Plasmacytoid variant of bladder cancer defines patients with poor prognosis if treated with cystectomy and adjuvant cisplatin-based chemotherapy

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.

Proposal for a Novel Histological Scoring System as a Potential Grading Approach for Muscle-invasive Urothelial Bladder Cancer Correlating with Disease Aggressiveness and Patient Outcomes

BACKGROUND

Grading of muscle-invasive bladder cancer (MIBC) according to the current World Health Organization (WHO) criteria is controversial due to its limited prognostic value. All MIBC cases except a tiny minority are of high grade.

OBJECTIVE

To develop a prognostic histological scoring system for MIBC integrating histomorphological phenotype, stromal tumor-infiltrating lymphocytes (sTILs), tumor budding, and growth and spreading patterns.

DESIGN, SETTING, AND PARTICIPANTS

Tissue specimens and clinical data of 484 patients receiving cystectomy and lymphadenectomy with curative intent with or without adjuvant chemotherapy. Histomorphological phenotypes, sTILs, tumor budding, and growth and spreading patterns were evaluated and categorized into four grade groups (GGs). GGs were correlated with molecular subtypes, immune infiltration, immune checkpoint expression, extracellular matrix (ECM) remodeling, and epithelial-mesenchymal transition (EMT) activity.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

GGs were associated with overall (OS), disease-specific (DSS), and progression-free (PFS) survival in univariable and multivariable analyses. Association with biological features was analyzed with descriptive statistics.

RESULTS AND LIMITATIONS

Integration of two histomorphological tumor groups, three sTILs groups, three tumor budding groups, and four growth/spread patterns yielded four novel GGs that had high significance in the univariable survival analysis (OS, DSS, and PFS). GGs were confirmed as independent prognostic predictors with the greatest effect in the multivariable Cox regression analysis. Correlation with molecular data showed a gradual transition from basal to luminal subtypes from GG1 to GG4; a gradual decrease in survival, immune infiltration, and immune checkpoint activity; and a gradual increase in ECM remodeling and EMT activity.

CONCLUSIONS

We propose a novel, prognostically relevant, and biologically based scoring system for MIBC in cystectomies applicable to routine pathological sections.

PATIENT SUMMARY

We developed a novel approach to assess the aggressiveness of advanced bladder cancer, which allows improved risk stratification compared with the method currently proposed by the World Health Organization.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer. Working Group 2: Grading of Mixed Grade, Invasive Urothelial Carcinoma Including Histologic Subtypes and Divergent Differentiations, and Non-Urothelial Carcinomas

The 2022 International Society of Urological Pathology (ISUP) Consensus Conference on Urinary Bladder Cancer Working Group 2 was tasked to provide evidence-based proposals on the applications of grading in noninvasive urothelial carcinoma with mixed grades, invasive urothelial carcinoma including subtypes (variants) and divergent differentiations, and in pure non-urothelial carcinomas. Studies suggested that predominantly low-grade noninvasive papillary urothelial carcinoma with focal high-grade component has intermediate outcome between low- and high-grade tumors. However, no consensus was reached on how to define a focal high-grade component. By 2004 WHO grading, the vast majority of lamina propria-invasive (T1) urothelial carcinomas are high-grade, and the rare invasive low-grade tumors show only limited superficial invasion. While by 1973 WHO grading, the vast majority of T1 urothelial carcinomas are G2 and G3 and show significant differences in outcome based on tumor grade. No consensus was reached if T1 tumors should be graded either by the 2004 WHO system or by the 1973 WHO system. Because of the concern for underdiagnosis and underreporting with potential undertreatment, participants unanimously recommended that the presence of urothelial carcinoma subtypes and divergent differentiations should be reported. There was consensus that the extent of these subtypes and divergent differentiations should also be documented in biopsy, transurethral resection, and cystectomy specimens. Any distinct subtype and divergent differentiation should be diagnosed without a threshold cutoff, and each type should be enumerated in tumors with combined morphologies. The participants agreed that all subtypes and divergent differentiations should be considered high-grade according to the 2004 WHO grading system. However, participants strongly acknowledged that subtypes and divergent differentiations should not be considered as a homogenous group in terms of behavior. Thus, future studies should focus on individual subtypes and divergent differentiations rather than lumping these different entities into a single clinicopathological group. Likewise, clinical recommendations should pay attention to the potential heterogeneity of subtypes and divergent differentiations in terms of behavior and response to therapy. There was consensus that invasive pure squamous cell carcinoma and pure adenocarcinoma of the bladder should be graded according to the degree of differentiation. In conclusion, this summary of the International Society of Urological Pathology Working Group 2 proceedings addresses some of the issues on grading beyond its traditional application, including for papillary urothelial carcinomas with mixed grades and with invasive components. Reporting of subtypes and divergent differentiation is also addressed in detail, acknowledging their role in risk stratification. This report could serve as a guide for best practices and may advise future research and proposals on the prognostication of these tumors.

Plasmacytoid urothelial carcinoma with duodenal metastasis-A rare tumor with unusual site of metastasis with grim outcome

Plasmacytoid urothelial carcinoma (PUC) is a newly recognized rare variant of urothelial carcinoma, which is now being increasingly diagnosed prospectively as well as by retrospective analysis of cases with a poor prognosis. Morphologically, these tumors simulate plasma cell neoplasms and pose a diagnostic challenge. Identifying this variant is essential in two aspects: therapy and prognosis. Here, we present a case who underwent multiple transurethral resection of bladder tumor (TURBT) procedures, each with a diagnosis of urothelial carcinoma, the plasmacytoid type which was confirmed on radical cystectomy, and after 1 year, the patient presented with duodenal metastasis. We discuss the morphological aspects of differentiating this tumor from variants of urothelial carcinoma and other tumors with a plasmacytoid appearance. Despite the recognition and aggressive treatment, the patient expires within 2 years of the first diagnosis of bladder carcinoma.

