Primary mucin-producing urothelial-type adenocarcinoma of prostate: report of 15 cases

Primary urethral carcinoma: Recommendations of the oncology committee of the French Urology Association

Primary urethral carcinoma (PUC) is defined as a tumor process arising within the urethra, with no history of other urinary tract localization or synchronous tumor of the urinary tract. The most common histological types are urothelial carcinoma (UC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). In men, UC predominates, while AC is rare. In women, AC affects around one in two patients, while EC and UC are equally divided between the remaining cases. Diagnosis is often delayed, and requires endoscopic examination with biopsies. MRI is the gold standard for local staging. FDG-PET scan can help in cases of doubt about regional or distant extension. The prognosis remains unfavorable despite aggressive surgical treatment. Multimodal management combining surgery, radiotherapy and chemotherapy appears to improve prognosis in severe forms.

Primary mucinous adenocarcinoma of the urethra: A contemporary clinicopathologic analysis of 17 patients

Mucinous adenocarcinoma of the urethra is rare. Here we performed a contemporary clinicopathologic analysis of this entity in both male and female patients. All cases with secondary tumors involving the urethra were excluded. Clinicopathologic parameters and follow up was obtained. Seventeen patients were included in the study, 9/17 (53 %) male and 8/17 (47 %) female. The mean patient age was 68 years (range: 53-88 years). The majority (11/17, 65 %) of patients were African American, with an even greater incidence (7/8, 87 %) in female patients. In male patients, prostatic urethra was the most common part of the urethra (6/9, 67 %) where the tumor arose from. Immunohistochemical stains were performed in 11/17 (65 %) tumors and were positive for CK20 (11/11, 100 %), CDX2 (11/12, 92 %), CK7 (8/9, 88 %), GATA3 (3/8, 37 %) and negative for NKX3.1, PSA, p63, PAX8, and Beta-Catenin. In resection specimens, tumors were categorized as pT2 (3/11, 27 %), pT3 (1/11, 9 %), and pT4 (7/11, 64 %). Lymph node status was categorized as pN0 (6/9, 67 %), pN1 (1/9, 11 %), and pN2 (2/9, 22 %). Available follow up data showed 7/13 (54 %) patients developed recurrence after surgical resection and chemotherapy, of which 3/7 (43 %) died of widespread metastatic disease. It is critical for pathologists and urologic oncologists to be aware of this entity in both male and female patients in view of potential diagnostic pitfalls, prognosis, and therapeutic implications.

Primary mucinous adenocarcinoma of the urethra: A clinicopathological analysis of 35 cases

AIM

Primary mucinous adenocarcinoma of the urethra represents an extremely rare entity. We sought to characterise further these tumours' clinicopathological, immunohistochemical and molecular features.

METHODS AND RESULTS

Thirty-five cases were identified, occurring in 18 males and 17 females. The mean age at diagnosis was 65 years (28-89 years). The main presentation symptoms were haematuria and urinary outlet obstruction. Microscopic analysis revealed that all 35 tumours have stromal dissection by mucin. Ten tumours showed villoglandular dysplasia, nine showed mucinous metaplasia, two showed adenocarcinoma in situ and four showed signet ring cell features. All tumours were immunopositive for CEA, while immunonegative for nuclear β-catenin; 19 of 23 (83%) expressed high molecular weight cytokeratin; 19 of 33 (58%) CK7; 28 of 34 (82%) CK20; 32 of 35 (91%) CDX2; 22 of 27 (81%) cadherin-17 (CDH-17); 26 of 29 (90%) SATB2; and one of 31 (3%) GATA3. Mismatch repair gene products, including MLH1, PMS2, MSH2 and MSH6, were immunopositive, suggesting the MSI-low genotype of mucinous adenocarcinoma of the urethra. BRAF V600E and ALK rearrangements were not detected. During the mean follow-up of 20 months, nine patients either developed distant metastasis or succumbed to the illness.

CONCLUSION

Our study, encompassing the most extensive series of 35 cases of primary mucinous adenocarcinoma of the urethra, provides crucial insights into its precise diagnosis, management and potential targeted treatments. We found a greater CDX2, SATB2 and CDH17 sensitivity in these urethral tumours for the first time, to our knowledge. We identified characteristics such as an MSI-low profile, non-V600E BRAF mutations and an absence of ALK rearrangements.

