Primary mucinous adenocarcinoma of the urethra: A contemporary clinicopathologic analysis of 17 patients.

Mucinous adenocarcinoma of the urethra is rare. Here we performed a contemporary clinicopathologic analysis of this entity in both male and female patients. All cases with secondary tumors involving the urethra were excluded. Clinicopathologic parameters and follow up was obtained. Seventeen patients were included in the study, 9/17 (53 %) male and 8/17 (47 %) female. The mean patient age was 68 years (range: 53-88 years). The majority (11/17, 65 %) of patients were African American, with an even greater incidence (7/8, 87 %) in female patients. In male patients, prostatic urethra was the most common part of the urethra (6/9, 67 %) where the tumor arose from. Immunohistochemical stains were performed in 11/17 (65 %) tumors and were positive for CK20 (11/11, 100 %), CDX2 (11/12, 92 %), CK7 (8/9, 88 %), GATA3 (3/8, 37 %) and negative for NKX3.1, PSA, p63, PAX8, and Beta-Catenin. In resection specimens, tumors were categorized as pT2 (3/11, 27 %), pT3 (1/11, 9 %), and pT4 (7/11, 64 %). Lymph node status was categorized as pN0 (6/9, 67 %), pN1 (1/9, 11 %), and pN2 (2/9, 22 %). Available follow up data showed 7/13 (54 %) patients developed recurrence after surgical resection and chemotherapy, of which 3/7 (43 %) died of widespread metastatic disease. It is critical for pathologists and urologic oncologists to be aware of this entity in both male and female patients in view of potential diagnostic pitfalls, prognosis, and therapeutic implications.

A Contemporary Clinicopathologic Analysis of Patients With Renal Cell Carcinoma and Vena Cava Involvement.

Renal cell carcinoma (RCC) is occasionally associated with vena cava involvement. Despite recent advances in therapeutic modalities, the 5-year survival in this population continues to be poor. Therefore, further studies are required to better characterize this patient population, especially from the clinicopathologic standpoint. A comprehensive review of patients with RCC and vena cava involvement managed at our institution from 2014 to 2022 was performed. Multiple clinicopathologic parameters including follow-up were obtained. A total of 114 patients were identified. The mean patient age was 63 years (range: 30-84 years). The cohort consisted of 78/114 (68%) males and 36/114 (32%) females. The mean primary tumor size (excluding tumor thrombus) was 11 cm. The majority of tumors (104/114, 91%) were unifocal. Tumor stages were categorized as follows: pT3b (51/114, 44%), pT3c (52/114, 46%), and pT4 (11/114, 10%). Most of the tumors were clear cell RCC 89/114 (78%), although other more aggressive RCC subtypes were also present. Most tumors were WHO/ISUP grade 3 (44/114, 39%) or 4 (67/114, 59%) with sarcomatoid differentiation present in 39/67 (58%). Necrosis was present in 94/114 (82%) tumors. Twenty-three of 114 (20%) tumors were categorized as pM1 and the ipsilateral adrenal gland was the most common site of metastasis. Of the 91 patients categorized as pM, not applicable at nephrectomy, 42/91 (46%) subsequently developed metastasis, most frequently to the lung. Of all patients, only 16/114 (14%) had positive vascular margins and 7/114 (6%) had positive soft tissue margins despite having very advanced disease and a subset considered inoperable at other centers.

2018 Leibovich prognostic model for renal cell carcinoma: Performance in a large population with special consideration of Black race.

