Unusual forms of carcinoma of the urinary bladder

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

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

Microcystic urothelial carcinoma of the bladder: A case report

Microcystic variant of urothelial carcinoma was recently added to the World Health organization classification of transitional cell carcinoma. This variant is characterized by its aggressiveness explaining the low long-term survival rate of the patients. Larger studies are needed to determine the adequate treatment course. We present the case of a 71-year-old patient who was diagnosed with muscle invasive microcystic variant of urothelial carcinoma of the bladder and remained free of tumor recurrence two year after surgery.

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

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

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.

Mixed adenoneuroendocrine carcinoma of the urethra

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumour found predominantly in the gastrointestinal tract. Comprising adenocarcinomatous and neuroendocrine components, MANEC have been reported in the bladder. We report the first case to our knowledge of a MANEC arising in the urethra. A 62-year-old woman presented with a suburethral mass. Initial excision of the mass revealed it to be a MANEC. Immunohistochemistry staining was positive for CK20 and synaptophysin associated with neuroendocrine tumours. Cross-sectional imaging ruled out metastases and the patient underwent radical urethrectomy, vaginal reconstruction and Mitrofanoff urinary diversion. The patient declined adjuvant chemotherapy and remained under regular surveillance. MANECs are uncommon tumours and treatment was therefore guided by expert opinion. A multidisciplinary approach is essential with the early involvement of surgeons, oncologists, histopathologist, radiologist and neuroendocrine specialists.

Lymphoepithelioma-like, a variant of urothelial carcinoma of the urinary bladder: a case report and systematic review for optimal treatment modality for disease-free survival

Background

Lymphoepithelioma-like carcinoma (LELC) is a rare high-grade carcinoma that resembles nasopharyngeal lymphoepithelioma and can occur throughout the body. First reported in 1991, bladder LELC has an incidence of about 1% of all bladder carcinomas. Due to its rare occurrence, prognoses and ideal treatment guidelines have not been clearly defined.

Methods

A PubMed search was performed using two terms, “lymphoepithelioma-like carcinoma” and “bladder.” Review articles, articles in foreign languages, expression studies, and studies not performed in the bladder were excluded. We report a case of LELC of the bladder including treatment and outcome and performed a systematic review of all 36 available English literatures from 1991 to 2016 including the present case to identify factors affecting disease-free survival.

Results

One hundred forty cases of bladder LELC were analyzed. The mean age of the patients was 70.1 years ranging from 43 to 90 years with 72% males and 28% females. Pure LELC occurs most often at 46% followed by mixed LELC 28% and predominant LELC 26%. EBV testing was negative in all cases tested. Mean follow-up length for all cases was 33.8 months with no evidence of disease in 62.2%, while 11.1% died of disease, 10.4% alive with metastasis, and 8.2% died without disease. 5.0% of cases had recurrence at an average of 31.3 months. Prognosis is significantly favorable for patients presenting with pure or predominant forms of LELC compared to mixed type (p < 0.0001). The treatment significantly associated with the highest disease mortality and lowest disease-free survival was TURBT alone when compared to any multi-modality treatment (p < 0.01).

Conclusion

We conclude that the best treatment modality associated with the highest disease-free survival is multi-modal treatment including radical cystectomy.

Transitional Cell Carcinoma Metastatic to Lung, With Dedifferentiation Into Small Cell Undifferentiated Carcinoma

Small-cell undifferentiated carcinoma (SCUC) has been increasingly recognized in the urinary tract. 1,2,3 Up to 66% of SCUCs in this location are associated with a minor component of a more differentiated carcinoma that most frequently represents transi tional-cell carcinoma (TCC), but adenocarcinoma, squamous-cell carcinoma, spindle- cell carcinoma, and carcinoid carcinoma have all been described. We report a case of low-grade TCC of the urinary tract metastasizing to a distant location and therein dedifferentiating into an SCUC and discuss the clinical and biologic implication of the process of dedifferentiation. Int J Surg Pathol 2(2):157-162, 1994

The 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs-Part B: Prostate and Bladder Tumours

It has been 12 yr since the publication of the last World Health Organization (WHO) classification of tumours of the prostate and bladder. During this time, significant new knowledge has been generated about the pathology and genetics of these tumours. Intraductal carcinoma of the prostate is a newly recognized entity in the 2016 WHO classification. In most cases, it represents intraductal spread of aggressive prostatic carcinoma and should be separated from high-grade prostatic intraepithelial neoplasia. New acinar adenocarcinoma variants are microcystic adenocarcinoma and pleomorphic giant cell adenocarcinoma. Modifications to the Gleason grading system are incorporated into the 2016 WHO section on grading of prostate cancer, and it is recommended that the percentage of pattern 4 should be reported for Gleason score 7. The new WHO classification further recommends the recently developed prostate cancer grade grouping with five grade groups. For bladder cancer, the 2016 WHO classification continues to recommend the 1997 International Society of Urological Pathology grading classification. Newly described or better defined noninvasive urothelial lesions include urothelial dysplasia and urothelial proliferation of uncertain malignant potential, which is frequently identified in patients with a prior history of urothelial carcinoma. Invasive urothelial carcinoma with divergent differentiation refers to tumours with some percentage of "usual type" urothelial carcinoma combined with other morphologies. Pathologists should mention the percentage of divergent histologies in the pathology report.

