Papillary urothelial neoplasm of low malignant potential of the urinary bladder: clinicopathologic and outcome analysis from a single academic center

Noninvasive Papillary Urothelial Carcinoma of the Bladder: An Institutional Experience Focusing on Tumors With Borderline Features

CONTEXT.—

Noninvasive papillary urothelial carcinomas (PUCs) comprise most urinary bladder tumors. Distinction between low-grade (LG-PUC) and high-grade (HG-PUC) PUCs is pivotal for determining prognosis and subsequent treatment.

OBJECTIVE.—

To investigate the histologic characteristics of tumors with borderline features between LG-PUC and HG-PUC, focusing on the risk of recurrence and progression.

DESIGN.—

We reviewed the clinicopathologic parameters of noninvasive PUC. Tumors with borderline features were subcategorized as follows: tumors that look like LG-PUC but have occasional pleomorphic nuclei (1-BORD-NUP) or elevated mitotic count (2-BORD-MIT), and tumors with side-by-side distinct LG-PUC and less than 50% HG-PUC (3-BORD-MIXED). Recurrence-free, total progression-free, and specific invasion-free survival curves were derived from the Kaplan-Meier method, and Cox regression analysis was performed.

RESULTS.—

A total of 138 patients with noninvasive PUC were included, with the following distribution: LG-PUC (n = 52; 38%), HG-PUC (n = 34; 25%), BORD-NUP (n = 21; 15%), BORD-MIT (n = 14; 10%), and BORD-MIXED (n = 17; 12%). Median (interquartile range) follow-up was 44.2 months (29.9-73.1 months). Invasion-free survival was different between the 5 groups (P = .004), and pairwise comparison showed that HG-PUC had a worse prognosis compared with LG-PUC (P ≤ .001). On univariate Cox analysis, HG-PUC and BORD-NUP were 10.5 times (95% CI, 2.3-48.3; P = .003) and 5.9 times (95% CI, 1.1-31.9; P = .04) more likely to invade, respectively, when compared to LG-PUC.

CONCLUSIONS.—

Our findings confirm a continuous spectrum of histologic changes in PUC. Approximately a third of noninvasive PUCs show borderline features between LG-PUC and HG-PUC. Compared with LG-PUC, BORD-NUP and HG-PUC were more likely to invade on follow-up. BORD-MIXED tumors did not statistically behave differently from LG-PUC.

Bladder Neoplasia in Pediatric Patients-A Single-Center Experience Including a Case Series

Objective: Bladder lesions like urothelial carcinoma are rare in the first two decades of life. A biopsy of the bladder or urinary cytological examination is seldom required. Gross painless hematuria is the most relevant clinical syndrome. Methods: A retrospective analysis of surgical pathology records collected between 1984 and 2014 at our institution was performed in a search for cases of urothelial neoplasms originating within the urinary bladder in pediatric patients. Diagnoses were confirmed based on pathologic examination using the 2004 World Health Organization (WHO) classification system. We selected keywords such as bladder neoplasia, bladder lesion, urothelial neoplasia, rhabdomyosarcoma, and children. In addition, we describe clinical presentation and diagnostic procedures as well as treatment and follow-up of two patients. A review of the literature was performed to analyze recommendations concerning diagnostic staging, treatment, and follow-up examinations as well as surveillance of urothelial tumors in the pediatric population. Results: Screening the pathology database of the Institute of Medical Genetics and Pathology of the University Hospital Basel between 1988 and 2014 yielded 287 samples involving the urinary bladder, 110 autopsies, 135 biopsies, and 42 cytology specimens. Of these, most samples originated from malformations and inflammation. Only five were tumors: two were urothelial tumors and three were rhabdomyosarcomas. The majority of specimens comprised resections of the diverticula or distal ureter. Our case reports include two patients with a urothelial tumor. Among the urothelial tumors, one was a papillary urothelial neoplasm of low malignant potential (PUNLMP). Painless hematuria was the directing clinical symptom. The tumor was investigated by FISH, and a 9p21 deletion was found. The second tumor-like lesion was a fibroepithelial polyp arising from the bladder neck. Conclusions: Bladder tumors in children are rare and mostly consist of urothelial and mesenchymal neoplasms. Rhabdomyosarcoma is the most common malignant bladder tumor in childhood. Similar to adult urothelial neoplasms, the loss of 9p21 is also implicated in urothelial neoplasms in childhood. Despite an increasing number of case reports and small series published within the last 2 decades, general treatment protocols including recommendations for staging, tumor markers, and follow-up examinations are still not yet available for this tumor entity in the pediatric population.

