Non-urothelial carcinomas of the bladder

Recurrent bladder urothelial carcinoma complicated with primary bladder large cell neuroendocrine carcinoma: a case report and literature review

Objective

To improve the understanding, diagnosis and treatment of bladder large cell neuroendocrine carcinoma (LCNEC).

Methods

A clinical case of bladder LCNEC admitted to our hospital was reported. The epidemiology, prognosis, diagnosis and treatment methods of large cell neuroendocrine carcinoma were reviewed. The diagnosis and treatment status and prognosis were discussed based on the literature.

Results

The female patient was admitted to hospital for "more than 4 years after TURBT and intermittent hematuria for more than 2 years". She was diagnosed as recurrent bladder cancer and underwent "radical cystotomy + hysterectomy". The postoperative pathological findings were high-grade urothelial carcinoma of the bladder neck and large cell neuroendocrine carcinoma of the bladder. The patient recovered well after surgery, but refused radiotherapy and chemotherapy and is still under close follow-up.

Conclusion

Bladder LCNEC is clinically rare, has unique pathological features, is more aggressive than traditional urothelial carcinoma, and has a poor prognosis. Surgery, chemotherapy and radiotherapy should be combined with multi-mode treatment.

Urachal and Nonurachal Adenocarcinomas of the Urinary Bladder: A Comprehensive Genomic Profiling Study

PURPOSE

Although both urachal (U) and nonurachal (NU) bladder adenocarcinomas (adenoCas) share several histologic similarities, they differ in location and sometimes in therapeutic options. We analyzed the differences in genomic alterations (GAs) between these tumor entities, with the aim of identifying potential therapeutic targets for clinical trials.

MATERIALS AND METHODS

Overall, 133 U and 328 NU adenoCas were analyzed. Hybrid capture-based comprehensive genomic profiling (CGP) was performed to evaluate all classes of GA. Germline status of GA was predicted using a validated somatic-germline computational method. CGP was performed using the FoundationOne and FoundationOne CDx assays (Foundation Medicine, Inc).

RESULTS

The most frequent GA in both U and NU cohorts included TP53 (86.5% v 81.1%) and KRAS (34.6% v 27.7%). GAs characteristic of colorectal adenoCa, such as SMAD4 (P = .069) and GNAS (P = .071), were more common in U versus NU. Conversely, TERT (P < .01) and RB1 (P = .071) were more prevalent in NU adenoCa. Notably, both U and NU adenoCas exhibited possibly targetable GA in PIK3CA (7.5% v 7.9%) and ERBB2 (6.8% v 7.6%). Biomarkers associated with potential benefit from anti-PD-1/L1 were infrequent. Median tumor mutational burden was 2.6 and 3.5 mutations per megabase for U and NU, respectively, and PD-L1 expression >1% was rare. Genomic ancestry and genomic signature distribution were similar in both tumor types. GAs were most commonly of somatic nature. Limitations include lack of clinical data, tumor heterogeneity, and retrospective nature.

CONCLUSION

U and NU adenoCAs revealed differences in GA, with PIK3CA and ERBB2 being identified as putative therapeutic targets. Biomarkers of response to anti-PD-(L)1 were uncommon. Results highlight the potential of CGP to personalize treatment options of bladder adenoCa and inform clinical trial designs.

Current Advances in the Management of Nonurothelial Subtypes of Bladder Cancer

Urothelial cancer (UC) is the most common histology seen in bladder tumors. The 2022 WHO classification of urinary tract tumors includes a list of less common subtypes (formerly known as variants) for invasive UC which are considered high-grade tumors. This review summarizes the most recent advances in the management of selected nonurothelial subtypes of bladder cancer: squamous cell carcinoma, small cell carcinoma, sarcomatoid urothelial carcinoma, micropapillary carcinoma, plasmacytoid carcinoma, adenocarcinoma, and urachal carcinoma. The role of neoadjuvant and adjuvant chemotherapy has not been well characterized for most of these histologies, and prospective data are extremely limited. Participation in clinical trials is recommended in advanced disease.