A case of Avelumab response to multiple bone and lymph node metastases of plasmacytoid variant bladder cancer

A 74-year-old man was diagnosed with bladder cancer and referred to our department. For definitive diagnosis, transurethral resection of the bladder tumor(TURBT) was performed. The pathological result showed plasmacytoid variant of urothelial carcinoma. Subsequently, robot-assisted radical cystectomy, lymph node dissection and ileal conduit was performed, but multiple bone metastases and periaortic lymph node metastases newly appeared 30 days later. Gemcitabine and cisplatin (GC) was started, and after 4 courses, the patient became Partial Response (PR), and was switched to Avelumab as maintenance therapy. After about 1 year of maintenance therapy, the patient is still in PR.

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.

Plasmacytoid Urothelial Carcinoma of the Bladder That Manifests Disseminated Carcinomatosis of the Bone Marrow: A Case Report of Extremely Rapid Progression

Plasmacytoid urothelial carcinoma (PUC) of the bladder is a rare variant of invasive urothelial carcinoma (UC) with aggressive behavior. Despite its prognosis being poorer than that of conventional UC, a median overall survival of approximately 2 years is ensured when it is treated with radical cystectomy (RC), and few patients die within a few months of RC. In this paper, we report the case of a patient with PUC who developed widespread bone metastasis only 6 weeks after RC, which resulted in death within 2 months postoperatively.

Overview of histologic variants of urothelial carcinoma: current trends and narrative review on treatment outcomes

Background and Objective

The histologic variants of urothelial carcinoma (UC) are tumors arising from within the urothelium in which some component of the tumor morphology is other than urothelial. They are underdiagnosed, aggressive and have varying pathologic response rates to systemic chemotherapy. There are no consensus guidelines on the use of systemic chemotherapy in variant histology (VH) of UC. We performed a contemporary review on pathologic response rates to neoadjuvant systemic therapy and survival outcomes following radical cystectomy in order to provide a rationale for clinical practice recommendations on the management of UC with VH.

Methods

A PubMed literature search was conducted for all English articles from inception reporting either pathological response rates to neoadjuvant treatment or survival outcomes after radical cystectomy in non-metastatic VH of UC.

Key Content and Findings

Neoadjuvant chemotherapy (NAC) prior to radical cystectomy was shown to be a beneficial treatment strategy in UC with VH. The micropapillary, plasmacytoid, nested and sarcomatoid histologic variants were associated with worse survival outcomes compared to conventional UC and UC with squamous or glandular differentiation despite initial downstaging with chemotherapy. There is evidence of improved survival in patients with sarcomatoid differentiation receiving NAC compared to RC alone. The major prognostic factors that affect survival outcomes in VH of UC include histologic variant subtype, patient age, presence of lymphovascular invasion, hydronephrosis, nodal metastasis and advanced T stage at diagnosis. Recent studies demonstrate that VH of UC are heterogenous tumors and responsiveness to NAC may be a function of the molecular subtypes present.

Conclusions

Based on these findings, NAC to achieve pathologic downstaging prior to radical cystectomy is recommended for MIBC with VH. Biomarkers identified by molecular profiling with immunohistochemistry will need to be validated as predictors of response to NAC in future trials.

Plasmacytoid variant urothelial carcinoma of the bladder: effect of radical cystectomy and chemotherapy in non-metastatic and metastatic patients

PURPOSE

Data about optimal management of plasmacytoid (PCV) bladder cancer patients are extremely scarce and limited by sample size. We focused on PCV bladder cancer patients to explore the effect of radical cystectomy (RC) and chemotherapy in non-metastatic (T _2-4N_0-3M₀), as well as in metastatic (T_anyN_anyM₁) subgroups.

METHODS

Using the Surveillance, Epidemiology and End Results database (2000-2016), we identified 332 PCV patients with muscle-invasive disease or higher (≥ T₂N₀M₀). Kaplan-Meier plots and Cox regression models addressed cancer-specific mortality (CSM).

RESULTS

In 332 PCV patients, median age was 68 years (Interquartile range [IQR]:58-76). Of those, 252 were non-metastatic patients (76%) vs 80 were metastatic patients (24%), at presentation. Of non-metastatic patients, 142 (56%) underwent RC and 131 (52%) underwent chemotherapy. Chemotherapy did not improve CSM in non-metastatic PCV. Conversely, RC was associated with lower CSM (hazard ratio [HR]: 0.51, p = 0.002). Median CSM-free survival was 48 vs 38 months for RC treated vs RC not treated. Of metastatic patients, 22 (28%) underwent RC and 42 (52%) underwent chemotherapy. Both chemotherapy and RC improved CSM in metastatic PCV. Median CSM-free survival was 12 vs 7 months for RC treated vs RC not treated (HR: 0.27, p < 0.001). Median CSM-free survival was 11 vs 4 months for chemotherapy exposed vs chemotherapy naïve (HR: 0.32, p = 0.002).

CONCLUSIONS

Although RC resulted in lower CSM, chemotherapy failed to show that effect in non-metastatic PCV patients. Conversely, both chemotherapy and RC resulted in statistically significantly lower CSM in metastatic PCV patients.

Histology of variants of urothelial carcinoma of the bladder: a Moroccan series of 39 cases

Background

The variant of urothelial carcinoma (UCV) is a rare and aggressive histological entity; its therapeutic management remains debated.

Methods

Between January 2017 and October 2019, 39 patients were diagnosed retrospectively with urothelial carcinoma with a histological variant. The aim of this study was to analyze the clinico-pathological and therapeutic aspects of these variants to better understand this invasive disease.

Results

In 39 cases, 36 (92%) were men and 3 (8%) were women; the average age was 62 years; 54% of patients had a ≥ cT3 stage with clinical lymph node involvement in 28% and 23% had distant metastases, 36% of patients were treated with RC and 54% by other therapeutic and 10% refused RC. No patient received neoadjuvant chemotherapy. Lymph node involvement was 28.5%. The two predominant histological types were squamous and micropapillary differentiation between the operating piece and bladder biopsy 28.5%, 30% and 21.5% and 13%, respectively. The overall survival at 20 months was 70 and 40% for RC and the other therapeutic (TURB alone or a TURB with an adjuvant), respectively. There was no significant difference in survival between the two groups (p = 0.27).