Papillary Urothelial Neoplasm of Low Malignant Potential (PUNLMP) After Initial TUR-BT: Comparative Analyses with Noninvasive Low-Grade Papillary Urothelial Carcinoma (LGPUC)

Purpose: To verify if the distinction between papillary urothelial neoplasm of low malignant potential (PUNLMP) and noninvasive low-grade papillary urothelial carcinoma (LGPUC) reflects a different biologic activity. Materials and Methods: We reviewed and analyzed the clinical data from 678 patients who had a diagnosis of PUNLMP (n=53) or noninvasive LGPUC (n=625) after initial TUR-BT for bladder neoplasm between 2000 and 2012. Results: The noninvasive LGPUC group showed a higher frequency of recurrence in comparison with the PUNLMP group (46.7% vs. 30.2%, p=0.022). In contrast, there were no significant differences in progression (15.2% vs. 18.9%, p=0.295) between the two groups. Grade progression was reported in 10 patients (LG: n=5; high grade: n=2; carcinoma in situ: n=3) and stage progression was reported in 2 patients (all: T1) in PUNLMP group. The Kaplan-Meier survival analysis showed significantly decreased 5-year recurrence-free survival (RFS) (50.3% vs. 74.6%, log-rank test, p=0.014) in the noninvasive LGPUC group compared to the PUNLMP group. However, there were no significant differences in progression-free survival (PFS) between the two groups. Multivariate analysis revealed that tumor grades according to 2004 WHO/ISUP classification system (PUNLMP vs. LG) were identified as significant predictors of RFS. However, it was not a significant predictor of both PFS and overall survival. Conclusions: PUNLMP had a substantial number of recurrences (30.2%), although RFS was better than noninvasive LGPUC. In addition, PUNLMP had a similar risk of progression compared with noninvasive LGPUC. Consequently, PUNLMP should be treated in a manner similar to noninvasive LGPUC, and long-term clinical follow-up should be recommended for patients with PUNLMP.

Progression to T1 High Grade (T1HG) from a Lower Stage/Grade is Associated with Poorer Survival Outcomes than Initial Diagnosis with T1HG Bladder Cancer

BACKGROUND

Several studies have documented a poor prognosis in those patients who were initially diagnosed with non-muscle-invasive bladder cancer (NMBIC) and progressed to muscle-invasive bladder cancer (MIBC) compared with those who initially presented with MIBC. However, studies regarding this issue have not yet been performed in patients with T1 high-grade (T1HG) tumor. We aimed to compare survival outcomes between patients diagnosed as T1HG after initial transurethral resection of the bladder tumor (TUR-BT) and patients who presented with lower stage and/or grade but progressed to T1HG at the time of tumor recurrence.

METHODS

The study comprised 499 patients who had a diagnosis of T1HG after initial TUR-BT (initial T1HG group) and 62 patients who progressed to T1HG after TUR-BT at the time of tumor recurrence (progressed T1HG group). Progression was defined as recurrence to a higher grade and/or stage than the previous result, while MIBC progression was defined as progression to stage T2 or higher and/or N+, and/or M1.

RESULTS

The median overall survival (OS) and cancer-specific survival (CSS) durations were 38.0 and 29.0 months, respectively. Kaplan-Meier curve analysis showed significantly decreased 5-year OS (74.4 vs. 57.4%), CSS (86.4 vs. 72.8%), and MIBC progression-free survival (82.6 vs. 62.2%) in the progressed T1HG group. Multivariate analysis revealed that progressed T1HG was a significant predictor of OS, CSS, and MIBC progression (all, p < 0.05).

