Immunohistochemical profile to distinguish urothelial from squamous differentiation in carcinomas of urothelial tract

Current Advances in the Management of Nonurothelial Subtypes of Bladder Cancer

Urothelial cancer (UC) is the most common histology seen in bladder tumors. The 2022 WHO classification of urinary tract tumors includes a list of less common subtypes (formerly known as variants) for invasive UC which are considered high-grade tumors. This review summarizes the most recent advances in the management of selected nonurothelial subtypes of bladder cancer: squamous cell carcinoma, small cell carcinoma, sarcomatoid urothelial carcinoma, micropapillary carcinoma, plasmacytoid carcinoma, adenocarcinoma, and urachal carcinoma. The role of neoadjuvant and adjuvant chemotherapy has not been well characterized for most of these histologies, and prospective data are extremely limited. Participation in clinical trials is recommended in advanced disease.

Cutaneous Metastasis Following a Six-Year History of Bladder Urothelial Carcinoma in Situ: A Case Report

Bladder cancer with cutaneous metastasis is a rare manifestation of the advanced stage of the disease. It can result from direct invasion, lymphatic or hematogenous spread, or iatrogenic implantation. We present a case of a 67-year-old patient initially diagnosed with urothelial carcinoma (UC) in situ of the bladder, who underwent transurethral resection of bladder tumor, along with induction and maintenance Bacillus Calmette-Guerin immunotherapy. Six years post-diagnosis, the patient developed multiple ulcerating fungating lesions in the right lower extremity, confirmed as metastases from UC. The patient additionally developed right foot gangrene with subsequent infection, which progressed into sepsis and caused the patient's demise.

Gene of the month: the uroplakins

Uroplakins are a family of membrane-spanning proteins highly specific to the urothelium. There are four uroplakin proteins in humans. These are encoded by the following UPK genes: UPK1A, UPK1B, UPK2 and UPK3 Uroplakin proteins span the apical membrane of umbrella cells of the urothelium, where they associate into urothelial plaques. This provides a barrier function to prevent passage of urine across the urothelium in the renal pelvis, ureters, and bladder. Uroplakins are also involved in developmental processes such as nephrogenesis. The specific localisation of uroplakins within the urothelium means that they are often expressed in primary and metastatic urothelial cell carcinoma and may be used as an immunohistochemical marker of urothelial malignancy.

GATA3 Expression in Prostatic Adenosquamous Carcinoma: A Potential Diagnostic Pitfall

Urothelial carcinoma and prostatic adenocarcinoma can have overlapping histologic features and in some instances pose challenges to pathologists. GATA binding protein 3 (GATA3) immunohistochemistry (IHC) is a well-established tool to aid in this specific diagnostic dilemma as it has been shown to be a sensitive marker for urothelial carcinoma and a putatively specific marker in excluding prostatic adenocarcinoma. However, in encountering an index tumor of prostatic adenosquamous carcinoma positive for GATA3, herein we sought to investigate this potential diagnostic pitfall in a larger series of tumors. In this study, we retrospectively reviewed prostatic adenosquamous carcinomas diagnosed in 17 patients across the authors' institutions and personal consult collections in the past 10 years. GATA3 IHC was either reviewed or performed on tumors not previously tested. We also recorded other immunostains that were performed at initial diagnosis. Positivity for GATA3 was found in 9 of 17 (53%) tumors, all within squamous regions (2 tumors also showed concomitant moderate GATA3 positivity within glandular elements). The GATA3 positive tumors were all positive for p63 in the 7 tumors where p63 was also performed. Of all tumors tested, NKX3.1 was positive in 100% (13/13) of the glandular elements (3 tumors also showed NKX3.1 concomitant positivity within squamous regions). In summary, when encountering a carcinoma with mixed glandular/squamous features in which prostatic origin is being considered, awareness of GATA3 immunoreactivity in a subset of prostatic adenosquamous carcinoma is critical to avoid diagnostic pitfalls.

The impact of squamous cell transformation on the prognosis of patients treated with radical nephroureterectomy

BACKGROUND

Limited information is available for guiding the management of upper urinary tract (UUT) urothelial carcinoma with squamous differentiation (UC-SqD). We did not even know about the difference between pure urothelial carcinoma (UC) and UC-SqD in the UUT regardless of treatment policy and prognosis. Instead of direct comparisons against each other, we included the third UUT malignancy, squamous cell carcinoma (SCC). This three-way-race model allows us to more clearly demonstrate the impact of squamous cell transformation on patient outcomes in UUT malignancy.

METHODS

We retrospectively analysed 327 patients with UC, UC-SqD, or SCC who underwent radical nephroureterectomy with bladder cuff excision (RNU) at Taichung Veterans General Hospital, Taichung, Taiwan, between January 2006 and December 2013. A Kaplan-Meier survival analysis was used to evaluate the relationship between patient outcomes and histology. Multivariate Cox proportional hazards modelling was also used to predict patient prognoses.

RESULTS

The five-year postoperative cancer-specific survival (CSS) rates were 83.6% (UC), 74.4% (UC-SqD), and 55.6% (SCC), and the 5-year recurrence-free survival (RFS) rates were 87.7% (UC), 61.5% (UC-SqD), and 51.9% (SCC). UC patients had significantly better 5-year RFS than UC-SqD and SCC patients (P = 0.001 and P < 0.0001, respectively). Patients with pure UC had significantly better 5-year CSS than SCC patients (P = 0.0045). SCC or UC-SqD did not independently predict disease-specific mortality (HR 0.999, p = 0.999; HR 0.775, p = 0.632, respectively) or disease recurrence compared to pure UC (HR 2.934, p = 0.239; HR 1.422, p = 0.525, respectively). Age, lymphovascular invasion (LVI), and lymph node (LN) status independently predicted CSS, while pathological tumour stage, LN status, and LVI predicted RFS.

CONCLUSIONS

SCC and UC-SqD are not independent predictors of survival outcomes in patients with UUT tumours. However, they are associated with other worse prognostic factors. Hence, different treatments are needed for these two conditions, especially for SCC.

