 had neoadjuvant therapy prior to RP. In this study, 163 DAC patients and 155 PAC patients undergoing RP were compared. Similarly, 34 DAC patients and 74 PAC patients undergoing RTx were compared. DAC patients undergoing RP or RTx had worse 5-yr MFS (75% vs 95% and 62% vs 93%, respectively, p < 0.001) and 5-yr OS (88% vs 97% and 82% vs 100%, respectively, p < 0.05) compared with PAC patients. In the 76 men who received adjuvant/salvage ADT after RP, DAC also had worse MFS and OS than PAC (p < 0.01). A genomic analysis revealed that 10/11 (91%) DACs treated with ADT had intrinsic upregulation of androgen-resistant pathways. Further, none of the DAC patients (0/15) who received only neoadjuvant ADT prior to RP had any pathologic downgrading. The retrospective nature was a limitation.

CONCLUSIONS

Men undergoing RP or RTx for DAC had worse outcomes than PAC patients, regardless of the treatment modality. Upregulation of several intrinsic resistance pathways in DAC rendered ADT less effective. Further evaluation of the underlying biology of DAC with clinical trials is needed.

PATIENT SUMMARY

This study demonstrated worse outcomes among patients with ductal adenocarcinoma of the prostate than among high-grade prostate adenocarcinoma patients, regardless of the treatment modality.

The Role of Radiotherapy Among Patients With Prostate Ductal Adenocarcinoma

INTRODUCTION

The aim of this study was to perform a Surveillance, Epidemiology, and End Results (SEER) analysis on the effect of radiotherapy (RT) on survival among patients with prostate ductal adenocarcinoma (DA), a rare variant of prostate cancer.

PATIENTS AND METHODS

Cases of T1 to 4 N0 M0 prostate DA diagnosed between 2004 and 2013 were extracted from SEER. The association between categorical variables and radiation therapy was assessed for statistical significance using the χ² test or Fisher exact test. Difference in continuous variables across the RT groups was assessed for statistical significance using the 2-sample t test or non-parametric test. The distribution of overall survival (OS) and disease-specific survival (DSS) between the RT groups was assessed using the Kaplan-Meier method and the log rank test and after propensity matching. The association between hazards of death (HR) and covariates was examined using Cox proportional hazards model. A 2-sided P-value of .05 was used to determine statistical significance.

RESULTS

A total of 205 patients met inclusion criteria. On univariate analysis, RT was associated with significant improvement in OS and DSS. On multivariate Cox regression, RT significantly decreased risk of death for both OS and DSS (HR, 0.516; 95% confidence interval [CI], 0.273-0.978 and HR, 0.232; 95% CI, 0.082-0.658, respectively). After propensity score matching, RT demonstrated a persistent improvement in both OS and DSS.

CONCLUSIONS

RT decreased risk of death for both OS and DSS in patients with node-negative, nonmetastatic prostate DA on multivariable analysis. RT was also associated with improved OS and DSS after propensity matching.

Morphological and Immunohistochemical Biomarkers in Distinguishing Prostate Carcinoma and Urothelial Carcinoma: A Comprehensive Review

The differential diagnosis between high-grade prostate carcinoma and infiltrating urothelial carcinoma (UC) in transurethral resection prostate specimens as well as cystoprostatectomy specimens may often be challenging due to morphologic and clinical overlap of the 2 entities. Such distinction has critical therapeutic and staging consequences, yet it is hampered by both issues in morphology and by the low accuracy rates of single immunohistochemical markers, as reported in literature. This review aims to provide a comprehensive analysis of the available morphological and immunohistochemical parameters, which may allow to discriminate between prostate carcinoma and urothelial carcinoma in the proper clinical context and to discuss their diagnostic applications in daily practice.

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.