PATIENT SUMMARY

Intraductal carcinoma of the prostate is a newly recognized entity in the 2016 World Health Organization classification. Better defined noninvasive urothelial lesions include urothelial dysplasia and urothelial proliferation of uncertain malignant potential.

Ossifying metaplasia of urothelial metastases: original case with review of the literature

Background

Ossifying metaplasia is an unusual feature of urothelial carcinoma, with only a few cases reported. The largest series included 17 cases and was published in 1991. The mechanism of ossification is unknown and hypotheses of osteogenic precursor cells, inducing bone formation, are proposed.

Case presentation

A 75 year-old patient was treated for a high grade transitional cell carcinoma of the bladder by surgery, chemotherapy and radiotherapy. Histology showed foci of bone metaplasia, both at the periphery of the tumor, and in a lymph node metastasis. 1 year later, a heterotopic bone formation was discovered in the right retroperitoneal space, near the lumbar spine, increasing rapidly in size during follow-up. Several imaging exams were performed (2 CT, 1 MRI, 1 Pet-CT), but in the absence of typical features of sarcoma, diagnosis remained unclear.

Histology of a CT-guided percutaneous biopsy showed urothelial carcinoma and mature lamellar bone. Integration of these findings with the radiological description of extraosseous localization was consistent with a diagnosis of osseous metaplasia of an urothelial carcinoma metastasis. The absence of bone atypia in both the primary and metastases argues against sarcomatoid urothelial carcinoma with osteosarcomatous differentiation.

Conclusion

Osseous metaplasia of an urothelial carcinoma metastasis is unusual, and difficult to distinguish from radiotherapy induced sarcoma, or from sarcomatoid carcinoma. Rapid progression, sheathing of adjacent structures such as vessels (like inferior vena cava in our case) and nerves and bony feature of lymph node metastases necessitate histological confirmation and rapid treatment. Our case illustrates this disease and evaluates the imaging features. In addition we discuss the differential diagnosis of osseous retroperitoneal masses.

Telomerase reverse transcriptase promoter mutations in glandular lesions of the urinary bladder

Glandular lesions of the urinary bladder include a broad spectrum of entities ranging from completely benign to primary and secondary malignancies. The accurate diagnosis of these lesions is both important and challenging. Recently, studies suggest that telomerase reverse transcriptase (TERT) promoter mutations could be a biomarker for urothelial carcinoma (UC). We hypothesized that these mutations can distinguish UC with glandular differentiation from nephrogenic adenoma, primary adenocarcinoma of the urinary bladder (PAUB), or secondary malignancies. Twenty-five cases of benign glandular lesions (including nephrogenic adenoma); 29 cases of UC with glandular differentiation; 10 cases of PAUB; and 10 cases each of metastatic colon cancer, prostatic carcinoma, and carcinoma from Mullerian origin were collected. Slides were reviewed and selected to make sure the lesion was at least 10% to 20% of all tissue. Macrodissection was performed in some of cases, and genomic DNA was extracted from the tissue. Telomerase reverse transcriptase promoter mutations were determined by standard polymerase chain reaction sequencing. Twenty-one cases (72%) of UC with glandular differentiation were positive for TERT promoter mutations. However, none of the remaining cases (total 65 cases of benign lesions, PAUB, and metastatic carcinomas) was positive for TERT promoter mutation. Telomerase reverse transcriptase promoter mutations were highly associated with UC including UC with glandular differentiation but not other glandular lesions of bladder. Therefore, in conjunction with morphologic features, Immunohistochemistry stain profile, and clinical information, TERT promoter mutations could distinguish UC with glandular differentiation from other bladder glandular lesions. In addition, lack of TERT promoter mutations in primary adenocarcinoma of bladder suggests that this entity may have different origin or carcinogenesis from those of UC.

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.

Sarcoma-like tumor of head and neck skin

A group of tumors referred to as atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) predominantly occur in sun-damaged skin of the elderly, particularly in the head and neck region. Although this group of tumors is often regarded as of mesenchymal phenotype, the matter of histogenesis has not been entirely resolved. Evans H and Smith JL reported in 1980 that prognosis was not significantly different irrespective of whether there was a definite squamous cell carcinoma component or not, supporting a view that these are all carcinomata in nature (sarcomatoid carcinoma [SC]). There are a number of clinicopathologic studies of AFX in the literature but information on morphologically similar sarcoma-like tumors with immunohistochemical evidence of epithelial differentiation is sparse. One hundred sarcoma-like tumors (SLTs) of head and neck skin of the elderly, treated by surgical excision, were studied. Clinical information was obtained, and pathology reports and hematoxylin and eosin sections were reviewed to document size (maximum dimension), extent of invasion, mitotic count, vascular and perineural invasion, margin status, ulceration, necrosis, and the presence of actinic keratosis in adjacent/overlying skin. Immunostains examined included: pan-cytokeratins (CKs) (AE1/AE3, MNF116), high-molecular weight CKs (34βE12, CK5/6, CK14), p63, and melanocytic (S100, Melan A, HMB-45, MITF), vascular (CD31, CD34), and muscle markers (SMA, desmin, h-caldesmon) to exclude melanoma and definite sarcoma entities. The tumors were divided into AFX/PDS (G1), the SC group, which was subdivided into SLT with only p63 positivity (G2a) and SLT with CK positivity regardless of p63 status (G2b), and SLT with a minor morphologic squamous cell carcinoma component (G3). Clinicopathologic findings of each group were compared, in relation to outcomes. Age at diagnosis ranged from 51 to 96 years (median, 79 y), with M:F=11.5:1. There were 53 tumors in G1 (19AFX, 34PDS), 37 in G2 (25 in G2a, 12 in G2b), and 10 in G3. There was no statistically significant difference in clinical and pathologic parameters or survival among all 3 groups. CKs and p63 expression, size, extent of invasion, vascular invasion, perineural invasion, mitotic count, and ulcer did not affect outcome, whereas margin status and necrosis did by both univariate and multivariate analysis and by only univariate analysis, respectively. Sixty patients had multiple nonmelanomatous skin cancers. Actinic keratosis was observed in overlying/adjacent epidermis in 51 cases. Eight patients had prior radiotherapy to head skin cancers; 1 patient developed 2 separate tumors (G1 and G3) after radiotherapy. Four patients died of tumor (1 G1, 2 G2b, and 1 G3); of these, 3 cases had positive margin, and 1 had narrow margin. Our results have shown similarities of various clinicopathologic parameters between AFX/PDS and SC, raising the possibility that both entities are related, and some of the former entities may represent complete dedifferentiation (complete loss of epithelial phenotype) with a gain of mesenchymal phenotype. In addition, the difference between AFX and PDS appears to be the extent of invasiveness (stage) rather than a different histogenesis. Further investigations are needed. However, from a practical point of view, efforts should be made to excise this group of tumors with clear margins, as margin status appears to be the most important prognostic factor regardless of the presence or absence of epithelial differentiation.

