Clear-cell variant urothelial carcinoma of the bladder: a case report and review of the literature

The optimal management of variant histology in muscle invasive bladder cancer

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

Clear cell urothelial carcinoma of the urinary bladder - a rare pathological entity. A case report and a systematic review of the literature

The most common histological type of urinary bladder cancer is urothelial carcinoma (UC). In contrast, the clear cell variant of urothelial carcinoma (CCUC) is quite a rare neoplasm. In this study, we report a case of an 81-year-old male, presenting with gross hematuria and acute urinary retention, which was subsequently diagnosed with CCUC at our pathology department. Furthermore, we provide a short systematic review of the literature (PubMed, Scopus, and Science Citation Index) for this rare histopathological entity and a brief discussion about its morphological and immunohistochemical (IHC) characteristics.

Primary clear-cell urothelial carcinoma of urinary bladder: a not-so-clear entity with review of literature

Primary clear-cell urothelial carcinoma (CCUC) is an uncommon type of urothelial cancer with only 16 cases reported in published literature. Due to the rarity of the tumour, its clinical and prognostic values have not been clearly understood. We present one such rare clinical diagnosis in a 60-year- old man who underwent radical cystectomy (RC) with ileal conduit for urinary bladder cancer. Histopathology showed features of high-grade CCUC infiltrating the muscularis propria. Immunohistochemistry revealed diffuse immunopositivity of pan cytokeratin (CK), GATA3, P40, CK7 but was immunonegative for CD10 and vimentin. Our patient expired 4 months after diagnosis. CCUC has recently been included in the WHO 2016 classification of urothelial tumours. Most of the patients present with poor prognosis. Accurate diagnosis and recognition of this unusual variant are essential for better patient management and prognosis. Early RC seems to be the preferred way of management.

Comparison of two patients presenting with the clear cell variant of urothelial cell carcinoma of the urinary bladder: laser-assisted partial cystectomy for local disease versus chemotherapy for locally advanced disease

A 43-year-old woman and a 73-year-old man were referred separately from primary care to the urology service with short histories of frank haematuria. In both cases, histology from transurethral resection of their bladder tumours demonstrated the rare clear cell variant of urothelial/transitional cell carcinoma. Staging scans found the former patient had low-volume local disease, and the latter had locally advanced disease. The former patient went on to have partial cystectomy and pelvic lymph node dissection (with the endoscopic portion of the partial cystectomy undertaken by holmium:YAG laser), while the latter was found to have inoperable disease, and proceeded to chemotherapy. The former patient was alive with no evidence of disease recurrence at 45 months, while the latter was alive but with extensive lymph nodal recurrence at 45 months.

Clear Cell Urothelial Carcinoma

Clear cell urothelial carcinoma (CCUC) is a rare variant of urothelial carcinoma (UC) and its clinical significance has not been well elucidated. Consecutive cases of UC over a period of 5 years were reviewed. Histopathological tumor parameters, including the proportion of tumor cells with clear cell change, and patient outcomes were recorded. Expression of the following immunohistochemical markers was investigated: CK7, CK20, CK5, CD44, and PAX8. We also conducted a review of the literature for case reports/series of CCUC. Ten CCUCs were identified out of a total of 872 cases of UC. The clear cell component was characterized by prominent cytoplasmic membranes and voluminous clear cytoplasm, and accounted for 30% to 90% of the invasive tumor component. Of all the non-CCUC cases reviewed, at least 50% (noninvasive or invasive UC) showed focal areas of clear cell change that accounted for less than 5% of the neoplastic cells. Immunohistochemically, CCUC exhibited positive reactivity for CK5/CD44 (n = 9); CK20 (n = 5), PAX8 (very focal to extensive) (n = 6), and GATA3/CK7 (n = 10). Eight of 10 CCUC were of advanced clinical stage (pT3/pT4) and 6 of 10 experienced tumor recurrence and/or death due to disease. In conclusion, CCUC can be distinguished from non-CCUC by the extensive clear cell change in more than 30% of cells. This variant is associated with rapid progression to muscle invasion and metastasis, with an aggressive clinical course. Expression of CK5/CD44 may represent basal cell features in most CCUC cases, while PAX8 expression is suggestive of mesonephric derivation.

The First Report of Urothelial (Clear Cell Variant) Bladder Cancer in a Child

Urothelial bladder tumours in childhood are extremely rare, with most cases being low grade, superficial disease of the papillary subtype with favourable outcomes. Urothelial (clear cell variant) carcinoma of bladder (UCCVCB) is an exceptional histological finding in both the adult and paediatric population. Herein we describe the first case of UCCVCB diagnosed in childhood. With this case being only the fourth report of confirmed muscle invasion in childhood, we discuss the entity of UCCVCB, and furthermore review all previously reported confirmed cases of childhood muscle invasive urothelial bladder cancer, in general.

Clear cell urothelial carcinoma of the urinary bladder: a case report and review of the literature

Introduction

The occurrence of clear cell tumors in the bladder is not uncommon. Clear cell dysplasia is well-described and characterized by focal replacement of transitional mucosa by cells with abundant clear cytoplasm, nuclear enlargement, and a granular chromatin pattern. Clear cells can also be seen in clear cell adenocarcinoma, which is rare, comprising 0.5% to 2.0% of the reported bladder carcinomas. Other clear cell tumors found in the bladder to be considered in the differential diagnosis are tumors of Müllerian origin and metastatic lesions, such as renal cell carcinoma, clear cell sarcoma, and malignant melanoma. Clear cell urothelial carcinoma is exceedingly rare, with only nine clinical cases described in the literature.