Diagnostic and Prognostic Roles of GATA3 Immunohistochemistry in Urothelial Carcinoma

This study aimed to evaluate the diagnostic and prognostic roles of GATA-binding protein 3 (GATA3) immunohistochemistry in urothelial carcinoma (UC) using a meta-analysis. We investigated GATA3 immunohistochemical expression rates and performed a subgroup analysis based on tumor site, study location, and histological subtypes. The overall survival rates of patients with GATA3-positive and -negative UC were compared. The estimated GATA3 expression rate was 0.748 (95% confidence interval [CI]: 0.704-0.787). GATA3 expression rates in the urinary bladder and urinary tract were 0.775 (95% CI: 0.727-0.818) and 0.614 (95% CI: 0.426-0.774), respectively. The GATA3 expression rates of noninvasive and invasive UCs were 0.965 (95% CI: 0.938-0.980) and 0.644 (95% CI: 0.581-0.702), respectively. In invasive UCs, there was a significant difference in GATA3 expression between non-muscular invasion and muscular invasion subgroups (0.937, 95% CI: 0.883-0.967 vs. 0.753, 95% CI: 0.645-0.836). GATA3 expression was the highest in the microcytic subtype among the histologic subtypes (0.952, 95% CI: 0.724-0.993). There was a significant correlation between GATA3 expression and better prognosis (hazard ratio: 0.402, 95% CI: 0.311-0.521). Taken together, GATA3 expression significantly correlated with low-stage and better prognosis in UC. GATA3 expression is highly variable across histological subtypes, and one should be careful while interpreting GATA3 expression.

Utility of GATA-3 and associated immunohistochemical markers in the differential diagnosis of poorly differentiated urothelial carcinoma

Aims

The aims are to study the utility of GATA-3 along with panel of immunohistochemical (IHC) markers in the differential diagnosis of primary and metastatic poorly differentiated urothelial carcinoma (UC).

Settings and Design

This is a prospective and retrospective observational study.

Subjects and Methods

Poorly differentiated carcinomas of urinary tract and metastatic sites from January 2016 to December 2017 were subjected to a panel of four IHC markers including GATA-3, p63, Cytokeratin (CK) 7, and CK20. Additional markers such as p16, an enzyme called alpha-methylacyl-CoA racemase, CDX2, and thyroid transcription factor 1 were also done depending on the morphology and site.

Statistical Analysis Used

The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of GATA-3 in making the diagnosis of UC were calculated.

Results

Forty-five cases were included in the study and after appropriate IHC, the diagnosis was resolved as UC in 24 cases. GATA-3 was positive in 83.33% of UC; all the four markers positive in 33.33% and all negative in 4.17% of UC. However, at least one of the four markers was present in 95.83% of UC, except in sarcomatoid UC. GATA-3 had 100% specificity in differentiating from prostate adenocarcinoma.

Conclusion

GATA-3 is a useful marker in the diagnosis of UC in the primary and metastatic sites with a sensitivity of 83.33%. GATA-3 along with other IHC markers in correlation with clinical and imageological features is necessary for making specific diagnosis of poorly differentiated carcinoma.

Scoring Systems for Immunohistochemistry in Urothelial Carcinoma

Immunohistochemistry is widely used in diagnostic and scientific analysis of urothelial carcinoma. Objective interpretation of staining results is mandatory for accuracy and comparability in diagnostic and therapeutic patient care as well as research.Herein we summarize and explain standardized microscopic evaluation and scoring approaches for immunohistochemical stainings. We focus on commonly used and generally feasible approaches for different cellular compartments and comment on their utility in diagnostics and research practice.

An Approach to Nonurothelial Malignancies of the Urinary Bladder in Urine Cytology

Urine cytology is an economical and convenient method of triaging patients who present with urinary symptoms as well as surveying those who have previously been diagnosed with urothelial carcinoma for recurrent or persistent disease. While the vast majority of malignancies diagnosed in urine cytology are urothelial carcinomas, it is important to recognize nonurothelial elements to inform patient prognosis and raise the possibility of involvement by a urothelial carcinoma variant, nonurothelial malignancy of the bladder, or a nonbladder primary, which may alter patient management pathways. As such, becoming familiar with morphologic features of nonurothelial malignancies in urine cytology as well as their related clinical risk factors, radiologic and cystoscopic features, differential diagnostic considerations, and the utility and pitfalls of ancillary tests can facilitate optimal patient care.

Are We Ready to Implement Molecular Subtyping of Bladder Cancer in Clinical Practice? Part 1: General Issues and Marker Expression

Bladder cancer (BC) is a heterogeneous disease with highly variable clinical and pathological features, and resulting in different outcomes. Such heterogeneity ensues from distinct pathogenetic mechanisms and may consistently affect treatment responses in single patients. Thus, over the last few years, several groups have developed molecular classification schemes for BC, mainly based on their mRNA expression profiles. A “consensus” classification has recently been proposed to combine the published systems, agreeing on a six-cluster scheme with distinct prognostic and predictive features. In order to implement molecular subtyping as a risk-stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The first part of this review deals with the steps resulting in the development of a molecular subtyping of BC, its prognostic and predictive implications, and the main features of immunohistochemical markers used as surrogates to stratify BC into pre-defined molecular clusters.

Expression of GATA3 and Cytokeratin 14 in Urinary Bladder Carcinoma (Histopathological and Immunohistochemical Study)

BACKGROUND: Urothelial carcinoma (UC) with squamous differentiation (SD) is the most common histologic variant of bladder carcinoma and its presence is associated with poor prognosis which may need early radical cystectomy to avoid progression and recurrence. It is difficult to detect few foci of SD, especially nonkeratinizing or early switch from urothelial to squamous epithelium on only morphological basis. Combination of GATA3 and Cytokeratin 14 (CK14) could be helpful in differentiating pure UC, UC with SD and pure squamous cell carcinoma (SCC). AIM: Assessment of GATA3 and CK14 expression in urinary bladder carcinoma and correlation with clinical and histopathological variables, for both diagnostic and prognostic purposes. MATERIALS AND METHODS: Sixty cases of archived paraffin blocks of urinary bladder carcinoma were tested for GATA3 and CK14 expression by immunohistochemistry using a rabbit monoclonal antibody against human CK 14 and mouse monoclonal antibody against GATA3, respectively. RESULTS: There is a significant correlation between GATA3 immunohistochemical expression and histological tumor subtypes of bladder carcinoma (p < 0.001), i.e. the GATA3 is a useful marker for urothelial origin especially in papillary UC. There is a significant correlation between GATA3 immunohistochemical expression and UC grade (p < 0.001). CK14 showed positive cytoplasmic staining in 9/14 (64.3%) cases of UC with SD and (13/13) (100%) cases of pure SCC and negative in 33/33(100%) cases of UC other than UC with SD. CK14 had sensitivity (64.3%) and specificity (100%) for areas of SD. CONCLUSION: GATA3 is a specific immunohistochemical marker for urothelial origin. CK14 is a highly specific and sensitive immunohistochemical marker of squamous cell carcinoma.

