Histologic variants of urothelial carcinoma: differential diagnosis and clinical implications

The association between variant histology and prognostic, histomorphological and clinical aspects of bladder urothelial carcinoma

This study underscores the imperative consideration of histological subtypes and divergent differentiation in accurately estimating bladder urothelial carcinoma prognosis and guiding treatment decisions. A comparative analysis was conducted, examining clinical, histological, and prognostic factors between conventional urothelial carcinoma and urothelial carcinoma with variant histology in a clinical sample. A retrospective analysis of slides and other clinicopathologic data was conducted these cases, with an emphasis on key diagnostic elements. We examined 829 cases of urothelial carcinoma of the bladder, comprising of 744 transurethral resection (TUR) and 85 radical cystectomy (RS) specimens, an analysis that showed that 80.5 % (667 cases) were conventional urothelial carcinoma (CUC) and that 19.5 % (162 cases) exhibited variant histology (hereafter "urothelial carcinoma with subtype histology" [UCSH]). TNM classifications for the RS cases were as follows: 2 cases were stage group 0a, 11 stage group 1, 16 stage group 2, 45 stage group 3a, 2 stage group 3b, 1 stage group 4a, and 8 stage group 4b. Only 2 of the RS cases were found to be non-invasive. Among 744 TUR specimens, 387 were found to have a non-invasive tumor whereas 357 had invasive tumors. The most prevalent subtype in the UCSH group was urothelial carcinoma with squamous differentiation, accounting for 54.3 % (88 cases). Notably, 8.02 % (13 cases) exhibited more than one histological subtype. Papillary configuration, histological grade, lamina propria, muscularis mucosa and serosa invasion, lymphovascular invasion, presence of urothelial carcinoma in situ, and overall survival significantly differed between the UCSH and CUC groups (p < 0.05). However, mean age, gender, tumor size, lymphocytic response, disease-free survival, and survival status did not differ significantly (p > 0.05). Among the UCSH group, lower levels of papillary configuration, higher histological grade, higher degree of lamina propria, muscularis mucosa and serosa invasion, and the presence of carcinoma in situ corresponded to higher percentage of histological subtype morphology (p < 0.05). No significant difference in survival status was observed between the groups with and without subtype histology (p = 0.083). This study found that clinical and histopathological prognostic factors associated with a more aggressive disease were linked to the presence and percentage of histological subtypes. Recognizing histological subtype is crucial for treatment decisions and prognosis prediction in urothelial carcinoma cases with these subtypes.

Tumor necrosis in magnetic resonance imaging predicts urothelial carcinoma with squamous differentiation in muscle-invasive bladder carcinoma

PURPOSE

This study investigated radiologic features on preoperative MRI to differentiate urothelial carcinoma with squamous differentiation (UCSD) from conventional urothelial carcinoma (UC) in muscle-invasive bladder carcinoma.

METHODS

Ninety-nine patients who underwent radical cystectomy and a preoperative bladder MRI scan within three months before surgery were retrospectively enrolled. Various MRI features, including tumor length, location, multiplicity, long-to-short axis ratio, morphology, radiologic stage, and degree of severe necrosis, were analyzed. Univariable and multivariable logistic regression analyses were performed to identify MRI features predictive of UCSD. The diagnostic performance of a significant MRI feature was assessed using 5-fold cross-validation.

RESULTS

Among the MRI features, significant radiologic findings associated with UCSD in the univariable analysis included heterogeneous tumor signal intensity in T2-weighted images (odds ratio [OR], 3.365; 95% confidence interval [CI], 1.213-9.986; P = 0.022) and contrast-enhanced T1-weighted images (OR, 4.428; 95% CI, 1.519-12.730; P = 0.007), as well as marked (≥ 50%) severe necrosis (OR, 17.100; 95% CI, 4.699-73.563; P < 0.001). In the multivariable analysis, marked (≥ 50%) severe necrosis (odds ratio [OR], 13.755; 95% confidence interval [CI], 2.796-89.118; P = 0.004) was a significant predictor of UCSD. Marked (≥ 50%) severe necrosis showed a high specificity of 95.0% with a precision of 65.0% for diagnosing UCSD based on 5-fold cross-validation.

CONCLUSION

Preoperative bladder MRI revealing marked severe necrosis may be indicative of UCSD and can assist in distinguishing it from conventional UC.

Advances, recognition, and interpretation of molecular heterogeneity among conventional and subtype histology of urothelial carcinoma (UC): a survey among urologic pathologists and comprehensive review of the literature

AIMS

Urothelial carcinoma (UC) demonstrates significant molecular and histologic heterogeneity. The WHO 2022 classification has hinted at adding molecular signatures to the morphologic diagnosis. As morphology and associated molecular repertoire may potentially translate to choices of and response to therapy and relapse rate, broader acceptability of recognizing these key features among uropathologists is needed. This prompted an international survey to ascertain the practice patterns in classical/subtype UC among uropathologists across the globe.

METHODS AND RESULTS

A survey instrument was shared among 98 uropathologists using SurveyMonkey software. Anonymized respondent data were analysed. The response rate was 85%. A majority were in concordance with the profiles of luminal (93%) and basal (82%) types. Opinion on the FGFR3 testing platform was variable. While 95% concurred that TERT promoter mutation is the key driver in UC, 72% had the opinion that APOBEC mutagenesis is the main signature in muscle invasive bladder cancer (MIBC). Uropathologists have divergent opinions on MIBC and ERCC2 mutations. Among the participants, 94% would quantify aggressive micropapillary and sarcomatoid histology, while 88% would reevaluate another transurethral resection of the bladder tumour specimen in nonmuscle invasive tumour with micropapillary, small cell, or sarcomatoid histology. A leading number agreed to specific molecular signatures of micropapillary (93%), plasmacytoid (97%), and small cell (86%) subtypes. Ninety-six percent of participants agreed that a small-cell component portends a more aggressive course and should be treated with neoadjuvant chemotherapy and 63% would perform HER2/neu testing only on oncologist's request in advanced tumours. Ninety percent agreed that microsatellite instability testing, although not a standard protocol, should be considered in young patients with upper tract UC. Eighty-six percent agreed that UC with high tumour mutational burden would be a better candidate for immunotherapy.

CONCLUSION

In the era of precision medicine, enhanced understanding of molecular heterogeneity of UC will contribute to better therapeutic options, novel biomarker discovery, innovative management protocols, and outcomes. Our survey provides a broad perspective of pathologists' perceptions and experience regarding incorporation of histomolecular approaches to "personalize" therapy. Due to variable clinical adoption, there is a need for additional data using uniform study criteria. This will drive generation of best practice guidelines in this area for widespread and consistent clinical utility.

Case report: Successful treatment of advanced urothelial carcinoma with trophoblastic differentiation using Tislelizumab and Disitamab vedotin

Background

Urothelial carcinoma with trophoblastic differentiation represents an uncommon and aggressive malignancy for which there is currently no established standard treatment. Systemic chemotherapy as the main treatment has limited efficacy. However, recent research has demonstrated significant improvements in patient survival with the use of immune checkpoint inhibitors and antibody-drug conjugates. To our knowledge, this case represents the first successful application of an immune checkpoint inhibitor (Tislelizumab) combined with human epidermal growth factor receptor 2-targeting antibody-drug conjugate (Disitamab vedotin) in the treatment of advanced urothelial carcinoma with trophoblastic differentiation.

