Primary adenocarcinoma of the urinary bladder: differential diagnosis and clinical relevance

[Mimickers and diagnostic pitfalls of urinary bladder cancer]

Urothelial carcinoma (UC) is by far the most common malignant neoplasm of the urinary bladder; however, there are both benign and malignant changes of the urothelium which morphologically resemble urothelial carcinomas or other carcinomas of the urinary bladder. Thus, these mimickers can cause problems in the histomorphological diagnosis. This article provides an overview of possible mimickers and pitfalls of bladder cancer as well as practical notes on the diagnostic procedure, partly using case studies.

Non-urothelial and urothelial variants of bladder cancer

Non-urothelial bladder cancers make up a rare minority of all genitourinary (GU) tract histologic cancers since urothelial cancer (UC) makes up the most common histologic subtype. Bladder cancer variant histology (BCVH) or urothelial variants also occur rarely though distinction is important given aggressive presentation and natural history. While methods for diagnosis and treatment of typical urothelial cancers (UC) are well-established, there are no clear guidelines with regard to the diagnosis of non-urothelial bladder cancers, which often results in misdiagnosis and treatment delay. This review will focus on the clinicopathologic characteristics of the most common non-urothelial bladder cancers, to be distinguished from bladder cancer variant histology containing a UC component. The role of genomics in non-urothelial bladder cancers is evolving and the use of biomarkers to guide the diagnosis and treatment of these tumors remains a key area of unmet need. Treatment of these cancers will be discussed in a companion review.

Extra-Gynecological Pelvic Pathology: A Challenge in the Differential Diagnosis of the Female Pelvis

Ultrasound technology with or without color Doppler allows a real-time evaluation of the entire female pelvis including gynecologic and non-gynecological organs, as well as their pathology. As ultrasound is an accurate tool for gynecological diagnosis and is less invasive and less expensive than other techniques, it should be the first imaging modality used in the evaluation of the female pelvis. We present a miscellany of non-gynecological pelvic images observed during the realization of gynecological ultrasound. Transvaginal and transabdominal ultrasound is the first choice among diagnostic techniques for the study of the female pelvis, providing information about gynecological and extra-gynecological organs, allowing for an orientation toward the pathology of a specific organ or system as well as for additional tests to be performed that are necessary for definitive diagnosis.

Survival of Patients With UrAC and Primary BAC and Urothelial Carcinoma With Glandular Differentiation

Purpose

To investigate the significance of demographic and pathological characteristics on the survival outcomes of urachal adenocarcinoma (UrAC), primary bladder adenocarcinoma (BAC) and urothelial carcinoma with glandular differentiation (UCGD) in China.

Materials and Methods

We retrospectively analyzed cases with non-distant metastases (≤ T4M0). Of 106 patients, 30 (28.3%), 40 (37.7%), and 36 (34.0%) met the criteria for UrAC, primary BAC, and UCGD, respectively. Data on patient demographics, tumor pathology, and survival outcomes were collected. The median follow-up was 36 months. Survival was analyzed using multivariate Cox regression.

Results

Patients with UrAC were younger (51.87 ± 15.25 years) than those with primary BAC (60.50 ± 12.56 years) and UCGD (63.83 ± 11.60 years) (P<0.001). Patients with UrAC were the most likely to be stage T3–4 (70.0% vs. 40.0% vs. 44.4%; P<0.001), while the primary BAC group had a higher rate of poor differentiation than the UrAC and UCGD groups (57.4% vs. 18.5% vs. 24.1%; P<0.001). The Kaplan–Meier curves showed that the overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS) of the primary BAC group were poorer than those of both the UrAC and UCGD groups (P=0.0046,P<0.0001,P=0.0077 respectively). Regarding BAC, patients with mucinous adenocarcinoma tended to have better OS and PFS than those with other histological types (P<0.005,P=0.0245). Multivariate Cox regression analysis revealed that tumor type (P=0.002), T stage (P=0.034), and the age-adjusted Charlson Comorbidity Index (aCCI) scores (P=0.005) predicted the postoperative OS and DSS of the patients. For PFS, the tumor type (P=0.011), grade (P=0.000), and aCCI (P=0.002) scores were predictive.