Stratification of urothelial bladder carcinoma depending on immunohistochemical expression of GATA3 and CK5/6

Bladder urothelial carcinoma (BUC) has two pathways with distinct molecular features and prognosis, non-muscle invasive (NMI) and muscle invasive (MI) tumors. The aim is to investigate the expression of GATA3 and CK5/6 in BUC with correlation to clinicopathologic parameters, including their impact on survival beside their potential use to stratify cases into prognostic subgroups. This study included 80 cases of BUC stained immunohistochemically by GATA3 and CK5/6. The cases were divided into four groups regarding expression status of both markers (luminal, basal, mixed, and null). GATA3 percentage of expression decreased in urothelial carcinoma with squamous differentiation, MI tumors, high-grade tumors, tumors with involved lymph nodes, presence of perineural invasion, presence of bilharziasis, presence of lympho-vascular invasion, and high mitotic count. CK5/6 positivity was higher in urothelial carcinoma cases with squamous differentiation, MI tumors, and presence of perineural invasion. Pure urothelial carcinoma and NMI were in favor of luminal group (GATA3 +ve/CK5/6 -ve). Univariate analysis showed that the presence of bilharziasis was associated with shorter PFS (p = .04). GATA3 and CK5/6 could be used for the stratification of urothelial bladder carcinoma into subtypes with different characteristics. Luminal bladder cancer represents the most common type (60%) that carries favorable features. Bilharziasis-associated urothelial carcinoma carries poor outcome manifested by short PFS.

Histological and immunohistochemical investigation of canine prostate carcinoma with identification of common intraductal carcinoma component

A limited number of species, including men and dogs, spontaneously develop prostate cancer (PC). The histological and molecular relevance of canine PC as a model for the disease in men remains controversial. To address this challenge, this study aimed to assess the histomorphology and expression of basal cell, urothelial and neuroendocrine markers [p63, high molecular weight cytokeratin (HMWCK), Uroplakin 3 (UPIII), neuron‐specific enolase (NSE)] in canine PC (n = 41). Based on histomorphology, 10/41 (24%), 21/41 (51%) and 9/41 (22%) were classified as adenocarcinoma (AC), urothelial carcinoma (UC), and mixed carcinoma, respectively. Tumour inflammation was common, frequently severe [20/41 (49%)], and associated with neutering (p < .02) and urothelial differentiation (p < .02). Most (36/40, 90%) cancers contained only rare cells with basal cell marker expression or were negative. The expression of UPIII was absent or weak in the majority (33/38, 87%) of tumours, with moderate to strong staining in the remaining cases. NSE expression in PC was rare and limited to 2/14 (14%) cases. Tumour extension into benign ducts and glands was a common finding with presence in 17/39 (44%) of carcinomas with and without urothelial differentiation. In conclusion, we confirm that canine PC is characterized by absent or weak expression of basal cell and urothelial markers. Although rare, NSE expression, potentially indicating neuroendocrine differentiation, is reported for the first time in canine PCa. Intraductal carcinoma of the prostate with concurrent invasive PCa (IDCP‐inv) is a frequent, not previously described, finding in dogs with PC.

Metastasis from tongue squamous cell carcinoma to the kidney

Metastasis to the kidney from other primary sites is extremely rare. Previous studies reported the lung as the most common primary site. Distant metastasis from the tongue to the kidney is exceedingly rare. Herein, we describe a case of metastatic squamous cell carcinoma to the kidney in a 71-year-old male with a detailed discussion of differentiating it from potential mimickers. The patient underwent a total glossectomy and bilateral cervical lymph node dissection. A diagnosis of well-differentiated squamous cell carcinoma of the tongue was rendered and the tumor was staged pT3 pN3b. Within two years of initial presentation, the patient developed widely metastatic disease, including pulmonary nodules, renal masses, left adrenal mass, and pancreatic mass. Accurate diagnosis of a secondary involvement of the kidney by a metastatic tumor requires the appropriate correlation of clinical and imaging findings as well as morphologic and immunohistochemical clues.

Association Between Estrogen Receptors and GATA3 in Bladder Cancer: A Systematic Review and Meta-Analysis of Their Clinicopathological Significance

BACKGROUND

Estrogen receptors alpha (ERα) and beta (ERβ) and the cooperating protein GATA-binding factor 3 (GATA3) have been implicated in bladder carcinogenesis and tumour progression. GATA3 and ER have been functionally linked in the establishment of luminal fate in breast tissue, but to date their relationship in bladder cancer has not been established. This information will be useful to advance diagnostic and prognostic markers.

AIM

To determine the relationship between the expression of ERα, ERβ and GATA3 in bladder cancer, disclose their prognostic and diagnostic value and their association with clinicopathological characteristics.

METHODS

A comprehensive literature search in PubMed database was performed for all immunohistochemical studies of ERα, ERβ and/or GATA3 in bladder cancer patients. We selected eligible studies in accordance with the PRISMA guidelines and evaluated methodological quality and risk of bias based on quality criteria from the reporting recommendations for tumour MARKer (REMARK) prognostic studies. Risk of bias assessment was performed using Review Manager 5. R software was used for all statistical analysis, the packages used were meta and dmetar for the standard meta-analysis, and netmeta for the network meta-analysis.

RESULTS

Thirteen studies were eligible for ERα, 5 for ERβ and 58 for GATA3 meta-analysis. Low grade tumours showed significantly lower ERα expression. GATA3 was widely expressed in bladder tumours, especially urothelial carcinomas, with higher expression of GATA3 in low grade and low stage tumours. Data was insufficient to determine the prognostic value of either ERα or ERβ, but GATA3-positivity was associated with higher recurrence free survival. A negative correlation between ERα or ERβ positivity and GATA3 expression was disclosed. Additionally, several sources of heterogeneity were identified, which can be used to improve future studies.