Case report

We describe the case of a 36-year-old male patient diagnosed with urothelial carcinoma with trophoblastic differentiation, showing high expression of programmed death-ligand 1. Tumor progression occurred after six cycles of Tislelizumab combined with chemotherapy (gemcitabine and cisplatin) followed by five cycles of Tislelizumab monotherapy. Re-biopsy confirmed metastatic urothelial carcinoma with trophoblastic differentiation, now with epidermal growth factor receptor 2 overexpression. Treatment with Disitamab vedotin in combination with Tislelizumab resulted in a biochemical and imaging complete response, leading to an overall survival exceeding 24 months. Notably, no grade 3 or 4 adverse events were observed during treatment.

Discussion

The prognosis of advanced urothelial carcinoma with trophoblastic differentiation is unfavorable, and the available therapeutic options are limited. Combining Tislelizumab with Disitamab vedotin presents a promising anti-tumor strategy that warrants further investigation.

Small cell neuroendocrine carcinoma and poorly differentiated rhabdomyosarcomas of the urinary bladder in adults-A comparative analysis in favor of a common histogenesis

Rhabdomyosarcoma (RMS) of the urinary bladder in adults and elderly is an exceptionally rare neoplasm that displays poorly differentiated solid (alveolar-like) small cell pattern, frequently indistinguishable from small cell neuroendocrine carcinoma (SCNEC). However, the histogenesis of RMS and SCNEC and their inter-relationship have not been well studied and remained controversial. We herein analyzed 23 SCNEC and 3 small round cell RMS of the bladder for neuroendocrine (synaptophysin + chromogranin A) and myogenic (desmin + myogenin) marker expression and for TERT promoter mutations. In addition, the RMS cohort and one SCNEC that was revised to RMS were tested for gene fusions using targeted RNA sequencing (TruSight Illumina Panel which includes FOXO1 and most of RMS-related other genes). Overall, significant expression of myogenin and desmin was observed in one of 23 original SCNEC justifying a revised diagnosis to RMS. On the other hand, diffuse expression of synaptophysin was noted in 2 of the 4 RMS, but chromogranin A was not expressed in 3 RMS tested. TERT promoter mutations were detected in 15 of 22 (68%) SCNEC and in two of three (67%) assessable RMS cases, respectively. None of the four RMS cases had gene fusions. Our data highlights phenotypic and genetic overlap between SCNEC and RMS of the urinary bladder. High frequency of TERT promoter mutations in SCNEC is in line with their presumable urothelial origin. In addition, the presence of TERT promoter mutation in 2 of 3 RMS and lack of FOXO1 and other gene fusions in all 4 RMSs suggest a mucosal (urothelial) origin, probably representing extensive monomorphic rhabdomyoblastic transdifferentiation in SCNEC.

Pictorial review of multiparametric MRI in bladder urothelial carcinoma with variant histology: pearls and pitfalls

Bladder cancer (BC), predominantly comprising urothelial carcinomas (UCs), ranks as the tenth most common cancer worldwide. UCs with variant histology (variant UC), including squamous differentiation, glandular differentiation, plasmacytoid variant, micropapillary variant, sarcomatoid variant, and nested variant, accounting for 5-10% of cases, exhibit more aggressive and advanced tumor characteristics compared to pure UC. The Vesical Imaging-Reporting and Data System (VI-RADS), established in 2018, provides guidelines for the preoperative evaluation of muscle-invasive bladder cancer (MIBC) using multiparametric magnetic resonance imaging (mpMRI). This technique integrates T2-weighted imaging (T2WI), dynamic contrast-enhanced (DCE)-MRI, and diffusion-weighted imaging (DWI) to distinguish MIBC from non-muscle-invasive bladder cancer (NMIBC). VI-RADS has demonstrated high diagnostic performance in differentiating these two categories for pure UC. However, its accuracy in detecting muscle invasion in variant UCs is currently under investigation. These variant UCs are associated with a higher likelihood of disease recurrence and require precise preoperative assessment and immediate surgical intervention. This review highlights the potential value of mpMRI for different variant UCs and explores the clinical implications and prospects of VI-RADS in managing these patients, emphasizing the need for careful interpretation of mpMRI examinations including DCE-MRI, particularly given the heterogeneity and aggressive nature of variant UCs. Additionally, the review addresses the fundamental MRI reading procedures, discusses potential causes of diagnostic errors, and considers future directions in the use of artificial intelligence and radiomics to further optimize the bladder MRI protocol.

Clear Cell Renal Cell Carcinoma With Syncytial-Type Multinucleated Giant Tumor Cells: A Clinicopathologic Study of 14 Cases

The presence of syncytial-type multinucleated giant tumor cells with emperipolesis in clear cell renal cell carcinoma (RCC) is uncommon, with only 31 cumulative published cases to date. After a rereview of 125 clear cell RCC of World Health Organization/International Society of Urological Pathology grade 3 or 4, 14 clear cell RCCs with admixed syncytial-type giant cells (to our knowledge, the largest series to date) were found with a mean patient age of 67 years and with no sex difference (M = 7, F = 7). Mean tumor size was 7.3 cm. The syncytial-type giant cells comprised between 2% and 20% of the tumor and were present mainly around areas of necrosis. Five tumors were staged as pT1 or pT2, 8 as pT3, and 1 as pT4. Other findings included sarcomatoid differentiation (3/14), rhabdoid differentiation (4/14), and emperipolesis (12/14). Positive immunostains included keratin AE1/AE3 (13/13), carbonic anhydrase 9 and CD10 (12/14 each), vimentin (8/14), EMA (5/12), and alpha-methyacyl-CoA racemase (3/12). Keratin 7, keratin 20, human melanoma black 45, KIT, TFE3, cathepsin K, CD68, CD61, and beta human chorionic gonadotropin were negative. Six of 13 patients had recurrence or metastases during a mean follow-up time of 56 months. Four of 13 patients died of disease, 2 of 13 patients were alive with the disease, and 7 of 13 patients had no evidence of disease. Although the incidence of finding syncytial-type multinucleated giant tumor cells in clear cell RCC is low (approximately 1.2%), given that a subset of the patients showed poor outcomes while lacking other poor histologic parameters (eg, sarcomatoid or rhabdoid differentiation), it may be prudent to recognize and report this feature when encountered.

Effectiveness of Adjuvant Chemotherapy in Variant Histology Upper Tract Urothelial Carcinoma Following Radical Nephroureterectomy: Stabilized Inverse Probability Treatment Weighting Analysis of Single Center Experience

PURPOSE

The study aimed to investigate the impact of adjuvant chemotherapy on time to recurrence (TTR) and overall survival (OS) in patients with histologic variants of upper tract urothelial carcinoma (VUTUC) following radical nephroureterectomy (RNU).

MATERIALS AND METHODS

A retrospective review of 131 VUTUC patients' medical records, from a pool of 368 non-metastatic localized or locally advanced UTUC cases, treated at a single tertiary referral center between January 2011 and January 2021. The intervention was adjuvant chemotherapy administration post-RNU. TTR and OS were evaluated using Kaplan-Meier and Cox proportional hazard regression, covariates adjusted for age, postoperative GFR, history of neoadjuvant chemotherapy, T and N stage with stabilized inverse probability of treatment weighting (sIPTW).