Intrinsic basal and luminal subtypes of muscle-invasive bladder cancer

Whole-genome analyses have revealed that muscle-invasive bladder cancers (MIBCs) are heterogeneous and can be grouped into basal and luminal subtypes that are highly reminiscent of those found in breast cancer. Basal MIBCs are enriched with squamous and sarcomatoid features and are associated with advanced stage and metastatic disease at presentation. Like basal breast cancers, basal bladder tumours contain a claudin-low subtype that is enriched with biomarkers characteristic of epithelial-to-mesenchymal transition. The stem cell transcription factor ΔNp63α controls basal MIBC gene expression, just as it does in basal breast cancers. Luminal MIBCs are enriched with activating FGFR3 and ERBB3 mutations and ERBB2 amplifications, and their gene expression profiles are controlled by peroxisome proliferator activator receptor γ (PPARγ) and possibly also by oestrogen receptor activation. Luminal bladder cancers can be further subdivided into two subtypes, p53-like and luminal, which can be distinguished from one another by different levels of biomarkers that are characteristic of stromal infiltration, cell cycle progression, and proliferation. Importantly, basal bladder cancers are intrinsically aggressive, but are highly sensitive to cisplatin-based combination chemotherapy. Although the luminal subtypes are not as intrinsically aggressive as basal cancers, p53-like tumours are resistant to chemotherapy and might, therefore, represent a problem for treated patients.

Microcystic variant of urothelial carcinoma

Background. Microcystic variant of urothelial carcinoma is one of the new variants of urothelial carcinoma that was added to the WHO classification in 2004. Aims. To review the literature on microcystic variant of urothelial carcinoma. Methods. Various internet search engines were used to identify reported cases of the tumour. Results. Microscopic features of the tumour include: (i) Conspicuous intracellular and intercellular lumina/microcysts encompassed by malignant urothelial or squamous cells. (ii) The lumina are usually empty; may contain granular eosinophilic debris, mucin, or necrotic cells. (iii) The cysts may be variable in size; round, or oval, up to 2 mm; lined by urothelium which are either flattened cells or low columnar cells however, they do not contain colonic epithelium or goblet cells; are infiltrative; invade the muscularis propria; mimic cystitis cystica and cystitis glandularis; occasionally exhibit neuroendocrine differentiation. (iv) Elongated and irregular branching spaces are usually seen. About 17 cases of the tumour have been reported with only 2 patients who have survived. The tumour tends to be of high-grade and high-stage. There is no consensus opinion on the best option of treatment of the tumour. Conclusions. It would prove difficult at the moment to be dogmatic regarding its prognosis but it is a highly aggressive tumour. New cases of the tumour should be reported in order to document its biological behaviour.

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

Clear cell variants of transitional cell carcinomas (TCC) of the bladder are extremely rare tumors. Only 6 cases have been reported until now. We report of a 67 year old man who presented with fast growing tumor disease. While initial diagnosis showed localized bladder tumor, final histopathology revealed pT4, G3, L1 urothelial carcinoma with clear cell differentiation. No more than 14 weeks after initial diagnosis the patient died from multi-organ failure after unsuccessful salvage laparotomy which showed massive tumor burden within the pelvis and peritoneal carcinosis. This case demonstrated an extremely fast tumor growth. Therefore, patients with clear cell urothelial carcinoma should be treated vigorously and without time delay. We present a case of clear cell variant of TCC which exhibited an extremely aggressive behavior. To our knowledge this is the fifth report of this rare disease.

