A 74-year-old man was suffering from nine months of perineal pain and progressive worsening of urinary symptoms including nocturia and urgency. His prostate-specific antigen (PSA) levels were 1.48 ng/mL at the time of referral. Initially, a differential diagnosis of prostatitis or seminal vesicle inflammation was made, and four weeks of antibiotics were prescribed, which were later extended to six weeks due to failure of symptoms to resolve. Magnetic resonance imaging (MRI) of the prostate was then conducted. The impression was that there was ejaculatory duct obstruction caused by enlarged seminal vesicles with no evidence of significant prostate cancer. The prostate-specific antigen density (PSAd) was 0.04, and the prostate imaging reporting and data system (PIRADS) score was I-II. A CT chest with contrast was conducted for further investigation of pulmonary nodules found on the CT urogram. It revealed multiple calcified pulmonary nodules which were suspicious of malignancy. A CT-guided biopsy of one of the pulmonary nodules was taken, and histopathological analysis revealed a mucinous adenocarcinoma. A transurethral resection of the prostate (TURP) was then performed. Histopathological analysis of the prostatic surgical specimen revealed invasive mucinous adenocarcinoma. Based on the findings, a diagnosis of mucinous adenocarcinoma of the prostate with atypical lung metastasis without osseous or regional lymph node involvement was made, stage T4 N0 M1a. The patient is currently on a treatment regimen consisting of carboplatin, pemetrexed, and pembrolizumab.

We present a case of mucinous adenocarcinoma of the prostate with testicular and lung metastases following robot-assisted radical prostatectomy, androgen deprivation therapy, and radiotherapy.

A 73-year-old man with a prostate-specific antigen level of 4.3 ng/mL was diagnosed with prostate cancer. Following the robot-assisted radical prostatectomy, the pathological diagnosis was mucinous adenocarcinoma of the prostate (pT3bpN0, Gleason score of 4 + 4). Salvage hormonal therapy and irradiation were performed after the prostatectomy. Enlargement of the left testis was noted, and 28 months after prostatectomy, computed tomography detected a left testicular tumor and nodular lesions in the bilateral lungs. The histopathological diagnosis of left high orchiectomy was metastasis of a mucinous adenocarcinoma of the prostate. Chemotherapy with docetaxel followed by cabazitaxel was initiated.

Mucinous prostate adenocarcinoma with distal metastases following prostatectomy has been managed for longer than 3 years with multiple treatments.

Prostatic mucinous carcinoma (MC) and prostatic signet ring cell carcinoma are two variants of prostate cancer. MC has a higher overall survival time among all variants, while signet ring cell carcinoma is associated with lower survival time relative to other carcinomas. Only a small proportion of prostatic MC may contain signet ring cells. Over the last several decades there were only 12 patients that were documented in two studies.

We report on a 64-year-old man who was diagnosed with prostatic MC after he received a robotic-assisted laparoscopic radical prostatectomy in the West China Hospital. After robotic-assisted laparoscopic radical prostatectomy, the patient underwent three successive transurethral resections of bladder tumors. Pathological examination of the first transurethral resection of bladder tumors specimen indicated that the neoplasm was prostatic MC that had metastasized to the urinary bladder. The subsequent two transurethral resections of bladder tumors indicated the presence of prostatic mucinous carcinoma with signet ring cells.

This case report aimed to share the management experience, raise awareness, and highlight the importance of multidisciplinary cooperation of prostatic mucinous carcinoma with signet ring cells.

Mucinous carcinoma is an unusual subtype of prostate cancer. In particular, mucinous adenocarcinomas identified following transurethral resection of the prostate (TURP) are extremely rare. The present study conducted are retrospective analysis of two cases of mucinous carcinoma of the prostate, which were incidentally diagnosed following histological examination of the specimens obtained by TURP. The pathological findings, treatment regimen and clinical course of the two cases were reviewed. One of the patients, whose surgical specimen stained positive for carcinoembryonic antigen (CEA) and negative for prostate-specific antigen (PSA), did not respond to androgen deprivation therapy (ADT). However, the other patient, whose specimen stained positive for PSA, was responsive to ADT, resulting in a better prognosis. Therefore, absence of PSA staining in surgical prostate specimens may be associated with a poor response to ADT and a worse prognosis.