Long-Term Survival After Definitive Concurrent Chemoradiation Therapy for Synchronous Small Cell Neuroendocrine Carcinoma of the Urinary Bladder and Adenocarcinoma of the Prostate: A Case Report

Available reports of synchronous prostate and bladder cancer have exclusively described radical cystoprostatectomy with or without perioperative chemotherapy as the treatment of choice. There are no reports of curative intent or definitive chemoradiation therapy for synchronous primary bladder and primary prostate cancers. Small cell carcinoma of the bladder is a rare and aggressive tumor. We present the first case of synchronous mixed small cell carcinoma and urothelial carcinoma of the urinary bladder and adenocarcinoma of the prostate in a 70-year-old male who attained long-term survival after curative intent and definitive concurrent chemoradiotherapy with minimal acute and late toxicities. The patient remained alive and disease-free at 41 months post-treatment and achieved excellent functional outcomes with organ preservation. Definitive chemoradiation therapy offers a safe and effective, curative-intent organ preservation treatment for localized synchronous prostate and bladder cancers.

CD271 promotes proliferation and migration in bladder cancer

Bladder cancer is a urothelial cancer and effective therapeutic strategies for its advanced stages are limited. Here, we report that CD271, a neurotrophin receptor, promotes the proliferation and migration of bladder cancer cells. CD271 knockdown decreased proliferation in both adherent and spheroid cultures, and vice versa when CD271 was overexpressed in bladder cancer cell lines. CD271 depletion impaired tumorigenicity in vivo. Migration activity was reduced by CD271 knockdown and TAT-Pep5, a known CD271-Rho GDI-binding inhibitor. Apoptosis was induced by CD271 knockdown. Comprehensive gene expression analysis revealed alterations in E2F- and Myc-related pathways upon CD271 expression. In clinical cases, patients with high CD271 expression showed significantly shortened overall survival. In surgically resected specimens, pERK, a known player in proliferation signaling, colocalizes with CD271. These data indicate that CD271 is involved in bladder cancer malignancy by promoting cell proliferation and migration, resulting in poor prognosis.

The perioperative and long-term outcomes of patients with variant histology bladder cancer undergoing radical cystectomy: A propensity score-matched analysis with pure urothelial carcinoma

OBJECTIVES

To assess the perioperative and long-term outcomes after open radical cystectomy in patients with histological variants versus pure urothelial carcinoma.

METHODS

Patients with a variant histology carcinoma of the urinary bladder were matched through a propensity score analysis with those with pure urothelial carcinoma on a 1:3 ratio. The two groups were compared in terms of perioperative and long-term morbidity and mortality.

RESULTS

Overall, 148 individuals were included in the present retrospective study (37 with variant histology and 111 with pure urothelial carcinoma). A total of 107 (72.3%) individuals presented at least one perioperative complication based on the Clavien-Dindo classification. This proportion was similar between patients with urothelial versus variant histology carcinoma (P = .22). In the long term, the number of patients with clinically significant incisional hernia requiring surgery [14 (12.7%) vs 3 (8.3%), P = .68], uretero-intestinal/uretero-cutaneous strictures or any other complication related to the applied urinary diversion [15 (13.6%) vs 7 (19.4%), P = .56], as well as the number of patients presenting with septicemia [17 (15.5%) vs 10 (27.8%), P = .16] or with urinary tract obstruction [12 (10.9%) vs 4 (11.1%), P > .99] at follow-up did not differ between urothelial versus variant histology carcinoma. The survival analysis with Kaplan-Meier curves and the univariate Cox regression model suggested that the risk of death from any cause was increased in patients with variant compared to pure urothelial histology (log-rank test = 0.045, hazard ratio: 1.7, 95% confidence interval: 1.01-2.87, P = .047).

CONCLUSIONS

Perioperative morbidity and mortality are comparable in patients with variant histology versus pure urothelial carcinoma.