Lymphoepithelioma-like carcinoma of ureter-a rare case report and review of the literature

Lymphoepithelioma-like carcinoma (LELC) is best known to occur in the nasopharynx. When LELC occurs in the urinary tract, this extremely rare neoplasm most commonly affects the bladder but has also been reported in the renal pelvis, ureter, prostate [1], and urethra [2]. We present a case of LELC arising in the right proximal ureter of a 64-year-old male patient with hydronephrosis and nausea. Computed tomography demonstrated right ureter tumor. On biopsy, the patient was diagnosed with infiltrating urothelial carcinoma. An operation consisting of right nephroureterectomy and bladder cuff removal was carried out. The pathologic examination showed pure subtype of LELC, pT3N0. Unlike lymphoepithelioma in the nasopharynx, immunohistochemical analysis of this urinary LELC was negative for the Epstein-Barr virus. No disease progression was noted at 6 months' follow-up. Only eight previous cases of LELC involving the ureter have been reported, and a review of the available literature and a summary of ureter cases are presented here. This is the first report of a ureteral LELC case and third urothelial LELC cases [3] in Taiwan.

Clinical utility of immunohistochemistry in the diagnoses of urinary bladder neoplasia

Urothelial carcinomas demonstrate diverse morphologic and immunologic features that frequently lead to diagnostic challenges. Recent advances have identified a number of immunohistochemical stains that, when used in the context of a panel, can be a valuable tool in properly classifying primary urothelial carcinoma and carcinomas secondarily involving the urinary bladder. In addition, new biomarkers prove helpful in the staging of bladder carcinoma. In this article, we review the clinical utility of immunohistochemistry in a series of diagnostic scenarios, including flat urothelial lesions with atypia, rare variants of urothelial carcinoma, primary adenocarcinoma versus secondary colorectal tumors, distinguishing prostate from urothelial carcinoma, and the utility of smoothelin in staging bladder carcinoma. Emphasis is placed on panels of commonly used biomarkers to establish diagnoses.

CA125-producing clear cell adenocarcinoma arising from the upper ureter and renal pelvis

Clear cell adenocarcinomas similar to those found in the female genital organs can arise in the lower urinary tract of both women and men. Clear cell adenocarcinomas occurring in the upper urinary system are exceedingly rare. Here, we present a case of clear cell adenocarcinoma arising from the upper ureter and renal pelvis of a postmenopausal woman with a ureteral stone. The patient had elevated serum levels of cancer antigen (CA) 125 (103.80 U/mL) and CA19-9 (151.96 U/mL). The tumor showed typical features of tubulopapillary structures lined with clear-to-eosinophilic cytoplasm and frequent hobnail configuration. The tumor cells were immunoreactive for cytokeratin 7, cytokeratin 20, carcinoembryonic antigen and CA125, but negative for PAX-2 and alpha-methylacyl coenzyme A racemase. Given the presence of intestinal and squamous metaplasia of the adjacent urothelium, we propose that this clear cell adenocarcinoma developed through a metaplastic process. The tumor behaved so aggressively that the patient developed multiple metastases and died of the disease 5 months after radical nephroureterectomy.

Urothelial carcinoma with villoglandular differentiation: a study of 14 cases

Tumors of the urinary bladder may have a variety of histological patterns. Tumors with either glandular or villous features, such as villous adenomas, in situ adenocarcinomas, invasive adenocarcinomas, and variants of urothelial carcinoma such as micropapillary carcinomas have been described. However, urothelial carcinomas with both villous and glandular features have not been well characterized. We identified 14 cases of urothelial carcinoma with villoglandular differentiation. These cases were defined as having villoglandular features if they contained superficial finger-like processes lined by epithelium having true glandular lumina. Mean patient age at presentation was 70 years (range: 46-84 years) with a male predominance (5:1). A total of 3 cases (21%) were non-invasive, five cases (36%) had lamina propria invasion, five cases (36%) had muscularis propria invasion and one case (7%) had extravesicular extension. A concurrent high-grade papillary urothelial carcinoma component was identified in 11 cases (79%), micropapillary component in 5 (36%) cases, in-situ urothelial carcinoma component in 3 cases (21%), plasmacytoid component in 3 cases (21%), invasive adenocarcinoma in 2 cases, sarcomatoid carcinoma component in one case (14%), and small-cell carcinoma component in 1 case (7%). Cystitis cystica et glandularis was present in 3 cases (21%). Angiolymphatic invasion was identified in 3 cases (21%). Histologically, the villoglandular components were composed of finger-like processes lined by glands intimately admixed with high-grade urothelial carcinoma. Many of the glands had cribriform features lined by non-mucin producing cuboidal to columnar cells. Urothelial carcinoma with villoglandular differentiation are high-grade tumors typically seen in elderly males, characterized by superficial filliform processes lined by glands intimately admixed with high-grade urothelial carcinoma (in situ or invasive) and other aggressive variants of urothelial carcinoma. These relatively rare tumors should be recognized as a variant of urothelial carcinoma.

Histological variants of urothelial carcinoma: diagnostic, therapeutic and prognostic implications

It is well established that invasive urothelial carcinoma, involving the urinary bladder and renal pelvis, has marked propensity for divergent differentiation. In recent years, several 'variant' morphologies have been described and most have been recognized in the 2004 World Health Organization Classification. These histological variants of urothelial carcinoma have clinical significance at various levels, including diagnostic, that is, awareness of the morphological variant is essential in order to avoid diagnostic misinterpretations; prognostic for patient risk stratification; and therapeutic, where a diagnostic assignment of a particular variant may be associated with the administration of a therapy distinctive from that used in conventional invasive urothelial carcinoma. The diagnoses of micropapillary urothelial carcinoma, small-cell carcinoma, lymphoepithelioma-like carcinoma and sarcomatoid carcinoma are prime examples where treatment protocols may be different than the usual muscle-invasive bladder cancer. This review discusses the variants of urothelial carcinoma, outlining for each the diagnostic features, differential diagnostic considerations and the clinical significance.