Conclusion

UCVs are heterogeneous groups of tumors which are increasingly identified due to their distinct morphological characteristics with variable clinical prognosis. Therapeutic management is not in favor of cystectomy in our study. However, a prospective study using a larger cohort is still necessary to validate our results.

A case report of a patient with plasmacytoid urothelial cancer with significant response to HER2-targeting therapy and enfortumab vedotin

In this case report, we present a patient with the rare plasmacytoid variant of urothelial cancer. Notable elements of his course include: complete response to neoadjuvant paclitaxel, gemcitabine, cisplatin, development of metastatic disease to the rectum, sustained disease control with dual HER2 targeting therapy, and subsequent complete response to enfortumab vedotin. Plasmacytoid urothelial cancer accounts for just 1-3% of all urothelial cancer cases and is associated with more aggressive disease, with a propensity for intra-abdominal spread and poor response to neoadjuvant therapy. Preliminary data indicate that the variant may generally have high levels of HER2 expression. We review the history of HER2 targeting in metastatic urothelial cancer, which has included single-agent as well as combination with chemotherapy; there are ongoing biomarker-based clinical trials. Furthermore, we highlight the complete response to enfortumab vedotin. To date, this is the first report of efficacy for enfortumab vedotin in the plasmacytoid variant.

Outcomes of poorly differentiated and plasmacytoid variant bladder urothelial carcinoma

Objectives

The aim of this study is to assess the course and management of poorly differentiated bladder urothelial carcinoma (UC), including plasmacytoid UC (PUC), in our local area. Although bladder cancer is relatively common, PUC is a rare and aggressive subtype with a poor prognosis that is still poorly understood.

Materials and Methods

A retrospective assessment of all poorly differentiated high‐grade UC over the last 15 years (2005–2020) in the Hunter New England area was completed. In total, 37 patients were included, and PUC variant was compared with the remaining poorly differentiated UC.

Results

Of the included cases, eight were PUC, nine squamous variant, two neuroendocrine, and one sarcomatoid. Overall, 23 cases proceeded to cystectomy, 15 had chemotherapy (six neoadjuvant), and 11 had radiation therapy. In the PUC subgroup, three had metastatic disease at diagnosis (37.5%). Of the three PUC patients who underwent cystectomy, all were upstaged. Two PUC cases had adjuvant chemotherapy, and one case had radiation. Within the follow‐up period, the PUC group had a cause‐specific mortality of 50% with a mean survival in these patients of 202 days, compared with 37.9% cause‐specific mortality with survival of 671.55 days (p = 0.23) in all other undifferentiated UC cases; 5‐year cause‐specific mortality with Kaplan–Meier analysis was estimated at 26% compared with 59%, respectively (p = 0.058).

Conclusion

Poorly differentiated UC is demonstrated to have a poor prognosis with a high mortality rate, particularly when PUC is present. Given the rarity of these variants, further studies are necessary to explore the impact of current treatment options.

The Genitourinary Pathology Society Update on Classification of Variant Histologies, T1 Substaging, Molecular Taxonomy, and Immunotherapy and PD-L1 Testing Implications of Urothelial Cancers

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder cancer focusing on important topics of high interest for the practicing surgical pathologist and urologist. This review represents the second of 2 manuscripts ensuing from this effort. Herein, we address the effective reporting of bladder cancer, focusing particularly on newly published data since the last 2016 World Health Organization (WHO) classification. In addition, this review focuses on the importance of reporting bladder cancer with divergent differentiation and variant (subtypes of urothelial carcinoma) histologies and the potential impact on patient care. We provide new recommendations for reporting pT1 staging in diagnostic pathology. Furthermore, we explore molecular evolution and classification, emphasizing aspects that impact the understanding of important concepts relevant to reporting and management of patients.

Natural history, response to systemic therapy, and genomic landscape of plasmacytoid urothelial carcinoma

Background

Plasmacytoid urothelial carcinoma (PUC) is a rare, aggressive histologic variant of urothelial cancer characterised by a diffuse growth pattern and CDH1 mutation. We studied the efficacy of preoperative platinum-based chemotherapy in nonmetastatic PUC and immune checkpoint inhibitors (ICIs) in advanced PUC.

Methods

Cases of nonmetastatic PUC and advanced PUC treated with ICIs at our institution were identified. Outcomes were compared to those of a published cohort of patients with urothelial carcinoma not otherwise specified.

Results

We identified 81 patients with nonmetastatic PUC. Of the patients with localised disease who underwent neoadjuvant chemotherapy, pathologic complete response and downstaging rates were 12 and 21%, respectively. Pathologic downstaging was not associated with significant improvement in clinical outcomes. Up to 18% of localised disease and 28% of locally advanced cases had unresectable disease at the time of surgery. ICI-treated advanced PUC (N = 21) had progression-free and overall survival of 4.5 and 10.5 months, respectively, and a 38% response rate. FGFR3 and DNA damage response gene alterations were observed in 3 and 15% of cases, respectively.

Conclusions

PUC is associated with high disease burden and poor chemosensitivity. Increased awareness and recognition of this disease variant will allow for new treatment strategies.

Histologically confirmed distant metastatic urothelial carcinoma from the urinary bladder: a retrospective review of one institution's 20-year experience

Background

Urothelial carcinoma (UC) accounts for roughly 90% of bladder cancer, and has a high propensity for diverse differentiation. Recently, certain histologic variants of UC have been recognized to be associated with unfavorable clinical outcomes. Several UC studies have also suggested that tumor budding is a poor prognostic marker. Distant metastasis of UC after radical cystectomy is not uncommon. However, these metastatic lesions are not routinely confirmed with histology.

Methods

We investigated the histopathologic features of 13 cases of UC with biopsy-proven distant metastases, with a special emphasis on histologic variants and tumor budding.

