Immunohistochemical analysis of uroplakins, urothelial specific proteins, in ovarian Brenner tumors, normal tissues, and benign and neoplastic lesions of the female genital tract

Large-scale human tissue analysis identifies Uroplakin 1a as a putative diagnostic marker for urothelial cancer

Uroplakin 1A (Upk1a) protein is relevant for stabilizing and strengthening urothelial cells and helps to prevent them from rupturing during bladder distension. Based on RNA expression data Upk1a is expressed in a limited number of normal tissues and tumors. To comprehensively evaluate the potential diagnostic and prognostic utility of Upk1a immunohistochemistry, a tissue microarray containing 6929 samples from 115 different tumor types and subtypes and 608 samples of 76 different normal tissue types was analyzed. Upk1a positivity was found in 34 (29.6 %) different tumor types including 9 (7.8 %) tumor types with at least one strongly positive case. The highest rates of Upk1a positivity were seen in various subtypes of urothelial neoplasms (42.6-98 %) including Brenner tumors of the ovary (64.9 %) followed by neoplasms of the thyroid (10.4-33.3 %). In urothelial tumors, Upk1a staining predominated at the cell membranes and staining intensity was often moderate to strong. In thyroidal neoplasms the staining was mostly purely cytoplasmic and of low to moderate intensity. Upk1a positivity was also seen in up to 15 % of cases in 25 additional tumor categories but the staining intensity was often cytoplasmic and the intensity was usually judged as weak and only rarely as moderate. Within non-invasive (pTa) tumors, the Upk1a positivity rate decreased from 94 % in pTa G2 (low grade) to 90.1 % in pTa G3 (p = 0.012) and was even lower in muscle-invasive carcinomas (41.5 %; p < 0.0001 vs pTaG3). Within muscle invasive carcinomas, Upk1a expression was unrelated to nodal metastasis (p > 0.05) and patient outcome (p > 0.05). In conclusion, Upk1a immunohistochemistry is a potentially useful and specific diagnostic marker for the distinction of urothelial carcinomas from other neoplasms. However, its sensitivity is less than 50 % in muscle-invasive cancers because Upk1a expression decreases during grade and stage progression.

Tetraspanins as Potential Modulators of Glutamatergic Synaptic Function

Tetraspanins (Tspans) comprise a membrane protein family structurally defined by four transmembrane domains and intracellular N and C termini that is found in almost all cell types and tissues of eukaryotes. Moreover, they are involved in a bewildering multitude of diverse biological processes such as cell adhesion, motility, protein trafficking, signaling, proliferation, and regulation of the immune system. Beside their physiological roles, they are linked to many pathophysiological phenomena, including tumor progression regulation, HIV-1 replication, diabetes, and hepatitis. Tetraspanins are involved in the formation of extensive protein networks, through interactions not only with themselves but also with numerous other specific proteins, including regulatory proteins in the central nervous system (CNS). Interestingly, recent studies showed that Tspan7 impacts dendritic spine formation, glutamatergic synaptic transmission and plasticity, and that Tspan6 is correlated with epilepsy and intellectual disability (formerly known as mental retardation), highlighting the importance of particular tetraspanins and their involvement in critical processes in the CNS. In this review, we summarize the current knowledge of tetraspanin functions in the brain, with a particular focus on their impact on glutamatergic neurotransmission. In addition, we compare available resolved structures of tetraspanin family members to those of auxiliary proteins of glutamate receptors that are known for their modulatory effects.

Prediction of Biochemical Recurrence-Free Survival of Prostate Cancer Patients Leveraging Multiple Gene Expression Profiles in Tumor Microenvironment

Tumor-adjacent normal (TAN) tissues, which constitute tumor microenvironment and are different from healthy tissues, provide critical information at molecular levels that can be used to differentiate aggressive tumors from indolent tumors. In this study, we analyzed 52 TAN samples from the Cancer Genome Atlas (TCGA) prostate cancer patients and developed a 10-gene prognostic model that can accurately predict biochemical recurrence-free survival based on the profiles of these genes in TAN tissues. The predictive ability was validated using TAN samples from an independent cohort. These 10 prognostic genes in tumor microenvironment are different from the prognostic genes detected in tumor tissues, indicating distinct progression-related mechanisms in two tissue types. Bioinformatics analysis showed that the prognostic genes in tumor microenvironment were significantly enriched by p53 signaling pathway, which may represent the crosstalk tunnels between tumor and its microenvironment and pathways involving cell-to-cell contact and paracrine/endocrine signaling. The insight acquired by this study has advanced our knowledge of the potential role of tumor microenvironment in prostate cancer progression.