Primary mucinous tumors and secondary tumors involving the prostate gland are relatively uncommon, however they have important diagnostic, therapeutic, and prognostic implications. The primary mucinous tumors of the prostate include mucinous (colloid) adenocarcinoma of the prostate, prostatic adenocarcinoma with mucinous features, and mucinous adenocarcinoma of the prostatic urethra (mucin-producing urothelial-type adenocarcinoma of the prostate). Mucinous adenocarcinoma of the prostate is defined as a primary prostatic acinar tumor characterized by the presence of at least 25% of the tumor composed of glands with extraluminal mucin. This diagnosis can only be made in radical prostatectomy specimens. Recent studies have shown that these tumors have a similar or in some cases better prognosis than conventional prostatic adenocarcinoma treated by radical prostatectomy. The preferred terminology for tumors that are composed of <25% extraluminal mucinous component in radical prostatectomy specimens is 'prostatic adenocarcinoma with mucinous features.' All cases of prostatic adenocarcinoma with extraluminal mucinous components in prostate needle core biopsies or transurethral resection of the prostate specimens are also referred to as 'prostatic adenocarcinoma with mucinous features.' Mucinous adenocarcinoma of the prostatic urethra (mucin-producing urothelial-type adenocarcinoma of the prostate) as the name implies, does not arise from prostatic acini or ducts, and is a distinct entity that arises from the prostatic urethra usually from urethritis glandularis or glandular metaplasia with malignant transformation, and is analogous to adenocarcinoma with mucinous differentiation arising from the urinary bladder. This tumor is aggressive and has a relatively poor prognosis. The most common secondary tumors that arise from adjacent organs and spread (direct extension or metastasis) to the prostate gland, include urothelial carcinoma of the bladder and colorectal adenocarcinoma. Other secondary tumors that may involve the prostate include metastatic epithelial tumors from several other sites, malignant melanoma and soft tissue tumors.

This review article will cover the evolution of grading of prostate cancer from the original Gleason system in the 1960-1970s to a more patient-centric grading system proposed in 2013 from a group at Johns Hopkins Hospital, validated in 2014 by a large multi-institutional study, and subsequently accepted by the World Health Organization (WHO), College of American Pathology (CAP), and the AJCC TNM system. Covered topics include: (1) historical background; (2) 2005 and 2014 International Society of Urological Pathology Grading Conferences; (3) Description of Gleason patterns; (4) new approaches to display Gleason grades; (5) grading variants and variations of acinar adenocarcinoma; (6) reporting rules for Gleason grading reporting secondary patterns of higher grade when present to a limited extent; (7) reporting secondary patterns of lower grade when present to a limited extent; (8) reporting percentage pattern 4; (9) general applications of the Gleason grading system; (10) needle biopsy with different cores showing different grades; (11) radical prostatectomy specimens with separate tumor nodules; and (12) a new grading system for prostate cancer.

This review focuses on histopathological aspects of carcinoma of the prostate. A tissue diagnosis of adenocarcinoma is often essential for establishing a diagnosis of prostate cancer, and the foundation for a tissue diagnosis is currently light microscopic examination of hematoxylin and eosin (H&E)-stained tissue sections. Markers detected by immunohistochemistry on tissue sections can support a diagnosis of adenocarcinoma that is primary in the prostate gland or metastatic. Histological variants of carcinoma of the prostate are important for diagnostic recognition of cancer or as clinicopathologic entities that have prognostic and/or therapeutic significance. Histological grading of adenocarcinoma of the prostate, including use of the 2014 International Society of Urological Pathology (ISUP) modified Gleason grades and the new grade groups, is one of the most powerful prognostic indicators for clinically localized prostate cancer, and is one of the most critical factors in determination of management of these patients.