High-grade urothelial carcinoma of the urinary bladder showing acquisition of microcystic histology in the penile metastasis: histogenetic considerations

Microcystic urothelial carcinoma is a rare variant of transitional cell carcinoma with an indefinite prognostic significance. Herein, we report for the first time the acquisition of microcystic histology in the penile metastasis of a high-grade urothelial carcinoma of the urinary bladder. The patient died of disseminated disease six months later. The immunohistochemical evaluation of mucin expression in the primitive and metastatic tumor suggests that the microcystic histotype may descend from the primitive urothelial carcinoma through a process of dedifferentiation and subsequent redifferentiation. In conclusion, the acquisition of microcystic histology seems to be associated with an aggressive clinical course of the urothelial carcinoma, as already suggested by other authors. Future studies investigating mucin expression in microcystic urothelial carcinoma may help to define the histogenesis of this tumor.

Urothelial Carcinoma and its Variants

Bladder cancer is the ninth most common cancer worldwide, and the most common malignancy affecting the urinary tract, with approximately 330,000 new cases and more than 130,000 deaths per year. Bladder cancer is primarily attributable to smoking, which accounts for 65% of male and 30% of female cases in some developed countries. Other major risk factors include analgesic abuse, some types of chemotherapy, occupational exposure to chemicals, and in Egypt and some Asian regions, endemic infection with Schistosoma haematobium. Approximately 90% of bladder tumors are classified as urothelial carcinoma (UC), also referred to as transitional cell carcinoma (TCC), and are believed to originate from transformation of the normal urothelium. UCs often exhibit elements of squamous or glandular differentiation. The spectrum of microscopic forms of urothelial carcinoma has been expanded recently to include several histologic variants, the recognition of which is important to avoid diagnostic misinterpretation, to predict outcome, and to guide the selection of the most appropriate therapeutic approach. This article reviews characteristic pathologic features and key clinical aspects of UC and its most common variants.

Divergent differentiation in urothelial carcinoma and other bladder cancer subtypes with selected mimics

Conventional urothelial carcinoma accounts for most carcinomas of the urinary tract lining. However, neoplastic urothelium has the capacity to demonstrate enormous plasticity. A variety of unusual architectural patterns of urothelial carcinoma, such as the nested, microcystic and inverted variants, can be mistaken for reactive processes or benign tumours. Others such as the micropapillary, plasmacytoid and discohesive variants, can mimic metastatic tumour from other sites. The micropapillary variant in particular is more aggressive. In addition, urothelial carcinoma has a propensity to demonstrate divergent differentiation with glandular, squamous, small cell neuroendocrine, lymphoepithelioma-like, sarcomatoid or other elements. Pure squamous carcinoma or adenocarcinoma (the latter in particular) can be difficult to distinguish from contiguous or metastatic spread. Some variants have prognostic and potential therapeutic implications. Molecular genetic evidence has emerged recently supporting a close relationship between urothelial carcinoma and various divergent elements. Sarcomatoid carcinoma and its differential diagnosis with other spindle cell lesions of urinary tract will be covered in a separate review.

Multicystic urothelial carcinoma of the bladder with gland-like lumina and with signet-ring cells. A case report

We present the case of 80-year-old male with superficial papillary urothelial carcinoma of the urinary bladder with striking multicystic architecture with a combination of features of urothelial carcinoma with gland-like lumina, with signet-ring cell differentiation and microcystic pattern. However, the tumor shared the morphologic features of several variants of urothelial carcinoma, the most important differential diagnosis covered so-called florid Brunneriosis, cystitis cystica, and primary adenocarcinomas of the urinary bladder.

Histologic Variants of Infiltrating Urothelial Carcinoma

Context.—The spectrum of urothelial carcinoma is broad, and variant morphologies are being reported continually. Many of these variants have been extensively documented and even established as subclasses of urothelial carcinoma.

Objective.—To review the established and more recently described variants of urothelial carcinoma. The significance of recognizing these variants is discussed.

Data Sources.—The literature is reviewed in conjunction with our experience pertaining to urothelial carcinomas of the bladder and ureters.

Conclusions.—Urothelial carcinoma displays many forms, and some of these variant morphologies may introduce diagnostic difficulties because of their similarity to other malignancies and/or benign lesions. Additionally, it is important to recognize variants that are associated with different outcomes from conventional urothelial carcinoma. For these reasons, familiarity with the diverse morphology of urothelial carcinoma is not simply an academic exercise but is important in providing quality care for patients affected by this disease.