Conclusion

Among UrAC, primary BAC, and UCGD patients, the prognosis was poorest for those with primary BAC. Attempts should be made to diagnose these aggressive tumors early, since patients in whom tumors are detected early appear to survive longer.

Metastatic Adenocarcinoma of the Bladder Presenting as Malignant Pleural Effusion: A Rare Presentation of Bladder Adenocarcinoma

Bladder cancers rarely are non-urothelial in origin. We present here, possibly the youngest case of a 35-year-old White female presenting with shortness of breath. She was found to have a malignant pleural effusion with unknown primary, eventually confirmed with genetic testing as metastatic adenocarcinoma of the urinary bladder with brain and lung metastasis. She was scheduled for palliative chemotherapy, however, passed away before it could be started. We highlight this rare case because of its unique presentation. Owing to similarity in receptors between adenocarcinoma and enteric cancer, similar chemotherapy regimens may be used for both. Unfortunately, treatment of metastatic disease remains highly controversial and needs to be studied further if there is an actual survival benefit to this or not.

Mucinous adenocarcinoma of renal pelvis in a young male: a diagnostic challenge

Primary mucinous adenocarcinoma of the renal pelvis is an extremely rare tumor with only a handful of cases reported to date. Clinical and radiological features are not specific, and hence, histopathological examination holds the key for definitive diagnosis. This tumor has mainly been described in the elderly population, with less than five cases reported in individuals aged <35 years. Here, we report a case of primary mucinous adenocarcinoma of the renal pelvis in a young male. A 31-year-old male presented with a history of right-sided flank pain for the past year. On examination, he had right-sided costovertebral tenderness. Computed tomography (CT) scan revealed the presence of a hyperdense mass lesion in the right renal pelvis with severe hydronephrosis and cortical thinning. Because of the non-functioning status, right nephrectomy was performed. To our surprise, histopathology showed the presence of mucinous adenocarcinoma of the renal pelvis with carcinoma in situ of the ureter. This case describes a rare presentation of primary mucinous adenocarcinoma of the renal pelvis, and highlights the importance of histopathological examination in reaching the correct diagnosis.

Histologic Variants of Urothelial Carcinoma: Morphology, Molecular Features and Clinical Implications

Bladder cancer is a heterogeneous disease including conventional urothelial carcinoma (UC) and its histologic variants, and non-urothelial carcinoma, including squamous and glandular neoplasms. Urothelial carcinoma accounts for the majority of bladder cancer cases, but morphologic variants are common and include nested, microcystic, micropapillary, lymphoepithelioma-like, plasmacytoid, sarcomatoid, giant cell, undifferentiated, clear cell and lipoid. Certain variants of UC tend to be associated with a poor prognosis and have diagnostic and potential treatment implications that make the identification of variant histology crucial to clinical decision making. While there is still uncertainty regarding the prognostic implications of many of these variants, identifying and reporting variant histology is important to develop our understanding of their biology. Unique molecular features accompany many of these morphologic variants and to better understand these tumors, we review the molecular and clinical implications of histologic variants of bladder cancer. Major efforts are underway to include variant histology and divergent differentiation of UC in clinical trials to develop evidence based approaches to treatment. The purpose of this article is to review the current literature on variant histology of urothelial cancer and to highlight molecular findings and the clinical relevance of these tumors.

The applicability and utility of immunohistochemical biomarkers in bladder pathology

Urinary bladder specimens are frequently encountered in the daily practice of surgical pathologists. The spectrum of pathologic entities encountered in bladder specimens is extraordinarily broad, and in some instances, immunohistochemical stains are used to help characterize challenging bladder lesions. Cost-effective biomarker selection tailored to the differential diagnosis facilitates an accurate diagnosis. This comprehensive review is prepared as a reference guide for the use of immunohistochemistry to categorize primary and secondary bladder neoplasms and to evaluate metastatic cancers for possible bladder origin.