Adenocarcinoma of prostate with mucinous differentiation arising in the male urethra is extremely rare, with only 21 cases reported in the previous literature. A diagnosis of mucin-producing urothelial carcinoma of the prostate is based on the pathology, immunohistochemistry, and clinical examination by excluding the secondary adenocarcinoma of the prostate. We present a case of unexpected mucinous urothelial carcinoma of prostate with co-existing inverted papilloma of bladder in a 57-year-old man. The patient underwent transurethral resection of the prostate (TURP) and transurethral resection of a bladder tumour (TUR-Bt), and the pathologic result showed mucinous prostate carcinoma and bladder inverted papilloma. Immunohistological stain was negative for prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and P63, but positive for cytokeratin 7 (CK 7), CK 20, clone 34βE12 and P504S. A complete endoscopic examination was performed to exclude the secondary adenocarcinoma of prostate. This case illustrates the clinical and pathological features of a rare and unexpected mucin-producing urothelial carcinoma of prostate in a bladder neoplasm patient.

Introduction. Mucinous adenocarcinoma of the prostate is a rare variant of prostate cancer. Its malignant potential and the clinical course of the affected patients remain, by and large, controversial. No data exist about the course of metastatic mucinous adenocarcinoma of the prostate. Case Presentation. This case report describes the excellent clinical course of a 68-year-old patient with metastatic mucinous adenocarcinoma of the prostate, treated by radical prostatectomy, irradiation, and androgen deprivation. Conclusion. In our case, mucinous adenocarcinoma of the prostate does not appear to behave differently than acinar prostate cancer. Its malignant potential is dependent on its Gleason score.

Mucin-producing tumors of the prostate include both primary and secondary tumors with mucinous differentiation or features involving the prostate gland. These tumors are relatively rare and have variable prognostic and therapeutic implications. Primary mucinous (colloid) adenocarcinoma of the prostate is defined as prostatic adenocarcinoma with mucinous differentiation involving 25% or more of the entire tumor. Another primary tumor of the prostate that may have mucinous features is primary mucin-producing urothelial-type adenocarcinoma of the prostate (mucinous prostatic urethral adenocarcinoma). Primary mucin-producing urothelial-type adenocarcinoma of the prostate is a distinct entity that typically arises from the prostatic urethra possibly from urethritis glandularis or glandular metaplasia with malignant transformation, and it is analogous to adenocarcinoma with mucinous differentiation arising from the urinary bladder. Signet ring cell tumors of the prostate, though rare, may also have mucinous features. Secondary tumors with mucinous differentiation that may involve the prostate include adenocarcinomas of the urinary bladder and colorectum. Pathologists should also be aware of mucin-producing tumor-like lesions involving the prostate, including mucinous metaplasia, and benign Cowper glands that may mimic malignancy. Herein we present an updated and comprehensive review of the clinicopathologic, immunohistochemical, molecular, and prognostic features of mucinous tumors and tumor-like lesions involving the prostate gland, with emphasis on mucinous prostatic adenocarcinoma and its mimickers, including potential diagnostic pitfalls.

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.

Endobronchial metastasis from prostate cancer is a rare neoplasm which metastasizes to the proximal central or subsegmental bronchus, in a bronchoscopically visible range. We present a 72-year-old man with a left superior lobar bronchus mass, intrapulmonary metastases, and bone metastases, mimicking primary lung bronchogenic carcinoma. Increasing tPSA, decreasing fPSA/tPSA level, and prostatic puncture pathology proved prostate cancer. Pathomorphology and immunohistochemistry of the mucosa specimen with P504S, PSA revealed the diagnosis of pulmonary metastases from prostate cancer. The patient was treated by hormonal treatment and chemotherapy. He was in remission thirteen months after diagnosis.

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.