Evaluating atezolizumab in patients with urinary tract squamous cell carcinoma (AURORA): study protocol for a single arm, open-label, multicentre, phase II clinical trial

BACKGROUND

Bladder and urinary tract cancers account for approximately 21,000 new diagnoses and 5,000 deaths annually in the UK. Approximately 90% are transitional cell carcinomas where advanced disease is treated with platinum based chemotherapy and PD-1/PD-L1 directed immunotherapy. Urinary tract squamous cell carcinoma (UTSCC) accounts for about 5% of urinary tract cancers overall making this a rare disease. We have yet to establish definitive systemic treatment options for advanced UTSCC. Preliminary translational data, from UTSCC patient tumour samples, indicate high PD-L1 expression and tumour infiltrating lymphocytes in a proportion of cases. Both of these features are associated with differential gene expression consistent with a tumour/immune microenvironment predicted to be susceptible to immune checkpoint directed immunotherapy which we will evaluate in the AURORA trial.

METHODS

AURORA is a single arm, open-label, multicentre,UK phase II clinical trial. 33 patients will be recruited from UK secondary care sites. Patients with UTSCC, suitable for treatment with palliative intent, will receive atezolizumab PD-L1 directed immunotherapy (IV infusion, 1680 mg, every 28 days) for one year if tolerated. Response assessment, by cross sectional imaging will occur every 12 weeks. AURORA uses a Simon's 2-stage optimal design with best overall objective response rate (ORR, by RECIST v1.1) at a minimum of 12 weeks from commencing treatment as the primary endpoint. Secondary endpoints will include overall survival, progression-free survival, duration of response, magnitude of response using waterfall plots of target lesion measurements, quality of life using the EORTC QLQ-C30 tool, safety and tolerability (CTCAE v5) and evaluation of potential biomarkers of treatment response including PD-L1 expression. Archival tumour samples and blood samples will be collected for translational analyses.

DISCUSSION

If this trial shows atezolizumab to be safe and effective it may lead to a future late phase randomised controlled trial in UTSCC. Ultimately, we hope to provide a new option for treatment for such patients.

TRIAL REGISTRATIONS

EudraCT Number: 2021-001995-32 (issued 8th September 2021); ISRCTN83474167 (registered 11 May 2022); NCT05038657 (issued 9th September 2021).

Alternative splicing in bladder cancer: potential strategies for cancer diagnosis, prognosis, and treatment

Bladder cancer is the most common malignancy of the urinary tract worldwide. The therapeutic options to tackle this disease comprise surgery, intravesical or systemic chemotherapy, and immunotherapy. Unfortunately, a wide number of patients ultimately become resistant to these treatments and develop aggressive metastatic disease, presenting a poor prognosis. Therefore, the identification of novel therapeutic approaches to tackle this devastating pathology is urgently needed. However, a significant limitation is that the progression and drug response of bladder cancer is strongly associated with its intrinsic molecular heterogeneity. In this sense, RNA splicing is recently gaining importance as a critical hallmark of cancer since can have a significant clinical value. In fact, a profound dysregulation of the splicing process has been reported in bladder cancer, especially in the expression of certain key splicing variants and circular RNAs with a potential clinical value as diagnostic/prognostic biomarkers or therapeutic targets in this pathology. Indeed, some authors have already evidenced a profound antitumor effect by targeting some splicing factors (e.g., PTBP1), mRNA splicing variants (e.g., PKM2, HYAL4-v1), and circular RNAs (e.g., circITCH, circMYLK), which illustrates new possibilities to significantly improve the management of this pathology. This review represents the first detailed overview of the splicing process and its alterations in bladder cancer, and highlights opportunities for the development of novel diagnostic/prognostic biomarkers and their clinical potential for the treatment of this devastating cancer type. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Disease.

Bladder colloid carcinoma: A case report

Non-urothelial bladder cancers are rare. We report the case of a 72-year-old who consulted for terminal hematuria evolving for three months. Computed Tomography scan showed a tumor of the anterior wall of the bladder. The patient underwent a transurethral resection of the bladder tumor. The histological examination of the tumor showed a bladder colloid carcinoma. The extension evaluation showed pulmonary and bone metastases. The patient received chemotherapy.