Lymphoepithelioma-like carcinoma of the urinary tract: a clinicopathological study of 30 pure and mixed cases

We studied 28 cases of lymphoepithelioma-like carcinoma of the bladder, one case in the renal pelvis, and one in the urethra. The mean age of the patients was 67.6 years with 21 (70%) males. Seventeen cases (56.7%) were pure with the remaining mixed with other patterns of carcinoma, including invasive urothelial carcinoma (n=10), invasive adenocarcinoma (n=3), and squamous cell carcinoma (n=2). The surface demonstrated carcinoma in situ (CIS) in six cases, noninvasive high-grade papillary urothelial carcinoma in three cases, and in situ adenocarcinoma in one case. In 19/30 (66%) cases, there was a heavy lymphocytic infiltrate and in the remaining 11/30 (34%) cases a mixed inflammatory infiltrate. None of the 26 cases labeled for EBV-encoded RNA by in situ hybridization. Tumor stages at presentation were: seven cases T1 (23%); 14 cases T2 (47%); seven cases T3 (23%); and two cases T4 (7%). Treatment consisted of radical cystectomy in 13/30 cases (43%); partial cystectomy in 4/30 cases (13%); nephrectomy in one case (3%), and transurethral resection often followed by radiation or chemotherapy in 12/30 (40%) cases. The mean follow up for patients without progression was 31 months. Eight of 27 cases with follow-up (30%) cases had tumor recurrence, with seven patients having metastases. In cases treated with cystectomy, the 5-year actuarial recurrence-free risk was 59% (62 and 57%, for pure and mixed cases, respectively). Lymphoepithelioma-like carcinoma, whether in pure or mixed form, has a similar prognosis to ordinary urothelial carcinoma when treated by cystectomy. Of the three pure cases treated by chemotherapy, two were free of disease at 4 and 65 months and the third had recurrent disease at 17 months. Given the association of lymphoepithelioma-like carcinoma with urothelial carcinoma in 47% of our cases and its propensity for multifocality, partial cystectomy would typically be ill advised for lymphoepithelioma-like carcinoma.

Microcystic urothelial carcinoma of the urinary bladder metastatic to the penis

Metastatic spread of primary bladder cancer to the penis is an extremely rare event. Microcystic urothelial carcinoma is a very rare variant of urothelial carcinoma. Due to its rareness and insufficient clinical follow-up data, the prognosis of microcystic urothelial carcinoma is still not clear. Here in we report a case of a penile metastasis from microcystic urothelial carcinoma of urinary bladder, in a 56-year-old man who died 6 months after radical cystoprostatectomy and total penectomy. To the best of our knowledge this is the first case report of microcystic variant of urothelial carcinoma which has metastasized to the penis.

The effect of squamous and/or glandular differentiation on recurrence, progression and survival in urothelial carcinoma of bladder

INTRODUCTION

The effects of squamous and/or glandular differentiation in urothelial carcinoma of bladder on recurrence, progression and survival rate were evaluated in this study.

PATIENTS AND METHODS

Between 1998 and 2003, a total of 223 patients who had been treated with transurethral resection for bladder cancers were evaluated. The patients were divided into two groups as; Group I: tumor patients with squamous and/or glandular differentiation, Group II: patients without these findings.

RESULTS

Histologically 189 (84.7%) were conventional urothelial carcinoma and 34 (15.2%) were tumors with squamous and/or glandular differentiation. The mean age of the patients was 64.4 +/- 12.7 (range 36-81) years. Survival rates within a period of 46.23 +/- 14.8 (12-67) months were 76.47% for Group I and 89.94% for Group II (P = 0.027). The stage distribution as pTa, pT1, and >/=pT2 was 2 (5.9%), 18 (52.9%), and 14 (41.2%) in Group I and 101 (53.4%), 51 (27%) and 37 (19.6%) in group II, respectively (P = 0.001). There was a statistically significant tendency towards higher stage at presentation in Group I and the grade distribution was significantly higher in Group I than Group II (P < 0.001).

CONCLUSION

High recurrence rates and poor prognosis of these patients should be kept in mind in the follow-up period. In this respect, these patients should be followed up closely.

Extrapulmonary Small Cell Carcinoma of the Bladder

Among the many sites for primary small cell cancer is the genitourinary system. The majority of cases have been observed in the bladder and prostate. Small cell carcinoma accounts for less than 1% of all bladder tumors. Definitive predisposing factors are unknown; however, small cell carcinoma of the bladder has been associated with cigarette smoking, long-standing cystitis, bladder calculus, and augmented cystoplasty. Contrary to the early theory of derivation from Kulchitsky cells, it is now believed that small cell carcinoma of the bladder originates from the totipotent stem cells present in the submucosa of the bladder wall. A number of chromosomal aberrations have been reported in small cell cancer of the bladder. There are no specific clinical features that differentiate these patients from transitional cell carcinoma of the bladder; however, some patients may have associated paraneoplastic conditions. Diagnosis is established by cystoscopic-assisted biopsy. Like small cell carcinoma of the lung, small cell carcinoma of the bladder has a propensity for early metastases. There is no standard therapy for small cell carcinoma of the bladder and the prognosis is poor; however, patients treated with cisplatin-based chemotherapy regimens seem to have a better prognosis.

Protocol consisting of cisplatin, etoposide and irinotecan induced complete pathological remission of primary small cell carcinoma of the bladder

A 73-year-old man with primary small-cell carcinoma of the bladder was treated by radical cystectomy with neoadjuvant chemotherapy. Pathological complete remission was achieved by combination chemotherapy composed of cisplatin, etoposide and irinotecan. The patient is free of disease 19 months after surgery.

