Primary urethral clear-cell adenocarcinoma: comprehensive analysis by surgical pathology, cytopathology, and next-generation sequencing

Clear Cell Adenocarcinoma of the Urinary Tract Primary to the Renal Pelvis: A Multi-institutional Clinicopathologic and Molecular Study of Five Patients

Clear cell adenocarcinoma (CCA) of the urinary tract is a rare malignancy and tumors involving the renal pelvis are notably sparse in the literature, with only 5 other patients reported. We present 5 patients, 4 women, and 1 man, with CCA of the renal pelvis. The age at presentation ranged from 29 to 81 years. The tumor size ranged from 4.5 to 8.0 cm. Tumors exhibited shared morphologic and immunohistochemical features with CCA of the female genital tract and those originating in the bladder and urethra, including cells with large nuclei, prominent nucleoli, nuclear hobnailing, and scant clear cytoplasm. Common immunohistochemical findings included reactivity for PAX8, CK7, HNF1β, and Napsin-A. One of the tumors arose in the background of a mixed epithelial and stromal tumor. Another tumor occurred in a renal allograft and tumor cells were positive for the BK virus, demonstrated by SV40 immunohistochemistry. All tumors were negative for TFE3 and TFEB rearrangement and lacked TERT alterations. Follow-up was limited with no recurrence in 4 patients at a maximum of 20 months follow-up and 1 patient died of an unrelated cause at 25 months of follow-up. Next-generation sequencing analysis of all 5 CCAs revealed mutations within genes implicated in DNA damage repair and chromatin remodeling pathways, including ATM, BRCA1, BRCA2, ARID1A, DICER1, SMAD4, NOTCH1, and MYC amplification. These molecular findings underscore the dysregulation of fundamental cellular processes essential for genomic integrity maintenance.

Mullerian Duct-Type Clear Cell Adenocarcinoma of the Urethra in a Woman Presenting As Groin Swelling

Primary Mullerian duct-type clear cell adenocarcinoma of the urethra is a rare clinical entity with a varied clinical presentation. This can be diagnosed only with a high index of suspicion. Clinical examination, biopsy, and immunohistochemistry are essential for diagnosis. Management will need a multimodal approach with a combination of chemotherapy and surgical excision.

Glandular Lesions of the Urinary Bladder: Diagnostic and Molecular Updates

Glandular lesions in the urinary tract or their associated pathologies can pose a diagnostic challenge. There is a variety of benign alterations and tumor types that need to be taken into account in differential diagnostic considerations. In recent times, efforts for better defining these alterations or lesions both on the histopathological and molecular levels have been undertaken. This article will provide an update on current diagnostic and molecular considerations of these lesions.

Novel Association of RAD54L Mutation with Müllerian Clear Cell Carcinoma of the Male Urethra: New Insights Regarding the Molecular Mechanisms of a Rare Tumour

INTRODUCTION

Müllerian clear cell carcinoma of the male urethra is similar to that of the female genital tract in terms of morphology and immunohistochemical expression but is rarely observed in clinical practice.

CASE PRESENTATION

Here, we report the case of a 65-year-old man diagnosed with Müllerian clear cell carcinoma who harboured a mutation in RAD54L. This patient was diagnosed by electrocautery and ultimately underwent prostatectomy. After a six-month follow-up period, no signs of recurrence or additional malignancy were found. Based on our analysis of the available literature, it appears that Müllerian clear cell carcinoma with RAD54L mutation has not been reported until now.

CONCLUSION

This case enhances our knowledge of the molecular biology of Müllerian clear cell carcinoma of the male urethra, which will help clinicians select optimal treatment options for this rare cancer in patients with specific driver mutations.

CDX2- and PAX8-Expressing Subtypes in Female Urethral Adenocarcinoma: Pathogenesis Insights through Immunohistochemical and Morphological Analyses

Female urethral adenocarcinoma has attracted attention as a rare tumor type based on its differential pathogenesis from its male counterpart. However, to date, our knowledge concerning its immunohistochemical and morphological characteristics remains limited due to the small number of cases studied. In this study, nine consecutive cases of female urethral adenocarcinoma were used for immunohistochemical and morphological characterization of the tumor based on semi-comprehensive immunohistochemical analysis and detailed morphological evaluations. Our immunohistochemical assay revealed two subtypes of female urethral adenocarcinoma with distinctive staining patterns: the CDX2- and PAX8-expressing subtypes. The former stained positive for other intestinal markers (e.g., HNF4α and TFF1) as well (7 of 7 cases); the latter stained negative for these intestinal markers (0 of 2 cases) but stained positive for clear cell carcinoma markers (e.g., Napsin A and HNF1β) (2 of 2 cases). Regarding cytokeratins, the former displayed a CK7- and CK20-positive immunoprofile (7 of 7 cases); the latter exhibited a CK7-positive and CK20-negative immunoprofile (2 of 2 cases). Morphologically, CDX2- and PAX8-expressing subtypes resembled intestinal-type adenocarcinoma and clear cell carcinoma (occurring in gynecological organs), respectively. The semi-comprehensive immunoprofiling data presented in this study can potentially contribute to the correct diagnosis of this rare tumor type. Finally, our study represents an important basis for future investigations aiming to further elucidate the details and origin of female urethral adenocarcinoma, and it can potentially contribute to developing diagnostic and therapeutic strategies for treating this malignancy.