RESULTS

The application of adjuvant chemotherapy showed a significant extension in TTR (P = .01), but no substantial impact on OS (P = .19) after sIPTW adjustment for covariates. Multivariate analysis revealed adjuvant chemotherapy, tumor size, and lymphovascular invasion as significant prognostic factors for TTR. In contrast, only tumor size and perineural invasion were significant for OS. Adjuvant chemotherapy reduced the progression risk in certain VUTUC subtypes (squamous or glandular/micropapillary), but not in sarcomatoid variants.

CONCLUSIONS

Adjuvant chemotherapy appears to improve TTR, albeit without a significant effect on OS, in nonmetastatic localized and locally advanced VUTUC patients post-RNU. While beneficial to some VUTUC subtypes, it did not yield significant advantages for sarcomatoid variants. Despite adjustments for known confounders, the study's findings may be subject to potential selection bias and unmeasured confounding factors.

Adenocarcinomas of the Gynecologic Tract Involving the Urinary Bladder: A Series of 16 Cases Potentially Mimicking Urothelial Malignancy

CONTEXT.—

There is limited literature describing gynecologic adenocarcinomas involving the urinary bladder and potential diagnostic pitfalls.

OBJECTIVE.—

To describe key features distinguishing metastatic (or extension of) gynecologic adenocarcinomas from urothelial carcinomas with glandular differentiation.

DESIGN.—

Retrospective review of surgical pathology cases of gynecologic adenocarcinomas involving the bladder from 2 different institutions, retrieved from surgical pathology archives, was performed. Morphologic features were recorded, along with immunohistochemistry results when available. Electronic medical records were reviewed for clinical and radiographic information.

RESULTS.—

Sixteen cases of gynecologic adenocarcinomas (9 endometrial endometrioid adenocarcinomas, 4 endometrial serous carcinomas, 2 high-grade tubo-ovarian serous carcinomas, and 1 cervical adenosquamous carcinoma) involving the bladder were identified. All included cases had mucosal involvement potentially mimicking primary bladder neoplasms, including 4 cases originally diagnosed as urinary carcinomas. Tumors expressed keratin 7 (12 of 13; 92%), PAX8 (11 of 12; 92%), estrogen receptor (11 of 15; 73%), p16 (8 of 11; 73%), progesterone receptor (8 of 14; 57%), GATA3 (5 of 12; 42%), and p63 (3 of 11; 27%); all tumors were negative for keratin 20 (0 of 12). Features supportive of Müllerian origin included prior history of gynecologic malignancy, lack of morphologic heterogeneity in nonendometrioid tumors, and immunophenotypic coexpression of PAX8 and estrogen receptor with absent GATA3. Potential pitfalls seen in a subset of cases included misleading radiologic and cystoscopic findings, replacement of the overlying urothelial mucosa by tumor mimicking precursor lesions, focal GATA3 and/or p63 positivity, and areas of squamous differentiation in tumors of endometrioid histology.

CONCLUSIONS.—

A combination of clinical history, certain morphologic features, and proper selection of immunohistochemical stains is key for the correct diagnosis of secondary gynecologic adenocarcinomas involving the urinary bladder.

Stromal osseous metaplasia in urothelial carcinoma of the bladder: An unusual and challenging feature. A case report

A 62-year-old male presented with pain and haematuria starting 3 months before. The computed tomography showed focal and mural bladder thickening with ureteropelvic dilatation. The following transurethral bladder resection revealed a high-grade muscle-invasive urothelial carcinoma. In the subsequent cystoprostatectomy we found the same tumour, but adding focal tumour-associated stromal osseous metaplasia. Ossifying metaplasia is an extremely rare feature in urothelial carcinoma, with a few reported cases and represents a diagnostic challenge, mimicking radiotherapy-induced sarcoma or sarcomatoid carcinoma.

Characterizing the Genomic Landscape of the Micropapillary Subtype of Urothelial Carcinoma of the Bladder Harboring Activating Extracellular Mutations of ERBB2

The micropapillary subtype of urothelial carcinoma (MPUC) of the bladder is a very aggressive histological variant of urothelial bladder cancer (UBC). A high frequency of MPUC contains activating mutations in the extracellular domain (ECD) of ERBB2. We sought to further characterize ERBB2 ECD-mutated MPUC to identify additional genomic alterations that have been associated with tumor progression and therapeutic response. In total, 5,485 cases of archived formalin-fixed, paraffin-embedded UBC underwent comprehensive genomic profiling to identify ERBB2 ECD-mutated MPUC and evaluate the frequencies of genomic co-alterations. We identified 219 cases of UBC with ERBB2 ECD mutations (74% S310F and 26% S310Y), of which 63 (28.8%) were MPUC. Genomic analysis revealed that TERT, TP53, and ARID1A were the most common co-altered genes in ERBB2-mutant MPUC (82.5%, 58.7%, and 39.7%, respectively) and did not differ from ERBB2-mutant non-MPUC (86.5%, 51.9%, and 35.3%). The main differences between ERBB2 ECD-mutated MPUC compared with non-MPUC were KMT2D, RB1, and MTAP alterations. KMT2D and RB1 are tumor-suppressor genes. KMT2D frequency was significantly decreased in ERBB2 ECD-mutated MPUC (6.3%) in contrast to non-MPUC (27.6%; P < .001). RB1 mutations were more frequent in ERBB2 ECD-mutated MPUC (33.3%) than in non-MPUC (17.3%; P = .012). Finally, MTAP loss, an emerging biomarker for new synthetic lethality-based anticancer drugs, was less frequent in ERBB2 ECD-mutated MPUC (11.1%) than in non-MPUC (26.9%; P = .018). Characterizing the genomic landscape of MPUC may not only improve our fundamental knowledge about this aggressive morphological variant of UBC but also has the potential to identify possible prognostic and predictive biomarkers that may drive tumor progression and dictate treatment response to therapeutic approaches.

Precision Medicine in Bladder Cancer: Present Challenges and Future Directions

Bladder cancer (BC) is characterized by significant histopathologic and molecular heterogeneity. The discovery of molecular pathways and knowledge of cellular mechanisms have grown exponentially and may allow for better disease classification, prognostication, and development of novel and more efficacious noninvasive detection and surveillance strategies, as well as selection of therapeutic targets, which can be used in BC, particularly in a neoadjuvant or adjuvant setting. This article outlines recent advances in the molecular pathology of BC with a better understanding and deeper focus on the development and deployment of promising biomarkers and therapeutic avenues that may soon make a transition into the domain of precision medicine and clinical management for patients with BC.

Identification of an Autophagy-Related Signature for Prognosis and Immunotherapy Response Prediction in Ovarian Cancer

BACKGROUND

Ovarian cancer (OC) is one of the most malignant tumors in the female reproductive system, with a poor prognosis. Various responses to treatments including chemotherapy and immunotherapy are observed among patients due to their individual characteristics. Applicable prognostic markers could make it easier to refine risk stratification for OC patients. Autophagy is closely implicated in the occurrence and development of tumors, including OC. Whether autophagy -related genes can be used as prognostic markers for OC patients remains unclear.