Patterns of invasion and histological growth as prognostic indicators in urothelial carcinoma of the upper urinary tract

The biological significance of squamous and glandular differentiation and different patterns of invasion in upper urinary tract urothelial carcinoma is unclear. We reviewed 268 cases of consecutive upper urinary tract carcinomas with respect to the presence of squamous and/or glandular differentiation and different patterns of invasion (nodular, trabecular, and infiltrative) and correlated data with patient outcome. Squamous or glandular differentiation occurred in 47/268 (18%) tumors and its presence correlated with high tumor stage (P<0.001) and grade (P<0.001). Invasive patterns were nodular in 49/227 (22%), trabecular in 95/227 (42%), and infiltrative in 83/227 (37%) tumors. The nodular pattern prevailed in low stage (P<0.001) and low-grade (P<0.001) tumors, whereas the infiltrative pattern prevailed in high stage (P<0.001) and high-grade (P<0.001) tumors. Multivariate analysis proved that tumor stage (P<0.001) and the infiltrative pattern (P<0.001) are independent predictors of metastasis-free survival, whereas tumor grade and squamous and glandular differentiation lacked independent influence on patient outcome. In conclusion, the infiltrative pattern of invasion significantly correlated with advanced disease and poor patient outcome. In contrast, the presence of squamous and/or glandular invasion did not prove independent influence on patient outcome. The pattern of invasion should be commented upon separately in the pathology report.

The pathology of bladder cancer

Pathologists play an important role in the management of urinary bladder cancer by making a careful morphologic assessment of the primary tumor and its relation to adjacent structures. Ideally, evaluation of the primary site will segregate patients into groups with distinct clinical features, biologic behavior, and response to therapy. Traditionally, to accomplish this goal, pathologists have relied on factors such as histologic tumor type, grade, depth of invasion, and presence or absence of vascular invasion. Recently, in an effort to enhance our ability to subclassify these patients, we have introduced new modalities, such as flow cytometry, monoclonal antibodies, assessment of proliferative rate, and cytogenetics and molecular genetics. Without question we are advancing into an era in which tumors will be classified based on their molecular "fingerprint." Nevertheless, at this time, morphology remains the "gold standard" and, consequently, the best tool to assess the biologic potential of early bladder cancer. Despite this undeniable fact, there are many problems with the pathologic evaluation of these tumors, mostly because of the inherent subjectivity of the field and the lack of universal, standardized criteria for the evaluation of the above-mentioned morphologic parameters. Publications in peer-reviewed journals and the proliferation of educational opportunities by way of seminars, conferences, and web-based tutorials play an important role in keeping the practicing pathologist informed and up to date. As novel concepts and modern techniques are reported, their clinical value must be validated prospectively. Expert pathology review and establishment of exportable practice standards play an important role in the process.

[Primary lymphoepithelioma-like carcinoma urinary bladder]

OBJECTIVE

To present a new case of a primary lymphoepithelioma-like carcinoma of the urinary bladder.

MATERIAL AND METHODS

We describe the clinical, diagnosis, treatment and development of this kind of tumor. Review of the literature.

CONCLUSIONS

It is an unusual type of bladder cancer that requires a carefully analyse from the pathologist and a confirmation by means of immunohistochemistry techniques. The focal form is associated with poor prognosis. Radical cystectomy is the gold standard. This kind of tumor has sensibility to chemo and radiotherapy, who can be used as adjuvant therapy.

Case report: Microcystic Transitional Cell Carcinoma of the Urinary Bladder

We report a rare case of microcystic transitional cell carcinoma involving the urinary bladder, in a 38-year-old man, and we add our experience in the treatment of this neoplasm. The tumor was muscle invasive, and a radical cystectomy was performed. The patient received no postoperative chemotherapy or radiotherapy, and he has not signs of local recurrence or distal metastasis after 3 years of intense follow up. Even though the number of cases documented so far, is insufficient to draw safe conclusions regarding the optimal treatment of the microcystic variant of transitional cell carcinoma. Our case indicates that even in cases of microcystic transitional cell carcinoma with infiltrative nature, aggressive therapy is associated with good control of the disease locally and distally.

Transitional cell carcinoma of the bladder mimicking lobular carcinoma of the breast: a discohesive variant of urothelial carcinoma

AIMS

To describe a series of 10 cases of transitional cell carcinoma which show morphological features which mimic lobular carcinoma of the breast and diffuse carcinoma of the stomach.

METHODS AND RESULTS

Ten cases were identified from the files at Southampton University Hospitals NHS Trust and from the authors' consultation files. Immunostains were performed and clinical information was obtained. Eight of the patients were male and two female. Ages ranged from 52 to 77 years at presentation. All of the tumours showed areas where the tumour was composed of uniform cells with a discohesive single-cell, diffusely invasive growth pattern. In areas the tumour cells were arranged in linear single-cell files and in separate areas solid sheets of discohesive cells. In all of the cases some tumour cells showed prominent intracytoplasmic vacuoles. In addition to this pattern, four cases showed typical transitional cell carcinoma or carcinoma in situ. The majority of the tumours expressed cytokeratin 20 but not oestrogen receptors.

CONCLUSION

This study highlights a pattern of diffusely invasive transitional cell carcinoma not previously described and one which is important to recognize in order to avoid misdiagnosis of metastatic lobular carcinoma of the breast, especially in small biopsies.

Urinary bladder pathology 2004: An update

The field of urinary bladder pathology is advancing at a rapid rate, with generation of significant new knowledge on molecular pathogenesis and cell and tissue-based diagnosis. The aim of this presentation is to survey selected, recent advances in this broad field, with specific focus on histologic typing, grading, staging, molecular classification, and reporting on neoplasia of the urinary bladder.