Urinary tract cytology showing variant morphology and divergent differentiation

Urothelial carcinoma represents a diverse group of tumours with distinct histologic subtypes, each exhibiting unique cytomorphologic features, architectural growth patterns, and/or well-developed aberrant differentiation. In fact, there are more than 13 subtypes of urothelial carcinoma recognized in the 2022 WHO classification of tumours in the urinary tract. The identification of these subtypes is crucial for an accurate diagnosis of urothelial carcinoma, and many have important clinical implications. Variant/divergent features may coexist with conventional high-grade urothelial carcinoma (HGUC) or present with 100% variant morphology. In urinary tract cytology (UTC), urothelial carcinoma can display divergent differentiation, such as squamous, glandular, or small cell carcinoma differentiation. The use of cell block preparations and immunohistochemistry with available residual urine can enhance diagnostic accuracy. On the other hand, identifying urothelial carcinoma variants, including nested, micropapillary, and plasmacytoid subtypes, poses significant challenges in UTC. Many cases of these variants are only detected retrospectively after variant histology has been established from resection specimens. Moreover, some variants exhibit features inconsistent with the diagnostic criteria for HGUC according to the Paris System for Reporting Urinary Tract Cytology. Nevertheless, the rarity of pure variant morphology and the occurrence of some false negatives for these variant cases are essential to maintain the specificity of UTC overall. This review covers the histology, cytomorphology, and important clinical aspects observed in urothelial carcinoma exhibiting divergent differentiation and various urothelial carcinoma variants detected in UTC.

Mucin-producing urothelial-type adenocarcinoma of the prostate with sarcomatoid features and novel molecular phenotype

Introduction

Mucin-producing urothelial-type adenocarcinoma of the prostate is a rare tumor that may not elevate serum prostate-specific antigen, creating significant diagnostic and monitoring challenges. We evaluate our case in detail and review prior studies to demonstrate that the pathologic and molecular features of this tumor are distinct from conventional prostate adenocarcinoma.

Case presentation

Our patient had a remote history of radiation-treated conventional prostate adenocarcinoma and presented many years later with an abscess-like prostate mass leading to urinary obstruction and hematuria. Biopsy revealed mucin-producing urothelial-type adenocarcinoma of the prostate with concurrent sarcomatoid features. Molecular studies showed a unique phenotype involving alterations in the KRAS, PTEN, RAD21, and TP53 genes.

Conclusions

To our knowledge, this is the first report that describes sarcomatoid features and molecular mutations in mucin-producing urothelial-type adenocarcinoma of the prostate.

Mucinous adenocarcinoma of the prostatic urethra after brachytherapy for prostatic adenocarcinoma: a case series

Mucinous adenocarcinoma of the urethra is extremely rare, even more so in a setting of postradiation therapy, with only 3 cases reported up to date including the first case published by our group in 2011. In the present study, we included the long-term follow-up on our previously reported case and report 3 additional cases. This is the first case series to date of this rare disease entity. The aim of this study is to review the clinicopathologic features of mucinous adenocarcinoma of the prostatic urethra in patients after receiving brachytherapy for prostatic adenocarcinoma. We identified 4 patients with a mean age of 72 years, and a mean interval of 14.8 years from brachytherapy for prostate carcinoma (grade group 1). Patients presented with hematuria or urinary retention. A colonoscopy was performed in three-fourth of patients and was within normal limits. Three patients underwent cystoprostatectomy and 1 had a transurethral resection of the prostate. On gross examination, only tumor formed a 3.5 cm tan-gray, ulcerated, friable, and necrotic mass and 2 displayed either irregular red granular or thickened areas within the prostatic urethra. Abundant extracellular mucin pools dissecting the prostatic stroma were present in all tumors, with clusters of tumor cells floating in the mucin. The mucin pools were lined by pleomorphic pseudostratified columnar mucinous epithelium. Tumors were diffusely positive for CK20, CDX2 (4/4), and AMACR (2/2); they focally expressed CK7 (2/4), and lacked nuclear β-catenin expression (3/3). PSA, PSAP, NKX3.1, p63, and GATA3 were negative in the tumors tested. Among the 3 patients who underwent radical surgery, 2 had stage 2 tumors (confined to the prostatic urethra and prostate), and 1 had a stage 3 tumor, with seminal vesicle involvement. All 4 patients were alive without disease with a mean follow-up of 4.9 years. In conclusion, brachytherapy-associated mucinous adenocarcinoma of the prostatic urethra displays intestinal-type features as its non-radiation-related counterpart. It appears to lack a villous adenoma component, displays a different immunohistochemical profile with diffuse CK20 and CDX2 positivity, and is associated with lower stage and less aggressive behavior.