Prostatic urothelial-type adenocarcinoma arises through a process of glandular metaplasia of the prostatic urethral urothelium and subsequent in situ adenocarcinoma sometimes associated with villous adenoma. These prostatic adenocarcinomas are analogous to nonurachal adenocarcinomas arising in the bladder from cystitis glandularis. Only 2 cases of urothelial-type adenocarcinoma from an institution other than our own have been previously described. The distinction between adenocarcinoma from another organ secondarily involving the prostate, usual adenocarcinoma of the prostate, and prostatic urothelial-type adenocarcinoma can present a significant diagnostic challenge and has significant therapeutic implications. Fifteen cases of prostatic urothelial-type adenocarcinoma were retrieved from the consult files of one of the authors. Mean patient age at diagnosis was 72 years (range 58 to 93 y). All men had negative colonoscopies, clinically excluding a colonic primary. Bladder primaries were ruled out clinically or pathologically in radical resection specimens. Follow-up was available on all men with a mean of 50.3 months (range 2 to 161 mo). All men presented with urinary obstruction symptoms with 3 (20%) also having mucusuria and 2 (13.3%) also having hematuria. Four men (26.7%) developed metastatic disease and 8 (53.3%) died of disease. In 8/15 (53%) cases, glandular metaplasia of the prostatic urethra and contiguous transition to adenocarcinoma were identified. Multiple histologic patterns were observed including dissection of the stroma by mucin pools 15/15 (100%), villous features 7/15 (47%), necrosis 2/15 (13.3%), signet ring cells 3/15 (20%), perineural invasion 1/15 (6.7%), focal squamous differentiation 1/15 (6.7%), and a granulomatous inflammatory response 1/15 (6.7%). Immunohistochemical stains were negative for prostate specific antigen, prostate specific acid phosphatase, CDX2, and beta-catenin in all cases. Stains were positive for high molecular weight cytokeratin in 12/12 cases (100%), and CK7 and CK20 in 10/12 cases (83.3%). Prostatic urothelial-type adenocarcinoma is a rare aggressive cancer arising in the prostate. The differential diagnosis includes conventional prostatic mucinous adenocarcinoma and secondary infiltration from a colonic or bladder adenocarcinoma. Immunohistochemistry for prostate specific antigen, prostate specific acid phosphatase, and high molecular weight cytokeratin along with morphology can help rule out conventional prostate carcinoma. beta-catenin, CDX2, and clinical studies are needed to rule out colonic adenocarcinoma. As prostatic urothelial-type adenocarcinoma is entirely analogous to bladder adenocarcinoma in both, its morphology and immunophenotype, only clinical studies or in some cases pathologic examination of the cystoprostatectomy specimen can exclude infiltration from a primary bladder adenocarcinoma.

To report a series of patients with mucinous (colloid) adenocarcinoma (MC) at prostatectomy who were treated at a single institution from 1987 to 2005. MC is a rare form of prostate cancer reported in some cases to have a more aggressive clinical course than conventional adenocarcinoma (AC).

Radical prostatectomy specimens with mucinous features were identified from a database of 3613 consecutive patients. Each case was reviewed again by a single pathologist who confirmed the diagnosis of MC in 14 patients. MC was defined by the presence of pools of extracellular mucin in more than 25% of the tumor. Eighteen additional cases were identified in which the mucinous component occupied only a small portion of the tumor and were referred to as AC with focal mucin (AFM). The biochemical and overall survival of 26 patients with MC or AFM who had completed > or = 6 months of follow-up was analyzed using Kaplan-Meier estimates.

No patients with MC or AFM died of disease, and 11 (91.7%) of 12 patients with MC and 9 (64.3%) of 14 patients with AFM were clinically and biochemically free of disease. No significant difference was found in biochemical recurrence or overall survival between those with MC or AFM and a matched group of patients with AC.

We report what we believe to be the largest published series of cases of MC (n = 14) with a median overall follow-up of 6.4 years. MC appears to behave clinically in a similar fashion to AC, with no statistically significant difference in biochemical failure or survival.