Histopathological and immunohistochemical study of papillary urothelial neoplasms of low malignant potential and grade associated with extensive invasive low-grade urothelial carcinoma

OBJECTIVE

To report five cases of papillary urothelial neoplasm of low malignant potential (UNLMP) and papillary urothelial carcinoma of low grade (UCLG) associated with extensive muscle invasion, and to investigate the clinical and histopathological presentation and their immunohistochemical properties.

MATERIALS AND METHODS

Consecutive cystectomy and correlating transurethral resection (TUR) of urinary bladder tumour specimens were reviewed to identify cases of UCLG having extensive invasion into the urinary bladder wall. All specimens were stained immunohistochemically, as were those from 10 control cases having reactive urothelium or superficial UNLMP. The clinical charts were reviewed.

RESULTS

Of a total of 95 cystectomy cases there were four of UNLMP or UCLG with extensive invasion. An additional case was added from our consultation file. All five cases had biopsies misdiagnosed as benign lesions or prostatic adenocarcinoma. The superficial invasive components consisted of UCLG conforming to the previously described entities of nested transitional cell carcinoma (TCC), microcystic or deceptively benign-appearing TCC. Immunostaining for cytokeratin 20, MIB-1 and p53 was similar to reactive epithelia, whereas E-cadherin immunoreactivity was slightly different, with focal negativity compared with extensive immunoreactivity in invasive vs noninvasive UCLG. Four patients developed distant metastases; three died within a follow-up of 3 years.

CONCLUSIONS

UNLMP and UCLG that widely and deeply invade the bladder accounted for 4% of urothelial carcinoma (UC) in cystectomy specimens and commonly pose diagnostic problems in superficial TUR specimens. From this study with few cases the diagnosis of this entity in superficial biopsies is aided by an awareness of it and by identifying 'benign appearing' nests of urothelial cells which are deeply seated in the stroma. Immunostaining is unlikely to be very useful.

Urothelial carcinoma of the urinary bladder with a component of acinar/tubular type differentiation simulating prostatic adenocarcinoma

We report a case of an 83-year-old man with a high-grade carcinoma of the urinary bladder who underwent cystoprostatectomy. The invasive carcinoma showed mixed, morphologically distinct patterns consisting of conventional high-grade urothelial carcinoma, glandular differentiation resembling enteric type adenocarcinoma, and acinar/tubular type differentiation, morphologically similar to Gleason grade 3 prostatic adenocarcinoma. Immunohistochemical studies revealed the acinar/tubular component of the tumor to be negative for prostate-specific antigen and prostatic acid phosphatase, but positive for cytokeratin 7, cytokeratin 20, high molecular weight cytokeratin (34 beta E12), and thrombomodulin, consistent with origin from the bladder rather than the prostate. Although bladder carcinomas composed of mixed morphologic patterns are not uncommon, to our knowledge, the presence of acinar/tubular type features simulating prostatic adenocarcinoma in such tumors has not been described elsewhere.

Transitional Cell Carcinoma of the Ovary

Transitional cell carcinoma (TCC) of the ovary is a recently recognized subtype of ovarian surface epithelial-stromal cancer, and studies of its morphology are few. As a result, the criteria for its diagnosis and spectrum of its morphology are not clearly established. One hundred consecutive consultation cases of ovarian carcinoma with a pure or partial transitional cell pattern (excluding malignant Brenner tumor) diagnosed between 1989 and 2001 were evaluated for the frequency of various pathologic features and the relation of TCC to other surface epithelial-stromal carcinomas. The women were 33 to 94 years of age (mean, 56 years). A total of 47 tumors were stage I, 21 stage II, 31 stage III, and 1 stage IV; 13% of the stage I tumors and 41% of tumors of all stages were bilateral. The tumors ranged from 3.0 to 30 cm in greatest dimension (mean, 10 cm); 60% of them were solid and cystic, 24% solid, and 16% cystic. TCC was the exclusive or predominant component in 93% of the tumors and showed undulating (93%), diffuse (57%), insular (55%), and trabecular (43%) patterns. In four tumors with an insular growth, the pattern focally mimicked a Brenner tumor. Necrosis was present in 57% of the cases. Features that were seen in the tumors that in aggregate produced a relatively consistent appearance were "punched out" microspaces (87%), often the size of Call-Exner bodies, large cystic spaces (73%), and large blunt papillae (63%). Features that were sometimes seen, usually as a focal finding, included slit-like fenestrations (49%), bizarre giant cells (35%), small filiform papillae (18%), gland-like tubules (17%), squamous differentiation (13%), and psammoma bodies (4%). In 23 cases, TCC was a component of a mixed epithelial carcinoma, the additional components being serous adenocarcinoma in 16, endometrioid in 5, mucinous in 1, and clear cell carcinoma in 1. The tumor cells of the TCC component often were relatively monomorphic; 6% of the tumors were grade 1, 43% grade 2, and 51% grade 3. The nuclei were oblong or round and often had large single nucleoli (69%) or longitudinal grooves (48%). The cytoplasm was typically pale and granular but was rarely strikingly clear or oxyphilic. TCC of the ovary usually occurs in pure form but is also common as a component of a surface epithelial carcinoma of mixed cell type. In either situation, TCC has a constellation of architectural and cytologic features that readily distinguish it in most cases from other types of ovarian cancer. Recognition of these features will lead to a more consistent diagnosis of this tumor and aid in determining whether it has distinctive clinical features, particularly with regard to its behavior.