Mutational Profile Using Next-Generation Sequencing May Aid in the Diagnosis and Treatment of Urachal Adenocarcinoma

Objectives. The rare urachal adenocarcinoma (UAC) of the bladder has striking morphologic and immunohistochemical overlap with colorectal adenocarcinoma (CAC) and bladder adenocarcinoma (BAC). To date, the mutational status in UAC and BAC has not been well investigated. Methods. We retrospectively evaluated 34 UACs (mucinous, n = 9; intestinal, n = 3; signet ring cell, n = 1; not otherwise specified, n = 21) and 4 BACs (n = 4). Next-generation sequencing analysis of 50 cancer "hotspot" gene mutations using the Ampliseq Cancer Hotspot Panel v2 was performed. Two UAC cases did not have adequate DNA quality with poor sequencing coverage and were excluded from the study. Results. RAS mutations were identified in 16 of 32 (50%) UACs (15 KRAS; 1 NRAS) and none of the BACs (0%). TP53 mutations were found in both UACs (18/32; 56%) and BACs (4/4; 100%). GNAS (n = 4), SMAD4 (n = 3), and BRAF (n = 1) mutations were only found in UACs. In contrast, APC (n = 2) mutations were only found in BACs. The mucinous subtype of UAC contained a SMAD4 mutation in 33% of cases (3/9), which was not identified in any other subtype (0/23; 0%) (P = .0169). The only BRAF mutation was identified in the single signet ring cell subtype of UAC. There were no other differences in the mutation profile when comparing histologic subtypes of UAC. Conclusions. In summary, UAC and BAC have overlapping but distinct mutation profiles and these differences may aid in separating these 2 entities. Next-generation sequencing to identify therapeutic targets or resistance markers may aid treatment decisions.

Villous Morphology in Urinary Bladder Biopsy: An Approach to Diagnosis

Villous morphology in urinary bladder biopsy is a relatively uncommon finding. Villi are slender, finger-like structures that are commonly seen in the small intestine or in neoplastic lesions of gastrointestinal lineage/differentiation. Importantly, placenta also exhibits villi that are morphologically and functionally different from the intestinal one. Majority of the neoplastic lesions of urinary bladder are urothelial in origin with a minor subset showing glandular differentiation. While the presence of benign villi in urinary bladder biopsy necessitates a search for an occult perforation, provided a sample mismatch is ruled out, cytoarchitecturally abnormal/dysplastic villi indicate a neoplastic lesion of the urinary bladder encompassing villous adenoma and adenocarcinoma and urothelial carcinoma with villoglandular differentiation. The dysplastic villi in urinary bladder also imply a lower gastrointestinal endoscopy to rule out a colorectal primary. The development of the villous lesions in the urinary bladder and the colorectum are embryologically related and pose a major diagnostic challenge to the clinicians and surgical pathologists due to identical histomorphology and immunohistochemistry. We tend to discuss the morphological differentials and diagnostic approach to the villous lesions in the urinary bladder biopsy.

Reviewing the Demographic, Prognostic, and Treatment Factors of Primary Adenocarcinoma of the Bladder: A SEER Population-based Study

INTRODUCTION

The objective of this study was to characterize the demographic, prognostic, and treatment factors for patients with primary adenocarcinoma of the bladder by analyzing the impact of histologic subtype in a large sample size and interpreting newly released Surveillance, Epidemiology, and End Results (SEER) chemotherapy data.

MATERIALS AND METHODS

The SEER 18 Registry was utilized to identify cases of primary adenocarcinoma diagnosed from 1973 to 2015. Demographic data, tumor and disease characteristics, treatment information, and survival outcome data were collected. Overall survival and disease-specific survival were determined using Kaplan-Meier curve analysis. Univariate and multivariate Cox regression analysis were then completed using SAS JMP.

RESULTS

A total of 2305 cases of primary adenocarcinoma of the bladder were identified. Overall survival at 2-, 5- and 10-year intervals was 54.8%, 36.1%, and 25.4%, respectively. Disease-specific survival at 2-, 5- and 10-year intervals was 62.0%, 47.1%, and 40.1%, respectively. Patients were treated with surgery (86.4%), chemotherapy (21.9%), and radiation (15.0%) (P < .0001). Multivariate Cox regression analysis showed independent prognostic value for gender, stage, grade, primary tumor location, and histologic subtype. The urachus/dome location conferred survival advantage over non-urachal locations on univariable and multivariable Cox regression analysis. The papillary adenocarcinoma subtype conferred the best survival outcome, whereas signet cell carcinoma (hazard ratio, 2.069; P < .0001) and unclassified adenocarcinoma (not otherwise specified) (hazard ratio, 1.524; P < .0001) conferred the worst prognoses.