BACKGROUND: The 2018 Leibovich prognostic model for nonmetastatic renal cell carcinoma (RCC) combines clinical, surgical, and pathologic factors to predict progression-free survival (PFS) and cancer-specific survival (CSS) for patients with clear cell (ccRCC), papillary (pRCC), and chromophobe (chRCC) histology. Despite high accuracy, <1% of the original cohort was Black. Here, the authors examined this model in a large population with greater Black patient representation. METHODS: By using a prospectively maintained RCC institutional database, patients were assigned Leibovich model risk scores. Survival outcomes included 5-year and 10-year PFS and CSS. Prognostic accuracy was determined using area under the curve (AUC) analysis and calibration plots. Black patient subanalyses were conducted. RESULTS: In total, 657 (29%) of 2295 patients analyzed identified as Black. Declines in PFS and CSS were observed as scores increased. Discrimination for ccRCC was strong for PFS (AUC: 5-year PFS, 0.81; 10-year PFS, 0.78) and for CSS (AUC: 5-year CSS, 0.82; 10-year CSS, 0.74). The pRCC AUC for PFS was 0.74 at 5 years and 0.71 at 10 years; and the AUC for CSS was 0.74 at 5 years and 0.70 at 10 years. In chRCC, better performance was observed for CSS (AUC at 5 years, 0.75) than for PFS (AUC: 0.66 at 5 years; 0.55 at 10 years). Black patient subanalysis revealed similar-to-improved performance for ccRCC at 5 years (AUC: PFS, 0.79; CSS, 0.87). For pRCC, performance was lower for PFS (AUC at 5 years, 0.63) and was similar for CSS (AUC at 5 years, 0.77). Sample size limited Black patient 10-year and chRCC analyses. CONCLUSIONS: The authors externally validated the 2018 Leibovich RCC prognostic model and found optimal performance for ccRCC, followed by pRCC, and then chRCC. Importantly, the results were consistent in this large representation of Black patients. PLAIN LANGUAGE SUMMARY: In 2018, a model to predict survival in patients with renal cell carcinoma (kidney cancer) was introduced by Leibovich et al. This model has performed well; however, Black patients have been under-represented in examination of its performance. In this study, 657 Black patients (29%) were included, and the results were consistent. This work is important for making sure the model can be applied to all patient populations.

Genomic analysis of spermatocytic tumors demonstrates recurrent molecular alterations in cases with malignant clinical behavior.

Spermatocytic tumor (ST) is a rare type of germ cell tumor that occurs exclusively in the postpubertal testis and typically affects elderly men. Most STs are benign, but rare cases exhibit aggressive clinical behavior, often in association with transition to sarcomatoid histology. Limited molecular analyses have been performed on STs; therefore, their genomic and epigenomic features remain incompletely described. Twenty-seven samples from 25 individual patients were analyzed with a combination of DNA sequencing panels, genomic methylation profiling, SNP array, isochromosome (12p) [i(12p)] FISH, and immunohistochemistry. The series included five metastasizing tumors (three with sarcomatoid transformation, one anaplastic, and one conventional) and 20 non-metastasizing tumors (14 anaplastic and six conventional). Anaplastic tumors comprised a monomorphic population of intermediate-sized neoplastic cells, as previously described. Multiomic analyses demonstrated that there were two genomic subgroups of STs: one with diploid genomes and hotspot RAS/RAF variants and the other with global ploidy shift and absence of recurrent mutations. Relative gain of chromosome 9 was a consistent finding in both subgroups. A comparison of metastasizing and non-metastasizing cases demonstrated that aggressive behavior was associated with the acquisition of pathogenic TP53 mutations and/or relative gains of 12p/i(12p). In cases with sarcomatoid transformation, TP53 mutations seem to underlie the transition to sarcomatoid histology. Genomic methylation analysis demonstrated that aggressive cases with gains of 12p cluster closer to pure seminomas than to STs without gains of 12p. In conclusion, STs include two genomic subgroups, characterized by global ploidy shifts without recurrent mutations and diploid genomes with RAS/RAF hotspot mutations, respectively. Biologic progression was associated with relative gains of 12p and TP53 mutations. The findings in STs with relative gains of 12p suggest that they may exhibit biologic characteristics akin to those seen in germ cell neoplasia in situ-related germ cell tumors rather than non-germ cell neoplasia in situ-derived STs. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Integrated Genomic Analysis of Primary Prostate Tumor Foci and Corresponding Lymph Node Metastases Identifies Mutations and Pathways Associated with Metastasis.

Prostate cancer is a highly heterogeneous disease and mortality is mainly due to metastases but the initial steps of metastasis have not been well characterized. We have performed integrative whole exome sequencing and transcriptome analysis of primary prostate tumor foci and corresponding lymph node metastases (LNM) from 43 patients enrolled in clinical trial. We present evidence that, while there are some cases of clonally independent primary tumor foci, 87% of primary tumor foci and metastases are descended from a common ancestor. We demonstrate that genes related to oxidative phosphorylation are upregulated in LNM and in African-American patients relative to White patients. We further show that mutations in TP53, FLT4, EYA1, NCOR2, CSMD3, and PCDH15 are enriched in prostate cancer metastases. These findings were validated in a meta-analysis of 3929 primary tumors and 2721 metastases and reveal a pattern of molecular alterations underlying the pathology of metastatic prostate cancer. We show that LNM contain multiple subclones that are already present in primary tumor foci. We observed enrichment of mutations in several genes including understudied genes such as EYA1, CSMD3, FLT4, NCOR2, and PCDH15 and found that mutations in EYA1 and CSMD3 are associated with a poor outcome in prostate cancer.