Extraovarian Brenner tumor in the uterus: a case report and review of literature

BACKGROUND

Extraovarian Brenner tumors (EOBTs) are extremely rare and can be observed incidentally in both female and male patients, raising concerns regarding the origin of Brenner tumors.

CASE PRESENTATION

A 53-year-old postmenopausal woman presented with a nodular lesion in the left side of the corpus uteri, which was found at a routine health check. Macroscopically, the lesion appeared as a solid nodule with a yellowish-gray cut surface, approximately 6 cm in greatest diameter. Microscopically, the lesion consisted of well-defined epithelial nests and spindled stromal cells. Parenchymal cells expressed CK7, GATA3, CK5/6, 34βE12, and p63. A single layer of cavity-lined cells with umbrella-like shape showed apical Uroplakin III positivity. Stromal cells were positive for SMA, ER, and PR. The final diagnosis was EOBT and the patient was followed for 2 months with no recurrence.

CONCLUSIONS

We report here the third case of EOBTs in the uterus. The combination of morphologic and immunohistochemical results supported the involvement of urothelial metaplasia in the development of EOBTs. The similarities between EOBTs and Walthard nests made Müllerian epithelium an attractive candidate as the cellular origin. Changes of tissue structure or sex hormones imbalance may lead to the translocation of Müllerian remnants to distant organs, explaining the pathogenesis of EOBTs.

Network analysis uncovers putative genes affecting resistance to tick infestation in Braford cattle skin

Background

Genetic resistance in cattle is considered a suitable way to control tick burden and its consequent losses for livestock production. Exploring tick-resistant (R) and tick-susceptible (S) hosts, we investigated the genetic mechanisms underlying the variation of Braford resistance to tick infestation. Skin biopsies from four-times-artificially infested R (n = 20) and S (n = 19) hosts, obtained before the first and 24 h after the fourth tick infestation were submitted to RNA-Sequencing. Differential gene expression, functional enrichment, and network analysis were performed to identify genetic pathways and transcription factors (TFs) affecting host resistance.

Results

Intergroup comparisons of hosts before (Rpre vs. Spre) and after (Rpost vs. Spost) tick infestation found 51 differentially expressed genes (DEGs), of which almost all presented high variation (TopDEGs), and 38 were redundant genes. Gene expression was consistently different between R and S hosts, suggesting the existence of specific anti-tick mechanisms. In the intragroup comparisons, Rpost vs. Rpre and Spost vs. Spre, we found more than two thousand DEGs in response to tick infestation in both resistance groups. Redundant and non-redundant TopDEGs with potential anti-tick functions suggested a role in the development of different levels of resistance within the same breed. Leukocyte chemotaxis was over-represented in both hosts, whereas skin degradation and remodeling were only found in TopDEGs from R hosts. Also, these genes indicated the participation of cytokines, such as IL6 and IL22, and the activation of Wingless (WNT)-signaling pathway. A central gene of this pathway, WNT7A, was consistently modulated when hosts were compared. Moreover, the findings based on a genome-wide association study (GWAS) corroborate the prediction of the WNT-signaling pathway as a candidate mechanism of resistance. The regulation of immune response was the most relevant pathway predicted for S hosts. Members of Ap1 and NF-kB families were the most relevant TFs predicted for R and S, respectively.

Conclusion

This work provides indications of genetic mechanisms presented by Braford cattle with different levels of resistance in response to tick infestation, contributing to the search of candidate genes for tick resistance in bovine.