The information provided in the surgical pathology report of a prostate needle biopsy of carcinoma has become critical in the subsequent management and prognostication of the cancer. The surgical pathology report should thus be comprehensive and yet succinct in providing relevant information consistently to urologists, radiation oncologists and oncologists and, thereby, to the patient. This paper reflects the current recommendations of the 2004 World Health Organization-sponsored International Consultation, which was co-sponsored by the College of American Pathologists. It builds on the existing work of several organizations, including the College of American Pathologists, the Association of Directors of Anatomic and Surgical Pathologists, the Royal Society of Pathologists, the European Society of Urologic Pathology and the European Randomized Study of Screening for Prostate Cancer.

We present a case of mucinous adenocarcinoma of intestinal type arising from the prostatic duct in a 72-year-old Japanese man. The patient presented with macroscopic hematuria. Cystourethroscopy exhibited a mucus deposit at the 5 o'clock position of the verumontanum portion. A transurethral biopsy specimen revealed mucinous adenocarcinoma. A radical retropubic prostatectomy was performed. In the prostatectomy specimen, the cancer lesion mainly showed intraductal growth in the prostatic ducts with scattered mucin lakes in the prostatic stroma. There were no abnormalities in the urethral epithelium. The cancer cells resembled the intestinal epithelium rather than either the prostatic duct or the acinar epithelium, which showed diffusely positive immunohistochemical staining for carcinoembryonic antigen, but showed negative staining for prostate-specific antigen. Therefore, these findings suggest mucinous adenocarcinoma of intestinal type arising from the prostatic duct. A number of cases with mucinous adenocarcinoma arising from the prostatic urethra resembling the present case have been reported, but this is the first known case of carcinoma arising from the prostatic duct.

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.

Prostate cancer (prostate adenocarcinoma) has become an important concern in terms of public health these past fifteen years; recent French epidemiological data revealed 10,104 deaths due to this disease in 2000. The two main factors involved are the serum prostatic specific antigen (PSA), routinely used since late 1980's and which allows early diagnosis (before symptom onset), and the lengthened duration of life. Such cancer is rare before the age of 50, but its frequency increases with age, making it the most frequent type of cancer in French men. Although the aetiology of this disease is unknown, the ethnic origin, and a familial history of prostate or breast cancer are known risk factors. Predisposing genes to such hereditary types remain to be identified. Other genetic factors (polymorphisms), combined with environmental factors such as nutrition, have been incriminated, which is likely to explain the geographical variations of this affection. At the molecular level, the mechanisms involved in the tumoral initiation and progression remain unclear. Various genetic alterations have been identified among the genome of cancerous cells, at various stages of the affection: intraepithelial neoplasia, localized, locally advanced, metastatic or hormone refractory stage -, hormonal escape). However, the precise sequence and nature of the complex molecular events remain to be determined prior to their routine utilisation in the determination of subjects at risk, or as prognostic factors, and even as therapeutic targets. The anatomopathology is a key for the diagnosis. Intraepithelial neoplasia is the pre-cancerous lesion observed in most adenocarcinomas; these are localized in the peripheral part of the prostate gland in 70% of the cases. Gleason's classification is the current gold standard for the determination of tumoral aggressiveness and categorisation of the adenocarcinomas which are basically heterogeneous (coexistence of tumors cells with different degrees of differenciation in the same tumor). This anatomopathological classification allows distinguishing the tumours in terms of potential progressiveness and prognosis, and hence, to orientate the therapeutic strategy in case of localised or locally advanced prostate cancer.