METHODS

The gene transcriptome data of 374 OC patients were downloaded from The Cancer Genome Atlas (TCGA) database. The correlation between the autophagy levels and outcomes of OC patients was identified through the single sample gene set enrichment analysis (ssGSEA). Recognized molecular markers of autophagy in different clinical specimens were detected by immunohistochemistry (IHC) assay. The gene set enrichment analysis (GSEA), ESTIMATE, and CIBERSORT analysis were applied to explore the correlation of autophagy with the tumor immune microenvironment (TIME). Single-cell RNA-sequencing (scRNA-seq) data from seven OC patients were included for characterizing cell-cell interaction patterns of autophagy-high or low tumor cells. Machine learning, Stepwise Cox regression and LASSO-Cox analysis were used to screen autophagy hub genes, which were used to establish an autophagy-related signature for prognosis evaluation. Four tumor immunotherapy cohorts were obtained from the GEO (Gene Expression Omnibus) database and the literature for autophagy risk score validation.

RESULTS

The autophagy levels were closely related to the prognosis of the OC patients. Additionally, the autophagy levels were correlated with TIME status including immune score, and immune-cell infiltration. The scRNA-seq analysis found that tumor cells with high or low autophagy levels had different interactions with immune cells, especially macrophages. Eight autophagy-hub genes (ZFYVE1, AMBRA1, LAMP2, TRAF6, PDPK1, ATG2B, DAPK1 and TP53INP2) were screened for an autophagy-related signature. According to this signature, higher risk score was correlated with poor prognosis and better immunotherapy response in the OC patients.

CONCLUSIONS

The autophagy-related signature is applicable to predict the prognosis and immune checkpoint inhibitors (ICIs) therapy efficiency in OC patients. It is possible to identify OC patients who will respond to ICIs therapy and have a favorable prognosis, although more verification is needed.

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.

T1 bladder carcinoma with variant histology: pathological features and clinical significance

The aim of the study was to stratify high-grade T1 (HGT1) bladder urothelial carcinoma into risk categories based on the presence of variant histology when compared to conventional urothelial carcinoma. The clinicopathological features of 104 HGT1 cases of urothelial carcinoma of the bladder with variant histology present in 34 (37%) were assessed. The endpoint of the study was disease-free survival and cancer-specific survival. Overall, variant histology was identified as a significant predictor of disease-free survival (P = 0.035). The presence of any specific variant histology (squamous, glandular, micropapillary, nested, microcystic, inverted growth, villous-like, basaloid, and lymphoepithelioma-like) was identified as a significant predictor of disease-free survival (P = 0.008) and cancer-specific survival (P = 0.0001) in HGT1 bladder cancer. Therefore, our results support including micropapillary HGT1 urothelial carcinoma within the aggressive high-risk category, as suggested by some recent clinical guidelines, but also favor nested, glandular, and basaloid to be placed in the high-risk category due to their potential of aggressive, life-threatening behavior and their limited response to bacillus Calmette-Guerin therapy. Conversely, the low-risk category would include urothelial carcinomas with squamous, inverted growth, or microcystic morphology, all with limited life-threatening potential and good response to current therapy. A very low-risk category would finally include patients whose tumors present villous-like or lymphoepithelioma-like morphology. In conclusion, our findings support the value of reporting the variant histology as a feature of variable aggressiveness in HGT1 urothelial carcinoma of the bladder.

Plasmacytoid urothelial carcinoma of the bladder: MRI features and their association with survival

OBJECTIVES

Plasmacytoid urothelial carcinomas (PUC) of the bladder are rare variants known for diffuse and infiltrative spread, however their magnetic resonance imaging (MRI) features are not well established. We aimed to evaluate MRI features of PUC of the bladder and their association with survival.

METHODS AND MATERIALS

This retrospective single-center study included 41 patients with pathologically-proven bladder PUC of the bladder that underwent pre-treatment MRI between January 2000 and March 2020. Two radiologists reviewed MRIs independently followed by consensus with a third radiologist. On MRI, tumor extent, size, Vesical Imaging-Reporting and Data System (VI-RADS) scores (≥4, muscle-invasive; 5, extravesical extension [EVE]), pelvic peritoneal spread (PPS), hydronephrosis, pelvic adenopathy and clinicopathological factors of age, gender, pathological stage, and treatment type were extracted. Kaplan-Meier curves and Cox proportional-hazards models were used to evaluate association with survival.

RESULTS

Thirty-two men and 9 women (median age 70 years, IQR 64-76) were included. Most were muscle-invasive (n = 30 [73.2%]). On MRI, most tumors were diffuse (n = 28 [68.3%]), >5 cm (n = 30 [73.2%]), VI-RADS 4 to 5 (n = 36 [87.8%]) with features of EVE and (n = 31 [75.6%]) and PPS (n = 25 [61.0%]). Variables associated with survival were: Larger tumors (>5 cm; hazard ratio [HR] = 5.0; 95% confidence interval [CI] 1.6-15.5; P < 0.01), diffuse extent (HR = 4.0; 95% CI 1.4-11.2; P = 0.01), EVE (HR = 4.5; 95% CI 1.5-13.6; P < 0.01), PPS (HR = 3.0; 95% CI 1.2-7.4; P = 0.01), hydronephrosis (HR = 13.7; 95% CI 3.1-60.9; P < 0.01), pathologic stage (≥pT3 vs. pT1; HR = 5.6; 95% CI 1.3-22.0; P = 0.02), and margin positivity (HR = 4.4 [95% CI 1.2-16.4], P = 0.03).

CONCLUSION

PUCs of the bladder are commonly large, diffuse VI-RADS score 4 to 5 tumors with MRI features of EVE and PPS. These features and pathological stage were associated with survival.

Bladder Cancer Sample Handling and Reporting: Pathologist's Point of View

The aim of this narrative review is to provide adequate information on handling and reporting of the bladder cancer samples to improve the closely collaboration between pathologists and urologists. The main (but not exclusive) research tool used was PubMed and 87 references were selected and quoted in the text. We have considered handling of biopsies, transurethral resection (TUR), and cystectomy specimens to summarize the different methods of sampling and the related issues. Moreover, we considered and discussed the main prognostic factors, such as histological tumor type, grade, and stage of bladder cancer, that should be described in the pathological report. In addition, critical issues encountered in the interpretation of histological samples were discussed.

The role of TAp63γ and P53 point mutations in regulating DNA repair, mutational susceptibility and invasion of bladder cancer cells

It has long been recognized that non-muscle-invasive bladder cancer (NMIBC) has a low propensity (20%) of becoming muscle-invasive (MIBC), and that MIBC carry many more p53 point mutations (p53m) than NMIBC (50% vs 10%). MIBC also has a higher mutation burden than NMIBC. These results suggest that DNA repair capacities, mutational susceptibility and p53m are crucial for MIBC development. We found MIBC cells are hypermutable, deficient in DNA repair and have markedly downregulated DNA repair genes, XPC, hOGG1/2 and Ref1, and the tumor suppressor, TAp63γ. In contrast, NMIBC cells are hyperactive in DNA repair and exhibit upregulated DNA repair genes and TAp63γ. A parallel exists in human tumors, as MIBC tissues have markedly lower DNA repair activity, and lower expression of DNA repair genes and TAp63γ compared to NMIBC tissues. Forced TAp63γ expression in MIBC significantly mitigates DNA repair deficiencies and reduces mutational susceptibility. Knockdown of TAp63γ in NMIBC greatly reduces DNA repair capacity and enhances mutational susceptibility. Manipulated TAp63γ expression or knockdown of p53m reduce the invasion of MIBC by 40–60%. However, the combination of p53m knockdown with forced TAp63γ expression reduce the invasion ability to nil suggesting that p53m contributes to invasion phenotype independent from TAp63γ. These results indicate that in BC, TAp63γ regulates DNA repair capacities, mutational susceptibility and invasion, and that p53m contribute to the invasion phenotype. We conclude that concurrent TAp63γ suppression and acquisition of p53m are a major cause for MIBC development.