FDG PET/CT in a Case With Primary Poorly Differentiated Urothelial-Type Adenocarcinoma of the Prostate

ABSTRACT

Primary urothelial-type adenocarcinoma of the prostate is extremely rare. We describe FDG PET/CT findings in a case with primary poorly differentiated urothelial-type adenocarcinoma of the prostate with pelvic lymph node metastases. Both the prostate tumor and its metastatic lesions showed intense FDG uptake. The patient had normal serum prostate-specific antigen and elevated carcinoembryonic antigen levels, which may be helpful for the differential diagnosis.

A Rare Case of Co-Existing Mucin-Producing Urothelial-Type Adenocarcinoma of the Prostate and Acinar Adenocarcinoma

Mucin-producing urothelial-type adenocarcinoma of the prostate is an extremely rare neoplasm, and its coexistence with acinar adenocarcinoma is exceptional. A 70-year-old man presented with treatment resistant symptoms of urinary obstruction. The serum prostate specific antigen (PSA) level was normal. Cystoscopy revealed a kind of "cottony fluff" in the prostatic urethra. A computed tomography (CT) scan and magnetic resonance imaging (MRI) showed a polylobulated, hyperintense lesion with mucinous content. It was located in the right lobe of the prostate and measured 35 × 27 × 35 mm. The bladder cavity did not show lesions and the gastrointestinal endoscopy was normal. Thus, the patient underwent a radical cystoprostatectomy. The histological sections showed the characteristics of a mucin-producing adenocarcinoma with extensive areas of mucin pools formation. No areas of necrosis, glandular urethritis, or carcinoma in situ were identified. Neither lymphovascular and perineural invasion nor lymph node metastases were identified. The immunohistochemical study showed diffuse positivity for keratin (KRT) 7, KRT20, and membranous beta-catenin and focal positivity for KRT34betaE12 and caudal-related homeobox gene 2 (CDX2). In addition, we identified a 10-mm focus of prostatic acinar adenocarcinoma that was positive for racemase and NKX3.1. There is no treatment algorithm for this condition; however, surgery (radical prostatectomy) with or without adjuvant chemotherapeutic treatment represents a therapeutic alternative.

Mucin-producing urothelial-type adenocarcinoma of the prostate diagnosed after robot-assisted radical prostatectomy

INTRODUCTION

Mucin-producing adenocarcinoma of the prostate is a rare disease that includes prostate adenocarcinoma with mucus production, secondary adenocarcinoma from the bladder or colorectum, and adenocarcinoma from the urothelium of the prostatic urethra. We describe prostate-specific antigen-negative mucin-producing urothelial-type adenocarcinoma of the prostate.

CASE PRESENTATION

The patient had urinary retention and a serum prostate-specific antigen level of 0.74 ng/mL. Computed tomography and magnetic resonance imaging revealed a prostate tumor with a mucous component. We diagnosed adenocarcinoma by prostate biopsy and subsequently performed robot-assisted radical prostatectomy. Mucin-producing urothelial-type adenocarcinoma of the prostate was diagnosed by pathological examinations. Lung metastasis, developing within 3 months after surgery, was treated using chemotherapy.

CONCLUSION

Endocrine therapy is ineffective for mucin-producing urothelial-type adenocarcinoma of the prostate. Mucin-producing urothelial-type adenocarcinoma of the prostate diagnosis requires pathological and immunohistochemical analyses. It is important to surgically remove the primary lesion, and robot-assisted radical prostatectomy may provide an effective approach. Multimodal therapy is essential to treat for mucin-producing urothelial-type adenocarcinoma of the prostate.

Systemic treatment for coexisting mucinous urethral adenocarcinoma and prostate adenocarcinoma

INTRODUCTION

Mucinous urethral adenocarcinoma is a rare and progressive cancer of the prostatic urethra. Reports on palliative systemic treatment for mucinous urethral adenocarcinoma are few. We present a case of coexisting mucinous urethral and prostate adenocarcinomas managed with systemic treatment.