Results

Lymph nodes (6/13, 46%) were the most common metastatic sites, followed by the lung (4/13, 31%), liver (4/13, 31%), and the adrenal gland (2/13, 15%). The histologic variants including squamous (n = 1), micropapillary (n = 4), and plasmacytoid (n = 1) variants in five cases of UC. Most histologic variants (4/5, 80%) of primary UCs appeared in the metastatic lesions. In contrast, high-grade tumor budding was detected in six cases (46%), including one case of non-muscle invasive UC. Our study demonstrates that histologic variants are not uncommonly detected in distant metastatic UCs. Most histologic variants seen in primary UCs persist in the distant metastatic lesions. In addition, high-grade tumor budding, which occurs frequently in primary tumors, may contribute to the development of distant metastasis.

Conclusions

Therefore, assessing the presence or absence of histologic variants and tumor budding in UCs of the urinary bladder, even in non-muscle invasive UCs, may be useful to predict distant metastasis.

The optimal management of variant histology in muscle invasive bladder cancer

Bladder cancer is a heterogenous disease that is associated with tangible mortality in muscle invasive disease. The WHO 2016 classification of urothelial tumours reflects the contemporary approach towards histological variants in bladder cancer, including variants of urothelial carcinoma (UC) and non-urothelial variants. This review focuses on variant histology in UC, and discusses the importance of accurate histological diagnosis, and subsequent risk stratification and therapeutic decision making based on proper variant recognition. Most urothelial variants are associated with poorer outcomes compared to conventional UC, although some perform reasonably better. However, high quality evidence detailing optimal treatment and survival outcomes are still lacking in literature, due to the rarity of these cases.

p-120 Catenin is a Useful Diagnostic Biomarker for Distinguishing Plasmacytoid and Sarcomatoid Variants From Conventional Urothelial Carcinoma

CONTEXT.—

Plasmacytoid urothelial carcinoma (PC-UC) is an aggressive variant of urothelial carcinoma (UC), characterized by loss of E-cadherin (E-Cad)-mediated intercellular adhesion. Loss of E-Cad by immunohistochemistry can help diagnose PC-UC; however, sensitivity is limited. Expression of other cadherin-catenin adhesion complex members, that is, p-120 catenin (p-120) and β-catenin (B-Cat), which are diagnostically useful for lobular breast carcinoma, remains unknown in UC.

OBJECTIVE.—

To determine the utility of p-120 and B-Cat in conventional and variant UC.

DESIGN.—

E-cadherin, B-Cat, and p-120 immunohistochemistry was performed in 25 conventional UCs and 33 variant UCs, including 22 PC-UCs, 6 sarcomatoid UCs (SUCs), and 5 micropapillary UCs. Membranous staining for all biomarkers was considered normal; however, any cytoplasmic staining or an absence of staining was considered diagnostically abnormal. Next-generation sequencing was performed on 8 PC-UC cases.

RESULTS.—

E-cadherin, B-Cat, and p-120 showed membranous staining in all conventional and micropapillary UCs. In contrast, most PC-UCs were negative for E-Cad (17 of 22; 77%) with an additional 2 of 22 cases (9%) showing cytoplasmic with partial membranous staining. p-120 catenin demonstrated cytoplasmic or negative staining in 21 of 22 cases (95%). Most SUCs showed an absence of E-Cad (5 of 6; 83%) and cytoplasmic or negative p-120 in 5 of 6 cases (83%). Staining for B-Cat was also abnormal in a subset of PC-UCs and SUCs. Five PC-UC cases that harbored CDH1 gene variants were p-120 cytoplasmic positive.

CONCLUSIONS.—

p-120 catenin is a useful adjunct biomarker to E-Cad in the clinically important distinction of PC-UC and SUC from conventional UC. In particular, the combination of cytoplasmic p-120 and loss of E-Cad is strongly supportive of PC-UC and SUC.

Current Management of Localized Muscle-Invasive Bladder Cancer: A Consensus Guideline from the Genitourinary Medical Oncologists of Canada

BACKGROUND: Despite recent advances in the management of muscle-invasive bladder cancer (MIBC), treatment outcomes remain suboptimal, and variability exists across current practice patterns. OBJECTIVE: To promote standardization of care for MIBC in Canada by developing a consensus guidelines using a multidisciplinary, evidence-based, patient-centered approach who specialize in bladder cancer. METHODS: A comprehensive literature search of PubMed, Medline, and Embase was performed; and most recent guidelines from national and international organizations were reviewed. Recommendations were made based on best available evidence, and strength of recommendations were graded based on quality of the evidence. RESULTS: Overall, 17 recommendations were made covering a broad range of topics including pathology review, staging investigations, systemic therapy, local definitive therapy and surveillance. Of these, 10 (59% ) were level 1 or 2, 7 (41% ) were level 3 or 4 recommendations. There were 2 recommendations which did not reach full consensus, and were based on majority opinion. This guideline also provides guidance for the management of cisplatin-ineligible patients, variant histologies, and bladder-sparing trimodality therapy. Potential biomarkers, ongoing clinical trials, and future directions are highlighted. CONCLUSIONS: This guideline embodies the collaborative expertise from all disciplines involved, and provides guidance to further optimize and standardize the management of MIBC.

Metastatic Plasmacytoid Bladder Cancer Harboring a CDH-1 Mutation and Producing High Levels of CA 19-9. A Case Report and Literature Review

Patient: Female, 64-year-old

Final Diagnosis: Plasmacytoid urothelial carcinoma of the bladder

Symptoms: Nausea • vomiting

Medication:—

Clinical Procedure: Cystoscopy

Specialty: Oncology

Plasmocytoid urothelial carcinoma - clinical, histological, immunohistochemical and molecular aspects

Plasmacytoid (PUC) variant is a rare and aggressive form of urothelial cancer representing 1 to 3% of the bladder cancer. The main differential diagnosis is the bladder involvement by lymphoma-plasmocytoma or metastasis from lobular breast cancer or diffuse gastric cancer. Immunexpression of cytokeratin 7 and GATA3 is the rule, but CD138 may be positive in high percentage of cases. CDH1 somatic mutation or, more rarely, methylation of the gene promoter is the main genetic characteristic of PUC, but germinative mutation is always negative. The recognition of this special histology is very important for the correct management of the patients because of the high rate of positive surgical margins and atypical disease progression. PUC is responsive to cisplatin-based chemotherapy but recurrence is the rule. Peritoneal dissemination is frequent and cancer specific mortality is as high as 56% in a range of 19 to 23 months.