CONCLUSION

This study utilized a population-based analysis to showcase the utility of various prognostic features in primary bladder adenocarcinoma cases. In characterizing treatments, we find the prevailing treatment remains surgical intervention, whereas a sizable minority receives chemotherapy and/or radiation, often in combination with surgery.

Diagnostic and prognostic roles of CK20 in the pathology of urothelial lesions. A systematic review

Cytokeratin 20 (CK20) is one of the most common immunohistochemical markers in the routine practice of a pathology lab, as biopsies from the urinary tract encompass a wide spectrum of lesions which may pose issues in their detection and classification. In this review, we aim to outline the diagnostic accuracy and prognostic value of CK20 in flat urothelial lesions, papillary non-invasive and invasive urothelial carcinoma, molecular subgroups and variant histology, and we briefly discuss its limitations and potential pitfalls.

Non-urothelial carcinomas of the bladder

Non-urothelial carcinomas involving the bladder are uncommon and often diagnostically challenging. These carcinomas may show squamous, adenocarcinomatous or neuroendocrine features, with immunohistochemical stains aiding the diagnosis in only a subset of cases. The clinical history in non-urothelial bladder carcinomas is important, given that the differential diagnosis often includes secondary involvement of the bladder by direct extension or metastasis from carcinomas at other sites. This paper will review non-urothelial carcinomas in each of these three morphological categories, emphasising recent changes in diagnostic grouping and challenges in the histopathological diagnosis. Review of bladder cancers with squamous morphology will include discussion of conventional squamous cell carcinoma and verrucous carcinoma and their distinction from urothelial carcinoma with extensive squamous differentiation. Bladder carcinomas with adenocarcinomatous change will include primary bladder adenocarcinoma, urachal adenocarcinoma and tumours of Müllerian type. Finally, neuroendocrine neoplasms of the bladder, including well-differentiated neuroendocrine tumour and neuroendocrine carcinomas, will be discussed. Associated surface findings, risk factors and prognostic features will be described.

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

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

Retrospective analysis of palliative chemotherapy for the patients with bladder adenocarcinoma: Korean Cancer Study Group Genitourinary and Gynecology Cancer Committee

BACKGROUND/AIMS

Because of rarity, role of chemotherapy of bladder adenocarcinoma are still unidentified. Therefore, we performed a retrospective analysis of the clinical features and chemotherapy outcomes of bladder adenocarcinoma.

METHODS

Eligible patients for this retrospective analysis were initially diagnosed with bladder adenocarcinoma and presented with a clinically no other primary site of origin. The collected data included age, gender, performance status, stage, hemoglobin, albumin, initial date of diagnosis, treatment modality utilized, response to treatment, presence of relapse, last status of patient, and last date of follow-up.

RESULTS

We retrospectively reviewed 29 patients, who were treated with chemotherapy for bladder adenocarcinoma at 10 Korean medical institutions from 2004 to 2014. The median age of patients was 58 years (range, 17 to 78) and 51.7% of the patients were female. Urachal adenocarcinoma was identified in 15 patients. Of 27 symptomatic patients, 22 experienced gross hematuria. Twelve patients were treated with 5-f luorouracil based chemotherapy, five were gemcitabine based, three were taxane and others. Thirteen of them achieved complete response (10.3%) or partial response (34.5%). Median progression-free survival (PFS) and overall survival (OS) for all patients were 10.6 months (95% confidence interval [CI], 9.5 to 11.6) and 24.5 months (95% CI, 1.2 to 47.8), respectively. The cases of urachal adenocarcinoma exhibited worse tendency in PFS and OS (p = 0.024 and p = 0.046, respectively).

CONCLUSIONS

Even though bladder adenocarcinoma had been observed moderate effectiveness to chemotherapy, bladder adenocarcinoma is a highly aggressive form of bladder cancer. PFS and OS were short especially in urachal carcinoma.