Uroplakin expression in the male reproductive tract of rat

Uroplakins (UPKs) play an important role in the normal and pathophysiology of the urothelium. They protect the urothelium and play a crucial role during urothelial infections by Uropathogenic E. coli. However, their functions beyond this organ system remain unexplored. A wide variety of proteins secreted in the male reproductive tract tissues contribute to spermatogenesis, sperm maturation, fertilization and innate immunity. However, the presence of UPKs and their possible contribution to the male reproductive tract physiology is not yet reported. Hence, in this study, we characterized UPKs in the male reproductive tract of rats. To the best of our knowledge, for the first time, we report the expression of UPKs in the male reproductive system. Upk1a, Upk1b, Upk2 and Upk3b mRNA and their corresponding proteins were abundantly expressed in the caput, cauda, testis, seminal vesicles and the prostate. Their expression was not developmentally regulated. UPK protein expression was also localized on the spermatozoa, suggesting a role for these proteins in sperm function. To study the role of UPKs in innate immunity, Upk mRNA expression in response to endotoxin challenge was evaluated in vitro and in vivo. In the rat testicular and epididymal cell lines, Upk mRNA levels increased in response to lipopolysaccharide challenge. However, in the caput, cauda, testes, seminal vesicle and prostate obtained from LPS treated rats, Upk mRNA expression was significantly reduced. Results of this study indicate a role for UPKs in male reproductive physiology and innate immune responses.

Role of renal urothelium in the development and progression of kidney disease

The clinical and financial impact of chronic kidney disease (CKD) is significant, while its progression and prognosis is variable and often poor. Studies using the megabladder (mgb ^-/- ) model of CKD show that renal urothelium plays a key role in modulating early injury responses following the development of congenital obstruction. The aim of this review is to examine the role that urothelium has in normal urinary tract development and pathogenesis. We discuss normal morphology of renal urothelium and then examine the role that uroplakins (Upks) play in its development. Histologic, biochemical, and molecular characterization of Upk1b ^RFP/RFP mice indicated Upk1b expression is essential for normal urinary tract development, apical plaque/asymmetric membrane unit (AUM) formation, and differentiation and functional integrity of the renal urothelium. Our studies provide the first evidence that Upk1b is directly associated with the development of congenital anomalies of the urinary tract (CAKUT), spontaneous age-dependent hydronephrosis, and dysplastic urothelia. These observations demonstrate the importance of proper urothelial differentiation in normal development and pathogenesis of the urinary tract and provide a unique working model to test the hypothesis that the complex etiology associated with CKD is dependent upon predetermined genetic susceptibilities that establish pathogenic thresholds for disease initiation and progression.

Precursors and pathogenesis of ovarian carcinoma

The ultimate goal of defining cancer specific precursors is to facilitate early detection and intervention before the development of invasive malignancy. Unlike other malignancies involving the female genital tract such as cervical or endometrial carcinomas, precursor lesions of ovarian carcinomas have not been well characterised, resulting in a failure to develop effective screening programs. Recent clinicopathological and molecular studies have provided new insight into the origin and pathogenesis of ovarian carcinomas. It has been shown that ovarian cancer is comprised of different tumour types differing not only in morphology, but also in pathogenesis, molecular alterations and clinical progression. A dualistic model of ovarian carcinogenesis has been proposed. Type I tumours which include low grade serous, low grade endometrioid, clear cell, mucinous carcinomas and Brenner tumours, are generally indolent and tend to be genetically stable, although clear cell carcinoma would probably belong to an intermediate category. They demonstrate a step-wise progression from a benign precursor such as a benign to borderline tumour or endometriosis and are characterised by genetic aberrations targeting specific cell signalling pathways. Type II tumours comprise high grade serous, high grade endometrioid, and undifferentiated carcinomas as well as malignant mixed mesodermal tumours. They are clinically aggressive and exhibit high genetic instability with frequent p53 mutations. Mounting evidence suggests that many high grade serous carcinomas originate from the epithelium of the distal fallopian tube, and that serous tubal intraepithelial carcinoma (STIC) represents the putative precursor of these neoplasms. Low grade serous carcinomas arise via transformation of benign and borderline serous tumours, thought to be derived from inclusion cysts originating from the ovarian surface or tubal epithelium. Recently it has been suggested that papillary tubal hyperplasia may be a putative precursor lesion for serous borderline tumours. Both endometrioid and clear cell carcinomas develop from endometriosis, via alterations affecting different genetic pathways. The origin of mucinous and transitional cell neoplasms is not well characterised, although new data suggest a possible origin from transitional cell nests present at the tubal-mesothelial junction. Likewise, the pathogenesis of carcinosarcomas is also not well established because of their rarity but there is accumulating evidence that the carcinomatous component determines the course of the disease and gives rise to the malignant mesenchymal component. This review discusses recent developments in the pathogenesis of ovarian carcinoma, with particular emphasis on the putative precursor lesions that give rise to the major histological subtypes. Recognition of these lesions is not only important in improving the understanding of ovarian carcinogenesis, but it will also influence our approach to prevent, detect and treat these tumours.