Impact of Gender on Chemotherapeutic Response and Oncologic Outcomes in Patients Treated With Radical Cystectomy and Perioperative Chemotherapy for Bladder Cancer: A Systematic Review and Meta-Analysis

Female patients with bladder cancer (BCa) have had more advanced disease than their male counterparts at diagnosis and have experienced worse oncologic outcomes. However, the effect of gender on the chemotherapeutic response and oncologic outcomes after radical cystectomy (RC) and perioperative chemotherapy remains to be elucidated. We performed a systematic literature search to identify eligible studies that had investigated the effect of gender on the chemotherapeutic response and oncologic outcomes after RC and perioperative chemotherapy. We identified 15 studies reported from 2008 to 2019. For the patients who had received neoadjuvant chemotherapy (NAC), female gender was not associated with a complete response (pooled odds ratio [OR], 0.94; 95% confidence interval [CI], 0.69-1.26) nor a complete or partial response (pooled OR, 0.96; 95% CI, 0.73-1.27). In addition, women experienced had less upstaging (pooled OR, 0.3; 95% CI, 0.14-0.68) at RC compared with their male counterparts. Moreover, female patients who had undergone RC and NAC were likely to have better disease recurrence and cancer-specific mortality rates than were the male patients (pooled hazard ratio [HR], 0.66 and 95% CI, 0.44-0.98; and pooled HR, 0.49 and 95% CI, 0.29-0.81, respectively). For the patients who had undergone adjuvant chemotherapy, female gender was not associated with overall mortality (pooled HR, 1.15; 95% CI, 0.7-1.89), disease recurrence (pooled HR, 0.95; 95% CI, 0.74-1.23), or cancer-specific mortality (pooled HR, 1.07; 95% CI, 0.81-1.43). Female patients with BCa seem to benefit more from NAC than do their male counterparts. This potential differential sensitivity of female BCa to cisplatin-based combination chemotherapy might help close the gender gap in BCa, suggesting that gender could be a biomarker to help select the best systemic therapy for patients with advanced BCa.

Glandular Tumors of the Urachus and Urinary Bladder: A Practical Overview of a Broad Differential Diagnosis

Primary glandular tumors of the urachus and urinary bladder are an intriguing group of clinically and morphologically diverse neoplasms for which there have been recent refinements in diagnostic subclassification and advances in molecular pathology. In addition, the urachus and urinary bladder may be secondarily involved by tumors with glandular differentiation that demonstrate remarkable morphologic, immunophenotypic, and molecular overlap. Thus, surgical pathologists need to be aware of the broad differential diagnosis of glandular tumors that involve the urachus and urinary bladder and have a practical diagnostic framework to evaluate these lesions in routine clinical practice. In this review, we summarize the salient clinical, morphologic, immunohistochemical, and molecular features of glandular tumors of the urachus and urinary bladder, including mucinous cystic tumors of the urachus, noncystic urachal adenocarcinomas, urothelial carcinomas with glandular or pseudoglandular features, primary urinary bladder adenocarcinomas, and Müllerian-type carcinomas, highlighting the strengths and limitations of various diagnostic features and ancillary tests, as well as the need for close clinical and radiographic correlation.

Plasmacytoid Urothelial Carcinoma: An Unusual Variant That Warrants Aggressive Management and Critical Distinction on Transurethral Resections

Plasmacytoid urothelial carcinoma (PUC) is a variant of infiltrating urothelial carcinoma that is characterized by tumor cells that have striking morphologic resemblance to and immunohistochemical overlap with plasma cells, and that harbors CDH1 mutation. Plasmacytoid urothelial carcinoma can be widely infiltrative and may permeate the urinary bladder in a linitis plastica-like manner and spread along the fascial planes and into the peritoneum. Compared with conventional urothelial carcinoma, PUCs have a greater chance for higher-stage disease, surgical margin positivity, and metastasis at presentation that translate into its poorer outcome. Upstaging of lamina propria-invasive (pT1) tumors diagnosed at transurethral resections is common. Because of its unfavorable behavior, a more aggressive management approach is being recommended for PUC, including consideration for upfront cystectomy in pT1 tumors. Thus, accurate distinction should be made especially on the initial transurethral resection specimens because of the therapeutic and prognostic implications. Awareness of PUC's unique clinical presentation, morphology, and immunohistochemical profile is important to avoid a potential misdiagnosis from its mimics.

First-line pembrolizumab therapy in a cisplatin-ineligible patient with plasmacytoid urothelial carcinoma: A case report

BACKGROUND

Plasmacytoid urothelial carcinoma (PUC) is a rare but aggressive variant of transitional cell carcinoma. In patients with unresectable disease, cisplatin-based combination chemotherapy is the most commonly used treatment. However, many patients are cisplatin-ineligible due to poor performance status or other comorbidities. We report a case of a cisplatin-ineligible patient with metastatic PUC who was treated with pembrolizumab.

CASE REPORT

A 71-year-old man with 30 pack-year smoking history and schizoaffective disorder was found to have multiple right-sided lung nodules after presenting with atypical chest pain. Staging CT showed bilateral adrenal masses and a large soft tissue mass in the right iliac fossa. Tissue pathology and immunohistochemical staining was consistent with PUC. As the patient was cisplatin-ineligible due to poor performance status and multiple medical comorbidities, the decision was made to treat with pembrolizumab. Repeat CT chest and abdomen showed partial response at three months and stable disease at six months.

DISCUSSION

The KEYNOTE-052 study found that first-line pembrolizumab in cisplatin-ineligible patients with urothelial cancer resulted in complete or partial response in 24% of patients with few adverse effects. However, it is unclear if patients with plasmacytoid variant were included. To our knowledge, this is the first case report of a patient with metastatic PUC not only treated with pembrolizumab but shown to have clinical response.

