Does prostatic ductal adenocarcinoma exist?

Chromosomal imbalances, loss of heterozygosity, and immunohistochemical expression of TP53, RB1, and PTEN in intraductal cancer, intraepithelial neoplasia, and invasive adenocarcinoma of the prostate

Recent studies have shown that intraductal prostate carcinoma (IDC-P) should be considered as a separate lesion distinct from prostatic intraepithelial neoplasia (PIN). The purpose of the present study was to analyze the genetic relationship between benign prostatic tissue, PIN, invasive cancer, IDC-P, and extracapsular tumor tissue to get further information about the role of IDC-P in the development of prostate cancer. One hundred five radical prostatectomy specimens were investigated immunohistochemically, 77 cases were analyzed by PCR for LOH of the tumor suppressor genes TP53 and RB1, and 11 cases of IDC-P and 10 cases of PIN were investigated using comparative genomic hybridization (CGH). At CGH analysis, IDC-P showed several chromosomal imbalances in contrast to PIN, where no changes were found. We could demonstrate a significant increase of LOH for TP53 or RB1 from benign tissue to PIN. LOH of both TP53 and RB1 were frequently found in IDC-P (52%), followed by extracapsular tumor tissue (44%), invasive cancer (24%), PIN (19%), and benign prostatic tissue (17%). Increased immunohistochemical expression was found in invasive cancer for TP53, RB1, and for PTEN. Decreased expression could be demonstrated in extracapsular tumor tissue and in IDC-P. Our results indicate that IDC-P in general follows the genetic pathway from normal epithelium over PIN lesion. IDC-P represents a separate prostatic lesion and should be graded as a poorly differentiated carcinoma.

Carbohydrate antigen 19-9-positive prostatic ductal adenocarcinoma effectively treated with cisplatin and gemcitabine

We performed a radical retropubic prostatectomy on a 59-year-old male patient who was diagnosed with prostatic carcinoma. Pathological findings revealed a ductal adenocarcinoma in the left lobe of the prostate, and a conventional well-differentiated adenocarcinoma in the right lobe. Immunohistochemistry revealed that CA19-9 was positive in the ductal adenocarcinoma, and prostate-specific antigen was positive in the conventional well-differentiated adenocarcinoma. Since there was an increase in the level of serum CA19-9, which had decreased postoperatively, along with the appearance of local recurrence and bone metastasis, we treated the patient with cisplatin and gemcitabine. As a result, the level of serum CA19-9 was normalized and a reduction of the metastatic focus was observed.

Primary prostatic central zone adenocarcinoma

The central zone (CZ) of the prostate is embryologically, anatomically, and histologically distinct. High-grade prostatic intraepithelial neoplasia (HGPIN) and prostatic adenocarcinoma (PAC) are encountered in the CZ, but have not been well studied. Non-CZ PAC that spread into the CZ can mimic CZ PAC. We reviewed 300 consecutive radical prostatectomies performed for PAC to identify cases showing PAC and HGPIN in the CZ. There were nine PAC (3%) localized predominantly in the CZ, presenting as a single tumor nodule (8/9) and associated with 4.5+/-1.1 foci HGPIN in the CZ and with only 1.7+/-0.5 foci in the PZ. Of the 291 non-CZ PAC, 24 cases showed satellite tumor nodules in the CZ, and 92 cases demonstrated secondary contiguous spread to the CZ. As compared to the non-CZ PAC, CZ PAC tended to have lower tumor volume, but had higher Gleason scores (8.10+/-0.6 vs. 6.30+/-0.7, p<0.05), as well as a higher incidence of a ductal carcinoma component (6/9), higher rates of capsular penetration, positive resection margins (4/9), and seminal vesicle spread (2/9). The CZ HGPIN associated with CZ PAC demonstrated cells with prominent nucleoli and formed either slender papillary structures or cribriform/solid patterns. The correlating positive biopsy cores were from the mid portion or from base of prostate and contained foci of HGPIN in 4/7 cases. The CZ PAC is characteristically accompanied by more foci of HGPIN in the CZ than in non-CZ and is associated with high grade and high stage. Preoperative diagnosis of CZ PAC can be suspected due to the histopathological features in the biopsy and is important to improve the free surgical resection rate.

A proposal on the identification, histologic reporting, and implications of intraductal prostatic carcinoma

CONTEXT

Prostatic adenocarcinoma growing within acinar-ductal spaces (intraductal carcinoma) in contrast to high-grade prostatic intraepithelial neoplasia (HG-PIN) impacts negatively on patient outcome. There is currently no generally accepted definition of this lesion nor is it classified in the current prostate cancer grading system (Gleason).

OBJECTIVE

To define intraductal carcinoma of the prostate (IDC-P) with major and minor diagnostic criteria that clearly separate it from HG-PIN. The implications of such a lesion are discussed with proposals to incorporate this entity into the Gleason grading system.

DATA SOURCES

We reviewed all published data referring to intraductal spread of prostate carcinoma. Articles discussing endometrial, endometrioid, and ductal carcinoma are included.

CONCLUSIONS

Intraductal carcinoma of the prostate as defined by major criteria that include enlarged gland structures, neoplastic cells spanning the gland lumen, central comedonecrosis, and further supported by minor diagnostic criteria including molecular biological markers, separate this entity from HG-PIN. Despite its perimeter basal cells, IDC-P should be interpreted as biologically equivalent to Gleason pattern 4 or 5 adenocarcinoma. Several hypotheses are proposed as to the evolution of IDC-P, which is almost always a late event in prostate carcinoma progression. Diagnosis of IDC-P on needle biopsy should prompt therapeutic intervention rather than surveillance or repeat biopsy, as is the case for HG-PIN.