Problems arising in the diagnosis of primary ovarian transitional cell carcinoma after the occurrence of a transitional cell carcinoma of the bladder: a report of a difficult case and a critical review of literature

Transitional cell carcinoma (TCC) of the ovary is a recently recognized subtype of ovarian surface epithelial-stromal cancer that morphologically resembles a TCC of the bladder. The most frequent metastases to ovaries come from the gastrointestinal tract and from breast carcinoma, but metastatic TCCs from the urinary tract to the ovary have been reported. TCC of the bladder is the sixth most common cancer in European and North American countries and its incidence has been increasing. We recently observed a woman, who previously had undergone endoscopic resection of a TCC of the bladder. She was affected by an ovarian bilateral tumor with features of malignant transitional cell tumor, characterized by papillae with multilayered transitional epithelium infiltrating the ovarian stroma. In this study, we showed the utility of WT1 and a panel of immunohistochemical markers in the difficult differential diagnosis between bladder and ovarian TCC.

p63 expression in ovarian tumours: a marker for Brenner tumours but not transitional cell carcinomas

AIMS

To investigate p63 expression in ovarian neoplasms.

METHODS AND RESULTS

Immunohistochemistry using an antibody that detects all p63 isoforms was performed on 103 primary ovarian neoplasms of different histological types. Diffuse nuclear immunoreactivity of p63 was demonstrated in the 17 benign and five borderline Brenner tumours. Only one of the six malignant Brenner tumours displayed p63 expression. p63 immunoreactivity was absent in all the ovarian transitional cell carcinomas (TCC), but was demonstrated extensively in TCCs of the urinary bladder. Besides focal p63 expression in epidermal basal cells of immature and mature teratomas, all other ovarian lesions were devoid of p63 expression. p63 expression was also demonstrated in cervical transitional cell metaplasia and Walthard cell nests of fallopian tubes.

CONCLUSIONS

Expression of p63 protein is apparently cell lineage specific and in ovarian neoplasms is confined to benign and borderline Brenner tumours. The loss of expression in malignant Benner tumours suggests a role for p63 in Brenner carcinogenesis. The distinct patterns of p63 expression in TCCs in the ovary and urinary bladder may help in their differential diagnosis.

Tbx18 regulates the development of the ureteral mesenchyme

Congenital malformations of the urinary tract are a major cause of renal failure in children and young adults. They are often caused by physical obstruction or by functional impairment of the peristaltic machinery of the ureter. The underlying molecular and cellular defects are, however, poorly understood. Here we present the phenotypic characterization of a new mouse model for congenital ureter malformation that revealed the molecular pathway important for the formation of the functional mesenchymal coating of the ureter. The gene encoding the T-box transcription factor Tbx18 was expressed in undifferentiated mesenchymal cells surrounding the distal ureter stalk. In Tbx18-/- mice, prospective ureteral mesenchymal cells largely dislocalized to the surface of the kidneys. The remaining ureteral mesenchymal cells showed reduced proliferation and failed to differentiate into smooth muscles, but instead became fibrous and ligamentous tissue. Absence of ureteral smooth muscles resulted in a short hydroureter and hydronephrosis at birth. Our analysis also showed that the ureteral mesenchyme derives from a distinct cell population that is separated early in kidney development from that of other mesenchymal cells of the renal system.