CASE PRESENTATION

A 66-year-old man presented with gross hematuria and urinary retention. Prostate-specific antigen level was elevated, at 99 ng/mL, and prostate biopsy revealed moderately to poorly differentiated adenocarcinoma. Hormone therapy and standard chemotherapy for prostate adenocarcinoma were ineffective. Prostate re-biopsy revealed coexisting mucinous urethral and prostate adenocarcinomas. Gemcitabine + cisplatin chemotherapy and folinic acid + 5-fluorouracil + irinotecan chemotherapy temporarily suppressed the cancer, but 14 months after presentation, he developed liver metastasis and died. Autopsy revealed metastasis of both mucinous urethral adenocarcinoma and carcinosarcoma.

CONCLUSION

Mucinous urethral adenocarcinoma is difficult to diagnose in coexistence with prostate adenocarcinoma. This was an extremely rare case showing chemoresistance due to epithelial-mesenchymal transition.

Urethral Mucinous Adenocarcinoma of the Prostate: An Uncommon and Diagnostically Complex Disease

A 66-year-old male presented with hematuria and mucosuria. A transurethral resection of the prostate revealed adenocarcinoma in situ with mucinous features. He underwent a robotic-assisted radical prostatectomy with lymph node dissection. Pathology confirmed T2 primary mucin-producing urothelial type adenocarcinoma in the prostatic urethra. Urothelial adenocarcinoma arising in the prostatic urethra is an uncommon disease that warrants clear differentiation from other malignancies due to its aggressive nature. The differential includes urologic and gastrointestinal malignancies making diagnosis complex. Accurate diagnosis is critical to providing appropriate treatment as these patients are at high risk of developing recurrence and metastatic disease.

Mucinous adenocarcinoma of the prostatic urethra following a remote history of primary brachytherapy for prostate cancer

Secondary malignancies are a known, albeit uncommon, complication of radiation for prostate cancer, either in the form of external beam radiotherapy or seed-implant brachytherapy. Of these secondary malignancies, mucinous adenocarcinoma of the prostatic urothelium is an extremely rare clinical entity that has only once been reported in the literature. We report the case of an 80-year-old gentleman who initially underwent low-dose brachytherapy for low-risk prostate cancer 18 years ago. He subsequently developed recurrent gross hematuria and obstructive voiding symptoms. He underwent cystoscopy and transurethral resection of a large tumor from within the prostate. Final pathology of the tumor revealed a mucinous adenocarcinoma. Further immunostaining revealed this is likely to have originated from the prostatic urothelium. Given his age, comorbidities, and no clear data demonstrating that aggressive extirpative surgery provides a clinical benefit, we elected to undergo surveillance. Clinicians should be aware of mucinous adenocarcinoma of the prostatic urethra as an extremely rare, radiation-induced malignancy. Once a diagnosis is made, extirpative surgery is an option for localized disease, although prognosis remains poor.

MRI of prostatic urethral mucinous urothelial carcinoma: Expanding the differential diagnosis for T2 hyperintense prostatic masses

We report the case of a 66-year-old previously healthy man presenting with blood and mucus in his urine. Cystoscopy revealed a mass in the prostatic urethra, and endoscopic biopsy showed adenocarcinoma in situ with mucinous features. Endorectal multiparametric prostate MRI demonstrated a 1.9 cm T2 hyperintense mass in the peripheral zone of the left prostatic apex with extension into the urethral lumen. No diffusion restriction or early enhancement was seen in the mass. Radical prostatectomy was performed, and final pathology demonstrated a mucin-producing urothelial adenocarcinoma arising from the prostatic urethra. The peripheral zone T2 hyperintense abnormality correlated with abundant pools of mucin extending into the prostatic stroma and surrounded by neoplastic prostatic glandular cells. We conclude prostatic urethral mucinous urothelial carcinoma should be included in the differential diagnosis for T2 hyperintense prostatic masses.

Aggressive course in a patient with mucin-producing urothelial-type adenocarcinoma of the prostate: A case report and review of the literature

Prostate cancer is one of the frequently seen types of cancers in men. The most frequent histological type of prostate cancer is the acinar adenocarcinoma. Mucin-producing urothelial-type adenocarcinoma of the prostate is a very rare subtype. The mucin-producing urothelial-type adenocarcinoma of the prostate has microscopic similarities with colon and bladder adenocarcinoma. It has a more aggressive clinical course and does not respond to androgen deprivation therapy. A 77-year-old male patient diagnosed with mucinous prostate cancer was presented in the current case report.