Evaluation of the Extent of Variant Histology in Urothelial Carcinoma as a Predictive Marker of Clinical Outcomes After Radical Cystectomy

BACKGROUND/AIM

This study investigated the impact of the extent of variant histology (VH) on the prognosis of patients with bladder cancer (BC).

PATIENTS AND METHODS

We retrospectively evaluated consecutive patients with muscle-invasive BC who were treated with radical cystectomy (RC) at our institution between 2005 and 2018. Recurrence-free survival (RFS) and overall survival (OS) rates were evaluated using Kaplan-Meier analysis and Cox regression.

RESULTS

We identified 103 and 47 patients with pure urothelial carcinoma (UC) and a VH in UC, respectively. At the cutoff of 80%, univariate analysis identified significant differences in RFS (p=0.046) and OS (p=0.038) between patients with ≥80% VH (n=21) and those with <80% VH (n=26). Multivariate analysis revealed that the presence of ≥80% VH was significantly associated with RFS and OS.

CONCLUSION

The presence of ≥80% VH in UC could be an independent predictor of recurrence and mortality after RC.

A Contemporary Clinicopathologic Analysis of Primary Urothelial Carcinoma of the Urethra Without Concurrent Renal Pelvic, Ureteral, or Bladder Carcinoma

Primary urothelial carcinoma (UCa) of the urethra is relatively uncommon, and the underlying pathogenesis has not been well characterized, especially in the absence of concurrent UCa at other sites. A search for cases of primary UCa of the urethra was conducted. Patients with concurrent UCa of the renal pelvis, ureter, or bladder at the time of diagnosis of the primary tumor were excluded. Clinicopathologic and follow-up data were obtained. A total of 35 cases from 30 patients (27 male and 3 female) were included in the study. The mean patient age at the initial diagnosis was 71 years (range: 41-90 years). Cases were composed of high-grade UCa (26 of 35 = 74%), low-grade UCa (4 of 35 = 11%), and UCa in situ (5 of 35 = 14%). Invasion was present in 14 of 26 (54%) cases of high-grade UCa. Interestingly, 23 of 30 (77%) patients had a previous history of UCa including 7 (30%) cases with divergent differentiation or variant histology. Follow-up data were available in 23 patients with a mean duration of 26.7 months (range: 0.6-87 months). Eleven patients (31%) died of metastatic UCa. This is one of the largest studies to date of primary UCa of the urethra without concurrent UCa of the renal pelvis, ureter, or bladder. Previous history of UCa of the bladder, especially with divergent differentiation or variant histology is conceivably a key risk factor for developing subsequent primary UCa of the urethra. These findings are important for the development of surveillance protocols and therapeutic strategies.

Telomerase reverse transcriptase (TERT) promoter mutations in primary adenocarcinoma of bladder and urothelial carcinoma with glandular differentiation: pathogenesis and diagnostic implications

Telomerase reverse transcriptase (TERT) promoter mutations have been implicated in urothelial carcinogenesis and are present in 60-80% of conventional and variants of urothelial carcinomas. We investigated the prevalence of TERT promoter mutations in 46 cases of bladder nonurachal adenocarcinoma, 30 cases of urothelial carcinoma with glandular differentiation, 24 cases of nephrogenic adenoma, eight cases of villous adenoma, 31 cases of florid cystitis glandularis, and 20 cases of intestinal metaplasia of the bladder. TERT promoter mutations were detected in 33% of adenocarcinomas of urinary bladder and in 67% of urothelial carcinomas with glandular differentiation. All 30 cases of urothelial carcinoma with glandular differentiation harbored identical TERT promoter mutation in both glandular and urothelial carcinoma components from the same tumor, suggesting a common clonal origin. TERT promoter mutations were absent in nephrogenic adenoma, villous adenoma, florid cystitis glandularis, and intestinal metaplasia of the bladder. TERT promoter mutation analysis may be a useful ancillary study in the differential diagnosis.

Distinctive morphological and molecular features of urothelial carcinoma with an inverted growth pattern

Urothelial carcinoma with an inverted growth pattern (UC-IGP) is a peculiar entity within the spectrum of urothelial lesions. While efforts have been made over the last few decades to unravel its carcinogenesis and relationship with conventional urothelial carcinoma, the exact classification of inverted urothelial lesions is a matter of debate. The morphological features of UC-IGP pose several issues in differential diagnosis with other mostly benign lesions. Various techniques, including immunohistochemistry, UroVysion, and many molecular methods, have been employed to study the exact nature of this lesion. The aim of this review is to provide a comprehensive overview of the morphological and immunophenotypical aspects of UC-IGP. Moreover, we present and discuss the immunohistochemical and molecular markers involved in diagnosis and prognosis of UC-IGP lesions.

Molecular pathology of urothelial carcinoma

The current personalized oncology era has witnessed significant efforts to integrate clinical, pathological, and molecular classifications. The growing need for molecular biomarkers to feed personalized oncology, together with the unprecedented wealth of knowledge on the molecular basis of bladder cancer, has led to a novel approach to this disease, incorporating molecularly generated data in clinical practice for locally advanced or metastatic disease. Translational research allows a better understanding of the early events in the development of urothelial carcinoma in the urinary bladder. Thus, mutations in the KMT2D and KDM6A chromatin-modifying genes confer competitive advantages that drive cells to colonize larger regions of the urothelium. Additional mutations in TP53, PIK3CA, FGFR3, or RB1 genes then trigger the process of malignant transformation in the urothelium. In the current review, we provide an overview of what could be the expected transition from the morphology-based classification to a combined, molecularly enriched reporting of clinically meaningful parameters aiming to promote personalized oncology of urothelial carcinoma.

Non-Muscle Invasive Bladder Cancer with Variant Histology: Biological Features and Clinical Implications

BACKGROUND

The most common bladder cancer (BC) histotype is pure urothelial carcinoma (UC), which may undergo divergent differentiation in some cases. Variant histology (VH) presents along variable morphologies, either single or combined between them or with pure UC. From a clinical standpoint, the vast majority of BC is diagnosed at non-invasive or minimally invasive stages, namely as non-muscle invasive BC (NMIBC). There is a wide range of therapeutic options for patients with NMIBC, according to their clinical and pathological features. However, current risk stratification models do not show optimal effectiveness. Evidence from the literature suggests that VH has peculiar biological features, and may be associated with poorer survival outcomes compared to pure UC.