Prostatic Duct Carcinoma with Combined Prostatic Duct Adenocarcinoma and Urothelial Carcinoma Features

We report a unique case of prostatic duct carcinoma (PDC) featuring both prostatic duct adenocarcinoma (PDA) and high-grade urothelial carcinoma (HG-UC). An 84-year-old man presenting with hematuria showed at ultrasonography and cystoscopy a papillary neoplasia located near to the verumontanum. Histopathologic examination of specimens from transurethral resection revealed a tumor originating from large prostatic ducts showing 2 different components: PDA with endometrioid features (main pattern) and HG-UC (minor part). Immunohistochemically, the areas of PDA were positive for prostatic acid phosphatase (PAP), prostatic specific antigen (PSA), and androgen receptors (AR), while negative for estrogen (ER) and progesterone receptors (PGR). Prognostic factors evaluation pointed out a low proliferation index (10%) and focal expression of p53 (6%); c-erb-B2 was not overexpressed. The HG-UC areas were negative for all previous markers, while positive for thromobomodulin. The proliferation index was high (60%), and p53 was diffusely expressed (55%). The incidence and significance of PDC with combined features is discussed with reference to literature data.

Beyond Prostate Adenocarcinoma: Expanding the Differential Diagnosis in Prostate Pathologic Conditions

Recent advances in magnetic resonance (MR) imaging of the prostate gland have dramatically improved the ability to detect and stage adenocarcinoma of the prostate, one of the most frequently diagnosed cancers in men and one of the most frequently diagnosed pathologic conditions of the prostate gland. A wide variety of nonadenocarcinoma diseases can also be seen with MR imaging, ranging from benign to malignant diseases, as well as infectious and inflammatory manifestations. Many of these diseases have distinctive imaging features that allow differentiation from prostate acinar adenocarcinoma. Early recognition of these entities produces a more accurate differential diagnosis and may enable more expeditious clinical workup. Benign neoplasms of the prostate include plexiform neurofibroma and cystadenoma, both of which demonstrate distinctive imaging features. Stromal neoplasms of uncertain malignant potential are rare tumors of uncertain malignant potential that are often difficult to distinguish at imaging from more-malignant prostate sarcomas. Other malignant neoplasms of the prostate include urothelial carcinoma, primary prostatic carcinoid, carcinosarcoma, endometrioid or ductal adenocarcinoma, and mucinous adenocarcinoma. Prostatic infections can lead to abscesses of pyogenic, tuberculous, or fungal origins. Finally, miscellaneous idiopathic disorders of the prostate include amyloidosis, exophytic benign prostatic hyperplasia, and various congenital cysts. Considerable overlap can exist in the clinical history and imaging findings associated with these prostate pathologic conditions, and biopsy is often required for ultimate confirmation of the diagnosis. However, many diagnoses, including cystadenoma, mucinous adenocarcinoma, sarcoma, and abscesses, have distinct imaging features, which can enable the informed radiologist to identify the diagnosis and recommend appropriate clinical workup and management. (©)RSNA, 2016.

Management and therapeutic response of a prostate ductal adenocarcinoma: a still unknown tumour?

Ductal adenocarcinoma is a rare subtype of prostate cancer with a worse prognosis.Histologically, it is characterized by the presence of tall, pseudostratified columnar epithelium with abundant cytoplasm organized in a papillary or cribriform-papillary pattern. Several clinical differences distinguish this subtype of prostate cancer by the conventional acinar adenocarcinoma: exophytic growth into the prostatic urethra, different clinical presentation, different sites of metastasis and more aggressiveness. The rarity of this tumour forced to base our knowledge on small case series or on individual case reports, and does not help to establish appropriate guidelines. Therefore, the diagnosis of this tumour masks clinical implications that are still not well-understood.We report the case of a 69-year-old Caucasian man with a diagnosis of pure prostate ductal adenocarcinoma that early developed multiple metastases after radical prostatectomy. The patient started hormonal therapy with a fast biochemical and radiologic (positron emission tomography-computed tomography, PET-CT) hormonal escape. Therefore, we took the decision to perform chemotherapy with Taxotere along with prednisolone with a relative stability of prostate-specific antigen (PSA) level, but a new PET-CT scan showed a further progression of the disease. Finally, the patient underwent therapy with Abiraterone acetate that did not stop the cancer progression.No therapeutic options available showed a good control of disease progression. PSA proved to be a poor marker while, on the contrary, PET-CT scan has proved to be particularly useful in the management of the disease progression. More efforts are required to add new knowledge about this tumour and assess what is known until now.

The update of prostatic ductal adenocarcinoma

Since initially described in 1967, prostatic ductal adenocarcinoma (PDA) has engendered a series of controversies on its origin, histological features, and biological behavior. Owing to the improvement of molecular biological technique, there are some updated findings on the characteristics of PDA. In the current review, we will mainly analyze its origin, clinical manifestations, morphological features, differential diagnosis, immunophenotype and molecular genetics, with the purpose of enhancing recognition of this tumor and making a correct diagnosis and treatment choice.