Scoring Systems for Immunohistochemistry in Urothelial Carcinoma

Immunohistochemistry is widely used in diagnostic and scientific analysis of urothelial carcinoma. Objective interpretation of staining results is mandatory for accuracy and comparability in diagnostic and therapeutic patient care as well as research.Herein we summarize and explain standardized microscopic evaluation and scoring approaches for immunohistochemical stainings. We focus on commonly used and generally feasible approaches for different cellular compartments and comment on their utility in diagnostics and research practice.

Bladder Preservation for Muscle-Invasive Bladder Cancer With Variant Histology

A growing body of evidence has shown bladder-preservation with chemo-radiotherapy achieves comparable survival to Radical Cystectomy (5-year OS 50%-70%) and superior quality of life outcomes for patients with muscle-invasive urothelial carcinoma of the bladder (UC). However, up to 55% of patients harbor variant histology and in this review we aim to clarify the role of bladder-preservation for this group. We first draw the distinction between urothelial carcinoma with divergent differentiation (UCDD) and non-urothelial carcinoma (NUC). UCDD is common, increasing in prevalence, and whilst each subtype may have its own characteristics current evidence suggests comparable outcomes with radical cystectomy and bladder-preservation. Non-urothelial carcinoma is a collection of distinct pathologies each deserving of its own management strategy. However, these tumors are rare, and evidence is generated from retrospective studies with significant inherent bias. Small cell carcinoma of the bladder has good evidence for bladder-preservation; however, other pathologies such as Squamous Cell Carcinoma and Adenocarcinoma are not well supported. We recommend careful multidisciplinary appraisal of the evidence for each subtype and honest patient discussion about the limited evidence before reaching management decisions. As we look to the future molecular-profiling may help better characterize these tumors and aid in treatment selection.

Urothelial Carcinoma: Divergent Differentiation and Morphologic Subtypes

Urothelial carcinoma (UC) is known to encompass a wide spectrum of morphologic features and molecular alterations. Approximately 15% to 25% of invasive UC exhibits histomorphologic features in the form of "divergent differentiation" along other epithelial lineages, or different "subtypes" of urothelial or sarcomatoid differentiation. It is recommended that the percentage of divergent differentiation and or subtype(s) be reported whenever possible. Recent advances in molecular biology have led to a better understanding of the molecular underpinning of these morphologic variations. In this review, we highlight histologic characteristics of the divergent differentiation and subtypes recognized by the latest version of WHO classification, with updates on their molecular and clinical features.

The 2022 ENCR Recommendations on recording and reporting of urothelial tumours of the urinary tract

An updated European Network of Cancer registries (ENCR) Recommendations on Recording and Reporting of Urothelial Tumours of the Urinary Tract had been published in 2022. After the publication by the ENCR of the "Recommendations for coding bladder cancers" in 1995, knowledge about the biology and pathology of urinary tract tumors and their classification has varied and increased substantially. On the other hand, several studies have shown that cancer registries use different definitions, criteria for inclusion and coding of urothelial tumors. This great variability among registries affects not only the criteria for recording (registration, coding and classification) but also the criteria of reporting (counting in the statistics of incidence and survival) urinary tract tumors. This causes difficulties in the data comparability from different registries. Recording and reporting of urothelial tumors requires the application of standard criteria that must take into account the combination of the multiple aspects as the primary topography, the histological type, the grade, the extent of invasion, the multi-centricity, the progressions and the time interval between tumors. This led to the creation of a Working Group of the ENCR that developed these recommendations on the recording and reporting of urothelial tumors of the urinary tract. This article reports these recommendations and the rationale for each.

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.