SWI/SNF complexes and cancers

Epigenetics refers to the study of genetic changes that can affect gene expression without altering the underlying DNA sequence, including DNA methylation, histone modification, chromatin remodelling, X chromosome inactivation and non-coding RNA regulation. Of these, DNA methylation, histone modification and chromatin remodelling constitute the three classical modes of epigenetic regulation. These three mechanisms alter gene transcription by adjusting chromatin accessibility, thereby affecting cell and tissue phenotypes in the absence of DNA sequence changes. In the presence of ATP hydrolases, chromatin remodelling alters the structure of chromatin and thus changes the transcription level of DNA-guided RNA. To date, four types of ATP-dependent chromatin remodelling complexes have been identified in humans, namely SWI/SNF, ISWI, INO80 and NURD/MI2/CHD. SWI/SNF mutations are prevalent in a wide variety of cancerous tissues and cancer-derived cell lines as discovered by next-generation sequencing technologies.. SWI/SNF can bind to nucleosomes and use the energy of ATP to disrupt DNA and histone interactions, sliding or ejecting histones, altering nucleosome structure, and changing transcriptional and regulatory mechanisms. Furthermore, mutations in the SWI/SNF complex have been observed in approximately 20% of all cancers. Together, these findings suggest that mutations targeting the SWI/SNF complex may have a positive impact on tumorigenesis and cancer progression.

Clear cell adenocarcinoma of the prostatic urethra with metachronous prostate adenocarcinoma

A 70-year-old male underwent a Transurethral Resection of Prostate for the management of obstructive voiding symptoms. On cystoscopy, papillary frond-like lesions up to 2cm in size were encountered, overlying the right side of the prostatic urethra. Histopathology from the resection revealed clear cell adenocarcinoma (CCA) of the prostatic urethra. Primary clear cell adenocarcinoma of the prostatic urethra is exceedingly rare, with as few as 9 cases reported. We review the literature for its oncogenesis, discuss the histopathological features for diagnosis and report on our surgical management and outcome.

Epidemiology of Unconventional Histological Subtypes of Urethral Cancer

INTRODUCTION

The aim of the study was to examine cancer-specific mortality (CSM) of unconventional urethral cancers.

METHODS

Within the SEER (2004-2016) database, we analyzed CSM of 165 patients with unconventional urethral-cancer histology. Kaplan-Meier plots were used to test the effect of unconventional histologies in urethral cancer on CSM.

RESULTS

Of 165 eligible patients, the Mullerian type accounted for 55 (33.3%) versus melanocytic (26.7%) versus neuroendocrine 25 (15.2%) versus lymphoma 22 (13.3%) versus mesenchymal/sarcoma 15 (9.1%) versus spindle cell 4 (2.1%) patients. Median age at diagnosis was 81 years in spindle cell, 75 in melanocytic, 74 in neuroendocrine and mesenchymal/sarcoma, 67 in lymphoma, and 62 years Mullerian type (p < 0.001). Of all, 116 (70.3%) were female. The Mullerian type exhibited the highest female ratio (96.4%) versus the lowest female ratio in neuroendocrine (24.0%). The Mullerian type was most frequent in African-American females. In Caucasian females, the melanocytic type was most frequent (49.1%). In African-American (38.9%) and Caucasian males (33.3%), neuroendocrine histology was most frequent. Three-year CSM was, respectively, 27.5%, 23.1% 22.3%, 20.5%, and 16.1% for melanocytic, mesenchymal/sarcoma, Mullerian type, neuroendocrine, and lymphoma histology. Median cancer-specific survival was 106 versus 10 months for combined nonmetastatic versus metastatic nonconventional histologies.

CONCLUSION

Important age, sex, racial/ethnic group distribution, and survival differences exist between each unconventional urethral-cancer histological subtypes.

Clear cell adenocarcinoma of the male urethra: a case report

Background

Primary urethral cancer in males is rare. Clear cell adenocarcinoma is more rare. We report a case in an African male suspected to have a urethral stricture.

Case presentation

A 66-year-old man presented in with preceding intermittent haematuria and acute urinary retention. Failed attempts at catheterisation necessitating a suprapubic catheter insertion raised the suspicion of a urethral stricture. Multiple irregular urethral filling defects were seen on a retrograde urethrogram. Urethroscopy revealed obstructing urethral masses. Histology reported clear cell adenocarcinoma.