CONCLUSION

Given our patient's clinical response, pembrolizumab is a promising first-line agent for treating cisplatin-ineligible patients with metastatic PUC. Further evaluation is warranted to confirm the benefit of treating this patient population with pembrolizumab.

Targeted sequencing of plasmacytoid urothelial carcinoma reveals frequent TERT promoter mutations

Activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the most common genetic alterations in urothelial carcinoma (UC) of the bladder and upper urinary tract. Although the cadherin 1 (CDH1) gene is commonly mutated in the clinically aggressive plasmacytoid variant of urothelial carcinoma (PUC), little is known about their TERT promoter mutation status. A retrospective search of our archives for PUC and UC with plasmacytoid and/or signet ring cell features (2007-2014) was performed. Ten specimens from 10 patients had archived material available for DNA analysis and were included in the study. Intratumoral areas of nonplasmacytoid histology were also evaluated when present. Samples were analyzed for TERT promoter mutations with Safe-SeqS, a sequencing error-reduction technology, and sequenced using a targeted panel of the 10 most commonly mutated genes in bladder cancer on the Illumina MiSeq platform. TERT promoter mutations were detected in specimens with pure and focal plasmacytoid features (6/10). Similar to conventional UC, the predominant mutation identified was g.1295228C>T. In heterogeneous tumors with focal variant histology, concordant mutations were found in plasmacytoid and corresponding conventional, glandular, or sarcomatoid areas. Co-occurring mutations in tumor protein p53 (TP53, 2 cases) and kirsten rat sarcoma (KRAS) viral proto-oncogene (1 case) were also detected. TERT promoter mutations are frequently present in PUC, which provides further evidence that TERT promoter mutations are common events in bladder cancer, regardless of histologic subtype, and supports their inclusion in any liquid biopsy assay for bladder cancer.

Advances in risk stratification of bladder cancer to guide personalized medicine

Bladder cancer is a heterogeneous disease that poses unique challenges to the treating clinician. It can be limited to a relatively indolent papillary tumor with low potential for progression beyond this stage to muscle-invasive disease prone to distant metastasis. The former is best treated as conservatively as possible, whereas the latter requires aggressive surgical intervention with adjuvant therapies in order to provide the best clinical outcomes. Risk stratification traditionally uses clinicopathologic features of the disease to provide prognostic information that assists in choosing the best therapy for each individual patient. For bladder cancer, this informs decisions regarding the type of intravesical therapy that is most appropriate for non-muscle-invasive disease or whether or not to administer neoadjuvant chemotherapy prior to radical cystectomy. More recently, tumor genetic sequencing data have been married to clinical outcomes data to add further sophistication and personalization. In the next generation of risk classification, we are likely to see the inclusion of molecular subtyping with specific treatment considerations based on a tumor’s mutational profile.

Do histological variants in urothelial carcinoma of the bladder portend poor prognosis? A systematic review and meta-analysis

The clinical implications of histological variants in urothelial carcinoma of the bladder has been a subject of significant controversy with many unanswered questions that remain. To clarify whether histological variants presage poor prognosis for patients suffering from urothelial carcinoma of the bladder, we scoured through various electronic databases such as Medline, Web of Knowledge, and the Cochrane Library up to August 18, 2016. Experts were consulted, and references from relevant articles were scanned. We identified thirteen eligible studies which met the inclusion criteria, including 9,533 participants. The existing evidence indicates that histological variants in urothelial carcinoma of the bladder patients do not alter their prognosis.

Plasmacytoid Urothelial Carcinoma of Ureter with Retroperitoneal Metastasis: A Case Report

Patient: Male, 60

Final Diagnosis: Plasmacytoid urothelial carcinoma of ureter

Symptoms: Constipation • epigastric pain • microscopic hematuria • nausea • vomiting

Medication: —

Clinical Procedure: —

Specialty: Oncology

Adjuvant treatment following radical cystectomy for muscle-invasive urothelial carcinoma and variant histologies: Is there a role for radiotherapy?

Comprehensive molecular characterisation of muscle-invasive urothelial carcinoma and variant histological subtypes has led to the identification of recurrent driver mutations that are distinct in these aggressive subgroups of bladder cancer. While distant metastasis dominates as a pattern of relapse following radical cystectomy or chemoradiotherapy, loco-regional control rates are also suboptimal with single modality local treatment, and likewise, harbour equivocal implications on the long-term prognosis of patients. The role of adjuvant radiotherapy for optimising disease control within the pelvis is controversial, with limited evidence to support its efficacy. Herein, we present a stepwise review on adjuvant radiotherapy post-cystectomy; first, discussing the evidence to date supporting the concept that adjuvant radiotherapy is effective in targeting occult metastases within the pelvis, and adds to the benefits of adjuvant chemotherapy. Next, we outlined the principles underlying the definition of radiotherapy target volumes. To conclude, we addressed the need for appropriate patient stratification for treatment intensification, based on existing clinical models and novel molecular indices of aggression in muscle-invasive urothelial cancers and variant histological subtypes.

The Impact of Plasmacytoid Variant Histology on the Survival of Patients with Urothelial Carcinoma of Bladder after Radical Cystectomy

BACKGROUND

The clinical significance of the plasmacytoid variant (PCV) in urothelial carcinoma (UC) is currently lacking.

OBJECTIVE

To compare clinical outcomes of patients with any PCV with that of patients with pure UC treated with radical cystectomy (RC).

DESIGN, SETTING, AND PARTICIPANTS

We identified 98 patients who had pathologically confirmed PCV UC and 1312 patients with pure UC and no variant history who underwent RC at our institution between 1995 and 2014.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Univariable and multivariable Cox regression and Cox proportional hazards regression to determine if PCV was associated with overall survival (OS).