Immunohistochemistry as a diagnostic aid in the evaluation of ovarian tumors

Aspects of immunohistochemistry (IHC), which are useful in the diagnosis of ovarian tumors (mostly neoplasms but also a few tumor-like lesions), are discussed. The topic is first approached by considering the different growth patterns and cell types that may be encountered. Then a few other specific situations in which IHC may assist are reviewed. Selected findings largely, or only, of academic interest are also mentioned. One of the most common situations in which IHC may aid is in the evaluation of tumors with follicles or other patterns which bring a sex cord-stromal tumor into the differential. The distinction between a sex cord tumor and an endometrioid carcinoma with sex-cord-like patterns may be greatly aided by the triad of epithelial membrane antigen (EMA), inhibin, and calretinin, the latter two being typically positive and EMA negative in sex cord tumors, the converse being typical of endometrioid carcinoma. It should be emphasized that granulosa cell tumors may be inhibin negative and, albeit less specific, calretinin is more reliable in evaluating this particular issue. Lack of staining for inhibin and calretinin may also be supportive in leading to consideration of diverse other neoplasms that may form follicles, including metastatic tumors as varied as carcinoid and melanoma. The well-known staining of the latter neoplasm for S-100 protein and HMB-45 may be very helpful in evaluating melanomas with follicular or other unusual patterns, a challenging aspect of ovarian tumor interpretation. The most common monodermal teratoma, struma ovarii, usually has an overt follicular pattern and is easily recognized, but recognition of unusual appearances ranging from oxyphilic to clear cell to various patterns of malignant struma may be greatly aided by a thyroglobulin or TTF 1 stain. IHC for neuroendocrine markers may assist in the diagnosis of primary and metastatic carcinoid tumor. The broad differential diagnosis of glandular neoplasms with an endometrioid-pseudoendometrioid morphology, or mucinous cell type, has been the subject of much exploration in recent years, particularly the distinction between primary and metastatic neoplasms. The well-known CK7 positive, CK20 negative phenotype of primary endometrioid carcinoma, and the converse profile in most metastatic large intestinal adenocarcinomas with a pseudoendometrioid morphology, has been much publicized but albeit an appropriate supportive adjunct in many cases, exceptions from the typical staining pattern may be encountered. It is even less helpful in the case of primary versus metastatic mucinous neoplasia. Evaluation of the expression of mucin gene products has shown mixed, essentially unreliable, results. Experience with other new markers, such as CDX-2, villin, beta catenin, and P504S (racemase), is limited but is in aggregate promising with regard to providing some aid in this area. The rare differential of metastatic cervical adenocarcinoma versus primary ovarian mucinous or endometrioid carcinoma may be aided by strong p16 staining of the former. Staining for alpha-fetoprotein may aid in confirming the diagnosis of endometrioid-like (and hepatoid) variants of yolk sac tumor. Ependymoma of the ovary may also have an endometrioid-like glandular pattern, but positive stains for glial fibrillary acidic protein contrast with the negative results in others neoplasms with a similar pattern. Immunostains may be very helpful in the evaluation of oxyphilic tumors and tumor-like lesions and in some unusual forms of clear cell neoplasia, such as clear cell struma, both subjects being reviewed herein. Immunostains may highlight both the presence and extent of epithelial cells in a variety of circumstances, including microinvasive foci in cases of serous borderline tumors and mucinous carcinomas, and in determining the extent of carcinoma cells and reactive cells within mural nodules of mucinous neoplasms. As in tumor pathology in general, various markers may be crucial in the diagnosis of small round cell tumors of the ovary, and familiar markers of epithelial, lymphoid, leukemic, and melanocytic neoplasms may assist in the analysis of high grade tumors with a poorly differentiated carcinoma, lymphoma-granulocytic sarcoma, malignant melanoma differential. The evaluation of ovarian cystic lesions may be aided by thyroglobulin or TTF 1 (cystic struma), glial fibrillary acid protein (ependymal cysts), and inhibin-calretinin (follicle cysts and unilocular granulosa cell tumors). Stains for trophoblast markers may occasionally aid in the evaluation of germ cell tumors, although routine stains should usually suffice; they may be of academic interest in confirming trophoblastic differentiation in some high grade surface epithelial carcinomas.