Conclusion

Primary urethral cancer should be entertained as a differential diagnosis of a urethral stricture in a patient with haematuria, difficult urethral catheterisation and ambiguous urethrogram findings. Cystoscopy and biopsy are essential in the investigative work-up to make the distinction.

Progress in the treatment of urethral adenocarcinoma

BACKGROUND

Urothelial adenocarcinoma (UA) is a rare subtype of primary urothelial carcinoma, which is more common in women and has a poor prognosis. Because of their low incidence, most of the existing literature is based on case reports and there is a lack of comprehensive literature on this type of tumor.

PURPOSE

This article provides a comprehensive and systematic review of the epidemiology, pathological types, treatment, and prognosis of UA. Especially in the treatment section, we reviewed the various treatment methods including surgery, radiotherapy, chemotherapy, immunotherapy and molecular targeted therapy. This review aims to provide a theoretical basis for the clinical diagnosis and management of UA.

METHODS

We reviewed the relevant literature of UA from Pubmed.

CONCLUSION

There is no standard treatment for UA. Multidisciplinary therapy, including surgery, radiotherapy and chemotherapy, is the current trend. Immunotherapy and molecular targeted therapy will also become viable options for the treatment of UA in future.

Primary mucinous cell adenocarcinoma of female urethra

Primary adenocarcinoma of the female urethra is a rare entity. Its incidence increases with age with the highest rate in women aged more than 65 years. Adenocarcinoma of the urethra is more common among women than men and is associated with a relatively poor prognosis. We report a case of primary adenocarcinoma of the urethra and review the literature with emphasis on the diagnosis, management and outcome of this rare tumour.

Primary clear cell adenocarcinoma of female urinary tract: a case report and literature review

Background

Primary clear cell adenocarcinoma of the urethra is extremely rare, reported only in single case reports, and its histological origin is not clear. There is no standard treatment for CCAU at present, and surgery is still the main treatment for CCAU without distant metastasis.

Case presentation

A 67-year-old female complained of gross hematuria with frequent micturition and urgency. No urethral diverticulum was found by cystoscopy or MRI, and the mass grew around the urethra. Urethral and anterior pelvic viscera resection was performed. Clear cell adenocarcinoma was confirmed by immunohistochemistry after the operation, and no recurrence or metastasis was found after one year of follow-up.

Conclusion

CCAU is very rare, and most cases originate from the urethral diverticulum and some may also originate from tissues around the urethra. For CCAU patients without distant metastasis, the main treatment is still surgery, and radiotherapy and chemotherapy can be performed for patients with distant metastasis. Gene detection may provide guidance for the precise chemotherapy of CCAU.

High expression of RIPK2 is associated with Taxol resistance in serous ovarian cancer

Background

Taxol resistance in serous ovarian cancer is responsible for its poor prognosis, yet the underlying mechanism is still poorly understood. Thus, we probed the mechanism of Taxol resistance in serous ovarian cancer with multiple bioinformatic methods to provide novel insights into potential therapies.

Methods

The differentially expressed genes (DEGs) in Taxol-sensitive and Taxol-resistant cell lines and their relationship with the overall survival (OS) and progression-free interval (PFI) of ovarian cancer patients were analyzed using gene expression datasets from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). The role of receptor interacting serine/threonine kinase 2 (RIPK2) was validated via identification of its coexpressed genes, functional analysis and generation of a protein-protein interaction (PPI) network. The single sample gene set enrichment analysis (ssGSEA) was used to explore immune infiltration, and genomic alterations of RIPK2 were also analyzed via cBio Cancer Genomics Portal (cBioProtal).

Results

RIPK2 was highly expressed in Taxol resistant ovarian cancer cell lines, and its high expression was also linked with shorter OS and PFI in serous ovarian cancer patients. The PPI network analysis and pathway analysis demonstrated that RIPK2 might participate in the positive regulation of NF-κB transcription factor activity. RIPK2 expression was related to tumor microenvironment alterations, which might participate in the formation of Taxol resistance.

Conclusions

Our studies suggested that high expression of RIPK2 is related to Taxol resistance in serous ovarian cancer, and that RIPK2 induces Taxol resistance through NOD1/RIPK2/NF-κB inflammatory pathway activation and tumor microenvironment changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00986-2.

Vesical clear cell adenocarcinoma of Müllerian origin treated conservatively with partial cystectomy

A 71-year-old woman presented with an intravesical bladder mass found to be a clear cell adenocarcinoma of Müllerian origin with positive PAX-8 staining after transurethral resection. Partial cystectomy along with total hysterectomy were performed, and final pathology revealed no residual tumour and extensive endometriosis. She declined adjuvant therapy and was dispositioned to surveillance.