Occult mucin-producing urothelial-type adenocarcinoma of the prostate with elevated serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9: Report of an autopsy-proven case

Mucin-producing urothelial-type adenocarcinoma of the prostate (MPUAP) is a rare, aggressive neoplasm thought to originate from the prostatic urethral urothelium. Our case is the first reported to show significantly increased serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in MPUAP. An autopsy revealed occult MPUAP with prominent seminal vesicle, perineural, lymphatic vessel, and vascular invasion and extensive bone metastases. Duration of survival in this case was far shorter than average, and extensive bone metastases were rare in previously reported cases. This suggests serum CEA and CA19-9 levels can be an important prognostic factor in MPUAP.

Incidental discovery of mucinous adenocarcinoma of the prostate following transurethral resection of the prostate: A report of two cases and a literature review

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.

Mucinous and secondary tumors of the prostate

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.

Co-existence of mucin-producing urothelial-type adenocarcinoma of the prostate and inverted papilloma of the bladder

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.

Reacquisition of E-cadherin expression in metastatic deposits of signet-ring cell carcinoma of the upper gastrointestinal system: a potential anchor for metastatic deposition

AIMS

To examine the expression of E-cadherin in paired primary and metastatic signet-ring cell carcinomas (SRCC) of various organ systems in order to explore the potential role of the molecule in metastatic dissemination of this unique tumour type.

METHODS

Thirty-seven consecutive cases of SRCC from various organs with paired primary and metastatic tumorous tissue available were retrieved. The intensity of membranous E-cadherin expression was semiquantitatively scored on a scale of 0-3+.

RESULTS

Reduced E-cadherin expression was a distinct feature of primary SRCC and was observed in 78% of primary tumours. Interestingly, the E-cadherin reduction was less frequently seen in metastatic SRCC when compared with their primary counterparts, and was only found in 57% of tumours in lymph node metastases or at distant sites of relapse. Furthermore, the mean score of E-cadherin expression of primary SRCC was significantly lower than that of their metastatic counterparts (2.3 vs 1.8; p=0.008). When divided by organ systems, the reacquisition of E-cadherin expression in the metastatic deposits was most remarkable in the SRCC of upper gastrointestinal tract origin (2.3 vs 1.4; p=0.003), whereas no significant difference was observed in other organ systems.

CONCLUSIONS

While the reduction of E-cadherin in primary SRCC supports its pivotal role in epithelial-mesenchymal transition, a process crucial in tumour progression and metastatic dissemination, the re-expression of this molecule in metastatic SRCC cells implies a reversal to their epithelial phenotype (thus mesenchymal-epithelial transition) which, in turn, theoretically helps tumour cells to anchor and form cohesive metastatic deposits.

Importance of an Early Diagnosis in Primary Adenocarcinoma of the Seminal Vesicle

The prognosis of seminal vesicle (SV) adenocarcinoma is often poor due to delayed diagnosis. About 95% of the patients die in less than 3 years. Diagnosis is difficult due to the absence of early clinical signs as hematuria, hematospermia and/or dysuria. We present the case of a 61-year-old Caucasian man with a left SV mass detected by transrectal ultrasound. SV ultrasound-guided biopsy showed an adenocarcinoma. The tumor was uniformly strongly immunoreactive for cytokeratin-7 and carcinoembryonic antigen. There was no immunoreactivity for prostate-specific acid phosphatase (PSAP) and CK-20. These tumors have been reported to be also positive for CA-125. Therefore a combination of positive staining for CK-7, CEA and CA-125; with negative staining for CK-20, PSA and PSAP is the pattern of immunohistochemical findings noted for this rare tumor. The computed tomography of the abdomen-pelvis and chest X-ray was negative for metastases. The patient underwent a radical prostatectomy and lymphadenectomy. The prostate, rectum, bladder and lymph nodes were free from tumor involvement. The patient did not receive any adjuvant chemotherapy or radiation; and remains free of disease 3 years post-surgery.

Primary mucin-producing urothelial-type adenocarcinoma of the prostatic urethra diagnosed on TURP: a case report and review of literature

BACKGROUND

Mucin-producing urothelial-type adenocarcinoma of the prostatic urethra is extremely rare. These lesions must be differentiated from other mucinous tumors including mucin-producing prostatic adenocarcinoma and metastases from either colonic or bladder primaries.