SUMMARY

In order to describe the biological features and prognostic/predictive role of VH in NMIBC, and to discuss current treatment options, we performed a systematic literature search through multiple databases (PubMed/Medline, Google Scholar) for relevant articles according to the following terms, single and/or in combination: "non-muscle invasive bladder cancer," "variant histology," "micropapillary variant," "glandular differentiation," "squamous differentiation," "nested variant," "plasmacytoid variant," and "sarcomatoid variant." We extracted 99 studies including original articles, reviews, and systematic reviews, and subsequently analyzed data from 16 studies reporting on the outcome of NMIBC with VH. We found that the relative rarity of these forms as well as the heterogeneity in study populations and therapeutic protocols results in conflicting findings overall. Key Messages: The presence of VH should be taken into account when counseling a patient with NMIBC, since it may upgrade the disease to high-risk tumor and thus warrant a more aggressive treatment.

Diagnostic value of urine cytology in detecting histologic variants of urothelial carcinomas in the urinary bladder: Cytopathologic correlation of 72 cases

BACKGROUND

Precise identification of histologic variants in urothelial carcinoma (UC) is important because some histologic types have a poor prognosis and clinical management varies. Urine cytology is used for bladder cancer screening, but the cytomorphologic features of histologic variants have not been well described. In the current study, we evaluate the effectiveness of urine cytology in detecting histologic variants of UC in the urinary bladder.

METHODS

Seventy-two urine cytology specimens from patients diagnosed with high-grade UCs by radical cystectomy were retrospectively reviewed and correlated with histopathologic findings of subsequent radical cystectomy specimens.

RESULTS

Of 72 total cases, 24 (33%) cases showed six histologic variants in corresponding surgical specimens, including squamous differentiation (13 cases), plasmacytoid variant (3 cases), micropapillary variant (3 cases), sarcomatoid variant (3 cases), giant cell variant (1 case), and glandular differentiation (1 case). Histopathology and cytomorphology were well correlated in 13 cases (54%), with squamous differentiation in 11 of 13 cases (85%), micropapillary features in 1 out of 3 cases (33%), and spindle cell/sarcomatoid features in 1 of 3 cases (33%). Furthermore, mucosal involvement by histologic variants, not amount of histologic variant, was related to high concordance rates between cytology and histology diagnosis.

CONCLUSIONS

The morphologic features of some histologic variants of high-grade UCs, such as squamous differentiation, micropapillary variant, and sarcomatoid variant, are partially reflected on urine cytology. In addition, mucosal involvement by histologic variants was associated with a higher detection rate of histologic variants in urine cytology.

Stage T1 bladder cancer: diagnostic criteria and pitfalls

Accurate pathological staging is crucial for patient management. Patients with T1 bladder cancer are at risk of recurrence, progression, and death of cancer. Recognition of early invasion (stage T1 disease) in urothelial carcinoma remains one of the most challenging areas in urological surgical pathology practice. A logical roadmap to T1 diagnosis would include careful evaluation of histological grade, stromal epithelial interface, characteristics of the invading epithelium, and the stroma associated responses. Tangential sectioning, crush and cautery artifacts, and associated inflammatory infiltrate are commonly encountered problems and the source of pitfalls. In this review, we outline diagnostic criteria, common pitfalls, and different histological patterns of invasion into the lamina propria. Current recommendations on reporting of biopsy and transurethral resection specimens, molecular biomarkers, clinical implications of T1 cancer diagnosis and recent developments on the T1 substaging are also discussed. Most T1 bladder cancer patients will benefit from conservative management after restaging transurethral resection of bladder and bacillus Calmette-Guérin maintenance. Patients with high risk features, such as concurrent urothelial carcinoma in situ, increased depth of invasion, lymphovascular invasion, and variant histology among others, should be considered for early cystectomy.

Imaging in gynecological disease (18): clinical and ultrasound characteristics of urinary bladder malignancies

OBJECTIVE

To describe the clinical and ultrasound characteristics of urinary bladder malignancies diagnosed on transvaginal ultrasound in women presenting with suspected gynecological problems.

METHODS

This was a multicenter retrospective study of women with a histological diagnosis of urinary bladder malignancy that was suspected on transvaginal ultrasound examination. The cases were collected from three centers that specialize in the use of pelvic ultrasound and had been examined between January 2007 and October 2018. Clinical data were obtained from the computer databases and all tumor images were assessed by two of the authors (D.J. and J.K.) to identify characteristic sonographic patterns. We compared the characteristics of tumors between women presenting with symptoms suspicious of urinary bladder malignancy and those without such symptoms.

RESULTS

Thirty women with a confirmed diagnosis of urinary bladder malignancy on histological examination were included. Median age at diagnosis was 70.5 (range 36-88) years. The most common presenting symptom was postmenopausal bleeding, which was recorded in 18 (60%) women. Ten (33%) women had symptoms suspicious of bladder malignancy, of whom six had unexplained visible hematuria, three had unexplained recurrent urinary tract infections and one had dysuria and microhematuria. On histological examination, 23 (77%) women were diagnosed with primary bladder malignancy whilst seven (23%) had metastases in the bladder from other primary tumors. Out of 23 primary tumors, 21 (91%) were of urothelial origin (12 low grade and nine high grade). Most low-grade urothelial carcinomas appeared on ultrasound as irregular papillary growth (11/12, 92%) and were moderately to highly vascular on color Doppler examination (8/12, 67%). The ultrasound appearances of primary non-urothelial and metastatic tumors varied, without a clear common morphological tumor pattern. The tumors found in women with symptoms suggestive of bladder malignancy did not differ unequivocally from those detected in other women in terms of size, ultrasound morphology, vascularity or histological type.

CONCLUSION

Urinary bladder malignancies can be detected in patients undergoing transvaginal ultrasound examination for suspected gynecological problems. Primary urothelial cancers have a relatively uniform morphological pattern, whilst the appearances of other bladder malignancies are more variable. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

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.

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

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

Clinicopathologic analysis of upper urinary tract carcinoma with variant histology

We report on the clinicopathologic features of 115 cases of high-grade urothelial carcinoma of the upper urinary tract with variant histology present in 39 (34%). Variant histology was typically seen in high pathological stage (pT2-pT4) (82%, 32 cases) patients with lower survival rate (70%, 27 cases, median survival 31 months) and consisted in urothelial with one (23%), two (3%), and three or more variants (3%); 4% of cases presented with pure variant histology. Squamous divergent differentiation was the most common variant (7%) followed by sarcomatoid (6%) and glandular (4%), followed by 3% each of micropapillary, diffuse-plasmacytoid, inverted growth, clear cell glycogenic, or lipid-rich. The pseudo-angiosarcomatous variant is seen in 2%, and 1% each of nested, giant-cell, lymphoepithelioma-like, small-cell, trophoblastic, rhabdoid, microcystic, lymphoid-rich stroma, or myxoid stroma/chordoid completed the study series. Loss of mismatch repair protein expression was identified in one case of upper urinary tract carcinoma with inverted growth variant (3.6%). Variant histology was associated to pathological stage (p = 0.007) and survival status (p = 0.039). The univariate survival analysis identified variant histology as a feature of lower recurrence-free survival (p = 0.046). Our findings suggest that variant histology is a feature of aggressiveness in urothelial carcinoma of the upper urinary tract worth it to be reported.