CONCLUSION

The clinicopathological value of ERα and ERβ was inconclusive due to low availability of studies using validated antibodies. Still, this meta-analysis supports GATA3 as good prognostic marker. On the contrary, ERα-positivity was associated to higher grade tumours; while ERα and ERβ were inversely correlated with GATA3 expression. Considering that it has previously been shown that bladder cancer cell lines have functional ERs, this suggests that ERα could be activated in less differentiated cells and independently of GATA3. Therefore, a comprehensive analysis of ERα and ERβ expression in BlaCa supported by complete patient clinical history is required for the identification of BlaCa subtypes and subgroups of patients expressing ERα, to investigate if they could benefit from treatment with hormonal therapy.

SYSTEMATIC REVIEW REGISTRATION

Prospero, CRD42021226836.

Stratification of urinary bladder carcinoma based on immunohistochemical expression of CK5, CK14 and CK20

Molecular subtyping of urothelial carcinoma (UC) is similar to that of breast cancer and is based on the developmental biology approach. The aim of the present study is to assess the prognostic impact of CK5, CK14, and CK20 expression in urinary bladder cancer (UBC) with the potential to stratify them into different subtypes. The current study examined the immunohistochemical expression of CK5, CK14, and CK20 in 90 specimens of UBC. CK5 was expressed in 81.1% of the cases and was significantly associated with old age, muscle invasion, presence of bilharziasis, and tendency for poor overall survival. CK20 was expressed in 47.8% of the cases and was associated with nonmuscle invasion and pure UC while 50% of the cases expressed CK14 that were associated with muscle invasion and perineural invasion. Most squamous cell carcinoma and those associated with bilharziasis were belonged to Ck5+/CK20- subgroup while pure UC and those lacked bilharziasis were located in the Ck5+/CK20+ subgroup. The basal group (Ck5+/CK14+/CK20-) showed high proliferative features compared to the intermediate group (Ck5+/CK14-/CK20-). Generally, presence of CK5 is associated with adverse features especially in the group lacking CK20; however, basal and intermediate subgroups share CK5 expression but they show different proliferative capacities, so their distinction by CK14 is helpful.

Urothelial carcinoma: variant histology, molecular subtyping, and immunophenotyping significant for treatment outcomes

Although urothelial carcinoma (UC) has been recognised as a homogenous disease entity until recently, it exhibits widely diverse histological variants. Recent studies have revealed that some histological variants may serve as markers of very high risk for advanced cancers and poor prognoses. Certain histological variants can generate a pathological T stage, which may result in unnecessary surgery. Though platinum based chemotherapy is the standard treatment, the use of immune checkpoint inhibitors (ICIs) for UC treatment has become a major trend in oncology. UCs showing specific histological variants have responded exceptionally well to chemotherapy and ICIs. Currently, molecular studies base molecular classification on gene expression profile signatures in order to make diagnoses or predict responses to chemotherapies and ICIs. Notably, some histological variants correlate with specific molecular subtypes. The usefulness of immunophenotyping for classification purposes was recognised only recently. Immunophenotypes are classified into three categories according to lymphocyte distribution in or around the cancer cell nest: desert, excluded, and inflamed. This immunophenotyping has been increasingly shown to be of value in predicting the response to ICIs. This review describes the morphological characteristics of histological variants as well as the advantages and limitations in determining them, with particular reference to clinical benefits. Subsequently, we describe the concept of molecular classification and immunophenotypes, and their morphological features, which are easily interpreted and amenable to daily practice via hematoxylin and eosin staining. We also consider the clinical advantages, limitations, and issues encountered while using these in routine clinical practice.

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.

An Algorithmic Immunohistochemical Approach to Define Tumor Type and Assign Site of Origin

Immunohistochemistry represents an indispensable complement to an epidemiology and morphology-driven approach to tumor diagnosis and site of origin assignment. This review reflects the state of my current practice, based on 15-years' experience in Pathology and a deep-dive into the literature, always striving to be better equipped to answer the age old questions, "What is it, and where is it from?" The tables and figures in this manuscript are the ones I "pull up on the computer" when I am teaching at the microscope and turn to myself when I am (frequently) stuck. This field is so exciting because I firmly believe that, through the application of next-generation immunohistochemistry, we can provide better answers than ever before. Specific topics covered in this review include (1) broad tumor classification and associated screening markers; (2) the role of cancer epidemiology in determining pretest probability; (3) broad-spectrum epithelial markers; (4) noncanonical expression of broad tumor class screening markers; (5) a morphologic pattern-based approach to poorly to undifferentiated malignant neoplasms; (6) a morphologic and immunohistochemical approach to define 4 main carcinoma types; (7) CK7/CK20 coordinate expression; (8) added value of semiquantitative immunohistochemical stain assessment; algorithmic immunohistochemical approaches to (9) "garden variety" adenocarcinomas presenting in the liver, (10) large polygonal cell adenocarcinomas, (11) the distinction of primary surface ovarian epithelial tumors with mucinous features from metastasis, (12) tumors presenting at alternative anatomic sites, (13) squamous cell carcinoma versus urothelial carcinoma, and neuroendocrine neoplasms, including (14) the distinction of pheochromocytoma/paraganglioma from well-differentiated neuroendocrine tumor, site of origin assignment in (15) well-differentiated neuroendocrine tumor and (16) poorly differentiated neuroendocrine carcinoma, and (17) the distinction of well-differentiated neuroendocrine tumor G3 from poorly differentiated neuroendocrine carcinoma; it concludes with (18) a discussion of diagnostic considerations in the broad-spectrum keratin/CD45/S-100-"triple-negative" neoplasm.