Nested and Large Nested Subtypes of Urothelial Carcinoma of the Upper Urinary Tract: A Multi-institutional Study.

Nested urothelial carcinoma (NUC) and large nested urothelial carcinoma (LNUC) of the upper urinary tract are exceedingly rare. This has contributed to the paucity of information regarding their clinicopathological and molecular characteristics. To address this knowledge gap, we explored the largest cohort to date of these rare tumors, comprising resection specimens of 10 LNUC and 7 NUC, from 7 participating institutions. Clinicopathological data were retrieved and documented. Whole exome sequencing and RNA sequencing were performed on the Illumina NovaSeq 6000 sequencer. The data generated were analyzed using the genome analysis toolkit pipeline. Somatic mutations were annotated using funcotator tool to identify pathogenic/likely pathogenic variants. Tumor mutational burden was calculated using python-based "pyTMB" tool. Microsatellite instability analysis was done using MSIsensor2 and the Idylla platform. Differential expression analysis of genes in LNUC and NUC along with mRNA expression-based molecular subtyping was performed by analyzing expression pattern of markers used in The Cancer Genome Atlas subclassification of bladder carcinoma. Both tumor types were more common in older males, were unifocal, and occurred more commonly mixed with minor components of predominantly conventional urothelial carcinoma. Overlying low-grade papillary urothelial carcinoma was significantly more common in LNUC (P = .034). On follow-up (LNUC: median, 10 months; range, 3-84 months; NUC: median, 9 months; range, 2-48 months), LNUC had better clinical outcomes (P = .031). Pathogenic mutations in FGFR3 and PIK3CA were significantly more common in LNUC (P = .049 and P = .044, respectively), with the latter present exclusively in LNUC. Seventy-five percent of the cases showed tumor mutational burden of <10, and all cases were microsatellite-stable. FGFR3 mutations were also more common in low-stage tumors. This study expands on the clinicopathological spectrum of NUC and LNUC of the upper urinary tract and is the first to comprehensively analyze the molecular profile of these tumors, highlighting pathogenic genetic alterations of potential therapeutic and prognostic value.

Wilms Tumor: An Unexpected Diagnosis in Adult Patients.

CONTEXT.­: Wilms tumor (WT) in adult patients is rare and has historically been a diagnostic and therapeutic conundrum, with limited data available in the literature. OBJECTIVE.­: To provide detailed diagnostic features, molecular profiling, and patient outcomes in a multi-institutional cohort of adult WT patients. DESIGN.­: We identified and retrospectively examined 4 adult WT cases. RESULTS.­: Two patients presented with metastatic disease, and diagnoses were made on fine-needle aspiration of their renal masses. The aspirates included malignant primitive-appearing epithelioid cells forming tubular rosettes and necrosis, and cell blocks demonstrated triphasic histology. In the remaining 2 cases, patients presented with localized disease and received a diagnosis on resection, with both patients demonstrating an epithelial-predominant morphology. Tumor cells in all cases were patchy variable positive for PAX8 and WT1 immunohistochemistry. Next-generation sequencing identified alterations previously reported in pediatric WT in 3 of 4 cases, including mutations in ASXL1 (2 of 4), WT1 (1 of 4), and the TERT promoter (1 of 4), as well as 1q gains (1 of 4); 1 case showed no alterations. Three patients were treated with pediatric chemotherapy protocols; during follow up (range, 26-60 months), 1 patient died of disease. CONCLUSIONS.­: WT is an unexpected and difficult entity to diagnose in adults and should be considered when faced with a primitive-appearing renal or metastatic tumor. Molecular testing may help exclude other possibilities but may not be sensitive or specific because of the relatively large number of driver mutations reported in WT.

Nicardipine is a putative EED inhibitor and has high selectivity and potency against chemoresistant prostate cancer in preclinical models.