Immunohistochemical profile of ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate (DAC) is considered to be an aggressive subtype of prostate cancer with greater risk of progression than acinar adenocarcinoma (AC). It has been debated whether DAC is a distinct subtype or a morphological variant of AC. Our aim was to examine the protein expression of DAC and to compare the results with AC. A tissue microarray was constructed from 60 DAC and 46 AC matched by Gleason score. The slides were stained for 28 immunomarkers (estrogen, progesterone and androgen receptor, prolactin, PSA, prostein, PSMA, PSAP, CDX2, lysozyme, villin, monoclonal CEA, CK7, CK20, HMWCK, p63, p504s, c-myc, EGFR, Ki-67, p16, p21, p27, p53, PTEN, ERG, PAX-2, and PAX-8). HMWCK was positive in 8.5 % of DAC, but negative in all cases of AC (p = 0.045). p16 was positive in 53.3 % of DAC and in 26.1 % of AC (p = 0.005). p53 was positive in 42.4 % of DAC and 26.7 % of AC (p = 0.031). A distinct patchy positivity of CK20 was seen in 23.7 % of DAC, and this pattern was also seen in 9.1 % of AC (p = 0.047). Villin was positive in 3.4 % of DAC while expression was negative in AC. Ki-67 labeling index was significantly higher in DAC than in AC (mean 9.2 % [95 % CI 6.4-12.0] and 2.6 % [1.9-3.4], p < 0.001). While there is some overlap in the immunohistochemical expression of DAC and AC, the differences between these two morphotypes of prostatic carcinoma are consistent with DAC having a more aggressive phenotype than AC.

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.

Histopathological features of ductal adenocarcinoma of the prostate in 1,051 radical prostatectomy specimens

Ductal adenocarcinoma (DAC) of the prostate is thought to have worse prognosis than prostatic acinar carcinoma (PAC). We aimed to evaluate the prognostic significance of histopathological patterns of DAC. A series of 1,051 radical prostatectomy specimens from Karolinska University Hospital 1998-2005 was reviewed. A ductal component was classified as classical DAC (DACC) if it had columnar, pseudostratified epithelium, elongated nuclei, and papillary, glandular, or cribriform architecture; borderline DAC (DACB) if it lacked elongated nuclei or classical architecture; and prostatic adenocarcinoma with ductal features (PCDF) if stratified high-grade nuclei were found. DACC, DACB, and PCDF were seen in 2.6, 4.0, and 1.6 % of the cases. DAC was usually mixed with PAC and constituted 10-100 % (mean 40 %) of the main tumor. Location was periurethral, peripheral, or both in 69.8, 3.5, and 26.7 %. Necrosis was seen in 31.3 %, stromal invasion of DAC in 52.3 %, and intraductal spread in 91.9 %. In DACC/DACB and PAC, extraprostatic extension was seen in 66.7 and 42.4 % (p < 0.001) and seminal vesicle invasion in 13.0 and 5.0 % (p = 0.0045). DACC, DACB, and PCDF had a hazard ratio for biochemical recurrence of 1.5 (0.7-2.8), 1.4 (0.8-2.6) and 1.2 (0.5-2.7). When PCDF was excluded from DAC, hazard ratio was 1.4 (95 % CI 0.9-2.3, p = 0.12). Location, % DAC, necrosis, stromal invasion, or Gleason score were not predictive of recurrence. This suggests that DACC and DACB are more aggressive than average PAC, while cancers with acinar architecture and pseudostratified high-grade nuclei should not be included in DAC.

Variants and unusual patterns of prostate cancer: clinicopathologic and differential diagnostic considerations

Beyond the typical acinar morphology observed in the majority of prostatic adenocarcinomas, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be classified as: (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features and/or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details a number of variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Improved differentiation between ductal and acinar prostate cancer using three-dimensional histology and biomarkers

OBJECTIVE

The aim of the study was to refine the methodology for discriminating the ductal (DAP) and acinar adenocarcinomas (AAP) of the prostate and confirm that prostate carcinoma of ductal origin is a more aggressive subtype.