BCG instillation versus radical cystectomy for high-risk NMIBC with squamous/glandular histologic variants

This study aims to evaluate the effect of Bacillus Calmette-Guérin (BCG) instillation and radical cystectomy on high-risk NMIBC with squamous or glandular variants. We retrospectively reviewed the data of high-risk (T1 or CIS or HG or TaG1/G2 with multiple, recurrent, large tumor) NMIBC patients from January 2000 to December 2017. Comparative analysis of radical cystectomy, intravesical BCG, and observation groups was conducted in high-risk NMIBC with squamous or glandular histologic variants. Among the 1263 high-risk NMIBC patient, 62 (4.9%) were reported squamous or glandular histologic variants. Thirty patients underwent BCG instillation and 15 patients were subjected to radical cystectomy. Statistically significant differences were found between the three treatment groups in terms of underlying hypertension (p = 0.031), T stage (p = 0.022) and tumor multiplicity (p = 0.019). Similar 5-year OS (p = 0.893) and CSS (p = 0.811) were observed in each of BCG instillation and radical cystectomy group. BCG instillation showed survival benefit in both OS (p = 0.019) and CSS (p = 0.038) than in the observation group. In high-risk patients diagnosed with NMIBC bladder cancer with squamous or glandular histologic variants, both intravesical BCG and radical cystectomy showed survival gain. In conclusion, BCG instillation represents an appropriate treatment option in high-risk NMIBC with squamous or glandular histologic variant.

Plasmacytoid urothelial carcinoma: a rapid autopsy case report with unique clinicopathologic and genomic profile

Background

Rapid (“warm”) autopsies of patients with advanced metastatic cancer provide important insight into the natural history, pathobiology and histomorphology of disease in treatment-resistant tumors. Plasmacytoid urothelial carcinoma (PUC) is a rare variant of urothelial carcinoma characterized by neoplastic cells morphologically resembling plasma cells. PUC is typically aggressive, high-stage at presentation, and associated with poor outcomes. Recurrence is common in PUC, with the majority of recurrences occurring in the peritoneum.

Case presentation

Here, we report rapid autopsy findings from a patient with recurrent PUC. The patient had persistent pain after cystoprostatectomy, although initial post-operative imaging showed no evidence of disease. Imaging obtained shortly before his death showed only subtle growth along vascular tissue planes; however, extensive disease was seen on autopsy. Plasmacytoid tumor cells formed sheets involving many serosal surfaces. Molecular interrogation confirmed a mutation in CDH1 exon 12 leading to early truncation of the CDH1 protein in the tumor cells.

Conclusions

The sheet-like growth pattern of PUC makes early phases of disease spread much more difficult to capture on cross-sectional imaging. Alternative forms of surveillance may be required for detection of recurrent PUC, and providers may need to treat based on symptoms and clinical suspicion.

[Morphological and immunohistochemical characteristics of the molecular subtypes of urothelial carcinomas]

The molecular subtypes of urothelial carcinoma in each classification scheme have characteristic immunohistochemical features. At the same time, the results of conducted studies often demonstrate a discrepancy between the genomic profile of urothelial carcinoma and its immunophenotype, which complicates the immunohistochemical verification of the molecular subtypes of these tumors.

OBJECTIVE

To compare the morphological and immunophenotypic characteristics of the molecular subtypes of urothelial carcinoma.

MATERIAL AND METHODS

Surgical specimens from 196 patients diagnosed with urothelial carcinoma of the renal pelvis and bladder were investigated. Paraffin-embedded sections were immunohistochemically examined using the standard protocol. Antibodies against CK5/6, CK17, Rb1 (Dako), CK14, CK18, CK20, Cyclin D1, Cyclin E1, Cyclin A, Cyclin B, Chromogranin, E-Cadherin, P-Cadherin, p16, Uroplakin II, TUBB2B, Vimentin, ZEB-2 ('Novocastra'), CD44, GATA-3, and Uroplakin III ('Cell Marque') were used.

RESULTS

Out of 68 (35%) superficial papillary urothelial carcinomas, 24 (12%) tumors constituted Molecular Class I and 12 (6%) and 32 (16%) ones did Molecular Classes II and III, respectively. Of the 128 (65%) muscle-invasive urothelial carcinomas, 57 (29%) tumors were referred to as the luminal-papillary molecular subtype, and 24 (12%) and 14 (7%) were as the luminal-infiltrated and luminal molecular subtypes, respectively. The basal squamous molecular subtype was verified in 31 (16%) neoplasms and the neuronal phenotype was detected in 2 (1%) cases.

CONCLUSION

Most pT₁ tissues correspond to Molecular Class II. In the muscle-invasive urothelial carcinoma group, the neoplasms with a luminal phenotype predominate over the tumors with basal and neuronal phenotypes.

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.

Glandular differentiation in pT1 urothelial carcinoma of bladder predicts poor prognosis

To evaluate the effect of glandular differentiation (GD) on tumor recurrence and progression of pT1 bladder urothelial carcinoma (UC). We performed a retrospective analysis of 82 bladder urothelial carcinoma with glandular differentiation (UCGD) patients which was pathologically diagnosed as pT1, 166 patients of pT1 UC of bladder without histologic variants served as controls. Patients of UCGD were more likely to have higher recurrence (P = 0.002) rate and higher progression rate (P < 0.001). Moreover, UCGD and a poor 5 -year overall survival (OS) (P = 0.02) while there was no difference in cancer-specific survival (CSS) (P = 0.062) between two groups. According to univariate analysis, largest tumor size (HR 1.502, CI 1.158–1.861, P = 0.029), UCGD (HR 1.787, CI 1.298–2.552, P = 0.001), lymphovascular invasion (LVI) (HR 1.226, CI 1.013–1.945, P = 0.039). UCGD (HR 1.367, CI 1.115–1.853, P = 0.038) and LVI (HR 1.416, CI 1.120–2.254, P = 0.013) were prognostic factors associated with disease recurrence and progression, respectively. Additionally, Additionally, UCGD significantly influence disease recurrence (HR 1.871, CI 1.338–2.589, P < 0.001) and progression (HR 1.462, CI 1.138–2.393, p = 0.007). Similarly, LVI significantly influence disease recurrence (HR 1.356, CI 1.053–2.174, P = 0.042) and progression (HR 1.348, CI 1.052–1.944, p = 0.022) in multivariate analysis. UCGD is significantly associated with higher recurrence and progression rate in patients with newly diagnosed pT1. Recurrent cases should be performed radical cystectomy (RC) earlier.

[Comparative morphological characteristics and immunophenotype of urothelial carcinomas of the renal pelvis and bladder]

Urothelial carcinoma is one of the most frequently diagnosed malignant tumors of the bladder and upper urinary tract, which ranks seventh in the pattern of cancer. Urothelial carcinoma of the renal pelvis is less common; but has a more aggressive clinical course and a worse prognosis than that of the bladder. This is due to the clinical and morphological features of this form of cancer, which, unlike bladder cancer, have not been studied enough.

OBJECTIVE

To comparatively analyze the morphological and immunophenotypic parameters of urothelial carcinomas of the renal pelvis and bladder.