Classifying Pulmonary and Urinary High-grade Neuroendocrine Carcinoma by CK7 Immunohistochemistry

High-grade neuroendocrine carcinoma (HGNEC) is subclassified into small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LCNEC). Although both are clinically aggressive, the SmCC and LCNEC need to have different treatment strategies, and accurate pathologic diagnosis is challenging. We studied a large retrospective cohort (186 cases) of HGNEC of bladder and lung to investigate the abundance of cytokeratin (CK) 7 expression and staining pattern in SmCC and LCNEC. Overall, the pulmonary and urinary HGNEC exhibited several different CK7 staining patterns, including negative staining (n=28), dot-like staining (n=73), partial membranous staining (n=26), and complete membranous staining (n=60). Overall, 88.9% (44/49) of pulmonary SmCC and 88.0% (44/50) of urinary SmCC showed negative or dot-like patterns for CK7, while 90.8% (59/65) of pulmonary LCNEC and 72.7% (16/22) of urinary LCNEC showed partial or complete membranous patterns for CK7 (χ 2 =105.05, P <0.0001). The distinct staining patterns were also present in those mixed SmCC and LCNEC. In addition, the specimen types or fixation did not affect CK7 staining patterns. In conclusion, CK7 has a high differential value for SmCC and LCNEC and could help guide personalized treatment for patients.

Molecular Oncology of Bladder Cancer from Inception to Modern Perspective

Within the last forty years, seminal contributions have been made in the areas of bladder cancer (BC) biology, driver genes, molecular profiling, biomarkers, and therapeutic targets for improving personalized patient care. This overview includes seminal discoveries and advances in the molecular oncology of BC. Starting with the concept of divergent molecular pathways for the development of low- and high-grade bladder tumors, field cancerization versus clonality of bladder tumors, cancer driver genes/mutations, genetic polymorphisms, and bacillus Calmette-Guérin (BCG) as an early form of immunotherapy are some of the conceptual contributions towards improving patient care. Although beginning with a promise of predicting prognosis and individualizing treatments, "-omic" approaches and molecular subtypes have revealed the importance of BC stem cells, lineage plasticity, and intra-tumor heterogeneity as the next frontiers for realizing individualized patient care. Along with urine as the optimal non-invasive liquid biopsy, BC is at the forefront of the biomarker field. If the goal is to reduce the number of cystoscopies but not to replace them for monitoring recurrence and asymptomatic microscopic hematuria, a BC marker may reach clinical acceptance. As advances in the molecular oncology of BC continue, the next twenty-five years should significantly advance personalized care for BC patients.

Identification of a Novel Ferroptosis-Related Gene Signature for Prediction of Prognosis in Bladder Urothelial Carcinoma

BACKGROUND

sBladder urothelial carcinoma is the most prevalent type of bladder cancer, characterized by drug resistance, high recurrence rate, and unfavorable prognosis. Ferroptosis is a newly discovered type of non-apoptotic cell death, which has been reported to be strongly correlated with tumor occurrence and development.

OBJECTIVE

In this study, we characterized ferroptosis-specific biomarkers to elucidate the association between ferroptosis-related genes (FRGs) and bladder urothelial carcinoma.

METHODS

The TCGA and GEO database were adopted to obtain data and corresponding clinicopathological information. Univariate and multivariate cox regression were performed to establish a ferroptosis-related model. Besides, the KM plot visualized prognosis between high risk and low risk groups. Moreover, cBioportal platform was used to gather information on genetic alteration and DNA methylation of hub FRGs in BLCA patients. Additionally, the GSEA software was used to detect the difference in gene expression between high-risk and low-risk subgroups.

RESULTS

Six ferroptosis-related genes were identified to be highly correlated with overall survival. Besides, we explored the genetic variations of these FRGs, as well as the correlation between FRG expression and copy number values. Additionally, the DNA methylation status of these FRGs was determined. Moreover, we constructed a ferroptosis risk model with the six FRGs to predict the prognosis of BLCA. The results demonstrated that a higher risk score indicated an unfavorable prognosis. The ferroptosis signature was associated with clinical and molecular characteristics and could be regarded as an independent prognostic factor for BLCA patients.