CONCLUSIONS

The progressed T1HG group showed poorer survival outcomes compared with the initial T1HG group. Consequently, in patients who progress to T1HG, intensive surveillance and treatment strategies should be considered.

Current concepts in the diagnosis and pathobiology of intraepithelial neoplasia: A review by organ system

Answer questions and earn CME/CNE In this report, a team of surgical pathologists has provided a review of intraepithelial neoplasia in a host of (but not all) anatomic sites of interest to colleagues in various medical specialties, namely, uterine cervix, ovary, breast, lung, head and neck, skin, prostate, bladder, pancreas, and esophagus. There is more experience with more readily accessible sites (such as the uterine cervix and skin) than with other anatomic sites, and the lack of uniform terminology, together with divergent biology in various sites, makes it difficult to paint a unifying, relevant portrait. The authors' aim was to provide a framework from which to move forward as we care for patients with such precancerous lesions. CA Cancer J Clin 2016;66:408-436. © 2016 American Cancer Society.

Downregulation of miR-133b predict progression and poor prognosis in patients with urothelial carcinoma of bladder

We found microRNA-133b (miR-133b) was downregulated in urothelial carcinoma of the bladder (UCB) tissues, and it could inhibit the proliferation and induce apoptosis in UCB cells. Consequently, we intend to explore the clinical significance of miR-133b in UCB patients. Expression of miR-133b in 146 UCB specimens and matched adjacent non-neoplastic bladder tissues were measured by quantitative real-time polymerase chain reaction. The overall survival (OS) curve and progression-free survival (PFS) curve were plotted using the Kaplan-Meier method. Prognostic factors for OS and PFS were identified by univariate and multivariate analyses using the Cox proportional hazards regression model. The expression of miR-133b was significantly downregulated in UCB tissues compared with those in adjacent non-neoplastic bladder tissues (P < 0.001). Among UCB patients, low expression of miR-133b significantly correlated with aggressive clinicopathological features. Multivariate analysis indicated that the expression of miR-133b was the independent prognostic factors for predicting PFS (RR: 2.97; 95% CI: 1.78-6.44; P = 0.009) and OS (RR: 4.23; 95% CI: 1.51-11.8; P = 0.011) in patients with UCB. Our study demonstrated that downregulation of miR-133b associated with aggressive clinicopathological features and predicted unfavorable prognosis in patients with UCB, might serve as feasible biomarker for clinical outcome of UCB patients after surgery and potential therapeutic target in the future.

Long-term outcome of primary Papillary Urothelial Neoplasm of Low Malignant Potential (PUNLMP) including PUNLMP with inverted growth

BACKGROUND

Few larger studies have evaluated the long-term outcome after a diagnosis of papillary urothelial neoplasm of low malignant potential (PUNLMP), demonstrating a broad range of recurrence and progression rates. Additionally, no study has addressed the outcome of PUNLMP exhibiting inverted growth. We evaluated the long term clinical outcome of primary papillary urothelial neoplasm of low malignant potential (PUNLMP), including PUNLMP with inverted growth in a large single center study.

METHODS

We evaluated 189 primary PUNLMP (177 exophytic, 12 inverted), diagnosed from January 1, 2000 to December 31, 2009, in a centralized uropathology practice. We excluded PUNLMP diagnosed after a previous or with a concurrent urothelial neoplasm. Recurrence was defined as any subsequent urothelial neoplasm, regardless of the grade. Progression was defined as any subsequent higher-grade or invasive urothelial neoplasm. Recurrence and progression were established only if documented on a subsequent biopsy. Descriptive statistical analysis was performed using Microsof Excel software package.