MATERIAL AND METHODS

A retrospective analysis of 110 consecutive radical prostatectomy cases operated on between 2000 and 2006 and worked up using large-format "two-dimensional" (2D; 4 μm thick) and "three-dimensional" (3D; 1500 μm thick) histology sections was carried out, with an average follow-up of 5.1 years. The same material was also analysed for selected biomarkers in tissue microarray blocks. The most discriminatory biomarkers were then tested on preoperative core biopsy specimens from 24 of these patients.

RESULTS

3D histology classified 97/110 (88%) cases of AAP and 13/110 (12%) DAP, which was then confirmed in 2D specimens. The DAP cases had a significantly greater frequency of pT3a and more advanced cancers, > 20 mm tumour focus, high-grade prostatic intraepithelial neoplasia, Gleason score ≥ 7, positive margin, extracapsular extension, vascular invasion, seminal vesicle infiltration, biochemical/local recurrence, regional lymph-node metastases and distant metastases. Three biomarkers in combination (chromogranin A, epidermal growth factor receptor and p53] distinguished DAP from AAP with an accuracy of 94% (area under the curve 0.94, 95% confidence interval 0.88-0.99). The same high accuracy was achieved using these three biomarkers on the preoperative specimens.

CONCLUSIONS

Both 3D histology and the three selected biomarkers can help in accurately distinguishing DAP from AAP. The clear-cut distinction of two forms of prostate cancers by the approach advocated in this paper would allow AAP patients to undergo less radical treatment and would segregate DAP patients into a subset requiring more effective treatment regimens.

A comprehensive review of incidence and survival in patients with rare histological variants of prostate cancer in the United States from 1973 to 2008

BACKGROUND

The American Joint Commission on Cancer (AJCC) identifies five rare variants of prostate adenocarcinoma: mucinous, ductal, signet ring cell, adenosquamous and neuroendocrine including small cell. No prior study has comprehensively detailed incidence and outcomes for all AJCC variants of prostate cancer.

METHODS

We used the Surveillance, Epidemiology and End Results (SEER) program to analyze prostate cancers diagnosed from 1973 to 2008. Cases of mucinous, ductal, signet ring cell, adenosquamous and neuroendocrine carcinoma were identified, along with cases of non-variant adenocarcinoma for comparison. Age-adjusted incidence rates (IRs) and overall survival (OS) were evaluated and stratified by race, age, stage and PSA. All IRs represent the number of cases per million people per year.

RESULTS

Each variant is rare, with IRs between 0.03 (adenosquamous) and 0.61 (mucinous). There was a significant difference in incidence between Caucasian and African American patients with mucinous adenocarcinoma. Median OS varied ranged from 10.0 months in neuroendocrine carcinoma to 125.0 months in mucinous adenocarcinoma. In all, 5-year OS ranged from 12.6% in neuroendocrine carcinoma to 75.1% in mucinous adenocarcinoma. There was a significant difference in survival between Caucasian and African American patients for mucinous adenocarcinoma (median survival 144.0 vs 99.0 months, P<0.01). African American patients with mucinous adenocarcinoma also presented with more advanced stage disease compared with Caucasian patients. Multivariate analysis demonstrated that African American race was not associated with worse survival when corrected for stage.

CONCLUSIONS

There are differences in IRs and OS among rare variants of prostate cancer. For mucinous adenocarcinoma, there are significant differences in incidence and survival between Caucasian and African American patients. These differences should be considered in clinical decision making for patients with these malignancies.

Immunohistochemical verification of ductal differentiation in prostate cancer

Recent studies have shown that patients with prostate carcinomas exhibiting ductal differentiation have an unfavourable prognosis compared with those with purely acinar adenocarcinomas. We studied the expression of nine immunohistochemical markers to evaluate their value in delineating carcinomas with and without ductal differentiation. Thirteen tumours showing cellular characteristics and growth patterns typical of ductal differentiation were identified among 110 analysed prostatectomy specimens. The levels of cytoplasmic expression of chromogranine A (69% vs 19%, p = 0.0003) and nuclear expression of p53 (76% vs 12%, p < 0.0001) as well as nuclear expression of Ki-67 (69% vs 26%, p = 0.0047) in the tumour cells, were found to be statistically significantly different in the two tumour categories. Assessment of chromogranine A, p53 and Ki-67 in prostate carcinoma may serve as useful adjunctive diagnostic tools for delineating more aggressive prostate cancer cases exhibiting ductal differentiation.