CONCLUSIONS

In summary, we established and verified a ferroptosis risk model which had the potential to independently predict the prognosis of bladder urothelial carcinoma.

Rare tumours of the bladder: A Saudi registry based descriptive study

Objective

There is limited literature focusing on the characteristics and behaviours of bladder tumours outside of the common three morphologies, that is, urothelial carcinoma, squamous cell carcinoma, and adenocarcinoma. The presented study provides a descriptive analysis of rare bladder tumours in KSA.

Methods

This retrospective cohort study included all patients with a primary rare bladder tumour between 1 January 2008 and 31 December 2017. The data were acquired from the Saudi Tumour Registry. Frequencies and percentages were then generated for the categorical variables, while means and standard deviations were calculated for quantitative variables.

Results

The study included 65 patients. The majority (n = 35, 53.8%) were aged 60 years and older. The patients were predominantly male (n = 53, 81.5%) and the majority lived in the Western region (n = 26, 40.?%). The most diagnosed tumour morphologies were small cell carcinoma in adults (n = 11, 16.9%) and embryonal rhabdomyosarcoma in children (n = 14, 21.5%), with the dominant diagnosis method being histology of primary tumour in 98.5% of the patients. Most tumours were localised (n = 30, 46.2%) and multifocal (n = 34, 52.3%). The overall mortality rate was 24.6%, with an overall diagnosis to death interval of 1.14 ± 0.75 years wherein small cell carcinoma was the shortest (0.84 ± 0.24) days.

Conclusion

There remains a gap in the literature regarding uncommon urologic tumours. Shedding light on these factors will aid in further understanding the patterns of tumour behaviour in the region. This will facilitate enhanced risk-and response-based screening strategies and more favourable outcomes. Additionally, formulating a global registry for such patients is recommended.

Treatment Outcomes for Small Cell Carcinoma of the Bladder: Results From a UK Patient Retrospective Cohort Study

PURPOSE

Small cell carcinoma of the bladder (SCCB) is rare, accounting for less than 1% of all bladder carcinomas. It is aggressive, and outcomes are poor as a result of its early metastatic spread. Owing to its rarity, there are limitations on data to propose standardized management pathways.

METHODS AND MATERIALS

We conducted a retrospective analysis of patients presenting with pure or predominant-histology SCCB to 26 institutions in the United Kingdom between 2006 and 2016. The data cutoff date was February 1, 2018. We report patient characteristics, treatment received, and subsequent clinical outcomes.

RESULTS

A total of 409 eligible patients were included. Among these, 306 (74.8%) were male, the median age was 71 years (range, 35-96 years), and 189 patients (46.2%) had pure-histology SCCB. At data cutoff, 301 patients (73.6%) had died. The median overall survival (OS) was 15.9 months (95% CI, 13.2-18.7 months). Two hundred patients (48.9%) were confirmed to have bladder-confined disease (N0, M0), with a median OS of 28.3 months (95% CI, 20.9-35.8 months), versus a median OS of 12.7 months (95% CI, 10.9-14.6 months) for the 172 patients (42.1%) with confirmed N1-3 and/or M1 disease (hazard ratio [HR], 2.03; 95% CI, 1.58-2.60; P < .001). A total of 247 patients (61.5%) received primary chemotherapy, with a median OS of 21.6 months (95% CI, 15.5-27.6 months), versus a median OS of 9.1 months (95% CI, 5.4-12.8 months) in patients who did not receive primary chemotherapy (HR, 0.46; 95% CI, 0.37-0.59; P < .001). Choice of chemotherapy agent did not alter outcomes. For those with bladder-confined disease, 61 (30.5%) underwent cystectomy, and 104 (52.0%) received radiation therapy. Survival outcomes were similar for both cystectomy and radiation therapy. Only 6 patients (1.5%) were identified as having brain metastases at any time point.

CONCLUSIONS

To our knowledge, this is the largest retrospective study of all-stage SCCB to date. Patients have a poor prognosis overall, but survival is improved in those able to receive chemotherapy and with organ-confined disease. Brain metastases are rare.