Comprehensive genomic profiling of histologic subtypes of urethral carcinomas

BACKGROUND

Carcinoma of the urethra (UrthCa) is an uncommon Genitourinary (GU) malignancy that can progress to advanced metastatic disease.

METHODS

One hundred twenty-seven metastatic UrthCa underwent hybrid capture-based comprehensive genomic profiling to evaluate all classes of genomic alterations (GA). Tumor mutational burden was determined on up to 1.1 Mbp of sequenced DNA, and microsatellite instability was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3).

RESULTS

Forty-nine (39%) urothelial (UrthUC), 31 (24%) squamous (UrthSCC), 24 (19%) adenocarcinomas NOS (UrthAC), and 12 (9%) clear cell (UrthCC) were evaluated. UrthUC and UrthSCC are more common in men; UrthAC and UrthCC are more common in women. Ages were similar in all 4 groups. GA in PIK3CA were the most frequent potentially targetable GA; mTOR pathway GA in PTEN were also identified. GA in other potentially targetable genes were also identified including ERBB2 (6% in UrthUC, 3% in UrthSCC, and 12% in UrthAC), FGFR1-3 (3% in UrthSCC), BRAF (3% in UrthAC), PTCH1 (8% in UrthCC), and MET (8% in UrthCC). Possibly reflecting their higher GA/tumor status, potential for immunotherapy benefit associated with higher tumor mutational burden and PD-L1 staining levels were seen in UrthUC and UrthSCC compared to UrthAC and UrthCC. Microsatellite instability high status was absent throughout.

CONCLUSIONS

Comprehensive genomic profiling reveals GA that may be predictive of both targeted and immunotherapy benefit in patients with advanced UrthCa and that could potentially be used in future adjuvant, neoadjuvant, and metastatic disease trials.

Clear cell urethral adenocarcinoma – a case report of an exceptional response to immunotherapy in a metastatic rare tumour

Primary clear cell adenocarcinoma of the urethra is extremely rare. Given the rarity of these tumours there is no high-level evidence available to guide treatments. Localized disease is typically treated with primary surgery or concurrent chemo-radiotherapy. In the advanced disease setting treatment options are limited and decisions are based on evidence in disease subtypes where similarities exist. Immuno-oncology and the use of checkpoint inhibitors, particularly for metastatic disease has transformed clinical practice over the past few years and patient outcomes continue to improve as a result of their introduction. Here we report the first case, to our knowledge, of a patient with advanced primary clear cell adenocarcinoma of the urethra who had a dramatic and almost complete response to anti-PD-1 therapy in the fourth line setting.

Level of evidence: 4

Histopathological Subtypes and PD-L1 Expression in Primary Urethral Adenocarcinoma: A Series of 5 Cases

BACKGROUND AND OBJECTIVES

Urethral adenocarcinoma is a rare disease with poor prognosis that can display multiple histologic patterns and has an unclear histogenesis. Radical surgery with extensive periurethral resection is the preferred therapeutic approach. Both chemotherapy and radiotherapy have been used as complementary treatment options. Due to the tendency of these tumors to recur, treatment-associated complications, and the limited choice of therapeutic options, patient management can be difficult. Given the lack of literature regarding immunotherapy in urethral adenocarcinoma, our objective was to explore the expression of programmed death receptor-ligand 1 (PD-L1) throughout the different histological subtypes of primary urethral adenocarcinoma.

METHODS

We reviewed all primary urethral adenocarcinomas diagnosed at our hospital between 1965 and 2019, performed immunohistochemical assays on the tissue blocks, classified them according to their histology and origin, and performed PD-L1 (22C3) immunohistochemistry assays in all cases.

RESULTS

We found a total of 5 cases of primary urethral adenocarcinoma. All of the patients were women. One of the cases was a cribriform adenocarcinoma, 2 were columnar-mucinous adenocarcinomas, and 2 were clear cell adenocarcinomas. One of the clear cell adenocarcinomas strongly expressed PD-L1. In addition, a profuse inflammatory infiltration constituted by CD3-positive and CD8-positive T lymphocytes within tumor cells was observed in this case. None of the other cases showed PD-L1 expression.

CONCLUSIONS

In conclusion, some urethral adenocarcinomas may strongly express PD-L1 and thus could potentially allow the use of immunotherapy in selected cases of advanced or recurrent adenocarcinoma.

European Association of Urology Guidelines on Primary Urethral Carcinoma-2020 Update

CONTEXT

Primary urethral carcinoma (PUC) is a rare cancer accounting for <1% of all genitourinary malignancies.

OBJECTIVE

To provide updated practical recommendations for the diagnosis and management of PUC.

EVIDENCE ACQUISITION

A systematic search interrogating Ovid (Medline), EMBASE, and the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews was performed.