RESULTS AND LIMITATIONS

Patients with PCV UC were more likely to have advanced tumor stage (p=0.001), positive lymph nodes (p=0.038), and receive neoadjuvant chemotherapy than those with pure UC (46% vs 22%, p<0.0001). The rate of positive soft tissue surgical margins was over five times greater in the PCV UC group compared with the pure UC group (21% vs 4.1%, respectively, p<0.0001). Median OS for the pure UC versus the PCV patients were 8 yr and 3.8 yr, respectively. On univariable analysis, PCV was associated with an increased risk of overall mortality (hazard ratio=1.34, 95% confidence interval: 1.02-1.78, p=0.039). However, on multivariable analysis adjusted for age, sex, neoadjuvant chemotherapy received, lymph node status, pathologic stage, and soft margin status, the association between PCV and OS was no longer significant (hazard ratio=1.06, 95% confidence interval: 0.78, 1.43, p=0.7). This retrospective study is limited by the lack of pathological reanalysis, and the impact of other concurrent mixed histology cannot be determined in this study.

CONCLUSIONS

Patients with PCV features have a higher disease burden at RC compared with those with pure UC. However, PCV was not an independent predictor of survival after RC on multivariable analysis, suggesting that PCV histology should not be used as an independent prognostic factor.

PATIENT SUMMARY

Plasmacytoid urothelial carcinoma is a rare and aggressive form of bladder cancer. Patients with plasmacytoid urothelial carcinoma had worse adverse pathologic features, but this was not associated with worse overall mortality when compared with patients with pure urothelial carcinoma.

Plasmacytoid Urothelial Carcinoma of the Urinary Bladder: A Clinicopathologic and Immunohistochemical Analysis of 49 Cases

OBJECTIVES

Plasmacytoid urothelial carcinoma (PUC) of the bladder is a rare histologic variant. We retrospectively analyzed a large series of bladder PUC from a single institution.

METHODS

The patients consisted of 44 men and five women with a mean age of 62 years (range, 45-86 years).

RESULTS

PUC was pure in 23 cases and mixed with other histologic types in 26 cases. All PUCs diffusely invaded the bladder wall. Most PUCs lacked immunoreactivity for the retinoblastoma (RB) gene protein (12/32) and E-cadherin (8/30). Of the 44 patients with follow-up information, 25 died of PUC at a mean of 23 months, whereas 19 patients were alive at a mean of 22 months.

CONCLUSIONS

Our findings support that bladder PUC is a highly aggressive disease. The lack of E-cadherin expression in PUCs may underlie the distinct discohesive histologic appearance, and abnormal function of the RB gene may be implicated in the development of PUC.

Urothelial carcinoma in first histological diagnosis of patients over 80 years has distinctive histological features: a retrospective single-institution study of 185 patients

Few histological data are known about patients with a first diagnosis of bladder cancer (BC) at the age ≥80 years. We describe the largest series in this patient group and their distinctive histological features. This unicentric retrospective study included patients at the age ≥80 years with a first diagnosis of bladder cancer between 2005 and 2015. All diagnosis was made by one senior uropathologist according to the WHO 2016 classification, pTNM 7th edition 2009. We examined samples of 185 patients, sex ratio M:W = 2.49:1, with ≥80 years at the time of first diagnosis of BC. The mean age was 85.1 years (84.8 for men and 85.8 for women). One hundred sixteen patients were diagnosed with NMIBC (non-muscle invasive bladder cancer) (62.7%). Sixty-nine patients were detected with MIBC (muscle invasive bladder cancer) (37.3%). In the MIBC, 20 (29.0%) cases, a divergent differentiation was reported. No patient had primary carcinoma in situ (Cis) at time of diagnosis, and concomitant Cis was observed in 18.9% (35 cases). According to our results, the histopathological findings are different from those of other patients' groups. The study shows a higher number of MIBC and a high percentage of histological variants. We could show distinctive pathological features in this patient group.

Plasmacytoid Urothelial Carcinoma of the Urinary Bladder Metastatic to the Duodenum: A Case Report-Diagnostic Relevance of GATA3 Immunohistochemistry

Plasmacytoid urothelial carcinoma (PUC) of the urinary bladder is a rare and aggressive subtype of urothelial carcinoma. Its deceptive morphology is characterized by a discohesive growth of cells with plasmacytoid morphology. Since this tumor might be confused with plasmacytoma, lymphoma, or carcinoma variants, appropriate diagnosis in small biopsy samples could be challenging. This study reports the case of a 53-year-old man who presented with frequent nocturnal urgency, without hematuria. A transurethral bladder and a prostate resection specimen displayed infiltration of neoplastic cells in a spray-like discohesive pattern with occasional formation of small irregular nests and cord-like arrangements. The basic morphology of the tumor cells was plasmacytoid, with eccentric nuclei and eosinophilic cytoplasm. Tumor cells grew through the lamina muscularis mucosae, with splintering of the bladder wall musculature and infiltration of prostatic tissue. They displayed strong and diffuse nuclear reactivity for p53 and GATA3. Eight months after surgery, the patient experienced upper abdominal discomfort. A duodenal biopsy showed infiltration of plasmacytoid atypical cells strongly immunoreactive for GATA3, consistent with the previously diagnosed PUC. The patient died eleven months after the primary diagnosis of his PUC of tumor cachexia losing about 50% of his original body weight, furthermore, with ascites and intraperitoneal tumor spread.

Plasmacytoid urothelial carcinoma (PUC): Imaging features with histopathological correlation

INTRODUCTION

Plasmacytoid urothelial carcinoma (PUC) is a high-grade variant of conventional urothelial cell carcinoma. This study is the first to describe the imaging findings of PUC, which are previously unreported, using clinical and histopathological correlation.

METHODS

With internal review board approval, we identified 22 consecutive patients with PUC from 2007-2014. Clinical parameters, including age, gender, therapy, surgical margins, and long-term outcome, were recorded. Baseline imaging was reviewed by an abdominal radiologist who evaluated for tumour detectability/location/morphology, local staging, and presence/location of metastases. Pelvic peritoneal spread of tumour (defined as >5mm thick soft tissue spreading along fascial planes) was also evaluated. Followup imaging was reviewed for presence of local recurrence or metastases.