Tubo-Ovarian Transitional Cell Carcinoma and High-grade Serous Carcinoma Show Subtly Different Immunohistochemistry Profiles

Tubo-ovarian transitional cell carcinoma (TCC) is grouped with high-grade serous carcinoma (HGSC) in the current World Health Organization classification. TCC is associated with BRCA mutations and a better prognosis compared with HGSC. Previous papers examining the immunohistochemical features of TCC have studied limited numbers of samples. No marker reflecting the biological difference between TCC and HGSC is known. We collected a large cohort of TCC to determine whether TCC and HGSC could be distinguished by immunohistochemistry. A tissue microarray was built from 89 TCC and a control cohort of 232 conventional HGSC. Immunohistochemistry was performed, scored, and statistically analyzed for routine markers of HGSC and urothelial tumors: PAX8, WT1, p53, p16, ER, p63, and GATA3. Using scoring cutoffs commonly employed in clinical practice, the immunohistochemical profile of TCC was indistinguishable from HGSC for all markers. However, more detailed scoring criteria revealed statistically significant differences between the 2 groups of tumors with respect to ER, PAX8, and WT1. HGSC showed more diffuse and intense staining for PAX8 (P=0.004 and 0.001, respectively) and WT1 (P=0.002 and 0.002, respectively); conversely, TCC showed more intense staining for ER (P=0.007). TCC and HGSC therefore show subtle differences in their immunohistochemical profiles which might reflect underlying (epi)genetic differences. Further studies using proteomic analysis will focus on the identification of differentially expressed proteins that might serve as markers of TCC-like differentiation, which could help explain biologic differences between TCC and HGSC and might identify other cases of HGSC with a better prognosis.

Non-invasive urinary sediment double-immunostaining predicts BK polyomavirus associated-nephropathy in kidney transplant recipients

Background

The positive predictive value (PPV) of urinary decoy cells for diagnosing BK polyomavirus associated-nephropathy (BKPyVAN) is low. This study was designed to increase the PPV of urinary decoy cells for diagnosing BKPyVAN in kidney transplant recipients.

Methods

A total of 105 urine sediment samples from 105 patients with positive BK viruria and decoy cells were evaluated by automatic double-immunostaining with anti-HGD (a renal tubular marker) antibody + anti-SV40-T antibody or anti-S100P (an urothelial marker) antibody + anti-SV40-T antibody.

Results

Of the 105 patients, 76 (72.4%) had both HGD(+)/SV40-T(+) cells and S100P(+)/SV40-T(+) cells (group A), 24 (22.9%) had only S100P(+)/SV40-T(+) cells (group B), and 5 (4.6%) had only S100P(-)/HGD(-)/SV40-T(+) cells (group C). Seventy patients in group A (92.1%), 3 patients in group B (12.5%), and no patients in group C were diagnosed with BKPyVAN. The area under the ROC curve of predicting BKPyVAN by decoy cells was 0.531 (0.431-0.630), with an optimal cut-off value of 29 (per 10 high power field), a sensitivity of 45.8% (95% CI: 34.0-58.0%), and a specificity of 68.8% (95% CI: 50.0-83.9%). Besides, the area under the ROC curve of predicting BKPyVAN by plasma BKPyV load was 0.735 (95% CI: 0.632-0.822), with an optimal cut-off value of 1,000 copies/mL, a sensitivity of 61.1% (95% CI: 48.9-72.4%) and a specificity of 84.2% (95% CI: 60.4-96.6%). In contrast, the PPV, negative predictive value, sensitivity, and specificity of HGD(+)/SV40-T(+) cells for diagnosing BKPyVAN were 92.1% [95% confidence interval (CI): 83.0-96.7%], 89.7% (95% CI: 71.5-97.3%), 95.9% (95% CI: 87.7-98.9%), and 81.3% (95% CI: 63.0-92.1%) respectively.

Conclusions

Double-immunostaining with anti-HGD or anti-S100P and anti-SV40-T antibodies helps to identify the origin of decoy cells and diagnose BKPyVAN.

Reduced expression of GATA3 predicts progression in non-muscle invasive urothelial carcinoma of the urinary bladder

Urothelial carcinoma (UC) of the urinary bladder is the ninth most common cancer worldwide. The majority of these patients present with non-muscle invasive bladder cancer (NMIBC). GATA3 has recently emerged as one of the diagnostically helpful immunohistochemical markers for UC. The published literature, however, lacks comprehensive studies on the impact of GATA3 expression on the prognosis of UC patients. This study evaluated and statistically analyzed the immunohistochemical expressions of GATA3 and Ki67 in 50 Egyptian patients with NMIBC and correlated the markers' expressions with clinicopathological variables and patients' outcome. Ten control cases were included. The expressions of GATA3 and Ki67 were significantly downregulated and upregulated respectively in UC cases compared to the control group. GATA3 down-expression was significantly associated with high grade tumors and tumor progression with 72% prediction accuracy. Higher proliferative activity was significantly correlated with high grade, non-papillary growth pattern, and lamina propria invasion. The predictive performance of GATA3 and Ki67 in predicting malignancy and tumor grade was good. We concluded that GATA3 downregulation and increased proliferative activity might be implicated in UC tumorigenesis, loss of differentiation, and aggressiveness. Reduced GATA3 expression could predict progression in NMIBC with an accuracy of 72% and thus it constitutes a potentially promising novel prognostic marker in patients with urothelial carcinoma.

Non-urothelial carcinomas of the bladder

Non-urothelial carcinomas involving the bladder are uncommon and often diagnostically challenging. These carcinomas may show squamous, adenocarcinomatous or neuroendocrine features, with immunohistochemical stains aiding the diagnosis in only a subset of cases. The clinical history in non-urothelial bladder carcinomas is important, given that the differential diagnosis often includes secondary involvement of the bladder by direct extension or metastasis from carcinomas at other sites. This paper will review non-urothelial carcinomas in each of these three morphological categories, emphasising recent changes in diagnostic grouping and challenges in the histopathological diagnosis. Review of bladder cancers with squamous morphology will include discussion of conventional squamous cell carcinoma and verrucous carcinoma and their distinction from urothelial carcinoma with extensive squamous differentiation. Bladder carcinomas with adenocarcinomatous change will include primary bladder adenocarcinoma, urachal adenocarcinoma and tumours of Müllerian type. Finally, neuroendocrine neoplasms of the bladder, including well-differentiated neuroendocrine tumour and neuroendocrine carcinomas, will be discussed. Associated surface findings, risk factors and prognostic features will be described.

Morphological and Immunohistochemical Biomarkers in Distinguishing Prostate Carcinoma and Urothelial Carcinoma: A Comprehensive Review

The differential diagnosis between high-grade prostate carcinoma and infiltrating urothelial carcinoma (UC) in transurethral resection prostate specimens as well as cystoprostatectomy specimens may often be challenging due to morphologic and clinical overlap of the 2 entities. Such distinction has critical therapeutic and staging consequences, yet it is hampered by both issues in morphology and by the low accuracy rates of single immunohistochemical markers, as reported in literature. This review aims to provide a comprehensive analysis of the available morphological and immunohistochemical parameters, which may allow to discriminate between prostate carcinoma and urothelial carcinoma in the proper clinical context and to discuss their diagnostic applications in daily practice.