Detection of circulating cancer cells expressing uroplakins and epidermal growth factor receptor in bladder cancer patients

Our purpose was to determine the clinical relevance of the detection of circulating tumor cells (CTCs) expressing urothelial and epithelial markers in bladder cancer patients. Sixty-two patients who presented to Memorial Sloan-Kettering Cancer Center between July 2000 and September 2001 were studied. Peripheral blood was tested by nested RT-PCR assay for uroplakins (UPs) Ia, Ib, II and III as well as for epidermal growth factor receptor (EGFR). We determined the sensitivity and specificity of each individual marker and the combinations of UPIa/UPII and UPIb/UPIII. The latter strategy was based on our data, which showed that UPIa and UPIb form heterodimers with UPII and UPIII, respectively. Forty patients had clinically advanced bladder cancer and 22 had no evidence of disease at the time of assay. Eight of the 22 patients recurred during the follow-up period. All 8 patients were positive at presentation for UPIa/UPII. The combination of UPIa/UPII provided the best sensitivity (75%) of detecting CTCs, with a specificity of 50%. The combination of UPIb/UPIII was the most specific (79%) but had modest sensitivity (31%). Detection of EGFR-positive cells alone and in combination with UPs was inferior to that for UPIa/UPII. Combinations of urothelial markers are superior to single urothelial or epithelial markers in detecting CTCs in bladder cancer patients. Further efforts are under way to confirm the potential predictive value of these markers in a prospectively designed study of a larger cohort of patients.

Immunoprofile of Ovarian Tumors With Putative Transitional Cell (Urothelial) Differentiation Using Novel Urothelial Markers

Ovarian tumors containing cells with transitional cell morphology are recognized in the 1999 World Health Organization classification of ovarian tumors and include benign Brenner tumor, borderline and malignant Brenner tumor, and transitional cell carcinoma. Recent immunohistochemical investigations have reached conflicting conclusions regarding true urothelial differentiation in ovarian Brenner tumors. We evaluated a panel consisting of antibodies to uroplakin III (UROIII), thrombomodulin (THR), cytokeratin 7 (CK7), cytokeratin 20 (CK20), and Wilms' tumor protein (WT1) to study urothelial differentiation in ovarian transitional cell tumors. Additionally, we compared the immunohistochemical profile of transitional cell carcinoma of the ovary (TCC-O) with that of transitional cell carcinoma of the bladder (TCC-B), to ascertain if immunohistochemistry may aid in distinguishing primary from metastatic TCC-O. Seventeen benign Brenner tumors and 17 TCC-O were stained with antibodies to UROIII, THR, CK7, CK20, and WT1. Additionally, 6 Brenner tumors of borderline malignancy were stained with antibodies to UROIII, THR, CK7, and CK20. The immunohistochemical results were compared with those of 30 cases of noninvasive TCC-B (low malignant potential n=14, low grade n=16) and 36 cases of invasive TCC-B stained with a similar panel of antibodies as part of another study. Twenty-one nontransitional cell ovarian carcinomas (9 serous, 4 clear cell, 5 endometrioid, 2 mixed endometrioid/serous, and 1 mucinous) were used as controls. Most Brenner tumors showed positivity with UROIII (82%) and THR (76%), supporting true urothelial differentiation in these tumors. Although TCC-O has considerable morphologic overlap with TCC-B, they had only partial immunophenotypic overlap. TCC-O rarely expressed UROIII (6%) and THR (18%) and none expressed CK20. In contrast, nearly 40% of invasive TCC-B expressed UROIII, 61% expressed THR, and 50% expressed CK20. Nearly 82% of TCC-O expressed WT1, which was negative in all TCC-B. Our results may have diagnostic value in distinguishing TCC-O (CK20-, UROIII-/+, WT1+) and invasive TCC-B (CK20+, UROIII+/-, WT1-) metastatic to the ovary. They also indicate that the morphologic similarity between TCC-O and TCC-B does not indicate any histogenic similarity and, as others have noted, TCC-O is a variant morphology in the spectrum of surface epithelial carcinomas.