Unusual Faces of Bladder Cancer

Simple Summary

The spectrum of architectural and cytological findings in UC is wide, although transitional cell carcinoma, either papillary or flat, low- or high-grade, constitutes the majority of cases in routine practice. Some of these changes are just mere morphological variations, but others must be recognized since they have importance for the patient. The goal of this review is to compile this histological variability giving to the general pathologist a general idea of this morphological spectrum in a few pages. The review also updates the literature focusing specifically on the morphological and immunohistochemical clues useful for the diagnosis and some selected molecular studies with prognostic and/or diagnostic implications.

Abstract

The overwhelming majority of bladder cancers are transitional cell carcinomas. Albeit mostly monotonous, carcinomas in the bladder may occasionally display a broad spectrum of histological features that should be recognized by pathologists because some of them represent a diagnostic problem and/or lead prognostic implications. Sometimes these features are focal in the context of conventional transitional cell carcinomas, but some others are generalized across the tumor making its recognition a challenge. For practical purposes, the review distributes the morphologic spectrum of changes in architecture and cytology. Thus, nested and large nested, micropapillary, myxoid stroma, small tubules and adenoma nephrogenic-like, microcystic, verrucous, and diffuse lymphoepithelioma-like, on one hand, and plasmacytoid, signet ring, basaloid-squamous, yolk-sac, trophoblastic, rhabdoid, lipid/lipoblastic, giant, clear, eosinophilic (oncocytoid), and sarcomatoid, on the other, are revisited. Key histological and immunohistochemical features useful in the differential diagnosis are mentioned. In selected cases, molecular data associated with the diagnosis, prognosis, and/or treatment are also included.

The Value of Preoperative Alpha-L-Fucosidase Levels in Evaluation of Malignancy and Differential Diagnosis of Urothelial Neoplasms

Purpose

To evaluate the role of Alpha-L-fucosidase (AFU) in diagnosis and differential diagnosis of pure urothelial carcinoma (UC), urothelial carcinoma with squamous differentiation (UCSD), and squamous cell carcinoma (SqCC).

Methods

A retrospective study was performed for 599 patients who were histologically confirmed with urothelial tumor. Preoperative AFU levels were compared across the distinct subgroups with different clinicopathological parameters. ROC curve analysis and logistic regression analysis were performed to further evaluate the clinical application value of serum AFU levels in diagnosis and differential diagnosis of urothelial tumors.

Results

There were no statistically significant differences in the AFU levels between different groups with different malignant degrees (UC versus papilloma and papillary urothelial neoplasm of low malignant potential [PUNLMP], high-grade UC versus low-grade UC, invasive versus noninvasive malignant uroepithelial tumor) and different pathological types (UC, UCSD, and SqCC) (all P > 0.05). ROC curve analysis and logistic regression analysis showed that there was no statistically significant association between AFU levels and the tumor characteristics (all P > 0.05).

Conclusions

Preoperative AFU levels cannot serve as a reliable predictor for malignant degree and differential diagnosis, including pure UC, UCSD, and SqCC of urothelial tumors.

Clinical Characteristics, Treatment Strategy, and Outcomes of Primary Large Cell Neuroendocrine Carcinoma of the Bladder: A Case Report and Systematic Review of the Literature

Purpose: The aim of this study was to review the clinicopathologic characteristics, treatments, and outcomes of patients with primary large cell neuroendocrine carcinoma of the bladder (LCNEC).

Patients and Methods: We report one patient diagnosed with primary pure LCNEC of the bladder in Sun Yat-sen Memorial Hospital. In addition, we performed a systematic literature review, in April 2020, on case report and case series of LCNEC of the bladder. The clinicopathologic characteristics, treatments and outcomes of this rare disease were analyzed.

