Endometrioid adenocarcinoma of the prostate: a clinicopathologic and immunohistochemical study

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.

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.

Advanced prostatic ductal carcinoma in a patient with a long survival time following a total pelvis exenteration: A case report

Ductal adenocarcinoma of the prostate (DAP) is a rare variant of prostate cancer, and has poorly-identified clinical characteristics. Few cases have been previously reported in Chinese males and DAP is more commonly reported in Caucasian males over 70-years of age. In the present study, a 55-year-old Chinese male patient that demonstrated typical lower urinary tract symptoms and normal prostatic-specific antigen levels underwent a transurethral resection of the prostate. The patient was subsequently diagnosed with DAP. A total pelvis exenteration was then conducted successfully. During the 40-month follow-up, the patient remained progression-free. A review of the literature was conducted in order to assess the clinical course, diagnosis, prognosis and optimal management for DAP. The review indicated that DAP is more likely to demonstrate an aggressive clinical course and an unfavorable prognosis; therefore, once the diagnosis has been confirmed, an aggressive management strategy is recommended for the patient, even in the case of metastatic disease.

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.

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.

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.

pS2 (TFF1) expression in prostate carcinoma: correlation with steroid receptor status

pS2 or TFF1 is a member of the trefoil factor family, which is distributed throughout the gastrointestinal tract in both normal and diseased tissues. It is also considered to be one of the major estrogen-regulated proteins and an indicator of estrogen receptor (ER) functionality. pS2 has previously been investigated in benign and malignant prostate lesions with little information about its relationship to steroid receptor status. Our purpose was to correlate pS2 expression with steroid receptor status (ER alpha and progesterone receptor (PR)) and other pathologic variables in prostate carcinoma. 15 benign prostate hyperplasia (BPH) and 47 prostate carcinoma cases were investigated by means of immunohistochemistry for pS2, ER and PR expression. 80% of BPH showed pS2 cytoplasmic immunoreactivity in hyperplastic acini and about half of these cases also exhibited nuclear staining decorating basal or both basal and luminal nuclei. pS2 was highly expressed in prostate carcinoma (91.4%) with both cytoplasmic and nuclear patterns of staining. The latter pattern was significantly associated with carcinoma having a low Gleason score (p=0.02). pS2 lacked any significant correlation with steroid receptor status, stage or grade. Univariate survival analysis revealed a significant impact of stage (p=0.03) and nodal status (p<0.0001) on patient outcome. The diagnostic value of pS2 expression in prostate carcinoma validated 74.19% accuracy, 91.48% sensitivity and 78.18% positive predictive value. The high sensitivity of pS2 expression in prostate carcinoma could make it a suitable marker for diagnosis of prostate carcinoma, especially in metastatic cases of unknown origin. The absence of correlation and dissimilarity in immunolocalization between pS2 and ER alpha leads to the assumption that ER alpha could not be the regulatory protein for pS2 and may raise questions about the functionality of ER alpha in prostate. The nuclear pattern of pS2 immunoreactivity either in benign or malignant prostatic lesions is similar to the published data on ER beta distribution and could also identify a subset of carcinoma patients with a favorable prognosis.

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.

Prostate carcinoma with testicular or penile metastases. Clinical, pathologic, and immunohistochemical features

BACKGROUND

Despite the proximity, prostate carcinoma seldom metastasizes to the penis or testis.

METHODS

In the current study, the authors retrospectively examined the clinical history of 12 patients with prostate carcinoma and testicular or penile metastases. Pathologic review and immunohistochemical staining were performed on tumors from eight of these patients.

RESULTS

Patients with prostate carcinoma and testicular or penile metastasis responded to androgen ablative therapy (median duration, 33 months). They were predisposed to developing persistent or recurrent urinary symptoms and visceral metastases. Six of 9 evaluable patients had elevated serum carcinoembryonic antigen levels (> 6 ng/mL), whereas 2 of 10 patients had low or undetectable serum prostate specific antigen levels (< 4 ng/mL). In seven of the eight patients for whom specimens were available, the tumors were found to contain histologic features that were compatible with a diagnosis of ductal or endometrioid adenocarcinoma of the prostate.

CONCLUSIONS

Patients with prostate carcinoma and testicular or penile metastases have unique clinical and pathologic characteristics. Many of these patients' tumors are compatible with a subtype of prostate carcinoma known as ductal adenocarcinoma. Further studies need to be performed to elucidate the biologic basis of the various histologic subtypes of prostate carcinoma.

Urinary cytologic findings in patients with benign and malignant adenomatous polyps of the prostatic urethra

CONTEXT

Urethral adenomatous polyps with prostatic epithelium (also known as benign prostatic epithelial polyps [BPEPs]) are a documented cause of hematuria, dysuria, and hematospermia, conditions that may prompt cytologic evaluation of urine.

DESIGN

The urine cytologic test findings in 5 cases of biopsy-proven BPEPs and in 1 case of prostatic ductal adenocarcinoma (PDA) that presented as a urethral polyp were retrospectively evaluated. Immunocytochemical stain for prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), and high-molecular-weight cytokeratin (34betaE12) were used in evaluation of the lesions.

RESULTS

In 4 of 5 cases of BPEPs, clusters of bland columnar cells with uniform, oval nuclei were seen. Positive immunostaining for PSA and PAP confirmed the prostatic origin of the clusters in 2 cases. One urine sample contained abundant goblet cells and extracellular mucin, consistent with intestinal metaplasia coexisting in the bladder biopsy specimen. The urine sample in the fifth case of BPEPs contained no columnar cells. The last case had multiple urine cytologic evaluations that demonstrated PSA-positive, malignant-appearing clusters of columnar cells. A biopsy specimen of the polyps was described as a high-grade prostatic intraepithelial neoplasm in adenomatous polyp. However, in this patient, PDA was diagnosed on transurethral resection of the prostate specimen 4 years after the initial urine cytologic test.