Immunohistochemical detection of uroplakin III, cytokeratin 7, and cytokeratin 20 in canine urothelial tumors

Immunohistochemistry for uroplakin III (UP III), cytokeratin 7 (CK 7), and cytokeratin 20 (CK 20) using commercially available antibodies was done in normal canine urinary bladder and 72 canine urinary bladder tumors that had been fixed in formalin and embedded in paraffin. Prolonged fixation (3-28 days) did not significantly alter the immunostaining for UP III. There was moderate reduction in the intensity for CK 7 and CK 20 after 1 week of fixation. UP III was detected in superficial (umbrella) cells and some intermediate cells of the normal urinary bladder, 7 of 7 transitional cell papillomas (TCPs), 50 of 55 transitional cell carcinomas (TCCs), and 4 of 5 metastatic TCCs. Staining was typically outlined in the plasma membrane, but diffuse or focal cytoplasmic staining was also observed. Intracytoplasmic lumina were usually positive for UP III. One squamous cell carcinoma of the bladder, 4 nonepithelial bladder tumors, and 285 nonurothelial tumors from different nonurinary locations were negative for UP III. CK 7 was detected in 7 of 7 TCPs, 53 of 54 TCCs, and 5 of 5 metastatic TCCs. The staining for CK 7 was diffuse cytoplasmic. CK 20 was detected in 1 of 7 TCPs, 37 of 54 TCCs, and 1 of 5 metastatic TCCs. The staining with CK 20 was cytoplasmic and weaker than with antibodies to UP III or CK 7. There was concurrent expression of UP III, CK 7, and CK 20 in 36 of 54 TCCs. UP III is a specific and sensitive marker for canine transitional epithelial (urothelial) neoplasms, detecting 91% of TCCs. Negative results may be observed with anaplastic tumors.

Frequent FGFR3 mutations in urothelial papilloma

Activating point mutations in the FGFR3 gene occur frequently in low-grade and low-stage bladder carcinomas, whereas they are rare in high-grade carcinomas. This study investigates the incidence of FGFR3 mutations in 12 urothelial papillomas and 79 pTaG1 tumours which were regraded according to the 1998 WHO/ISUP classification system, resulting in 62 papillary urothelial neoplasms of low malignant potential (PUNs-LMP) and 17 low-grade papillary urothelial carcinomas (LG-PUCs). FGFR3 mutation analysis of 21 ovarian Brenner tumours was also performed. Seventy-seven cases were detected with a mutation in the FGFR3 gene. The mutations were exclusively found in bladder neoplasms. In urothelial papilloma, generally considered a benign lesion, 9/12 (75%) mutations were found. This report is the first to describe a genetic defect in urothelial papilloma. A comparable percentage of mutations was found in PUNs-LMP (85%) and LG-PUCs (88%). No mutations were found in matched normal DNA from bladder tumour patients. The mean follow-up was 5.78 years (range 0.21-17.60 years). Five patients developed high-grade papillary urothelial carcinoma from 2.5 to 12 years after first diagnosis. Two patients died of bladder cancer. The mean number of recurrences (recurrence rate) per year was 0.03, 0.21, and 0.46, respectively, for papilloma, PUN-LMP, and LG-PUC. Urothelial papilloma is a rare lesion with a benign natural behaviour compared with PUN-LMP and LG-PUC of the bladder, but from a molecular perspective, papillomas should be classified together with all well-differentiated urothelial neoplasms.

High expression of human uroplakin Ia in urinary bladder transitional cell carcinoma

Uroplakins (UPs) Ia, Ib, II, and III are tissue-specific and differentiation-dependent transmembrane proteins of the urothelium. We assessed the usefulness of human UP Ia as a histological marker by examining its expression in urinary bladder transitional cell carcinoma (TCC). A polyclonal antibody against human UP Ia was raised using a synthesized polypeptide. We applied our antibody to various organ tissues, including urothelium, and observed no crossreactivity. Analysis by RT-PCR of normal urothelium, TCC and other organ tissues indicated that the human UP Ia gene expression is highly specialized to urothelium, and is conserved in TCC. Using immunohistochemistry, we investigated the expression of UP Ia in TCC from patients who had undergone radical cystectomy and from autopsy cases. Positive staining (10% or more positive cancer cells) was noted in primary lesions from 61 of 63 (96.8%) cystectomy patients. Depending on pathological grade, high expression (50% or more positive cancer cells) was observed in 17 of 18 (94.4%) moderately- to well-differentiated TCC and in 36 of 45 (80.0%) poorly differentiated TCC. With regard to tumor invasion, high expression was noted in 20 of 22 (90.9%) superficial and 33 of 41 (80.5%) muscle-invasive TCC. Cause-specific survival rates were 68.6% and 75.0% in high- and low-expression patients, respectively (log-rank test, P = 0.855, mean follow-up; 65.0 months). In metastases, positive reactions were observed in 13 of 18 (72.2%) lesions. UP Ia may represent a specific histological marker judging from the stable expression, although its value as a prognostic factor remains undetermined.