The Utility of GATA3 in the Diagnosis of Urothelial Carcinomas With Variant Morphologic Patterns

The transcription factor GATA3 is a recently described biomarker that is highly expressed in bladder and breast carcinomas. Although it has shown sensitivity as a marker of primary bladder carcinomas with purely urothelial differentiation, the ability of GATA3 to label primary bladder carcinomas with variant morphologic patterns has been incompletely assessed to date. The current study was designed to determine whether GATA3 staining is retained in "unconventional" bladder carcinomas. Eighty-eight cases of primary bladder cancers were retrieved from the authors' institutional archive, and they included the following histomorphologic types: 6 small cell carcinomas, 12 sarcomatoid carcinomas, 17 adenocarcinomas (both primary and urothelial variants with glandular differentiation), 24 micropapillary carcinomas, and 27 squamous cell carcinomas (both primary and urothelial variants with squamous differentiation). A tissue microarray was constructed and automated immunostaining for GATA3 (Clone L50-823, Biocare Medical, Concord, CA) was performed using standard technique. Among the 5 variants of unconventional bladder carcinoma, only the micropapillary and sarcomatoid forms exhibited consistent and strong immunolabeling for GATA3. Hence, the sensitivity of this determinant is diminished in several histologic forms of primary bladder carcinoma. That fact will affect the interpretation of GATA3 stains in the context of possible metastasis from primary bladder carcinomas with variant morphologic patterns, as well as their distinction from secondary bladder involvement by tumors of nonurothelial origin.

S100P as a Marker for Urothelial Histogenesis: A Critical Review and Comparison With Novel and Traditional Urothelial Immunohistochemical Markers

S100P, or placental S100, is a member of a large family of S100 proteins and considered to be a promising immunohistochemical marker to support urothelial differentiation. This review synthesizes published data regarding the expression of S100P in urothelial carcinoma across histological grade and variant patterns, and in other malignancies, in an effort to summarize the state of understanding of this marker and evaluate its potential. We provide also a broad comparison of S100P with other contemporary and traditional urothelial markers and outline the potential utility of S100P in various diagnostically challenging scenarios. Taken in context, we recommend that to provide immunohistochemical support for consideration of urothelial differentiation, S100P may be included in a panel of markers (due to its high sensitivity), with better established (GATA3) and more specific (uroplakin 2) markers, for comparison with corresponding markers of other primary sites under consideration, depending on the clinical context. We emphasize that the overall most appropriate panel for any given case depends on the differential diagnosis engendered by the morphology encountered, and the constellation of clinical findings. As always with immunohistochemical panels, expected positive and negative markers for each diagnostic consideration should be included. Finally, since as of date there are no optimally sensitive or specific markers of urothelial differentiation, all final diagnoses relying on immunohistochemical support should be made in the appropriate clinical and histological context.

Unsuspected Malignancy During Percutaneous Nephrolithotomy: The Snake in the Grass

Squamous cell carcinoma of the upper tract (SCC-UT) is a rare neoplasm that disproportionately affects patients with longstanding nephrolithiasis. Diagnosis is challenging and typically comes at late stages; as such, the prognosis is poor. The absence of a reliable diagnostic predictor for SCC highlights the need to keep the diagnosis in mind for at-risk patient populations. In this study, we describe a small case series of rapidly progressive SCC-UT incidentally discovered during percutaneous nephrolithotomy.

Cutaneous squamous cell carcinoma progression is associated with decreased GATA-3 immunohistochemical staining

BACKGROUND

The GATA family of transcription factors is an essential regulator of cellular proliferation and differentiation. In the skin, GATA-3 is critical for epidermal stratification and maintenance of barrier function. A role for GATA-3 in the development of human cutaneous squamous cell carcinoma (SCC) is not known. Here, we investigated GATA-3 immunohistochemical staining in premalignant and invasive cutaneous SCC from sun-exposed and sun-protected skin.

METHODS

GATA-3 immunohistochemistry was performed on actinic keratoses (AK) (n = 19), in situ squamous cell carcinomas with actinic [SCCIS (A)] (n = 9) or bowenoid features [SCCIS (B)] (n = 17), well-, moderately and poorly differentiated SCC (n = 36), Bowenoid papulosis of the perineum (n = 15) and penile SCC (pSCC) (n = 10).

RESULTS

We found that GATA-3 immunohistochemical staining is progressively lost in sun-exposed skin as neoplasia progresses from pre-cancerous AK to SCCIS (A), and ultimately, to SCC, which shows near absent GATA-3 staining. This reduction in GATA-3 staining is independent of histological grade in SCC. Only slight down-regulation of GATA-3 was seen in all cases of SCCIS (B) and Bowenoid papulosis, while near absent GATA-3 expression was seen in pSCC.

CONCLUSION

We propose that decreased GATA-3 immunohistochemical staining is associated with cutaneous SCC progression on both sun-exposed and sun-protected sites.

Solitary renal metastasis of esophageal squamous cell carcinoma mimicking primary renal neoplasm - A case report and literature review

Solitary renal metastasis of esophageal cancer is rare clinically, with only 14 cases being reported in the literature. The authors here report a case of a 53-year-old man with a metachronous hypopharyngeal and esophageal squamous cell carcinoma who developed a solitary renal metastasis after complete chemoradiotherapy for esophageal cancer, and subsequently received a left nephrectomy. The metastatic esophageal cancer was indistinguishable from primary renal neoplasm in the computed tomography but showed the histopathologic characteristic of esophageal cancer in directly invading the renal artery, and the tumor spreading in the kidney. The patient died of pneumonia two months after diagnosis. Among the previous 14 reported cases, 12 occurred in Asians, and their overall survival time ranges from two months to nine years after nephrectomy, either with or without adjuvant chemotherapy. Accordingly, a solitary renal mass in patients with a history of esophageal cancer is warranted to differentiate metastatic esophageal cancer from primary renal neoplasm, and a reliable therapy needs to be planned early for improving the patient's chance of survival.