EVIDENCE SYNTHESIS

Urothelial carcinoma of the urethra is the predominant histological type of PUC (54-65%), followed by squamous cell carcinoma (16-22%) and adenocarcinoma (10-16%). Diagnosis of PUC depends on urethrocystoscopy with biopsy and urinary cytology. Pathological staging and grading are based on the tumour, node, metastasis (TNM) classification and the 2016 World Health Organization grading systems. Local tumour extent and regional lymph nodes are assessed by magnetic resonance imaging, and the presence of distant metastases is assessed by computed tomography of the thorax/abdomen and pelvis. For all patients with localised distal tumours (≤T2N0M0), partial urethrectomy or urethra-sparing surgery is a valid treatment option, provided that negative intraoperative surgical margins can be achieved. Prostatic Ta-Tis-T1 PUC can be treated with repeat transurethral resection of the prostate and bacillus Calmette-Guérin. In prostatic or proximal ≥ T2N0 disease, neoadjuvant cisplatin-based chemotherapy should be considered prior to radical surgery. All patients with locally advanced disease (≥T3N0-2M0) should be discussed within a multidisciplinary team. In men with locally advanced squamous cell carcinoma, curative radiotherapy combined with radiosensitising chemotherapy can be offered for definitive treatment and genital preservation. In patients with local urethral recurrence, salvage surgery or radiotherapy can be offered. For patients with distant metastatic disease, systemic therapy based on tumour characteristics can be evaluated.

CONCLUSIONS

These updated European Association of Urology guidelines provide up-to-date guidance for the contemporary diagnosis and management of patients with suspected PUC.

PATIENT SUMMARY

Primary urethral carcinoma (PUC) is a very rare, but aggressive disease. These updated European Association of Urology guidelines provide evidence-based guidance for clinicians treating patients with PUC.

A scoping review and proposed workflow for multi-omic rare disease research

BACKGROUND

Patients with rare diseases face unique challenges in obtaining a diagnosis, appropriate medical care and access to support services. Whole genome and exome sequencing have increased identification of causal variants compared to single gene testing alone, with diagnostic rates of approximately 50% for inherited diseases, however integrated multi-omic analysis may further increase diagnostic yield. Additionally, multi-omic analysis can aid the explanation of genotypic and phenotypic heterogeneity, which may not be evident from single omic analyses.

MAIN BODY

This scoping review took a systematic approach to comprehensively search the electronic databases MEDLINE, EMBASE, PubMed, Web of Science, Scopus, Google Scholar, and the grey literature databases OpenGrey / GreyLit for journal articles pertaining to multi-omics and rare disease, written in English and published prior to the 30th December 2018. Additionally, The Cancer Genome Atlas publications were searched for relevant studies and forward citation searching / screening of reference lists was performed to identify further eligible articles. Following title, abstract and full text screening, 66 articles were found to be eligible for inclusion in this review. Of these 42 (64%) were studies of multi-omics and rare cancer, two (3%) were studies of multi-omics and a pre-cancerous condition, and 22 (33.3%) were studies of non-cancerous rare diseases. The average age of participants (where known) across studies was 39.4 years. There has been a significant increase in the number of multi-omic studies in recent years, with 66.7% of included studies conducted since 2016 and 33% since 2018. Fourteen combinations of multi-omic analyses for rare disease research were returned spanning genomics, epigenomics, transcriptomics, proteomics, phenomics and metabolomics.

CONCLUSIONS

This scoping review emphasises the value of multi-omic analysis for rare disease research in several ways compared to single omic analysis, ranging from the provision of a diagnosis, identification of prognostic biomarkers, distinct molecular subtypes (particularly for rare cancers), and identification of novel therapeutic targets. Moving forward there is a critical need for collaboration of multi-omic rare disease studies to increase the potential to generate robust outcomes and development of standardised biorepository collection and reporting structures for multi-omic studies.

Personalized chemotherapy in clear cell adenocarcinoma of the urethra: A case report

BACKGROUND

Clear cell adenocarcinoma of the urethra is a rare type of aggressive cancer with a poor prognosis. Clear cell carcinoma of the urethra represents less than 0.02% of all malignancies in women. Adenocarcinomas account for 10% of female urethral carcinomas, of which 40% are the clear cell variant. Determining the presence or absence of certain mutations through genetic testing may predict whether a patient with cancer may benefit from a particular chemotherapy regimen.

CASE SUMMARY

A 40-year-old woman presented with a 3-year history of slow urinary flow and a 3-mo history of urinary urgency and frequency as well as gross hematuria. An abdominal and pelvic computed tomography scan demonstrated enlarged lymph nodes in the abdomen and pelvis. A biopsy of a left inguinal lymph node microscopically confirmed a metastatic adenocarcinoma of the urethra. Specialized genetic testing determined personalized chemotherapy. She was treated successfully with a non-platinum-based chemotherapy consisting of paclitaxel and bevacizumab. Following 3 cycles of paclitaxel and bevacizumab, she attained significant clinical improvement, and response by FDG-Positron emission tomography (PET) imaging showed a definite improvement in size and metabolic activity. She achieved complete response after 6 cycles of therapy by PET scan. The patient concluded 11 cycles of paclitaxel and bevacizumab, and a subsequent PET scan confirmed progression of metastatic disease. The patient was then treated with two cycles of doxorubicin after which a PET scan revealed a mixed response to the treatment.