Case presentation

We report the case of a 75-year-old Caucasian man who presented with intermittent hematuria, in whom a bladder tumor was identified. A final histopathology examination of a cystoprostatectomy specimen revealed a pT3b, G3 urothelial carcinoma of clear cell type (>90% clear cells) and a prostatic adenocarcinoma of Gleason grade 3+3 (score=6). The bladder tumor consisted of sheets of malignant cells with severe nuclear atypia and abundant clear cytoplasm; no glandular or tubular structures were identified. Tumor cells were periodic acid-Schiff positive and negative after diastase treatment; additional mucicarmine and oil red O stains were negative. Immunohistochemical stains showed the tumor cells positive for cytokeratin 7 (CK7), p63 (>80% nuclei), p53 (about 30% nuclei), vimentin, E-cadherin, cluster of differentiation (CD10), and Ki-67 (>70% nuclei). Stains for cell adhesion molecule 5.2 (CAM 5.2), CD117, cytokeratin 20 (CK20), human melanoma black 45 (HMB-45), paired box protein (PAX 8), placental alkaline phosphatase (PLAP), prostate specific antigen (PSA), renal cell carcinoma (RCC), cancer antigen 25 (CA25), leukocyte common antigen (LC), S-100 protein, and uroplakin III were all negative.

Conclusions

The tumor marker profile was consistent with clear cell type carcinoma of urothelial origin. Within the differential diagnoses, we ruled out other possible tumor types such as urothelial carcinoma with focal clear cell differentiation, clear cell adenocarcinoma, Müllerian tumors, and metastatic disease.

Immunohistochemical evaluation of novel and traditional markers associated with urothelial differentiation in a spectrum of variants of urothelial carcinoma of the urinary bladder

Data on immunohistochemical expression of novel and traditional urothelial markers in the wide range of urothelial carcinoma variants have so far been very limited. In this study, whole tissue sections from 130 bladder urothelial carcinoma and variants were stained with a panel of novel and traditional immunomarkers supportive of urothelial lineage. The positivity rates were as follows: (a) urothelial carcinomas with or without divergent differentiation: GATA3 (50%), S-100P (86%), uroplakin III (20%), thrombomodulin (40%), cytokeratin 7 (CK7) (80%), CK20 (55%), p63 (87%), and high molecular weight cytokeratin (HMCK) (89%); (b) urothelial carcinoma variants (micropapillary, plasmacytoid, nested, clear cell, and microcystic): GATA3 (88%), S-100P (96%), uroplakin III (33%), thrombomodulin (49%), CK7 (95%), CK20 (61%), p63 (69%), and HMCK (96%); and (c) undifferentiated carcinomas (lymphoepithelioma-like carcinoma, small cell carcinoma, sarcomatoid carcinoma and carcinoma with rhabdoid and giant cells): GATA3 (28%), S-100P (31%), uroplakin III (0%), thrombomodulin (22%), CK7 (50%), CK20 (3%), p63 (50%), and HMCK (49%). In urothelial carcinoma with squamous differentiation, GATA3 expression was lower (20%) in contrast to p63 and S-100P. In urothelial carcinoma with glandular differentiation, GATA3 (50%) and p63 (60%) expression was lower than S-100P (100%). p63 expression was relatively lower in micropapillary (54%) and plasmacytoid (50%) variants compared with the other urothelial carcinoma variants. This study provides comprehensive data for novel and traditionally used markers to support urothelial lineage in urothelial carcinoma variants. Our findings show that GATA3, S-100P, CK7, CK20, HMCK, and p63, in the appropriate differential diagnostic setting, are useful to support urothelial lineage of variant morphologies.

Primary multiple clear cell variant urothelial carcinomas of urinary bladder: a rare case report

Clear cell variant urothelial carcinoma of urinary bladder was very rare. There were only 6 report articles included by Pubmed and total 8 cases had been described till now. All of the past reports described single tumor of urinary bladder, but multiple carcinomas had not been reported. Here we reported a 65-years-old Chinese man who complained of intermittent gross hematuria and odynuria for more than 2 months in January 2013. Only one cauliflower-like tumor was detected approximately in the left wall of the urinary bladder with cystoscopy and the biopsy specimen was diagnosed as "urothelial carcinoma, high grade". However, three tumors were found in anterior wall (×2) near neck of urinary bladder and posterior wall (×1) of the urinary bladder during transurethral resection of the bladder tumor. Typical urothelial carcinoma with partial clear cell appearance made it difficult to make a precise pathological diagnosis and immunohistochemical stain helped to diagnose the case as clear cell variant urothelial carcinoma, but not metastasis of the renal cell carcinoma. Finally, computerized tomographic scanning confirmed that there was no primary tumor in the kidney. The clinical and pathological characteristic had not been identified for the limited reports. More work should be done to know this kind of tumor well for guiding clinical therapy.