Role of SATB2 in distinguishing the site of origin in glandular lesions of the bladder/urinary tract

The differential diagnosis of glandular lesions of the bladder/urinary tract can be challenging because of significant morphologic and immunohistochemical overlap between primary lesions and metastasis/direct extension from adjacent organs. Special AT-rich sequence-binding protein 2 (SATB2), encoded on chromosome 2q32-33, is a recently described DNA-binding protein involved in osteoblast lineage commitment and expressed in colorectal and appendiceal neoplasms. In this study, we hypothesized that immunohistochemistry for SATB2 may be of value in distinguishing primary adenocarcinoma of the bladder/urinary tract and urothelial carcinoma with glandular differentiation from gastrointestinal and endocervical primaries. Intensity and distribution of SATB2 nuclear labeling were semiquantitatively scored and compared with those of CDX2. The study included 43 primary adenocarcinomas of the bladder/urinary tract, 20 urothelial carcinomas with glandular differentiation, 26 adenocarcinomas of the uterine cervix, and 22 colorectal adenocarcinomas involving the bladder. Positive SATB2 immunostaining was observed in 21 of 43 (49%) primary bladder/urinary tract adenocarcinomas, in 17 of 22 (77%) colorectal adenocarcinomas, and in the glandular component of 4 of 18 (22%) urothelial carcinomas with glandular differentiation. SATB2 was negative in 25 of 26 endocervical adenocarcinomas and showed focal weak immunostaining (1+) in 1 of 26 (4%). The results were not significantly different from those seen with CDX2. We conclude that SATB2 immunohistochemistry is not useful in supporting urothelial versus gastrointestinal or endocervical origin in the differential diagnosis of glandular lesions of the bladder/urinary tract.

Detection of TERT promoter mutations in primary adenocarcinoma of the urinary bladder

TERT promoter mutations (TERT-mut) have been detected in 60% to 80% of urothelial carcinomas. A molecular urine-based screening assay for the detection of TERT-mut is currently being pursued by our group and others. A small but significant number of bladder carcinomas are adenocarcinoma. The current study assesses the incidence of TERT-mut in primary adenocarcinomas of urinary bladder. A retrospective search of our institutional pathology records identified 23 cystectomy specimens with a diagnosis of adenocarcinoma (2000-2014). All slides were reviewed by a senior urologic pathologist to confirm tumor type and select a representative formalin-fixed, paraffin-embedded block for mutational analysis. Adequate material for DNA testing was available in 14 cases (7 enteric type and 7 not otherwise specified). TERT-mut sequencing analysis was performed using previously described SafeSeq technique. Overall, 28.5% of primary adenocarcinoma harbored TERT-mut. Interestingly, 57% of nonenteric adenocarcinomas were mutation positive, whereas none of the enteric-type tumors harbored mutations. Similar to urothelial carcinoma, we found a relatively higher rate of TERT-mut among nonenteric-type adenocarcinomas further supporting the potential utility of TERT-mut urine-based screening assay for bladder cancer.

Urinary Bladder Adenocarcinoma Metastatic to the Abdominal Wall: Report of a Case with Cytohistologic Correlation

We report a case of adenocarcinoma metastatic to the abdominal wall in a 71-year-old man with a history of primary bladder adenocarcinoma. CT-guided core biopsy was performed; imprints and histologic sections showed malignant glands lined by tumor cells with hyperchromatic nuclei and prominent nucleoli, infiltrating through skeletal muscle. Immunohistochemistry revealed positivity for CK7, membranous/cytoplasmic β-catenin, caudal-type homeobox transcription factor 2 (CDX2), and α-methylacyl coenzyme A racemase and negativity for CK20, p63, prostate-specific antigen (PSA), and prostate-specific acid phosphatase (PSAP). These findings were interpreted as metastatic adenocarcinoma, consistent with bladder primary. Primary bladder adenocarcinoma is a rare malignancy arising within glandular metaplasia and is associated with cystitis cystica and cystitis glandularis. Predisposing factors include bladder exstrophy, schistosomiasis, and other causes of chronic bladder irritation. This tumor is divided into intestinal, clear cell, and signet ring cell subtypes. Treatment involves radical cystectomy with pelvic lymph node dissection, and prognosis is unfavorable. Primary bladder adenocarcinoma should be differentiated from urachal adenocarcinoma, which arises from urachal remnants near the bladder dome, and secondary adenocarcinoma, or vesical involvement by adenocarcinoma from a different primary. CK7, CK20, CDX2, thrombomodulin, and β-catenin can help distinguish primary bladder adenocarcinoma from colonic adenocarcinoma; PSA and PSAP can help distinguish primary bladder adenocarcinoma from prostate adenocarcinoma.