BACKGROUND: It is imperative to develop novel therapeutics to overcome chemoresistance, a significant obstacle in the clinical management of prostate cancer (PCa) and other cancers. METHODS: A phenotypic screen was performed to identify novel inhibitors of chemoresistant PCa cells. The mechanism of action of potential candidate(s) was investigated using in silico docking, and molecular and cellular assays in chemoresistant PCa cells. The in vivo efficacy was evaluated in mouse xenograft models of chemoresistant PCa. RESULTS: Nicardipine exhibited high selectivity and potency against chemoresistant PCa cells via inducing apoptosis and cell cycle arrest. Computational, molecular, and cellular studies identified nicardipine as a putative inhibitor of embryonic ectoderm development (EED) protein, and the results are consistent with a proposed mechanism of action that nicardipine destabilised enhancer of zeste homologue 2 (EZH2) and inhibited key components of noncanonical EZH2 signalling, including transducer and activator of transcription 3, S-phase kinase-associated protein 2, ATP binding cassette B1, and survivin. As a monotherapy, nicardipine effectively inhibited the skeletal growth of chemoresistant C4-2B-TaxR tumours. As a combination regimen, nicardipine synergistically enhanced the in vivo efficacy of docetaxel against C4-2 xenografts. CONCLUSION: Our findings provided the first preclinical evidence supporting nicardipine as a novel EED inhibitor that has the potential to be promptly tested in PCa patients to overcome chemoresistance and improve clinical outcomes.

Radical prostatectomy findings in patients with locally aggressive Grade group 5 prostatic adenocarcinoma and negative limited or extended pelvic lymph node dissection.

Current management options for high-risk prostate cancer (PCa) patients include radical prostatectomy with lymph node dissection and other local or systemic therapeutic approaches. However, there is paucity of data in the pathology literature on the radical prostatectomy findings in patients with locally aggressive Grade group 5 PCa with negative limited or extended lymph node dissection. A search was made through our Urologic Pathology files and consults of the senior author for patients who had radical prostatectomy specimens with locally aggressive Grade group 5 PCa and limited or extended lymph node dissection from 2010 to 2022. Patients with lymph node metastasis were excluded. Clinicopathologic and follow up data were obtained. Forty-two patients were included in the study. Mean age was 64 years (range: 49-79 years). Forty-one (98 %) patients had PCa Gleason score 4 + 5 = 9 and 1 (2 %) patient had Gleason score 5 + 4 = 9. Extraprostatic extension and/or bladder neck invasion was present in 30 (71 %) patients and seminal vesicle invasion was present in 20 (48 %) patients, of which 10 (50 %) were bilateral. Extended lymph node dissection was performed in 18 patients with mean of 22 lymph nodes (range: 6-51 lymph nodes). Limited lymph node dissection was performed in 24 patients with mean of 7 lymph nodes (range: 2-25 lymph nodes). This study demonstrates that a subset of patients with very advanced/high grade PCa still benefit from radical prostatectomy/tumor debulking even in the setting of positive margins, and may not have lymph node metastasis.

Frequent Telomerase Reverse Transcriptase Promoter and Fibroblast Growth Factor Receptor 3 Mutations Support the Precursor Nature of Papillary Urothelial Hyperplasia of the Urinary Bladder.

The precursor nature of papillary urothelial hyperplasia of the urinary bladder is uncertain. In this study, we investigated the telomerase reverse transcriptase (TERT) promoter and fibroblast growth factor receptor 3 (FGFR3) mutations in 82 patients with papillary urothelial hyperplasia lesions. Thirty-eight patients presented with papillary urothelial hyperplasia and concurrent noninvasive papillary urothelial carcinoma, and 44 patients presented with de novo papillary urothelial hyperplasia. The prevalence of the TERT promoter and FGFR3 mutations is compared between de novo papillary urothelial hyperplasia and those with concurrent papillary urothelial carcinoma. Mutational concordance between papillary urothelial hyperplasia and concurrent carcinoma was also compared. The TERT promoter mutations were detected in 44% (36/82) of papillary urothelial hyperplasia, including 23 (23/38, 61%) papillary urothelial hyperplasia with urothelial carcinoma and 13 (13/44, 29%) de novo papillary urothelial hyperplasia. The overall concordance of TERT promoter mutation status between papillary urothelial hyperplasia and concurrent urothelial carcinoma was 76%. The overall FGFR3 mutation rate of papillary urothelial hyperplasia was 23% (19/82). FGFR3 mutations were detected in 11 patients with papillary urothelial hyperplasia and concurrent urothelial carcinoma (11/38, 29%) and 8 patients with de novo papillary urothelial hyperplasia (8/44, 18%). Identical FGFR3 mutation status was detected in both papillary urothelial hyperplasia and urothelial carcinoma components in all 11 patients with FGFR3 mutations. Our findings provide strong evidence of a genetic association between papillary urothelial hyperplasia and urothelial carcinoma. High frequency of TERT promoter and FGFR3 mutations suggests the precursor role of papillary urothelial hyperplasia in urothelial carcinogenesis.