RESULTS

Median age at presentation was 74 years (range 51-86), with only three female patients. Imaging features of the primary tumour in this study were not unique for PUC. Muscle-invasive disease was present on pathology in 19/22 (86%) of tumours, with distant metastases in 2/22 (9%) at baseline imaging. Pelvic peritoneal spread of tumour was radiologically present in 4/20 (20%) at baseline. During followup, recurrent/residual tumour was documented in 16/22 (73%) patients and 7/16 (44%) patients eventually developed distant metastases. Median time to disease recurrence in patients who underwent curative surgery was three months (range 0-19).

CONCLUSIONS

PUC is an aggressive variant of urothelial carcinoma with poor prognosis. Pelvic peritoneal spread of tumour as thick sheets extending along fascial planes may represent a characteristic imaging finding of locally advanced PUC.

Variant histology in bladder cancer: how it should change the management in non-muscle invasive and muscle invasive disease?

Bladder cancer (BC) is a frequent type of carcinoma with an estimated incidence of approximately 100,000 men and women each year in the European Union (EU) with an associated mortality of 30,000 of these patients. In more than 70% the disease is diagnosed in a non-muscle invasive stage with the chance of minimally invasive, local treatment only, which might be required repetitively due to high rate of recurrence. In contrast, muscle invasive or metastatic stages need multimodal treatment strategies including surgical treatment and chemotherapy (CTX) in neoadjuvant (NAC), adjuvant, or palliative settings. Therapy recommendations and guidelines mainly refer to the most common histological type of BC, pure urothelial carcinoma (UC). However, BC can be classified as urothelial and non-UC. Non-urothelial BC and variants of UC account for up to 25% of all BCs. Further discrimination can be made into epithelial and non-epithelial non-UC. Most of the non-UCs are of epithelial origin (approximately 90%) including squamous-cell carcinoma, adenocarcinoma and small-cell carcinoma. Non-epithelial tumors are rare and include variants as sarcoma, carcinosarcoma, paraganglioma, melanoma and lymphoma. Even though it is unclear whether the prognosis of non-urothelial cancer truly differs from that of UC, there is evidence that additional variant histology might prognosticate an impaired prognosis. Accordingly, aggressive behavior and often advanced stages at primary presentation are frequently observed in non-UC arguing for radical and sometimes different treatment strategies as compared to pure UC. This review aims to summarize the available data for the most common histological variants of non-urothelial BC.

[Update on molecular classifications and new histological classification of bladder cancer]

OBJECTIVE

Comment the new WHO histological classification of tumors of the urinary system and male genital organs 2016 and expose the state of art about urothelial carcinogenesis and molecular modifications of bladder cancer, with the consequences on the treatments.

MATERIAL AND METHOD

A systematic review of the literature search was performed from the data base PubMed, focused on the following keywords: "bladder cancer", "molecular", "subtypes".

RESULTS

The new WHO histological classification of tumors of the urinary system 2016 confirm the importance of pathology in determining the care of patients, especially the grade, the histological type and the infiltration, while taking into account the difficulties. In 2014, the Cancer Genome Atlas reported genetic modifications of bladder cancer. Recently, several studies explored molecular anomalies of bladder cancer and elaborated molecular classifications, analyzing their predictive value. According to the groups, different molecular subtype had been defined: Urobasal A, Urobasal B, genomically unstable, infiltrated, squamous cell carcinoma-like and p53-like luminal bladder cancers. This latter subgroup seems to be chemoresistant.

CONCLUSIONS

The molecular biology and classifications allow a better understanding of bladder cancer and could complete in near future histological data to improve patient management.

Neoadjuvant chemotherapy in urothelial bladder cancer: impact of regimen and variant histology

Aim: We compared the efficacy of methotrexate/vinblastine/doxorubicin/cisplatin (MVAC) versus gemcitabine/cisplatin in urothelial cancer and neoadjuvant chemotherapy (NACT) efficacy in variant histology (VH). Materials & methods: Radical cystectomy patients were retrospectively compared with those who received NACT. Factors associated with survival, pathologic complete response (pCR) and downstaging (pDS) were evaluated in multivariable models. Results: 9% of radical cystectomy patients (84/919) received NACT, with improved survival, pCR and pDS on both regimens. MVAC lead to higher pDS without an increase in pCR. On multivariable analysis, there was a nonsignificant increase in pDS with MVAC. NACT conferred similar responses in squamous and glandular differentiation VH. Conclusion: NACT was associated with improved survival, pCR and pDS. Furthermore, responses to NACT were not dependent on presence of VH.

[From new genetic and histological classifications to direct treatment]

The most important criterion for optimal cancer treatment is a correct classification of the tumour. During the last three years, several very important progresses have been made with a better definition of urothelial carcinoma (UC), especially from a molecular point of view. We start having a global understanding of UC, although many details are still not completely understood.

Plasmacytoid urothelial carcinoma of the bladder with extensive scrotal wall invasion

Plasmacytoid urothelial carcinoma (PUC) is an extremely rare and aggressive variant of urothelial carcinoma. We report a case of a 62-year-old male who presented with a rapid spread of PUC to involve his entire scrotal wall after failed surgery and chemotherapy. The second course of chemotherapy was effective in providing symptom control. We believe this is the first case report of PUC causing such rapid and extensive scrotal invasion. This case highlights the important features of PUC including the pattern of tumor spread along fascial planes, the tendency for initial understaging, and the rapid recurrence after initially response to chemotherapy.

Frequent somatic CDH1 loss-of-function mutations in plasmacytoid variant bladder cancer

Plasmacytoid bladder cancer is an aggressive histologic variant with a high risk of disease-specific mortality. Using whole-exome and targeted sequencing, we find that truncating somatic alterations in the CDH1 gene occur in 84% of plasmacytoid carcinomas and are specific to this histologic variant. Consistent with the aggressive clinical behavior of plasmacytoid carcinomas, which frequently recur locally, CRISPR/Cas9-mediated knockout of CDH1 in bladder cancer cells enhanced cell migration.