Expressional profiles of transcription factors in the progression of Helicobacter pylori-associated gastric carcinoma based on protein/DNA array analysis

Transcription factors (TFs) are crucial modulators of gene expression during the development and progression of gastric carcinoma. Helicobacter pylori (H. pylori) is one of the most significant risk factors of gastric carcinoma, and it is widely known that chronic inflammation with H. pylori infection triggers gastric carcinogenesis through inflammation-carcinoma chain [gastric carcinogenesis stages: non-atrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia and gastric carcinoma (GC)], but its mechanism regarding changed TFs remains unknown. In this study, we investigated the expressional profiles of 345 transcription factors in gastric mucosa of healthy volunteers and patients at different gastric carcinogenesis stages using protein/DNA array-based approach. The data demonstrated the up-regulated TFs such as GATA-3, AP4, c-Myc and Pbx1 in the gastric mucosa of GC patients compared with the healthy volunteers, while other TFs, particularly CCAAT and CACC, showed the consistently decreasing trend along the gastric carcinogenesis. The increased expressions of AP4, Pbx1 and C/EBPα were further validated by quantitative real-time PCR and Western blot in various H. pylori-infected models such as clinical gastric tissues, gastric epithelial cell lines and Mongolian gerbils. This study provides insights into and potential laws for gene transcriptional regulation by identifying potential TFs targets against the development of H. pylori-associated gastric carcinoma.

The role of GATA3 in breast carcinomas: a review

GATA3 is a zinc-binding transcription factor that regulates the differentiation of many human tissue types, including the mammary gland. In surgical pathology, immunohistochemistry for GATA3 is largely used to support urothelial or breast origin in a carcinoma of unknown origin. GATA3 is sensitive but not entirely specific in this setting. Although GATA3 labeling is highest in estrogen receptor-positive carcinomas, it also labels estrogen receptor-negative carcinomas and thus has particular diagnostic utility in the setting of triple-negative breast carcinomas, which are typically negative for other mammary-specific markers.

Practical Applications in Immunohistochemistry: Carcinomas of Unknown Primary Site

CONTEXT

-Identification of the site of origin of carcinoma of unknown primary using immunohistochemistry is a frequent requirement of anatomic pathologists. Diagnostic accuracy is crucial, particularly in the current era of targeted therapies and smaller sample sizes.

OBJECTIVES

-To provide practical guidance and suggestions for classifying carcinoma of unknown primary using both proven and new antibodies, as well as targeting panels based on integration of morphologic and clinical features.

DATA SOURCES

-Literature review, the authors' practice experience, and authors' research.

CONCLUSIONS

-With well-performed and interpreted immunohistochemistry panels, anatomic pathologists can successfully identify the site of origin of carcinoma of unknown primary. It is crucial to understand not only the diagnostic uses of the many available antibodies but also the potential limits and pitfalls.

Urothelial carcinoma with squamous differentiation--the pathologists׳ perspective

Squamous differentiation is the most common variant histology in urothelial carcinoma and may have effects on clinical outcome. Inconsistencies in reporting variant histologies in urothelial carcinoma are well documented. Immunohistochemical and molecular markers may help identify tumors with squamous differentiation beyond light microscopy.

Utility of GATA3, mammaglobin, GCDFP-15, and ER in the detection of intrathoracic metastatic breast carcinoma

INTRODUCTION

Breast carcinoma (BC) metastatic to the intrathoracic cavity is difficult to diagnose due to low sensitivity of current immunohistochemical (IHC) stains. Mammaglobin, gross cystic disease fluid protein-15 (GCDFP-15), and estrogen receptor (ER) immunomarkers show variable results. GATA3 is a recently described marker for detecting urothelial and breast cancers. Our goal is to test the utility of GATA3 in cell blocks from thoracic cytology specimens.

MATERIALS AND METHODS

We retrieved cases of BC that metastasized to the thoracic cavity from January 1, 2005 to September 30, 2013. IHC was performed on the cell blocks for the presence of GATA3, ER, GCDFP-15, and mammaglobin. Stains were scored quantitatively and qualitatively.

RESULTS

Fifty cases of metastatic BC found in pleural effusions and endobronchial ultrasound-guided fine-needle aspirates were identified in 48 patients. Thirty-four cases had sufficient material for IHC (19 pleural effusions, 15 endobronchial ultrasound-guided fine-needle aspirates). GATA3 showed strong nuclear positivity in 31 of 34 cases (91.2%). ER (25 of 34, 73.5%), mammaglobin (23 of 34, 67.6%) and GCDFP-15 (11 of 34, 32.6%) were positive in fewer cases. GATA3 and ER were concordant in 26 of 34 cases (76.5%) (24 ER/GATA3-positive, 2 ER/GATA3-negative). Discordant results were found in 8 of 34 cases (23.5%). Of these, GATA3 was positive and ER was negative in 7 cases. GATA3 was negative and ER was positive in 1 case.

CONCLUSIONS

GATA3 is more sensitive than ER, mammaglobin, or GCDFP-15 in detecting metastatic BC in cytologic specimens. GATA3 may be positive when ER is negative. In cytologic specimens with limited diagnostic material, GATA3 may be used as a first-line marker in a limited IHC panel to support metastatic BC.

Immunohistochemistry in undifferentiated neoplasm/tumor of uncertain origin

CONTEXT

Immunohistochemistry has become an indispensable ancillary study in the identification and classification of undifferentiated neoplasms/tumors of uncertain origin. The diagnostic accuracy has significantly improved because of the continuous discoveries of tissue-specific biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify undifferentiated neoplasms/tumors of uncertain origin by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict prognostic outcomes, it is crucial to differentiate the specific lineage of an undifferentiated neoplasm. Application of appropriate immunohistochemical panels enables the accurate classification of most undifferentiated neoplasms. Knowing the utilities and pitfalls of each tissue-specific biomarker is essential for avoiding potential diagnostic errors because an absolutely tissue-specific biomarker is exceptionally rare. We review frequently used tissue-specific biomarkers, provide effective panels, and recommend diagnostic algorithms as a standard approach to undifferentiated neoplasms.