A 65-year-old man presented with hematuria, postcoital bleeding, and mucoid-appearing prostatic secretions. The prostate was normal in size, boggy, and with no palpable masses. Cystoscopy revealed a prostatic wall cavity with gelatinous material exuding from the lesion. Extensive transurethral resection was performed, with approximately 37 g of tissue retrieved. Flexible sigmoidoscopy was performed to 60 cm, revealing no lesions, and stool was negative for occult blood. The pathologic diagnosis was mucinous adenocarcinoma of the prostate. Computed tomography and bone scan were negative for metastatic disease. The patient underwent uncomplicated radical prostatectomy. Fifteen years later, the patient was disease free and maintaining a healthy, active lifestyle.

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.

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.

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

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.

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".

Many rare variants of prostatic carcinoma have been described and characterized in recent years. Accurate diagnosis of these variants is necessary in order to determine appropriate therapy. Unusual tumors arising in the prostate raise questions of histogenesis, and may carry a better or worse prognosis than typical adenocarcinoma. Virtually the entire spectrum of cellular differentiation has been observed within prostatic epithelium, and rare neoplasms exhibit these unusual forms of differentiation as the chief component of the tumor. Except in sarcoma (marked prostatic enlargement), imaging plays a limited role in the diagnoses of these entities. Biopsy and histologic diagnoses are essential and the role of imaging is restricted to the evaluation of locoregional and distant spread of the disease.

Mucinous prostate adenocarcinoma is an infrequent tumour, with no more that 50 cases described to date. This paper contributes a new case of the entity. Rather than on the rarity of the tumour, the interest in our case focuses in the unusual nature of its clinical presentation. It initially appeared as a presumable rectoanal neoplasia but the pathoanatomical examination discovered the prostatic origin of the tumoration.

To report on a case of mucinous carcinoma of the prostate and discuss the clinical and histopathologic features of the mucin-producing carcinoma of the prostate from a review of published reports.

Our case and 87 other previously reported cases were evaluated clinically and histologically.

We encountered a case of mucinous carcinoma of the prostate, Stage C, which was treated by radical prostatectomy. After reviewing it and the 87 other cases, we believe that these cases of mucin-producing carcinomas can be divided into three groups: 60 cases of mucinous carcinoma, 17 cases of primary signet-ring cell carcinoma, and 11 cases of mucinous carcinoma with signet-ring cells. Mucinous carcinoma is a variant of high-grade adenocarcinoma of the prostate, wherein there is a 77.8% rate of prostate-specific antigen elevation and a similar rate (77.8%) of response to endocrine therapy. Fifty percent of patients survived 3 years and 25%, 5 years. In contrast, primary signet-ring cell carcinoma conveys one of the worst prognoses among patients with prostate cancer. There are no reliable tumor markers, and there was no response to endocrine therapy. Patients with primary signet-ring cell carcinoma had a 27.3% 3-year survival rate; none survived to 5 years. The clinical features of mucinous carcinoma with signet-ring cells are very similar to primary signet-ring cell carcinoma; again, there was no response to endocrine therapy and the 3-year survival rate was 16.7%.

Although it has been suggested that mucinous carcinoma is a variant of high-grade adenocarcinoma of the prostate, signet-ring cell carcinoma and mucinous carcinoma with signet-ring cells are other variants of carcinoma that develop in the prostate, and their prognoses are very poor.

To determine if the monoclonal antibody 7E12H12, which reacts with a 40 kDa protein in normal human enterocytes and has been shown to be a marker for intestinal metaplasia and adenocarcinoma arising in the bladder, could assist in distinguishing prostatic, urachal and vesical adenocarcinoma, using a sensitive immunohistochemical assay.

Fifteen primary prostatic adenocarcinomas and five adenocarcinomas of the urinary bladder were selected for a retrospective evaluation. The monoclonal antibody 7E12H12 (IgM isotype) was used in an immunoperoxidase assay to survey formalin-fixed, paraffin-embedded archival tissue specimens.

All vesical adenocarcinomas reacted positively with the antibody, regardless of grade; none of the 15 prostatic specimens reacted positively in either the benign or malignant glandular epithelium.

The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder from secondary adenocarcinoma arising in the prostate and may be a useful tool in diagnostic pathology.