Neoadjuvant Nivolumab and Ipilimumab for Nonmetastatic Renal Cell Carcinoma with Tumor Thrombus.

Renal cell carcinoma with level IV tumor thrombus is a condition necessitating aggressive surgical management. Many solid organ malignancies often benefit from neoadjuvant treatments for tumor debulking and improvement of surgical outcomes. However, neoadjuvant treatments for renal cell carcinoma have been limited by its resistance to traditional chemotherapy and radiation. Emerging treatment modalities, such as immunotherapies, are exciting new options that may be therapeutically effective. The combination of nivolumab and ipilimumab has exhibited success in managing metastatic renal cell carcinoma. Limited data exist for its use in nonmetastatic renal cell carcinoma with tumor thrombus. This case illustrates the use of nivolumab and ipilimumab combination therapy in delaying tumor growth, producing observable tumor thrombus histologic and radiologic treatment changes, and, most importantly, facilitating a less invasive surgical approach of a level IV renal cell carcinoma tumor thrombus.

DNA Methylation Landscapes of Prostate Cancer Brain Metastasis Are Shaped by Early Driver Genetic Alterations.

Metastases from primary prostate cancers to rare locations, such as the brain, are becoming more common due to longer life expectancy resulting from improved treatments. Epigenetic dysregulation is a feature of primary prostate cancer, and distinct DNA methylation profiles have been shown to be associated with the mutually exclusive SPOP-mutant or TMPRSS2-ERG fusion genetic backgrounds. Using a cohort of prostate cancer brain metastases (PCBM) from 42 patients, with matched primary tumors for 17 patients, we carried out a DNA methylation analysis to examine the epigenetic distinction between primary prostate cancer and PCBM, the association between epigenetic alterations and mutational background, and particular epigenetic alterations that may be associated with PCBM. Multiregion sampling of PCBM revealed epigenetic stability within metastases. Aberrant methylation in PCBM was associated with mutational background and PRC2 complex activity, an effect that is particularly pronounced in SPOP-mutant PCBM. While PCBM displayed a CpG island hypermethylator phenotype, hypomethylation at the promoters of genes involved in neuroactive ligand-receptor interaction and cell adhesion molecules such as GABRB3, CLDN8, and CLDN4 was also observed, suggesting that cells from primary tumors may require specific reprogramming to form brain metastasis. This study revealed the DNA methylation landscapes of PCBM and the potential mechanisms and effects of PCBM-associated aberrant DNA methylation. SIGNIFICANCE: DNA methylation analysis reveals the molecular characteristics of PCBM and may serve as a starting point for efforts to identify and target susceptibilities of these rare metastases.

Clinicopathologic analysis of patients undergoing repeat transurethral resection of bladder tumour following an initial diagnosis of urothelial carcinoma with lamina propria invasion and variant/divergent histology.