An 82-year-old Caucasian man with a ductal prostate adenocarcinoma with unusual cystoscopic appearance: a case report

Introduction

Ductal adenocarcinoma is a rare variety of the common acinar adenocarcinoma. It usually presents with refractory symptoms, and during cystoscopy, it is seen as an exophytic lesion at the area of the verumontanum.

Case presentation

An 82-year-old Caucasian man was diagnosed with ductal adenocarcinoma of the prostate after undergoing transurethral resection of the prostate for urinary retention. Immunohistochemistry confirmed the nature of the tumor. The patient was treated with triptorelin, 3.75 mg once/month, and bicalutamide, 50 mg 1 × 1. The serum prostate-specific antigen at three, six and 12 months after transurethral resection of the prostate was 0.1 ng/ml. The patient remains asymptomatic, and he entered a six-month follow-up protocol.

Conclusion

Ductal adenocarcinoma often involves the central ducts of the gland and may present as an exophytic papillary lesion in the prostatic urethra. This is why it usually presents with refractory symptoms. The outcome for men with prostatic ductal adenocarcinoma is, in most studies, worse than the outcome for men with prostatic acinar adenocarcinoma. Aggressive management is indicated, even with low-volume metastatic disease.

Ductal adenocarcinoma of the prostate: increased mortality risk and decreased serum prostate specific antigen

PURPOSE

The clinical significance of ductal prostatic carcinoma is not well-defined. In a population based cancer registry we identified a large group of patients with ductal carcinoma to characterize the impact of the ductal subtype on presentation and survival in men with prostate cancer.

MATERIALS AND METHODS

We used a national cancer registry to identify incident cases of ductal and acinar adenocarcinoma from 1996 to 2006. We analyzed clinicopathological variables and performed Cox multivariate survival analysis. Prostate specific antigen values were available for 2004 to 2006 and used to assess differences in Gleason grade and serum prostate specific antigen between ductal and acinar cancer cases at diagnosis.

RESULTS

We identified 442,881 acinar and 371 ductal cases. Ductal cases were more likely to present with distant disease (12% vs 4%, p <0.001) and be poorly differentiated (50% vs 32%, p <0.001). Ductal histology was associated with a 30% decrease in geometric mean prostate specific antigen (adjusted coefficient 0.7, 95% CI 0.6-0.8) and more than 2-fold increased odds of prostate specific antigen less than 4.0 ng/ml (OR 2.4, 95% CI 1.4-4.0) independent of other clinicopathological variables. In men with nondistant disease at diagnosis ductal histology was associated with 2.2-fold (CI 1.4-3.5) increased disease specific mortality.

CONCLUSIONS

In what is to our knowledge the largest series of this histological subtype ductal cancer cases were more likely to present with advanced stage cancer and lower prostate specific antigen, suggesting that timely disease detection is a significant challenge. Also, men with locoregional disease were more likely to die of the disease.

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.

Ductal adenocarcinoma of the prostate: clinical features and implications after local therapy

BACKGROUND

Ductal or endometrioid adenocarcinoma of the prostate may be a subtype of prostate cancer that is amenable to aggressive local therapeutic strategies. The authors of this report investigated the clinical outcome of patients who had prostate ductal adenocarcinoma after primary radical prostatectomy or radiotherapy.

METHODS

The clinical features of 108 patients with locally confined or advanced prostate ductal adenocarcinoma who had undergone primary radical prostatectomy (surgical group, n = 76 men) or no surgery (nonsurgical group, n = 32 men) were evaluated retrospectively. Clinical records were reviewed, and Gleason scores, clinical/pathologic stages, and preoperative prostate-specific antigen levels were examined. The clinical features that were assessed included local recurrence, distant metastasis, and progression-free and overall survival after primary therapy.

RESULTS

In the surgical group, patients who had pure ductal prostate cancer survived longer (median, 13.8 years; 95% confidence interval [CI], from 13.8 years to not attained) than patients who had mixed ductal prostate cancer (median, 8.9 years; 95% CI, from 7.1 years to not attained; P = .05). In addition, the median time to local progression was shorter (2.8 years vs 4.9 years) and the median time to distant metastasis was longer (3.9 years vs 2.0 years) for patients who had pure ductal adenocarcinoma than for patients who had mixed ductal adenocarcinoma of the prostate after surgery, respectively.