CONCLUSION

We report the first case of a patient with metastatic clear cell adenocarcinoma of the urethra who underwent personalized chemotherapy after testing for cancer gene alterations. Our unique case represents the safe and effective use of non-platinum-based chemotherapy in clear cell adenocarcinoma of the urethra.

Three female patients with a periurethral mass: from various complaints to rare pathology

In this case report, we will discuss three cases of women diagnosed with a periurethral mass. The specific diagnosis of a periurethral mass can vary and includes rare diseases. Therefore, they provide a challenge to medical professionals. All patients underwent diagnostic evaluation with cystoscopy and pelvic MRI followed by surgical removal. Based on the MRI and pathology report, different diagnoses were made for each patient. The three diagnoses will be discussed: subpubic cartilaginous cyst, leiomyoma and clear cell adenocarcinoma of the urethra. Our case report is useful for other medical professionals, and they can evaluate how to optimal approach a periurethral mass.

Case Study: Systematic Detection and Prioritization of Gene Fusions in Cancer by RNA-Seq: A DIY Toolkit

RNA-seq provides an efficient and sensitive methodology to identify fusion transcripts in cancer tissues. Chimeric reads mapping across two different genes represent potential gene fusions. Various methodologies have been implemented in the detection of gene fusions by RNA-seq. Here we describe a general methodology used in processing and filtering of RNA-seq data, followed by filtering of multiple varieties of artifacts to nominate potentially relevant gene fusions. Functional relevance of gene fusions is assessed based on the predicted domain architecture of the putative fusion proteins.

Molecular profiling of clear cell adenocarcinoma of the urinary tract

Clear cell adenocarcinoma (CCA) of the urinary tract is a rare type of malignancy whose molecular profiles remain undefined. Here we reported an integrated clinicopathologic and molecular profiling analysis of four cases of clear cell adenocarcinoma arising in the urethra or the bladder. Utilizing a clinically validated 130-gene exon-sequencing assay, we identified recurrent pathogenic PIK3CA (p. E545K) and KRAS (p.G12D) variants in three of four (75%) of the cases. In addition, an APC variant (P.S2310X), a TP53 variant (p.R273C), and a MYC amplification event were identified. The only CCA case without either PIK3CA or KRAS variants has a distinct pathogenesis through BK virus, demonstrated by positive BK virus PCR and SV40 immunohistochemistry. The novel finding of recurrent variants in the PI3K/AKT/mTOR pathway provides not only insights into oncogenesis but also potential clinical therapeutic targets for patients with clear cell adenocarcinoma of the urinary tract.

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.

Presentación de reporte de caso: adenocarcinoma de célula clara de uretra

El adenocarcinoma de célula clara de uretra es un tumor agresivo, poco frecuente, que afecta predominantemente a mujeres adultas. Se presenta el caso de una paciente de 64 años con hematuria de larga data, en quien se diagnostica este tipo de tumor se realiza tratamiento quirúrgico y actualmente presenta evolución satisfactoria.

Unusual Features of Clear Cell Adenocarcinoma of the Female Urethra: A Case Report and Literature Review

Background

There has been scarce information about clear cell adenocarcinoma of the urethra (CCAU), an extremely rare type of cancer. A few case reports show that CCAU tends to have similar clinical manifestation to the other urethral carcinomas, urethrocystoscopy can easily identify tumoral lesions in the urethra, and bloody drainage from the urethral meatus is often seen during physical exams.

Methods

A 52-year-old woman presented with dysuria for 6 months. Urethrocystoscopy did not reveal abnormality, and there was no bloody vaginal drainage or bloody drainage from the urethral meatus during physical exams. Ultrasonography demonstrated a solid mass with well-defined margins located between the anterior vaginal wall and the posterior urethral wall. Computed tomography showed the mass with smooth margins at the level of vaginal fornix, and magnetic resonance imaging showed the same location of the tumor as ultrasonography.

Results

Surgical removal of the tumor was successfully performed and histological and immunohistochemical analysis confirmed the final diagnosis of CCAU.

Conclusion

Abnormality in urethrocystoscopy and bloody drainage during the physical exam were not found in this case, which is in contrast to the findings reported in literature. These unusual features add new knowledge about CCAU that deserves dissemination for improved CCAU diagnosis and management.