AIMS: A subset of patients with urothelial carcinoma (UCa) and lamina propria (LP) invasion in bladder biopsies/transurethral resections (TURs) are at significant risk for recurrence and have increased rates of progression to UCa with muscularis propria (MP) invasion. The clinicopathologic features of this patient population has not been well characterised in the Pathology literature. METHODS: We performed a search through our urologic pathology files and expert consult cases of the senior author for bladder biopsies/TURs of UCa with LP invasion and variant/divergent histology from 2014 to 2020. Patients with a prior diagnosis of UCa with MP invasion or upper tract UCa were excluded. Clinicopathologic data were obtained. RESULTS: Ninety-five patients with at least one biopsy/TUR of UCa with LP invasion and variant/divergent histology were identified. Mean patient age was 72 years (range: 46-92 years) with a male predominance 2.3:1. Initial variant/divergent histologies identified were: glandular (35.8%), squamous (23.2%), micropapillary (20%), clear cell/lipid rich (12.6%), diffuse/signet ring/plasmacytoid (10.5%), nested (9.5%), sarcomatoid (6.3%), poorly differentiated/anaplastic (4.2%), small cell (2.1%), lymphoepithelioma-like (2.1%), osteoclast-like giant cells (1.1%) and tumour giant cells (1.1%). Two or more variant histologies were identified in 18.9% of these cases. The rate of micropapillary UCa was significantly higher in multifocal tumours compared with unifocal tumours (37% vs 7.1%). CONCLUSIONS: In our cohort of patients undergoing early repeat biopsy/TUR, 75% of patients had persistent UCa. Additionally, almost 25% of patients had a prior diagnosis of UCa without a variant/divergent histology identified. Our findings highlight the critical role of repeat biopsy/TUR especially in a subset of patients who have variant/divergent histology, even in the absence of MP invasion.

A Contemporary Clinicopathologic Analysis of Primary Sarcomas of the Perinephric Soft Tissue and Hilar Vessels Including a Subset Secondarily Involving the Kidney.

A variety of primary malignant mesenchymal neoplasms can arise from the perinephric soft tissue and hilar vessels and potentially involve the kidney, mimicking primary renal tumors. A search was made at our institution for patients that underwent radical nephrectomy with associated perinephric or hilar sarcomas from 2010 to 2021. Twenty-six patients were identified. Mean patient age was 60 years (range: 34-83 years), with 16 (62%) females and 10 (38%) males. The mean tumor size was 21.6 cm (range: 8.1-36.5 cm). Among the perinephric/retroperitoneal sarcomas, 14/20 (70%) were dedifferentiated liposarcoma, 4/20 (20%) were well-differentiated liposarcoma, and 2/20 (10%) were leiomyosarcoma. There were 4 grade 1 (20%; all well-differentiated liposarcoma), 9 grade 2 (45%), and 7 grade 3 (35%) tumors. All 6 sarcomas arising from the renal vein/inferior vena cava were leiomyosarcoma: grade 2 in 1 (17%), grade 3 in 4 (67%), and ungraded (due to neoadjuvant therapy effect) in 1 (17%) patient. Four of the 26 (15%) tumors involved the ipsilateral kidney. All 4 tumors were grade 3 sarcomas. On follow-up, 8/26 (31%) patients developed local recurrence and/or metastasis. The mean time for recurrence was 22 months (range: 7-48 months). Two patients progressed with metastasis to the lungs, both of which were grade 3 leiomyosarcoma, and appeared 11 months after the initial diagnosis. Our data suggest that while local recurrence is prevalent with most subtypes of perinephric sarcomas, high-grade leiomyosarcoma has a distinct proclivity for distant metastasis, with the lungs being the most common site.

Characterization of protein S-(2-succino)-cysteine (2SC) succination as a biomarker for fumarate hydratase-deficient renal cell carcinoma.

Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is an aggressive, rare genetic disease affecting the kidney and other organ systems. We constructed a specialized multi-institutional cohort of 20 primary FH-deficient RCC cases with aims of characterizing a new commercially available antibody, S-(2-succino)-cysteine (2SC). Herein, we present our findings on the biomarker characterization and performance of 2SC expression by immunohistochemistry (IHC) in FH-deficient RCC and other common and rare RCC subtypes. Morphological assessment revealed characteristic cytomorphologic features and a majority (55%) of FH-deficient RCC had mixed architectural growth patterns. We observed predominantly diffuse and strong cytoplasmic staining with limited nuclear positivity for 2SC staining on IHC. Receiver operating characteristic curves (ROC) for 2SC identified the threshold IHC score (cutoff) as 90, with the sensitivity and specificity being 100% and 91%, respectively. The findings of the present study along with the prior evidence in literature encourage utilization of 2SC as a positive marker along with the loss of FH expression by anti-FH IHC staining as a negative marker, in clinical and/or pathologic scenarios when considering FH-deficient RCC in the differential diagnosis. FH-/2SC+ may serve as a comprehensive IHC panel in identifying such cases and excluding morphologically similar entities.

Reporting Trends, Practices, and Resource Utilization in Neuroendocrine Tumors of the Prostate Gland: A Survey among Thirty-Nine Genitourinary Pathologists.