Recent advances in immunohistochemistry in gynaecological pathology

Recent years have witnessed significant developments in the use of immunohistochemistry in diagnostic gynaecological pathology. This review details the most significant of these. In ovarian pathology, differential cytokeratin staining (CK7 and 20) assists in distinguishing between a primary ovarian adenocarcinoma and a metastatic adenocarcinoma, especially of colorectal origin. The development of markers characteristic of ovarian sex cord-stromal tumours (especially alpha-inhibin) facilitates diagnosis of these neoplasms which is often difficult by morphology alone due to the wide differential diagnosis. In the uterus, the distinction between a primary endometrial and endocervical adenocarcinoma may be facilitated by use of a small panel of antibodies, including CEA, ER and vimentin. Newly developed antibodies such as CD10 and h-caldesmon may be of use in the diagnosis of uterine mesenchymal lesions, especially in the distinction between endometrial stromal and smooth muscle lesions. Proliferation markers, such as MIB1, are of value in the cervix in the diagnosis of preinvasive squamous and glandular lesions. Recent studies have shown that cervical adenoma malignum exhibits a gastric phenotype. Advances have also been made in trophoblastic disease with the development of antibodies reactive against trophoblast such as alpha-inhibin, mel-Cam and p57. A newly developed monoclonal antibody HMGIC which is expressed in vulvovaginal aggressive angiomyxoma may prove to be of value in the often difficult distinction of this lesion from its histological mimics.

Polypoid Brenner tumor of the uterus

Extraovarian Brenner tumors (BT) are very rare. We report such a tumor that was an intracavitary polyp in the uterus of a 63-year-old woman. The differential diagnosis included a pure transitional cell tumor, a mixed mullerian tumor, and a uterine tumor resembling an ovarian sex cord tumor. The histogenesis of BT remains controversial; in this particular case the location of the BT suggests a mullerian origin.

Immunohistochemical analysis of gynecologic tumors

Ancillary techniques such as immunohistochemistry (IHC) enable the surgical pathologist to extract additional information from fixed, deparaffinized tissue specimens and to provide data critical to optimal clinical management of the patient. In this review of applications of IHC to the analysis of gynecologic malignancies, the usefulness of immunohistochemical analysis of neoplasms of the cervix, endometrium, and ovary is summarized. In the uterine cervix, dysplasia is associated with qualitative and quantitative alterations in the expression of the Ki-67 antigen expression, as well as an ability to detect human papillomavirus. Endometrial endometrioid adenocarcinomas display a highly characteristic immunophenotype, with coexpression of cytokeratin and vimentin and demonstration of foci of high molecular weight cytokeratin expression; in addition, IHC analysis of estrogen and progesterone receptor and p53 expression can provide important prognostic information about this tumor. Stromal tumors of the endometrium may display a partial smooth muscle immunophenotype, but novel markers such as CD10 provide new tools for the identification of these tumors. The immunophenotypes of the normal ovarian surface epithelium (OSE) and corresponding tumors display significant overlap with, but important distinctions from, mesothelium, and important new markers such as the Wilms tumor gene product can prove useful in the identification of carcinomas of the OSE. Important prognostic markers for carcinomas of the OSE include the HER-2/neu gene product and p53, alterations of which can both be assessed by IHC techniques. Finally, the recent availability of markers of ovarian stroma, including Melan-A and inhibin-alpha, has provided a means for the positive identification of ovarian stromal tumors, which can manifest protean histological appearances.