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.

My approach to intraductal lesions of the prostate gland

The morphologically heterogeneous (intra)ductal lesions of the prostate frequently present a diagnostic challenge, particularly when found within prostate needle biopsies. By current convention, all high-grade intra-acinar and intraductal neoplastic lesions of prostatic origin fall under the diagnostic umbrella term: prostatic intraepithelial neoplasm (PIN). Although a long-standing contentious issue, some lesions currently adhering to the diagnostic criteria of PIN may actually represent the intraductal spread of (generally high grade) invasive cancer. Illustrating this fact, the well-described ductal subtype of prostatic adenocarcinoma is frequently associated with conventional-type acinar adenocarcinoma, and has a tendency to propagate within adjacent intact prostatic ducts. Clearly, the misdiagnosis of lesions representing invasive disease as preinvasive has the potential for unfavourable clinical sequelae. As yet, however, many of these lesions have escaped the establishment of reliable morphologic criteria or immunohistochemical differentiation for diagnosis. By defining stringent architectural and cytonuclear features specific for each of these lesions, it may be feasible to separate potentially sinister lesions from the subset of traditional (preinvasive) PIN lesions with limited clinical urgency. This review discusses the (intra)ductal lesions of the prostate, along with their differential diagnoses. Given the current state of knowledge, a pragmatic approach to their effective reporting is outlined, taking into consideration the clinical implications, as well as current guidelines for treatment and follow-up.

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.

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.

Canine prostate carcinomas express markers of urothelial and prostatic differentiation

Prostate carcinoma and transitional cell carcinoma (TCC) occur in the prostate gland of older dogs and have morphologic similarities when evaluated by light microscopy. The dog is a commonly used animal model for studying human prostate carcinoma; therefore, it is important to accurately differentiate canine prostate carcinomas from TCCs. We investigated whether keratin 7 (K7) and arginine esterase (AE) would aid differentiation of canine prostate carcinoma from TCC. K7 expression was evaluated in normal and neoplastic canine prostate and bladder tissues using immunohistochemistry. The expression of AE messenger ribonucleic acid (mRNA) in normal and neoplastic canine prostate and bladder was detected using northern blots and reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, AE enzyme activity was measured in normal and neoplastic canine prostate and bladder tissues. We found marked similarities in K7 expression in prostate carcinomas and TCCs. AE mRNA was present in high levels in normal prostatic tissue but was reduced in prostate carcinoma by northern blot assay. Nested RT-PCR detected AE mRNA both in TCCs (13 of 15) and in prostate carcinomas (13 of 13). Enzymatic activity of AE was high in normal prostate gland and in some prostate carcinomas, whereas normal bladder and TCCs produced lower levels of AE. In conclusion, K7 and AE cannot be used to differentiate TCC from prostate carcinoma in dogs.

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.

High-grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely preinvasive stage of adenocarcinoma, almost two decades after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen (PSA) concentration or its derivatives and cannot be detected by current imaging techniques, including ultrasound. Most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype, which are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.

Contemporary pathology of prostate cancer

In less than 20 years since the introduction of serum PSA and the spring-loaded 18-gauge prostatic biopsy needle, pathologists have adjusted to the limited tissue requirements of narrow needle specimens to apply criteria for diagnosis and grading of prostate cancer, borrowing from lessons learned from radical prostatectomies. Substantial gains have been made during this period in the understanding of precancerous lesions, mimics of malignancy, the criteria for minimal cancer, variants of cancer, and treatment-induced changes. The light microscopic findings remain the criterion standard for diagnosis against which all new techniques should be measured. Numerous findings have proven to be of value, including simple quantitation of histopathologic features, cancer volume, perineural invasion, and others.

Ductal adenocarcinoma of the prostate associated with prostatic multilocular cyst

A case is reported here of ductal adenocarcinoma of the prostate forming a multilocular cyst, which responded well to androgen deprivation therapy.

Prostatic carcinosarcoma: a case originating in a previous ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate is a variant of prostatic carcinoma that appears to originate in the ducts of the prostate. Carcinosarcoma of the prostate is an uncommon and aggressive tumour composed of an intimate admixture of adenocarcinoma and sarcoma. In this report we describe the clinicopathological and immunohistochemical characteristics of a case of prostatic carcinosarcoma that appeared in a 66-year-old man who had had a ductal adenocarcinoma of the prostate diagnosed 3 years previously. The patient died of the disease 3 months after the carcinosarcoma was diagnosed. This case may represent further evidence of the dedifferentiation theory in the origin of carcinosarcoma. The case also illustrates that this dedifferentiation may occur from any type of prostatic carcinoma.

Morphological identification of the patterns of prostatic intraepithelial neoplasia and their importance

High grade prostatic intraepithelial neoplasia (PIN) is the most likely precursor of prostatic carcinoma. PIN has a high predictive value as a marker for carcinoma, and its identification in biopsy specimens warrants repeat biopsy for concurrent or subsequent carcinoma. The only methods of detection are biopsy and transurethral resection; PIN does not greatly raise the concentration of serum prostate specific antigen (PSA) or its derivatives, does not induce a palpable mass, and cannot be detected by ultrasound. Androgen deprivation decreases the prevalence and extent of PIN, suggesting that this form of treatment might play a role in chemoprevention. Radiotherapy is also associated with a decreased incidence of PIN.

Prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely pre-invasive stage of adenocarcinoma, a decade after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen concentration or its derivatives and cannot be detected by ultrasound. Most studies suggest that most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype that are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.