CONCLUSIONS

The results of this preliminary study suggested that pure ductal prostate adenocarcinoma tends to pursue an indolent clinical course and poses an increased risk for local recurrence. Local control (particularly prostatectomy) may improve the clinical outcome of patients with pure prostate ductal adenocarcinoma. These results need to be confirmed in prospective studies.

TMPRSS2-ERG gene fusions are infrequent in prostatic ductal adenocarcinomas

Ductal adenocarcinoma of the prostate is an unusual subtype that may be associated with a more aggressive clinical course, and is less responsive to conventional therapies than the more common prostatic acinar adenocarcinoma. However, given its frequent association with an acinar component at prostatectomy, some have challenged the concept of prostatic ductal adenocarcinoma as a distinct clinicopathologic entity. We studied the occurrence of the TMPRSS2-ERG gene fusion, in 40 surgically resected ductal adenocarcinoma cases, and in their associated acinar component using fluorescence in situ hybridization. A group of 38 'pure' acinar adenocarcinoma cases matched with the ductal adenocarcinoma group for pathological grade and stage was studied as a control. Compared with the matched acinar adenocarcinoma cases, the TMPRSS2-ERG gene fusion was significantly less frequently observed in ductal adenocarcinoma (45 vs 11% of cases, P=0.002, Fisher's exact test). Here, of the ductal adenocarcinoma cases with the gene fusion, 75% were fused through deletion, and the remaining case was fused through translocation. The TMPRSS2-ERG gene fusion was also rare in the acinar component of mixed ductal-acinar tumors when compared with the pure acinar adenocarcinoma controls (5 vs 45%, P=0.001, Fisher's exact test). In 95% of the ductal adenocarcinoma cases in which a concurrent acinar component was analyzed, there was concordance for presence/absence of the TMPRSS2-ERG gene fusion between the different histologic subtypes. In the control group of pure acinar adenocarcinoma cases, 59% were fused through deletion and 41% were fused through translocation. The presence of the TMPRSS2-ERG gene fusion in some cases of prostatic ductal adenocarcinoma supports the concept that ductal adenocarcinoma and acinar adenocarcinoma may be related genetically. However, the significantly lower rate of the gene fusion in pure ductal adenocarcinoma cases underscores the fact that genetic and biologic differences exist between these two tumors that may be important for future therapeutic strategies.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Rare and unusual histological variants of prostatic carcinoma: clinical significance

We review the clinicopathological features of the following unusual histological variants of prostatic carcinoma: small cell carcinoma, ductal adenocarcinoma, sarcomatoid (carcinosarcoma), basal cell, squamous cell and adenosquamous, and urothelial carcinoma. These variants are rare and account for 5-10% of carcinomas that originate in the prostate. Some develop from acinar adenocarcinoma after hormonal or radiation therapy. They are usually aggressive tumours that often present with secondary deposits. The outcome is generally poor. Only basal cell carcinoma is seen as a low-grade carcinoma.

Prostatic ductal adenocarcinoma presenting as a urethral polyp: a clinicopathological study of eight cases of a lesion with the potential to be misdiagnosed as a benign prostatic urethral polyp

AIMS

Centrally located prostatic ductal adenocarcinoma can present as a single urethral polyp mimicking a benign polyp. Such lesions have not been formally studied.

METHODS AND RESULTS

Clinicopathological and immunohistochemical findings of eight cases were analysed. Patients (mean age 76 years) presented with urinary symptoms and haematuria. Mean serum prostate specific antigen (PSA) was 7.01 ng/mL (range 1.04-21). Single small polyps were seen on cystourethroscopy with a clinical diagnosis of benign polyps. The most common architectural patterns were cribriform and papillary. Five cases had mild cytological atypia, three of which were initially diagnosed as benign prostatic urethral polyps. All cases were positive for PSA and 34betaE12. Seven cases tested were positive for AMACR (a-methylacyl-CoA racemase), p63 and cytokeratin (CK) 7 and 70% for CK20. Proliferative activity defined as Ki-67 labelling index was high (mean 26%, range 20-35%). Adenocarcinoma, predominantly ductal, was found in other specimens in four patients.