Background. Neuroendocrine differentiation in the prostate gland ranges from clinically insignificant neuroendocrine differentiation detected with markers in an otherwise conventional prostatic adenocarcinoma to a lethal high-grade small/large cell neuroendocrine carcinoma. The concept of neuroendocrine differentiation in prostatic adenocarcinoma has gained considerable importance due to its prognostic and therapeutic ramifications and pathologists play a pivotal role in its recognition. However, its awareness, reporting, and resource utilization practice patterns among pathologists are largely unknown. Methods. Representative examples of different spectrums of neuroendocrine differentiation along with a detailed questionnaire were shared among 39 urologic pathologists using the survey monkey software. Participants were specifically questioned about the use and awareness of the 2016 WHO classification of neuroendocrine tumors of the prostate, understanding of the clinical significance of each entity, and use of different immunohistochemical (IHC) markers. De-identified respondent data were analyzed. Results. A vast majority (90%) of the participants utilize IHC markers to confirm the diagnosis of small cell neuroendocrine carcinoma. A majority (87%) of the respondents were in agreement regarding the utilization of type of IHC markers for small cell neuroendocrine carcinoma for which 85% of the pathologists agreed that determination of the site of origin of a high-grade neuroendocrine carcinoma is not critical, as these are treated similarly. In the setting of mixed carcinomas, 62% of respondents indicated that they provide quantification and grading of the acinar component. There were varied responses regarding the prognostic implication of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and for Paneth cell-like differentiation. The classification of large cell neuroendocrine carcinoma was highly varied, with only 38% agreement in the illustrated case. Finally, despite the recommendation not to perform neuroendocrine markers in the absence of morphologic evidence of neuroendocrine differentiation, 62% would routinely utilize IHC in the work-up of a Gleason score 5 + 5 = 10 acinar adenocarcinoma and its differentiation from high-grade neuroendocrine carcinoma. Conclusion. There is a disparity in the practice utilization patterns among the urologic pathologists with regard to diagnosing high-grade neuroendocrine carcinoma and in understanding the clinical significance of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and Paneth cell-like neuroendocrine differentiation. There seems to have a trend towards overutilization of IHC to determine neuroendocrine differentiation in the absence of neuroendocrine features on morphology. The survey results suggest a need for further refinement and development of standardized guidelines for the classification and reporting of neuroendocrine differentiation in the prostate gland.

GATA3 expression in clear cell adenocarcinoma of the lower urinary tract: a potential diagnostic pitfall.

BACKGROUND: Clear cell adenocarcinoma of the lower urinary tract (CCACLUT) is a rare primary malignant neoplasm with heterogenous morphology. There is a paucity of data in the literature regarding its immunohistochemical profile. METHODS: The immunohistochemical features (extent and intensity) of a multinational cohort of CCACLUT were evaluated with comparison between clear cell adenocarcinoma of the female genital tract (CCACFGT, tissue microarray) and nephrogenic adenoma (NA). RESULTS: 33 CCACLUT (24 female, 9 male; mean age 59 years) were collected. CCACLUT most commonly arose from the urinary bladder (26/33, 78%), particularly from the trigone (10/33, 30.3%) followed by the urethra (8/33, 22%). All 12 NA cases were located at the urinary bladder, whereas the most common CCACFGT location was the ovary (29/56, 52%). None of the CCACLUT patients had, intestinal metaplasia, NA, or urothelial carcinoma. One patient had concurrent endometriosis of the sigmoid colon. Most frequently observed morphology in CCACLUT was papillary/tubulocystic (9/3; 27.3%), followed by papillary/tubular (6/33; 18.2%) and papillary/solid (5/33; 15.2%). GATA3 expression was significantly higher in CCACLUT (18/33, 54.5%) and NA (6/12, 50%), when compared to CCACFGT cases 6/56, 11.7%)(p = 0.001 and p = 0.022, respectively). The extent of GATA3 was significantly higher in CCACLUT group (19.2 ± 16.6%) than the other groups (9.6 ± 22.5% in NA and 2.6 ± 9% in CCACFGT group) (p = 0.001). 4/33 patients (12.1) had weak, 10/33 patients (30.3%) had moderate, and 4/33 patients (12.1%) had strong GATA3 intensity in CCACLUT group. In NA group, one patient (8.3%, 1/12) had weak, one patient (8.3%, 1/12) had moderate and 4 patients (33.3%, 4/12) had strong GATA3 intensity. Most cases (CCACLUT 29/33, 88%; NA 11/12, 92%; CCACFGT 46/56, 82.1%) had positive Napsin A expression, by which CCACLUT had significantly more cases with Napsin A expression (p = 0.034). p63 was consistently negative in all cases (30/33 (91.9%) CCACLUT; 12/12 (100%) NA; 42/56 (75%) CCACFGT. Ki67 (MIB) proliferation index was significantly higher in CCACLUT group (54.6 ± 21%) when compared to NA group (4.5 ± 2.7%) and CCACFGT group (35.5 ± 25.8%) (p = 0.001). CONCLUSION: CCACLUT has consistent GATA3 expression, which may cause challenge in the diagnosis of urothelial carcinoma but can be used to distinguish CCACLUT from CCACFGT.