Glycosylation of uroplakins. Implications for bladder physiopathology

Urothelium, a specialized epithelium, covers the urinary tract and act not only as a barrier separating its light from the surrounding tissues, but fulfills an important role in maintaining the homeostasis of the urothelial tract and well-being of the whole organism. Proper function of urothelium is dependent on the precise assemble of highly specialized glycoproteins called uroplakins, the end products and differentiation markers of the urothelial cells. Glycosylation changes in uroplakins correlate with and might reflect progressive stages of pathological conditions of the urothelium such as cancer, urinary tract infections, interstitial cystitis and others. In this review we focus on sugar components of uroplakins, their emerging role in urothelial biology and disease implications. The advances in our understanding of uroplakins changes in glycan moieties composition, structure, assembly and expression of their glycovariants could potentially lead to the development of targeted therapies and discoveries of novel urine and plasma markers for the benefit of patients with urinary tract diseases.

Simultaneous immunostaining with anti-S100P and anti-SV40 antibodies revealed the origin of BK virus-infected decoy cells in voided urine samples

BACKGROUND

Methods for determining the origin of BK virus (BKV)-infected cells (decoy cells) in clinical urine samples have not been established although they could enhance the diagnosis of BKV infection in immunocompromised patients.

METHODS

We performed simultaneous immunostaining with anti-S100P (a urothelial marker) and anti-SV40 antibodies in 66 clinical urine samples exhibiting SV40 positivity and a decoy-cell appearance on Papanicolaou staining. The clinical voided urine samples included seven cases of renal transplantation, 47 cases of cancer therapy and 12 cases of non-neoplastic disease. SurePath(™) liquid-based cytology was used for the urine samples.

RESULTS

BKV-infected cells were categorized as SV40(+)/S100P(+) and SV40 (+)/S100p(-). SV40(+)/S100P(-) cells were found in 55 cases (83.4%); nine cases (13.6%) carried both SV40(+)/S100P(-) and SV40(+)/S100P(+) cells. The former were identified as BKV infection in renal tubules and the latter in both the renal tubules and urothelial epithelia. The remaining two cases (3.0%) had only SV40(+)/S100P(+) cells of urothelial origin.

CONCLUSION

Simultaneous immunostaining with anti-S100P and anti-SV40 is a useful method for determining the origin of BKV-infected cells in clinical urine samples from immunocompromised patients such as renal transplantation recipients.

Evaluation of contemporary prostate and urothelial lineage biomarkers in a consecutive cohort of poorly differentiated bladder neck carcinomas

OBJECTIVES

New immunohistochemical (IHC) markers of urothelial carcinoma (UCa) and prostatic adenocarcinoma (PCa) have emerged in recent years, yet comparative studies to establish markers remain lacking. We aimed to identify an effective but parsimonious approach for poorly differentiated bladder neck lesions, to establish a best practice panel approach in a setting simulating prospective use.

METHODS

We tested the performance of a panel of IHC markers on whole sections of a consecutive cohort of transurethral resection specimens of poorly differentiated, challenging bladder neck resections (n=36).

RESULTS

In the setting of poorly differentiated bladder neck carcinomas, biomarker sensitivities for UCa were as follows: GATA3, 100%; S100P, 88%; p63, 75%; and cytokeratin (CK) 5/6, 56%; specificities of each were 100%. CK7 and CK20 showed sensitivities of 75% and 63%, though these were only 85% and 80% specific. For PCa markers, NKX3.1, p501S, prostate-specific membrane antigen, and androgen receptor (AR) each showed 100% sensitivity, outperforming ERG (35%) and prostate-specific antigen (PSA; 25%). All the prostate histogenesis markers were 100% specific, except for AR, which was positive in 13% of the UCa cases.

CONCLUSIONS

Novel IHC markers show improved diagnostic performance that enables positive and negative support for identifying histogenesis with the use of as few as two markers for this critical therapeutic distinction. PSA underperforms newer markers.

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.

Differential expression of GATA-3 in urothelial carcinoma variants

GATA binding protein 3 (GATA-3) is a novel immunohistochemical marker for urothelial carcinoma (UC); however, few studies have investigated GATA-3's role as a marker for UC variants. We used immunohistochemistry to assess GATA-3 expression in different UC variants, including micropapillary (n = 46), sarcomatoid (n = 43), small cell carcinoma (n = 22), and plasmacytoid (n = 16) variants, and we also compared GATA-3 expression in conventional bladder UC (n = 103) to that in squamous cell carcinoma (n = 14). GATA-3 expression was present in 70% (72/103) of conventional bladder UCs and highly concordant between matched primary and metastatic UCs. The GATA-3 expression levels of the micropapillary variants (57%; 26/46) and plasmacytoid variants (44%; 7/16) were not significantly different from that of conventional UC. However, the GATA-3 expression levels of the sarcomatoid variants (16%; 7/43) and small cell carcinoma variants (5%; 1/22), which only weakly expressed the protein, were significantly lower than that of conventional UC (P < .001). Only 7% of squamous cell carcinomas (1/14) expressed GATA-3, and it was also significantly lower than that of conventional UC (P < .001). GATA-3 expression was not significantly associated with tumor stage or patients' clinical outcomes. In conclusion, GATA-3 expression differed among UC variants. GATA-3 is a useful marker for confirming the urothelial origin of micropapillary and plasmacytoid UC variants but not that of sarcomatoid or small cell carcinoma variants. GATA-3 can also be used in differentiating UC from squamous cell carcinoma.

Immunohistochemical evaluation of GATA-3 expression in ER-negative breast carcinomas

OBJECTIVES

Estrogen receptor (ER), gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin (MGB) are commonly used breast-specific immunomarkers; however, about half of metastatic breast carcinomas are negative for all three. GATA-binding protein 3 (GATA-3) has emerged recently as a sensitive and relatively specific immunomarker for breast and urothelial carcinomas, but the data documenting its expression in ER-negative breast carcinomas are limited; this often poses a dilemma in the setting of metastases. The purpose of this study is to investigate expression of GATA-3 in ER-negative breast carcinomas.

METHODS

Immunohistochemical evaluation of GATA-3, GCDFP-15, and MGB on 96 ER-negative breast carcinomas was performed.

RESULTS

Overall, 69% (66/96), 15% (14/96), and 35% (34/96) of ER-negative breast carcinomas expressed GATA-3, GCDFP-15, and MGB, respectively.

CONCLUSIONS

Our data suggest that GATA-3 is, so far, the best breast-specific immunomarker, especially when encountering ER-negative metastatic breast carcinomas. GATA-3 should be included in the panel of immunomarkers in the workup of tumors of unknown primary.