RESULTS

The location of PUNLMP included bladder (187) and renal pelvis and ureter (1 each). After a median follow-up of 61 months (range, 9-128 months), 20.1% patients developed a recurrence. Recurrence with PUNLMP only was found in 9% of patients. Subsequent low-grade urothelial carcinoma was documented in 9.5% of patients. Progression to high-grade urothelial carcinoma was found in 1.6% patients (1% with muscle invasion). No patients with recurrent PUNLMP or subsequent low-grade carcinoma demonstrated invasion. All patients with PUNLMP exhibiting an inverted growth had no recurrence or progression on follow-up.

CONCLUSION

In this study, primary PUNLMP recurred primarily either as PUNLMP or low grade urothelial carcinoma. Primary PUNLMP rarely progressed to high grade or invasive carcinoma on long term follow-up. No recurrence or progression was documented on follow-up for PUNLMP that demonstrated exclusively inverted growth.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1332825572154074.

Urothelial bladder tumour in childhood: A report of two cases and a review

Urothelial bladder tumour in childhood is extremely rare, and almost all the reported cases have been low-grade tumours with a favourable outcome. Here we review 57 reports comprising 127 cases, and we report two new cases.

A Rare Case of Papillary Bladder Neoplasm Detected by Sonography in a Young Male

Bladder tumors are extremely rare in young adults and are usually linked to tobacco abuse, chronic infections, or occupational exposure to carcinogens. We present a case of a papillary urothelial neoplasm in a 19-year-old man with no significant risk factors, initially detected by sonography and later confirmed with computed tomographic urography and cystoscopy. The tumor was quickly resected and mitomycin C instilled in the bladder prophylactically. This is an atypical situation in a patient with none of the common risk factors.

Mismatch repair hMSH2, hMLH1, hMSH6 and hPMS2 mRNA expression profiles in precancerous and cancerous urothelium

Changes in the expression of the mismatch repair (MMR) genes hMSH2, hMLH1, hMSH6 and hPMS2 reflect dysfunction of the DNA repair system that may allow the malignant transformation of tissue cells. The aim of the present study was to address the mRNA expression profiles of the mismatch DNA repair system in cancerous and precancerous urothelium. This is the first study to quantify MMR mRNA expression by applying quantitative real-time PCR (qPCR) and translate the results to mRNA phenotypic profiles (r, reduced; R, regular or elevated) in bladder tumors [24 urothelial cell carcinomas (UCCs) and 1 papillary urothelial neoplasm of low malignant potential (PUNLMP)] paired with their adjacent normal tissues (ANTs). Genetic instability analysis was applied at polymorphic sites distal or close to the hMSH2 and hMLH1 locus. Presenting our data, reduced hMSH2, hMSH6 and hPMS2 mRNA expression profiles were observed in cancerous and precancerous urothelia. Significantly, the ANTs of UCCs revealed the highest percentages of reduced hMSH2 (r(2)), hMSH6 (r(6)) and hPMS2 (p(2)) mRNA phenotypes relative to their tumors (P<0.03). In particular, combined r(2)r(6) (P<0.02) presented a greater difference between ANTs of low-grade UCCs vs. their tumors compared with ANTs of high-grade UCCs (P= 0.000). Reduced hMLH1 (r(1)) phenotype was not expressed in precancerous or cancerous urothelia. The hMSH6 mRNA was the most changed in UCCs (47.8%), while hMSH2, hMLH1 and hPMS2 showed overexpression (47.8, 35 and 30%, respectively) that was associated with gender and histological tumor grading or staging. Genetic instability was rare in polymorphic regions distal to hMLH1. Our data reveal a previously unrecognized hMSH2 and hMSH6 mRNA combined phenotype (r(2)r(6)) correlated with a precancerous urothelium and show that hMLH1 is transcriptionally activated in precancerous or cancerous urothelium. In the present study, it is demonstrated that reduction of hMSH6 mRNA is a frequent event in bladder tumorigenesis and reflects a common mechanism of suppression with hMSH2, while alterations of hMSH2 or hMLH1 mRNA expression in UCCs does not correlate with the allelic imbalance of polymorphic regions harboring the genes.