Clear cell adenocarcinoma of female urethra: A case report

Primary malignancies of the female urethra are rare, accounting for less than 1% of genitourinary malignancies. Clear cell adenocarcinoma of the urethra (CCAU) occurs more infrequently, accounting for 0.003% of malignancies of the female urogenital tract. Definitive clinical diagnosis of CCAU is difficult and must be differentiated from tumors of the vagina. Currently, there is limited understanding of the causes of CCAU and there is no established standard of care for treatment. Immunohistochemistry and pathologic analysis can be used to identify the origin of the tumor.

Lower tract neoplasm: Update of imaging evaluation

Cancers of the lower urinary tract can arise from the bladder, urachus or urethra. Urothelial carcinoma of the bladder (UCB) is the most common of these. The presentation of bladder, urachal and urethral cancers can differ but many result in hematuria as an initial indication. The diagnosis and staging of these cancers often necessitate radiologic imaging often in the form of cross-section CT urography or MR urography. The following article reviews the specific nature of lower tract cancers and their imaging.

NS5ABP37 inhibits liver cancer by impeding lipogenesis and cholesterogenesis

The molecular mechanism underlying non‐alcoholic fatty liver disease progression to hepatocellular carcinoma (HCC) remains unknown. In this study, immunohistochemistry staining results showed that NS5ABP37 protein, which is in a state of lower expression in tumor tissues, decreased with increasing degree of HCC malignancy. Two cell models, HepG2 and L02, were used to analyze the mechanism between NS5ABP37 and HCC. In agreement, NS5ABP37 protein overexpression significantly suppressed cell proliferation, caused G₁/S cell cycle arrest, and induced apoptosis by increasing caspase‐3/7 activity and cleaved caspase‐3 levels. In addition, NS5ABP37 overexpression resulted in decreased intracellular triglyceride and total cholesterol contents, with level reduction in sterol regulatory element‐binding proteins (SREBPs) and downstream effectors. Furthermore, NS5ABP37 overexpression decreased SREBP1c and SREBP2 levels by reducing their respective promoters. Finally, reactive oxygen species levels and endoplasmic reticulum stress were both induced by NS5ABP37 overexpression. These findings together indicate that NS5ABP37 inhibits cancer cell proliferation and promotes apoptosis, by altering SREBP‐dependent lipogenesis and cholesterogenesis in HepG2 and L02 cells and inducing oxidative stress and endoplasmic reticulum stress.

Transcriptome and long noncoding RNA sequencing of three extracellular vesicle subtypes released from the human colon cancer LIM1863 cell line

Previously we reported that LIM1863 colorectal cancer (CRC) cells secrete three distinct extracellular vesicle subtypes – two subpopulations of exosomes (apical EpCAM-Exos and basolateral A33-Exos) and shed microvesicles (sMVs) – with distinct protein and miRNA signatures. Here, we extend our omics approach to understand the fundamental role of LIM1863-derived EVs by performing a comprehensive analysis of their mRNAs and long non-coding RNAs (lncRNAs) using RNA-Seq. We show that 2,389 mRNAs, 317 pseudogene transcripts, 1,028 lncRNAs and 206 short non-coding RNAs selectively distributed to (i.e., are enriched in) LIM1863 EVs, relative to the parent cell. An Ensembl/UniProtKB analysis revealed 1,937 mRNAs encode canonical proteins, 348 isoforms (including splice-variant proteins), and 119 ‘missing proteins’ (i.e., annotated in Ensembl but not UniProtKB). Further dissection of our protein/RNA data revealed that 6/151 observed RNA binding proteins have the potential to interact with ~75% of EV-enriched RNAs. Intriguingly, the co-existence of U1 and U2 ribonucleoproteins and their cognate snRNAs in LIM1863 EVs suggests a possible association of CRC EVs with recipient cell splicing events. Our data reveal several potential lncRNA CRC biomarkers and novel splicing/fusion genes that, collectively, will advance our understanding of EV biology in CRC and accelerate the development of EV-based diagnostics and therapeutics.

Biallelic Alteration and Dysregulation of the Hippo Pathway in Mucinous Tubular and Spindle Cell Carcinoma of the Kidney

Mucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare subtype of renal cell carcinoma (RCC) with distinctive morphologic and cytogenetic features. Here, we carry out whole-exome and transcriptome sequencing of a multi-institutional cohort of MTSCC (n = 22). We demonstrate the presence of either biallelic loss of Hippo pathway tumor suppressor genes (TSG) and/or evidence of alteration of Hippo pathway genes in 85% of samples. PTPN14 (31%) and NF2 (22%) were the most commonly implicated Hippo pathway genes, whereas other genes such as SAV1 and HIPK2 were also involved in a mutually exclusive fashion. Mutations in the context of recurrent chromosomal losses amounted to biallelic alterations in these TSGs. As a readout of Hippo pathway inactivation, a majority of cases (90%) exhibited increased nuclear YAP1 protein expression. Taken together, nearly all cases of MTSCC exhibit some evidence of Hippo pathway dysregulation.