Results: A total of 39 patients were included in our analysis (1 case from our institution and 38 cases from the literature). Most patients (79.5%) were male. The average age at the surgery for the patients is 61.5 years (range 19–85 years). The most common symptom was hematuria (n = 20, 76.9%). Almost all patients (38, 97.4%) underwent surgery, with 26 (66.7%) receiving multimodality therapy. Out of 24 patients with available data, regional or distant recurrences developed in 14 patients (58.3%). The median overall survival of the patients was 11.5 months, with 1- and 3-year survival rates of 54.0 and 21.4%, respectively. In the survival analysis, theT1–2 tumors (P = 0.025), no distant metastases at diagnosis (P = 0.001), and multimodality therapy (P = 0.017) were associated with better overall survival (OS).

Conclusions: LCNEC of the bladder is an extremely rare neoplasm. The available data suggest that the disease has an aggressive natural history with poor prognosis. Early pathologic stage and multimodality treatment may be important factors in determining prognosis.

Facing treatment of non-urothelial bladder cancers in the immunotherapy era

Non-urothelial Bladder Cancer (BC) and variants of urothelial carcinoma account for up to 25 % of all BCs. Given their heterogeneity, these entities are not well represented in clinical trials and treatment remains challenging. Checkpoint inhibitor therapy has shown a role in the treatment of urothelial BC. By contrast, robust evidence regarding its use in other histological types is lacking. We aimed to provide a comprehensive update of non-urothelial and variant urothelial BC, exploring the evidence for immune checkpoint inhibitor therapy. A detailed analysis of the literature was conducted regarding epidemiology, aetiology, diagnosis, prognosis, treatment and outcomes of these patients in the immunotherapy era. A growing body of evidence suggests that immune checkpoint inhibition might have a role to play in non-urothelial BC, similarly to what happened with urothelial carcinomas.

Expression of novel neuroendocrine marker insulinoma-associated protein 1 (INSM1) in genitourinary high-grade neuroendocrine carcinomas: An immunohistochemical study with specificity analysis and comparison to chromogranin, synaptophysin, and CD56

Confirmation of genitourinary high-grade neuroendocrine carcinomas (GU-HGNECs) often requires immunohistochemical staining. Here we evaluated a novel neuroendocrine marker, insulinoma-associated protein 1 (INSM1), in GU-HGNECs with comparison to chromogranin, synaptophysin and CD56. Immunohistochemical expression of INSM1, chromogranin, synaptophysin, and CD56 was evaluated in 39 GU-HGNECs using full tissue sections [4 in kidney, 28 in urinary bladder, and 7 in prostate; 31 small cell carcinomas (SmCCs), 6 large cell neuroendocrine carcinomas (LCNECs), 2 mixed SmCC-LCNECs]. In 33 SmCCs/components, INSM1 showed similar sensitivity (93.9 %) to chromogranin (87.8 %), synaptophysin (93.9 %) and CD56 (87.8 %), and stained a similar percentage of tumor cells (52 %) to chromogranin (49 %) and CD56 (52 %), but lower than synaptophysin (87 %) (p < 0.0001). In 8 LCNECs/components, INSM1 is similar to chromogranin, synaptophysin or CD56 in sensitivity (62.5 %, 62.5 %, 75 %, 62.5 %, respectively) and the mean percentage of positively stained tumor cells (21 %, 44 %, 48 %, 37 %, respectively). INSM1 is more sensitive for SmCCs than LCNECs (93.9 % vs. 62.5 %, p = 0.015). INSM1 showed 97.4 % specificity upon analyzing 273 genitourinary non-neuroendocrine tumors on tissue microarrays. Our study indicates that INSM1 is a sensitive marker for genitourinary HGNECs with high specificity. For genitourinary SmCCs, INSM1 shows similar sensitivity to chromogranin, synaptophysin and CD56 but stains a lower percentage of tumor cells than synaptophysin. For genitourinary LCNECs, INSM1 showed similar sensitivity to chromogranin, synaptophysin and CD56. INSM1 is more sensitive for genitourinary SmCCs than LCNECs. Our result and literature review indicate that whether INSM1 is more sensitive than conventional neuroendocrine markers for HGNECs depends on the tumor primary sites.

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.