SUBJECT AND METHODS

Surgical specimens from 196 patients diagnosed with urothelial carcinoma of the renal pelvis and bladder were investigated. Paraffin sections were immunohistochemically examined using the standard protocol. Antibodies against CK5/6, CD138, CDX2 ('Dako'), CK7, CK14, CK20, CEA, CD10, CD117, EMA, E-Cadherin, HMWCK, p63, Uroplakin III, Vimentin ('Novocastra'), CD44, GATA-3, MUC1, MUC2, and MUC-5AC ('Cell Marque') were used.

RESULTS

Most tumors (n=147 (75%)) were invasive. Of them, 65 (33%) cases had a histological structure of conventional urothelial cancer; and 3 (1.5%) had paradoxical differentiation. Divergent tumor zones were verified in 66 (34%) neoplasms; 4 (2%) cases showed an inverted growth pattern. Pseudosarcomatous stroma reaction in the invasion zones was verified in 9 (5%) cases. The tumor stage corresponded to pT2-pT4 in 128 (65%) tumors.

CONCLUSION

Urothelial carcinomas of the renal pelvis and bladder show a broad spectrum of histological variants. The findings support that, unlike urothelial carcinomas of the bladder, the majority of primary urothelial carcinomas of the renal pelvis are high-grade and highly invasive.

Naturally-occurring canine invasive urothelial carcinoma harbors luminal and basal transcriptional subtypes found in human muscle invasive bladder cancer

There is growing evidence that molecular subtypes (e.g. luminal and basal subtypes) affect the prognosis and treatment response in patients with muscle invasive urinary bladder cancer (invasive urothelial carcinoma, iUC). Modeling these subtypes in pre-clinical animal studies is essential, but it is challenging to produce these subtypes, along with other critical host and tumor features, in experimentally-induced animal models. This study was conducted to determine if luminal and basal molecular subtypes are present in naturally-occurring canine iUC, a cancer that mimics the human condition in other key aspects. RNA sequencing was performed on 29 canine treatment naive iUC tissue samples and on four normal canine bladder mucosal samples. Data were aligned to CanFam 3.1, and differentially expressed genes were identified. Unsupervised hierarchical clustering of these genes revealed two distinct groups (n = 13, n = 16). When genes that distinguish basal and luminal subtypes in human cancer (n = 2015) were used to probe genes differentially expressed between normal canine bladder and iUC, 829 enriched signature genes were identified. Unsupervised hierarchical clustering of these genes revealed two distinct groups comprised of 18 luminal subtype tumors and 11 basal subtype tumors. The enriched genes included MMP9, SERPINE2, CAV1, KRT14, and RASA3 in basal tumors, and PPARG, LY6E, CTSE, CDK3, and TBX2 in luminal tumors. In supervised clustering, additional genes of importance in human iUC were identified in canine iUC associated with claudin-low and infiltrated tumors. A smaller panel of genes (n = 60) was identified that distinguished canine luminal and basal iUC with overall 93.1% accuracy. Immune signature patterns similar to those in human iUC were also identified with the greatest enrichment of immune genes being in the basal subtype tumors. These findings provide additional compelling evidence that naturally-occurring canine iUC is a highly relevant and much needed model of human iUC for translational research.

Bacillus Calmette-Guérin may have clinical benefit for glandular or squamous differentiation in non-muscle invasive bladder cancer patients: retrospective multicenter study

Objectives

To clarify the efficacy of intravesical Bacillus Calmette-Guérin (BCG) instillation for non-muscle invasive bladder (NMIBC) cancer with variant histology, especially glandular differentiation or squamous differentiation.

Materials and methods

From May 1991 through June 2016, 53 patients were diagnosed retrospectively as having NMIBC with variant histology. Among these patients, 47 NMIBC patients with squamous differentiation or glandular differentiation were analyzed for this study. The median follow-up interval from diagnosis of NMIBC with variant histology was 28.9 months (1.5-168.8).

Results

Of these patients, 38 (80.9%) and 9 (19.1%) were diagnosed as having glandular differentiation and squamous differentiation, respectively. Radical cystectomy was conducted for six (12.8%) immediately after the diagnosis of NMIBC with variant histology. Of the 41 patients with bladder preservation, 20 (48.8%), 3 (7.3%), 3 (7.3%) and 15 (36.6%) underwent BCG, THP, MMC and no additional treatment, respectively. There were significant differences between BCG and other treatments or no additional treatment for recurrence (P = 0.034), progression (P = 0.004) and cancer-specific survival (P = 0.014).

Conclusion

Overall, our results show that intravesical BCG instillation for variant histology in NMIBC leads to a better prognosis with regard to progression and cause-specific survival than other intravesical treatments or no additional treatment. BCG treatment may also have a clinical benefit for variant histology in non-muscle invasive bladder cancer patients.

Metastatic Urothelial Carcinoma with Glandular Differentiation That Confirmed the Response by Autopsy Specimen to Second-Line mFOLFOX6 (Fluorouracil, Oxaliplatin, and Leucovorin) plus Bevacizumab Chemotherapy

The prognostic significance of glandular differentiation in urothelial carcinoma (UC) is controversial, and thus far there is no established treatment strategy against metastasis of glandular component. We describe here a case of metastatic UC with glandular differentiation that had histological disappearance of adenocarcinoma components at autopsy after sequential chemotherapy with S-1 and cisplatin (CDDP) and with mFOLFOX6 (fluorouracil, oxaliplatin, and leucovorin) plus bevacizumab (mFOLFOX6+Bev). A 62-year-old Asian male was diagnosed with invasive UC with glandular differentiation (T2N0M0) by radical cystectomy and ileal conduit, and careful follow-up observation was made. Eight years after radical operation, peritoneal metastases occurred, and a biopsy specimen using colon fiber revealed high-grade adenocarcinomas with an immunohistochemical profile that included positivity for cytokeratin 7 (CK7) and negativity for cytokeratin 20 (CK20) and uroplakin, which was identical to the radical cystectomy specimen. Thus, he received combination chemotherapy consisting of S-1 and CDDP; however, the peritoneal metastasis worsened after 2 cycles. Therefore, second-line mFOLFOX6+Bev chemotherapy was performed for a total of 5 courses. In spite of this, the patient died, and the final diagnosis by autopsy was multiple metastases of infiltrating pure UC to the lung, bone, and peritoneum. Interestingly, there were no pathological findings of adenocarcinoma, and the immunohistochemical profile of the metastatic lesions was identical to that of the previous specimens from the bladder and colon. This suggests that sequential chemotherapy of S-1 and CDDP and second-line mFOLFOX6+Bev might be a feasible option in metastatic UC with glandular differentiation.

Contribution of bladder cancer pathology assessment in planning clinical trials

Bladder cancer is a heterogeneous disease that demonstrates a wide spectrum of histologic features. The modern classification of bladder cancer is largely based on pathologic analysis, which assesses tumor grade, stage, type, size, and other features that are essential for understanding the biological behavior of bladder cancer. Bladder cancers with similar histologic features are likely to show comparable responses to a new therapeutic agent in clinical trial. Furthermore, pathologic analysis also evaluates the quality of tissue samples in clinical trial to ensure the integrity of various molecular tests. In spite of the emerging role of genomic and molecular studies, pathology remains the cornerstone in the diagnosis, prognosis, and treatment of bladder cancer. Herein, the pathologic considerations for bladder cancer clinical trial planning are reviewed.