Primary adenocarcinoma of the renal pelvis, ureter and the urinary bladder: A case report and review of the literature

Primary adenocarcinoma is a rare type of urological neoplasm. The present study reports the case of a 55-year-old man with multifocal adenocarcinoma of the renal pelvis, ureter and urinary bladder that occurred in association with a large cystic calculus and perinephric abscess. The patient had suffered from gross hematuria for 2 years and right flank pain for 2 months. Following a series of investigations, a large cystic calculus with multiple tumors in the renal pelvis and ureter was identified. Multifocal tumors and a large calculus were located in the bladder using a cystoscope. The pathological report of 3 individual biopsies revealed a moderately differentiated tubular adenocarcinoma. Right nephrectomy, ureterectomy, radical cystectomy and left ureterocutaneostomy were performed. The pathological investigation revealed a moderately differentiated adenocarcinoma of the renal pelvis, ureter and urinary bladder. No additional treatment was administered and the patient remains alive at follow-up without disease recurrence or metastasis. Although uncommon, the development of a tumor is possible in patients that possess long-standing urolithiasis, particularly when accompanied by hydronephrosis or infection.

Adenocarcinoma arising in urinary bladder endocervicosis

Endocervicosis is a rare benign condition characterized by the presence of endocervical-type mucinous glands. Urinary bladder endocervicosis forms an elevated lesion in the posterior wall of the urinary bladder and is sometimes misdiagnosed as a malignant tumor clinically and pathologically. Herein we describe the first case of adenocarcinoma arising in urinary bladder endocervicosis. The patient, a 58-year-old woman, presented with asymptomatic hematuria. Cystoscopy revealed a nodular mass measuring 4 cm in diameter in the posterior wall, and total cystectomy was performed. Histology revealed that the elevated lesion of the bladder wall was composed of haphazard proliferation of cystic glands lined by benign endocervical-type epithelium. An adenocarcinoma arose at the center of this endocervicosis. Mucin histochemistry revealed the presence of sulfomucin in both the endocervicosis and adenocarcinoma components. Immunohistochemically, the endocervicosis was positive for cytokeratin (CK) 7, AE1/AE3, CAM5.2, HBME1, CA19-9, and estrogen receptor (ER), and negative for CK20, CDX2, progesterone receptor (PR), MUC5AC, and β-catenin. The adenocarcinoma showed similar immunohistochemical results, except for loss of ER expression and a slight increase in the ratio of Ki-67-positive cells. This case indicates that endocervicosis, known as a benign lesion, harbors the possibility of malignant transformation.

Telomerase reverse transcriptase promoter mutations in glandular lesions of the urinary bladder

Glandular lesions of the urinary bladder include a broad spectrum of entities ranging from completely benign to primary and secondary malignancies. The accurate diagnosis of these lesions is both important and challenging. Recently, studies suggest that telomerase reverse transcriptase (TERT) promoter mutations could be a biomarker for urothelial carcinoma (UC). We hypothesized that these mutations can distinguish UC with glandular differentiation from nephrogenic adenoma, primary adenocarcinoma of the urinary bladder (PAUB), or secondary malignancies. Twenty-five cases of benign glandular lesions (including nephrogenic adenoma); 29 cases of UC with glandular differentiation; 10 cases of PAUB; and 10 cases each of metastatic colon cancer, prostatic carcinoma, and carcinoma from Mullerian origin were collected. Slides were reviewed and selected to make sure the lesion was at least 10% to 20% of all tissue. Macrodissection was performed in some of cases, and genomic DNA was extracted from the tissue. Telomerase reverse transcriptase promoter mutations were determined by standard polymerase chain reaction sequencing. Twenty-one cases (72%) of UC with glandular differentiation were positive for TERT promoter mutations. However, none of the remaining cases (total 65 cases of benign lesions, PAUB, and metastatic carcinomas) was positive for TERT promoter mutation. Telomerase reverse transcriptase promoter mutations were highly associated with UC including UC with glandular differentiation but not other glandular lesions of bladder. Therefore, in conjunction with morphologic features, Immunohistochemistry stain profile, and clinical information, TERT promoter mutations could distinguish UC with glandular differentiation from other bladder glandular lesions. In addition, lack of TERT promoter mutations in primary adenocarcinoma of bladder suggests that this entity may have different origin or carcinogenesis from those of UC.