Molecular characterization of adenocarcinomas arising in the urinary bladder following augmentation cystoplasty: a multi-institutional study.

Development of malignancy is a rare complication following augmentation cystoplasty, and the majority of tumors observed in this setting are adenocarcinomas. Here, we sought to genetically profile these tumors by targeted DNA sequencing of a multi-institutional cohort of adenocarcinomas that developed in the urinary bladder following augmentation cystoplasty. Carcinomas arising in the urinary bladder of patients with history of augmentation cystoplasty were obtained from 4 major academic institutions, with cases diagnosed as urothelial carcinoma excluded from the study. The cases were analyzed using a DNA sequencing panel that includes 529 genes and genome-wide copy number assessment. The most frequently altered genes included TP53, KRAS, and MYC, and the vast majority of cases demonstrated mutational profiles consistent with gastrointestinal adenocarcinomas. One case demonstrated an EML4::ALK fusion together with an MSH3 frameshift mutation and hypermutated phenotype, characteristic of a rare but aggressive subtype of colorectal adenocarcinoma that may benefit from targeted ALK inhibition therapy. Importantly, six other tumors in the cohort also had potentially targetable molecular alterations, involving ATM (2 cases), BRCA1 (2 cases), EGFR (1 case), and ERBB2 (1 case). To our knowledge, this study represents the most comprehensive molecular characterization to date of adenocarcinomas arising in the urinary bladder following augmentation cystoplasty. Despite the unique environment of the augmented tissue, the resulting tumors demonstrate a spectrum of driver mutations similar to that of primary gastrointestinal adenocarcinomas. Importantly, molecular alterations potentially amenable to targeted therapy were identified in the majority of cases.

Prostatic malakoplakia: clinicopathological assessment of a multi-institutional series of 49 patients.

Prostatic malakoplakia (MP) is rare, with only case reports and small series (< five patients) available in the literature. In this study we analysed an international multi-institutional series of 49 patients with prostatic MP to more clearly define its clinicopathological features. The median age was 67 years and the median serum prostate-specific antigen (PSA) was 7.5 ng/ml. MP was clinically manifest in most cases (28 of 45 patients with data available, 62%). Of 43 patients with detailed clinical history available, 21 (49%) had concurrent or metachronous malignancies (including prostate cancer). Diabetes or insulin resistance was present in 11 patients (26%). Additionally, three patients had a history of solid organ transplantation and one had HIV. Of note, six of 34 patients (18%) without concurrent prostate cancer had an abnormal digital rectal examination and/or lesions on magnetic resonance imaging (MRI) with prostate imaging reporting and data system (PIRADS) scores 4-5. The initial diagnosis was made on core biopsies (25 of 49, 51%), transurethal resection specimens (12 of 49, 24%), radical prostatectomies (10 of 49, 20%), Holmium-laser enucleation (one of 49, 2%) and cystoprostatectomy (one of 49, 2%). Tissue involvement was more commonly diffuse or multifocal (40 of 49, 82%). Von Kossa and periodic acid-Schiff stains were positive in 35 of 38 (92%) and 26 of 27 lesions (96%), respectively. Of note, two cases were received in consultation by the authors with a preliminary diagnosis of mesenchymal tumour/tumour of the specialised prostatic stroma. The present study suggests that prostatic MP is often associated with clinical findings that may mimic those of prostate cancer in a subset of patients. Moreover, MP may be found incidentally in patients with concurrent prostate cancer.