CASE PRESENTATION

We report here a case of urothelial-type adenocarcinoma arising from the prostatic urethra. The patient is an 81 year-old man with a history of pT1 urothelial cell carcinoma of the bladder status post trans-urethral resection of bladder tumor (TURBT) who initially presented with irritative lower urinary tract symptoms and mucosuria refractory to Flomax and finasteride. A shared decision was made for the patient to undergo trans-urethral resection of prostate (TURP). At the time of surgery, a papillary tumor emanating from the prostatic urethra was found and no urothelial lesions were noted in the bladder. Pathology of the resected prostatic chips revealed an invasive adenocarcinoma with intestinal-type differentiation that stained positive for CK7, CK20, and villin, but negative for PSA, PSAP, uroplakin, and CDX-2. Colonoscopy was normal and CT scan did not show any evidence of colonic lesions nor visceral or lymph node metastases. Thus, the patient was diagnosed with a primary urothelial-type adenocarcinoma of the prostatic urethra.

CONCLUSION

Herein we review the literature regarding this unusual entity, and discuss the differential diagnosis, immunohistochemistry, and the importance of correctly identifying this rare tumor.

Metastatic Mucinous Adenocarcinoma of the Prostate with PSA Value of 8.6 ng/mL at 5-Year-Followup after Prostatectomy, Radiotherapy, and Androgen Deprivation

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.

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

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

Mucin-producing tumors and tumor-like lesions involving the prostate: a comprehensive review

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.

Determining the site of origin of mucinous adenocarcinoma: an immunohistochemical study of 175 cases

Mucinous adenocarcinomas (MAs) of various origins may have a similar histologic appearance and frequently metastasize to distant sites, which often causes diagnostic problems in surgical pathology practice. The immunohistochemical profiles of MAs of various origins have not been well studied. We investigated the expression of 10 immunohistochemical markers (CK7, CK20, CDX-2, β-catenin, MUC-1, MUC-2, MUC-6, ER, WT-1, and PAX-8) in 175 cases of MA, including 69 cases from the lower gastrointestinal (GI) tract, 41 from the upper GI tract, 27 from gynecologic organs, 4 from the urinary bladder, 18 from the breast, and 16 from the lung. We found that lower GI MAs (colon, rectum, and anus) frequently expressed CDX-2 (42 of 42, 100%; 33 of 42 with homogenous positivity, 79%), MUC-2 (42 of 42; 100%), CK20 (41 of 42; 98%), and β-catenin (nuclear) (27 of 42; 64%) and rarely expressed MUC-6 (2 of 42; 5%) and CK7 (8 of 42; 19%). Most of the CK7-positive cases were from the rectum and anus (7 of 8; 88%). The expression of these markers in appendiceal MAs was similar to that of low GI tract MAs, except for a lower percentage of homogenous CDX-2 (3 of 27; 11%) and nuclear β-catenin (3 of 27; 11%) expression. Unlike their lower GI tract counterparts, the upper GI tract MAs (ampulla, pancreas/biliary tree, and stomach/esophagus) frequently expressed CK7 (38 of 41; 93%) and MUC-6 (31 of 41; 76%) and were rarely homogenously positive for CDX-2 (4 of 41; 10%) and nuclear positive for β-catenin (8 of 41; 19%). Breast MAs were frequently positive for CK7 (18 of 18; 100%), MUC-1 (18 of 18; 100%), MUC-2 (18 of 18; 100%), ER (16 of 18; 89%), MUC-6 (9 of 18; 50%), and WT-1 (9 of 18; 50%). Lung MAs were frequently positive for CK7 (16 of 16; 100%) and MUC-1 (15 of 16; 94%). Gynecologic MAs were positive for CK7 (25 of 27; 93%) and PAX-8 (13 of 27; 48%). We conclude that homogenous CDX-2 and nuclear β-catenin expressions are commonly seen in lower GI tract MAs. In contrast, appendiceal MAs are usually heterogenously positive for CDX-2 and show cytoplasmic positivity for β-catenin. Unlike lower GI tract MAs, upper GI tract MAs are frequently positive for CK7 and MUC-6. As is the case in appendiceal MAs, the upper GI tract MAs may also be heterogenously positive for CDX-2. Breast MAs are positive for ER and WT-1, whereas gynecologic MAs are positive for PAX-8 and negative for WT-1.