SIGNIFICANCE

MTSCC is a rare and relatively recently described subtype of RCC. Next-generation sequencing of a multi-institutional MTSCC cohort revealed recurrent chromosomal losses and somatic mutations in the Hippo signaling pathway genes leading to potential YAP1 activation. In virtually all cases of MTSCC, there was evidence of Hippo pathway dysregulation, suggesting a common mechanistic basis for this disease. Cancer Discov; 6(11); 1258-66. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1197.

BRCA1 affects protein phosphatase 6 signalling through its interaction with ANKRD28

The tumour suppressor BRCA1 (breast and ovarian cancer-susceptibility gene 1) is implicated in several nuclear processes including DNA repair, transcription regulation and chromatin remodelling. BRCA1 also has some cytoplasmic functions including a pro-apoptotic activity. We identified ANKRD28 (ankyrin repeat domain 28) as a novel BRCA1-interacting protein in a yeast two-hybrid screen and confirmed this interaction by reciprocal immunoprecipitations of the two overexpressed proteins. Endogenous interaction between BRCA1 and ANKRD28 was also observed by co-immunoprecipitation and located in the cytoplasm by proximity ligation assay. The main site of interaction of ANKRD28 on BRCA1 is located in its intrinsically disordered scaffold central region. Whereas ANKRD28 silencing results in a destabilization of IκBε (inhibitor of nuclear factor κBε) through its activation of PP6 (protein phosphatase 6) co-regulator upon TNFα (tumour necrosis factor α) stimulation, BRCA1 overexpression stabilizes IκBε. A truncated form of BRCA1 that does not interact with ANKRD28 has no such effect. Our findings suggest that BRCA1 is a novel modulator of PP6 signalling via its interaction with ANKRD28. This new cytoplasmic process might participate in BRCA1 tumour-suppressor function.

Construction and analysis of three networks of genes and microRNAs in adenocarcinoma

Adenocarcinoma is one of the most serious diseases that threaten human health. Numerous studies have investigated adenocarcinoma and have obtained a considerable amount of data regarding genes and microRNA (miRNA) in adenocarcinoma. However, studies have only focused on one or a small number of genes and miRNAs, and the data is stored in a scattered form, making it challenging to summarize and assess the associations between the genes and miRNAs. In the present study, three networks of genes and miRNAs in adenocarcinoma were focused on. This enabled the construction of networks of elements involved in adenocarcinoma and the analysis of these networks, rather than only discussing one gene. Transcription factors (TFs), miRNAs, and target and host genes of miRNAs in adenocarcinoma, and the regulatory associations between these elements were identified in the present study. These elements and associations were then used to construct three networks, which consisted of the differentially-expressed, associated and global networks. The similarities and differences between the three networks were compared and analyzed. In total, 3 notable TFs, consisting of TP53, phosphatase and tensin homolog and SMAD4, were identified in adenocarcinoma. These TFs were able to regulate the differentially-expressed genes and the majority of the differentially-expressed miRNAs. Certain important regulatory associations were also found in adenocarcinoma, in addition to self-regulating associations between TFs and miRNAs. The upstream and downstream elements of the differentially-expressed genes and miRNAs were recorded, which revealed the regulatory associations between genes and miRNAs. The present study clearly revealed components of the pathogenesis of adenocarcinoma and the regulatory associations between the elements in adenocarcinoma. The present study may aid the investigation of gene therapy in adenocarcinoma and provides a theoretical basis for studies of gene therapy methods as a treatment for adenocarcinoma.

Adenocarcinoma of the urethra with mucinous features

Primary adenocarcinoma of the female urethra is a rare malignancy. Previous studies hypothesize multiple origins, including periurethral glands or intestinal metaplasia. We report a case of a 60-year-old white woman with adenocarcinoma of the urethra who initially presented with obstructive voiding complaints secondary to a urethral mass. Wide local excision revealed invasive adenocarcinoma of the urethra with mucinous features. There was intestinal metaplasia adjacent to the tumor, as well as separate identification of intestinal metaplasia along the urethra. Ultimately, the patient underwent radical cystectomy with ileal conduit urinary diversion with no evidence of recurrence, indicating the role of early identification and surgical intervention for such cases.

Clear cell adenocarcinoma of the urethra: 18F-FDG PET/CT imaging

Clear cell adenocarcinoma of the urethra is a rare and aggressive tumor of female gender preponderance. This neoplasm, the origin of which is still widely debated, has been reported with CT and MRI in case reports and small series. To the previously published conventional cross-sectional imaging description, the authors add the PET/CT features of this uncommon urologic neoplasm at its advanced stage in a 60-year-old patient complaining of urinary retention.