Intestinal metaplasia of the bladder with dysplasia: a risk factor for carcinoma?

AIMS

Intestinal metaplasia (IM) of the bladder is a benign glandular proliferation, where the urothelium becomes lined by intestinal-type epithelium. There is no association between IM and an increased risk for the development of adenocarcinoma. However, in rare cases IM shows dysplasia, similar to that of the gastrointestinal tract. We evaluated the significance of urothelial IM with dysplasia.

METHODS AND RESULTS

Consultation cases were searched for IM of the bladder with dysplasia. We identified 20 cases, including 17 males and females, aged 31-85 years (mean 60 years). Twelve (60%) patients had low-grade dysplasia and eight (40%) patients had high-grade dysplasia. Focal dysplasia was found in eight (40%) patients and non-focal dysplasia in 12 (60%) patients. IM with dysplasia was found with concurrent adenocarcinoma in eight (40%) cases. Five of these patients (63%) had disease recurrence and three (38%) patients died from their disease. IM with dysplasia was found with concurrent urothelial carcinoma in one case. Eleven patients had IM with dysplasia without evidence of malignancy. Of these, one went on to develop non-invasive, high-grade papillary urothelial carcinoma.

CONCLUSIONS

Clinical follow-up is recommended in cases of IM with dysplasia, as a significant number of these cases are associated with concurrent carcinoma.

Primary appendiceal adenocarcinoma masquerading as primary bladder tumor: a case report and review of literatures

Adenocarcinoma of the appendix invading the urinary bladder is very rare. We describe such a case in a 42-year-old man and review the relevant literatures. In the present case, although ultrasonography and computed tomography scan revealed a mass in the bladder or in the pelvic and biopsies by cystoscopy showed an adenocarcinoma suspicious for primary of the bladder, its real origin was hard to distinguish. An open exploratory surgery was performed with subsequent resection of appendix and partial bladder. Postoperative histopathological examinations revealed the appendiceal adenocarcinoma infiltrating the bladder wall. The patient refused the right hemicolectomy and received 3 cycles of adjuvant radiotherapy. However, tumor recurrence was found in the bladder 6 months after surgery, and radical cystectomy was eventually performed.

Expression of Aggrus/podoplanin in bladder cancer and its role in pulmonary metastasis

Platelet aggregation-inducing factor Aggrus, also known as podoplanin, is associated with tumor malignancy by promoting hematogenous metastasis. Aggrus overexpression has been reported in some tumor tissues including lung, esophagus, head and neck and brain. We here found the frequent upregulation of aggrus mRNA in urinary bladder cancers using cancer tissue panels from various organs. Immunohistochemical analysis confirmed Aggrus protein expression in urinary bladder cancers and suggested a positive correlation between Aggrus expression and metastatic tendency in bladder cancers. Endogenous expression of Aggrus protein on the cell surface was found in the mouse bladder cancer MBT-2 cell line and human bladder cancer SCaBER cell lines. Knockdown of Aggrus expression in MBT-2 cells decreased their ability to induce platelet aggregation and form pulmonary metastasis in syngeneic mouse models. Knockdown of Aggrus expression in the human bladder cancer SCaBER cells also attenuated their ability to induce platelet aggregation and form pulmonary metastasis in mice. Moreover, pulmonary metastasis of SCaBER cells was prevented by prior administration of our generated anti-Aggrus neutralizing monoclonal antibodies by attenuating their retention in lung. These results indicate that Aggrus plays an important role in bladder cancer metastasis. Thus, anti-Aggrus neutralizing antibodies would be useful for the prevention of hematogenous metastasis of Aggrus-positive bladder cancer.