Mucin-producing urothelial-type adenocarcinoma of the prostate as a mimicker of colonic adenocarcinoma: a case report and review of the literature

A 59-year-old man presented with persistent urinary obstructive symptoms, gross hematuria, and mucusuria. Subsequently, a prostate-specific antigen (PSA)-negative mucin-producing urothelial type adenocarcinoma of prostate was found. The serum PSA level was within the normal limit. Colonoscopy, positron emission tomography, and other tumor surveys showed this to be the only prostate lesion. Microscopically, there was an adenocarcinoma with copious mucin production, with the formation of mucin pools. The neoplastic glands were variously arranged in cribriform, glandular, and villous adenoma-like patterns. This is a very rare tumor, of which there are only 20 cases reported in the literature in the English language. It is critical to distinguish it from mucinous acinar adenocarcinoma of the prostate and from metastatic adenocarcinoma of either the bladder or colon. This is mainly because mucin-producing urothelial type adenocarcinoma of the prostate has a different clinical behavior, and hence, the treatment plan is different from that for conventional prostatic adenocarcinoma. Specifically, it has a more aggressive clinical course and is unresponsive to hormone therapy.

Primary Seminal Vesicle Carcinoma

Criteria for the very rare diagnosis of primary seminal vesicle carcinoma have traditionally been highly stringent but may be relaxed with the application of immunohistochemistry to the diagnosis of mass lesions that occur in the male pelvis. The authors report a case of disseminated carcinoma with a clinically occult primary site that apparently had its origin in the seminal vesicle. Autopsy revealed a 10-cm tumor enveloping the prostate and seminal vesicles without involvement of colonic or urothelial mucosa. Much smaller tumors were present in other sites outside the pelvis. The tumor was composed of poorly formed glands and sheets of malignant-appearing cells, involved the seminal vesicle, and had the immunohistochemical profile of seminal vesicle carcinoma, notably strong immunoreactivity for CA-125 and no immunoreactivity for cytokeratin-20 or prostate-specific markers.

Radical exenteration surgery is curative in locally advance mucinous prostatic adenocarcinoma involving bladder and rectum

The management of mucinous prostatic adenocarcinoma include hormonal treatment, radiotherapy and radical prostatectomy with variable long-term outcome. We report a 59 year old man with advanced mucinous prostatic adenocarcinoma involving almost the entire bladder and had failed treatment with hormonal and radiotherapy, but subsequently underwent radical pelvic exenteration surgery that resulted in long-term cure. He remains alive, his PSA remains undetectable and his surveillance CT scans did not show any evidence of recurrence after 11 years post-surgery. The favourable outcome of radical surgery suggests that radical surgery should be considered, especially in cases with failed initial treatments.

MUC2 expression in primary mucinous and nonmucinous adenocarcinoma of the prostate: an analysis of 50 cases on radical prostatectomy

The expression of mucin (MUC2) in prostate cancer has not been well studied previously and may be of prognostic and pathobiologic significance. It is, however, well known that MUC2 expression in mucinous pancreatic and breast cancer represents an indolent pathway since these tumors have a significantly better outcome than their conventional counterparts. Twenty-five cases each of Gleason pattern 3 and 4 mucinous adenocarcinoma of the prostate defined by greater than 25% mucinous component and nonmucinous adenocarcinoma of the prostate were obtained from the surgical pathology files of the Johns Hopkins Hospital and Emory University Hospital. Immunohistochemical stains were performed for MUC2 on all 50 cases. Mean patient age was 60 years (range 44-72 years). MUC2 was expressed in all 25 cases (100%) of mucinous adenocarcinoma of the prostate, irrespective of the Gleason pattern. The nonmucinous component of these cases was negative for MUC2. In contrast, MUC2 expression was significantly lower in nonmucinous adenocarcinoma of the prostate, detected in only 6/25 cases as a focal finding, while 19/25 (76%) of nonmucinous adenocarcinoma of the prostate were completely negative for MUC2 (P<0.01). In six cases that showed focal positivity, MUC2 was expressed in areas with Gleason pattern 3 cancer with extensive mucinous fibroplasia (one case) and prominent intraluminal mucin (five cases). Other areas of these tumors were negative for MUC2. Mucinous adenocarcinoma of the prostate shows diffuse expression of MUC2, a known tumor suppressor, which is not present in either normal prostate or the majority of conventional adenocarcinomas of this organ. This indicates that mucinous adenocarcinoma of the prostate is indeed of the 'colloid type' akin to those in other exocrine organs. It is highly conceivable that this de novo expression of MUC2 has a role, not only in the mucinous differentiation of these tumors and their colloid pattern, but also in their relatively indolent behavior that has been recently elucidated.