CONCLUSIONS

Centrally located prostatic ductal adenocarcinoma has the propensity to mimic benign urethral polyps clinically and histopathologically. Basal cell immunostaining may not help with this distinction but AMACR is useful. Prominent glandular complexity including cribriform patterns, nuclear pseudostratification, at least mild atypia and a high Ki-67 index distinguish these lesions from prostatic urethral polyps.

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.

Immunohistochemical Antibody Cocktail Staining (p63/HMWCK/AMACR) of Ductal Adenocarcinoma and Gleason Pattern 4 Cribriform and Noncribriform Acinar Adenocarcinomas of the Prostate

Overexpression of alpha-methylacyl coenzyme A racemase (AMACR) in combination with absence of basal cell markers [ie, p63 and high molecular weight cytokeratin (HMWCK)] is typical of classic acinar prostatic adenocarcinoma. We studied the expression and diagnostic utility of p63/HMWCK/AMACR immunohistochemical cocktail staining in ductal adenocarcinoma and cribriform Gleason pattern 4 acinar prostate cancer and compared it to noncribriform Gleason pattern 4 acinar prostate cancer. One to 4 representative formalin-fixed paraffin-embedded archival tissue blocks from 62 radical prostatectomy specimens harboring prostate cancer of ductal (n=51), cribriform Gleason pattern 4 acinar (n=27), and noncribriform Gleason pattern 4 acinar adenocarcinoma (n=48) were included in this study. Immunohistochemistry was performed using a triple stain of AMACR, p63, and HMWCK. Only staining that was moderate or strong was considered positive. The percentage of staining intensity and the presence of occasional basal cells positive with p63/HMWCK were recorded in each histologic type of prostatic adenocarcinoma. Seventy-seven percent of ductal prostatic adenocarcinoma, 67% of cribriform acinar prostatic carcinoma, and 81% of noncribriform acinar prostatic carcinoma showed positive staining for AMACR. There was no statistically significant difference between AMACR staining among the 3 histologic types, although there was a trend for noncribriform acinar prostatic carcinoma to have greater expression of AMACR than cribriform acinar prostatic carcinoma (P=0.07). Staining was often heterogeneous, varying in staining intensities within the same histologic type of carcinoma. Basal cells were detectable by p63 and HMWCK in a patchy fashion in 31.4% (16/51) of ductal and 29.6% (8/27) of cribriform acinar carcinomas compared with 2.1% (1/48) of noncribriform acinar carcinomas. In summary: (1) the majority of prostatic ductal and cribriform acinar carcinomas strongly expressed AMACR, however, subpopulations of these prostatic carcinoma were either completely negative or only weakly positive; (2) AMACR staining was often heterogeneous in intensity in the same histologic type of tumor, even within the same case; (3) patchy basal cell staining in noncribriform acinar prostatic carcinoma is rare. In contrast, remnants of basal cells identified by p63/HMWCK were seen in a patchy fashion in a significant minority of both ductal and cribriform acinar prostatic adenocarcinoma, which most likely represents intraductal spread of tumor.

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.

Proliferative lesions of prostate: a multivariate approach to differential diagnosis

Prostatic needle biopsies from 142 patients were studied: 61 cases were "benign", 19 atypical small acinar proliferation, 31 high-grade prostatic intraepithelial neoplasia, and 31 adenocarcinoma. Using univariate analysis of 46 previously described morphological features, 16 variables were selected, which were followed by multivariate discriminant analysis. Of these parameters, seven (glandular fusion, crystalloids, nucleolomegaly, papillary architecture, visibility of basal cell layer, areas of normal luminal cell nucleus/cytoplasm ratio and areas of high luminal cell nucleus/cytoplasm ratio) remained significant in discriminating the groups. Multivariate analysis selected a small panel of histological features as those most helpful in the differential diagnosis of proliferative lesions in prostate biopsies.

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.

Molecular Techniques and Prostate Cancer Diagnostic

Recent advances in molecular techniques have given the opportunity to assess genomic and proteomic alterations comprehensively and rapidly in routinely acquired tissue samples. In particular, new markers derived from qualitative and quantitative DNA, RNA, and protein analysis have provided additional objective information to supplant and extend the morphologic interpretations and have been increasingly integrated into the final surgical pathology diagnosis. In this review several recently developed molecular techniques are described and illustrated. The focus is on prostate cancer diagnostics, as an example of their application.