CONCLUSION

Benign prostatic epithelial polyps should be considered in the differential diagnosis of clusters of columnar cells in urine cytologic testing. Cells with malignant nuclear features should instigate a careful search for a (prostatic) neoplasm, which may present as urethral polyps (e.g., PDA). Stains for PSA or PAP are useful adjuncts in differential diagnosis of this condition.

[Mucinous carcinoma of the prostate: critical review of Elbadawi's criteria]

OBJECTIVES

We present our experience on prostatic mucinous adenocarcinoma and at once we practice an actualization and a critical review of Elbadawi's criteria.

METHODS

After reviewing 206 prostatic carcinomas diagnosed in our hospital, we describe one case that fulfill criteria for being considered a prostatic mucinous adenocarcinoma. We also carry out a wide literature review trying to define anew the including criteria of this tumour by the light of modern knowledge and technology.

CONCLUSIONS

We think that for accepting a tumour as a prostatic mucinous adenocarcinoma, this have to fulfill the following criteria: 1. "More than 25% of a significative tumoral sample is mucinous pattern and present, single or clustered, tumour cells floating in immunohistochemically probed, acidic and neutral, mucin lakes". 2. "Tumour is Gleason 3-4 cribiform pattern with direct transition to colloid areas and usually coexist with classic adenocarcinoma but papillary growth patterns should be excluded. Tumour may contain a moderate proportion of signet-ring cells". 3. "Immunohistochemical staining for PSA have to be strongly positive in both, cribiform and mucinous, areas". 4. "Those PSA nonreactive, or only focally positive, mucinous adenocarcinomas, could be labeled as prostatic only when local or distant mucinous carcinomas are ruled out".

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.

Ductal carcinomas of the prostate: a clinicopathological and immunohistochemical study

OBJECTIVES

To confirm the expression of prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) in ductal carcinomas of the prostate, and to analyse p53, Ki67, oestrogen (ER) and androgen (AR) receptors in these tumours.

MATERIALS AND METHODS

Paraffin-embedded samples from 12 patients with ductal carcinoma of the prostate were assessed for pattern, mitotic count and the presence of a microacinar carcinoma component. There were six pure ductal and six mixed microacinar and ductal carcinomas. Sections were stained immunohistochemically for the expression of PSA, PAP, Ki67, p53, AR and ER. Clinical data were obtained from case notes.

RESULTS

Six of the ductal tumours had a papillary pattern whilst the others had a cribriform appearance. The mitotic rates in the ductal areas were high in the tumours from eight of the 12 patients. PSA and PAP immunohistochemistry were positive in all the cases. No ER immunoreactivity was found in any of the patients. Ten of the ductal tumours showed strong reactivity with AR, the other two were weakly positive; two of the tumours were strongly positive for p53 protein. All the ductal carcinomas expressed Ki67, three having > 25% nuclear marking. One patient who was strongly positive for p53 and had a high Ki67 score survived only one year after diagnosis. Survival ranged from 1 to 13 years after diagnosis.

CONCLUSION

This study confirms the expression of PSA and PAP in ductal carcinomas of the prostate. The percentage of tumours expressing p53 was similar to that published for high-grade microacinar carcinomas. The results for Ki67 suggest that ductal tumours have higher scores than microacinar tumours, but further studies are required to ascertain if this is significantly different. As half the patients with ductal tumours had co-existent microacinar tumours, we advise transrectal prostatic biopsies in patients diagnosed with pure ductal carcinomas on transurethral resection specimens, to exclude high-grade microacinar carcinomas. The presence of AR and the lack of ER in all the ductal carcinomas confirms that these tumours are prostatic in origin and should be treated with antiandrogen therapy.

Distribution pattern of basal cells detected by cytokeratin 34 beta E12 in primary prostatic duct adenocarcinoma

Primary prostatic duct adenocarcinoma, initially labeled as endometrioid carcinoma of the prostate, is a rare neoplasm that displays exophytic growth into the prostatic urethra with involvement of prostatic ducts. Because this tumour arises from preexisting epithelia, there is a possibility that a remnant basal epithelium may be seen in association with these tumours. If this hypothesis is correct, then prostatic duct adenocarcinoma may possibly be mistaken for high-grade prostatic intraepithelial neoplasia (PIN) on needle biopsies. The distribution of basal cells in this tumour has not been described previously. Nine cases of prostatic duct adenocarcinoma and prostatic adenocarcinoma with focal ductal differentiation were studied immunohistochemically with antibodies specifying cytokeratin 34 beta E12, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP). All cases were positive for PSA and PAP. In some areas of the tumour in eight cases there was a continuous and discontinuous layer of basal cells surrounding islands of carcinoma. This was found with cribriform, comedo, solid, and papillary components of ductal type adenocarcinoma. It is necessary to be aware of the presence of basal cells in association with primary prostatic duct adenocarcinoma. Differentiation of high-grade PIN from this lesion should depend on complex architectural characteristics and Cytologic features rather than presence of a basal cell layer. This finding confirms that the solid, cribriform, papillary, and comedo components initially grow intraluminally within ducts before invasion into surrounding stroma occurs.

Papillary cystadenocarcinoma of the prostate

We report a papillary adenocarcinoma with cystic formation in the prostate of a 64-year-old man, who presented with gross hematuria and pollakisuria. Immunohistochemically, the origin of this tumor was considered to be the prostate gland. Interestingly, this tumor grew into the muscle layer of the bladder with large glandular formation but no stromal changes.