Differential Expression of WT-1 in Serous Carcinomas in the Peritoneum With or Without Associated Serous Carcinoma in Endometrial Polyps

Origin of Peritoneal Cancer With Features of High-grade Serous Carcinoma: A Detailed Molecular Analysis

Primary peritoneal cancer has characteristics similar to high-grade serous carcinomas of ovarian and fallopian tube origin. However, the relationship between endometriosis and primary peritoneal cancer is not well understood. This study focuses on a case of peritoneal cancer in a patient who had undergone hysterectomy and bilateral salpingo-oophorectomy 5 yr before. In addition to morphology, there was a positive for TP53 in immunohistochemistry and homologous recombination deficiency test, which were similar to high-grade serous carcinomas. However, WT1 was negative in the tumor, and extensive endometriosis coexisted. To reveal the clonal relationship between tumor and endometriosis, we dissected 3 sites each from the tumor and endometriosis and performed whole-exome sequencing analysis. As a result, we found that the tumors were of identical origin. Contrarily, no shared mutations were found in the 3 endometriosis sites. Furthermore, several shared mutations were found between the tumor and 1 endometriosis tissue, showing that the tumor and 1 ectopic endometrial gland originated from the same clone. This study indicates that several peritoneal cancers may be derived from endometriosis. We should consider the possibility of more diverse origins of peritoneal cancer than we speculated before.

DNA Methylation Signature of Synchronous Endometrioid Endometrial and Ovarian Carcinomas

Next-generation sequencing (NGS) studies have demonstrated that co-occurring sporadic endometrioid endometrial carcinoma (EEC) and endometrioid ovarian carcinoma (EOC) are clonally related, suggesting that they originate from a single primary tumor. Despite clonality, synchronous EEC and EOC when diagnosed at early stage behave indolently, similar to isolated primary EEC or isolated primary EOC. In the present study, we compared the DNA methylation signatures of co-occurring EEC and EOC with those of isolated primary EEC and isolated primary EOC. We also performed targeted NGS to assess the clonal relatedness of 7 co-occurring EEC and EOC (4 synchronous EEC and EOC and 3 metastatic EEC based on pathologic criteria). NGS confirmed a clonal relationship in all co-occurring EEC and EOC. DNA methylation profiling showed distinct epigenetic signatures of isolated primary EEC and isolated primary EOC. Endometrial tumors from co-occurring EEC and EOC clustered with isolated primary EEC while their ovarian counterparts clustered with isolated primary EOC. Three co-occurring EEC and EOC cases with peritoneal lesions showed a closer epigenetic signature and copy number variation profile between the peritoneal lesion and EOC than EEC. In conclusion, synchronous sporadic EEC and EOC are clonally related but demonstrate a shift in DNA methylation signatures between ovarian and endometrial tumors as well as epigenetic overlap between ovarian and peritoneal tumors. Our results suggest that tumor microenvironment in the ovary may play a role in epigenetic modulation of metastatic EEC.

A guided tour of selected issues pertaining to metastatic carcinomas involving or originating from the gynecologic tract

Epithelial metastases originating from the gynecologic tract or secondarily involving it frequently display a different morphology when compared to the primary tumor. Furthermore, issues such as modes of metastasis, appropriate nomenclature and prognostic significance remain subjects of discussion and some skepticism. In this review, we will discuss: metastases to uterine adnexa; serous tubal intraepithelial carcinoma (STIC); serous borderline tumors; metastases from the uterine corpus; and “synchronous” endometrial and ovarian tumors. Three additional themes that will run through the discussions are those that are peculiar, although not restricted to the gynecologic tract: metastasis from non-invasive primary tumors, metastases that look benign and metastases that are benign or clinically indolent.

Synchronous tumours of the female reproductive tract

Many ovarian endometrioid carcinomas present with concurrent endometrial carcinoma, and these organ-confined, low-grade synchronous endometrial and ovarian tumours consistently behave as independent primary tumours, rather than a single advanced-stage carcinoma; they are associated with a very favourable prognosis and there is no need for adjuvant treatment. This phenomenon of synchronous tumours involving two or more sites within the female reproductive tract is well recognised, occurring in 1-2% of cases. Although some tumours can be recognised as metastasis, in many the relationship between the synchronous tumours is uncertain. Recently, application of next generation sequencing to synchronous endometrial and ovarian carcinomas has shed light on the relationship between these tumours, but raised more questions about the biology of this curious phenomenon. Herein, we review synchronous tumours involving more than one site in the female genital tract, discuss the pathogenesis, and offer guidelines for how to handle in routine practice.

[New features in the 2014 WHO classification of uterine neoplasms]

The 2014 World Health Organization (WHO) classification of uterine tumors revealed simplification of the classification by fusion of several entities and the introduction of novel entities. Among the multitude of alterations, the following are named: a simplified classification for precursor lesions of endometrial carcinoma now distinguishes between hyperplasia without atypia and atypical hyperplasia, the latter also known as endometrioid intraepithelial neoplasia (EIN). For endometrial carcinoma a differentiation is made between type 1 (endometrioid carcinoma with variants and mucinous carcinoma) and type 2 (serous and clear cell carcinoma). Besides a papillary architecture serous carcinomas may show solid and glandular features and TP53 immunohistochemistry with an "all or null pattern" assists in the diagnosis of serous carcinoma with ambiguous features. Neuroendocrine neoplasms are categorized in a similar way to the gastrointestinal tract into well differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas (small cell and large cell types). Leiomyosarcomas of the uterus are typically high grade and characterized by marked nuclear atypia and lively mitotic activity. Low grade stromal neoplasms frequently show gene fusions, such as JAZF1/SUZ12. High grade endometrial stromal sarcoma is newly defined by cyclin D1 overexpression and the presence of the fusion gene YWHAE/FAM22 and must be distinguished from undifferentiated uterine sarcoma. Carcinosarcomas (malignant mixed Mullerian tumors MMMT) show biological and molecular similarities to high-grade carcinomas.

Metachronous serous endometrial intraepithelial carcinoma and serous peritoneal carcinoma: analysis of probable independent lesions

Background

Uterine serous endometrial intraepithelial carcinoma (SEIC) is an immediate precursor of invasive carcinoma. The majority of stage IA SEICs are curable, but those with latent peritoneal metastasis and/or capillary lymphatics invasion may have poor prognoses Careful pathologic staging is thus needed to predict the risk of recurrence and to determine postoperative therapeutic strategies.

Case Presentation

A 71-year-old woman was hospitalized for the treatment of peritoneal carcinoma. She had undergone total hysterectomy and bilateral salpingo-oophorectomy due to SEIC (stage IA) at age 63 years, and had received medical check-ups every year since. Elevated serum CA125 (184 U/mL) was detected for the first time 8 years after surgery. A thorough workup revealed no potential primary lesion other than that in the peritoneum. Tumor reduction surgery was performed. Histologic analysis of the peritoneal lesion was high-grade serous carcinoma. The peritoneal carcinoma was diffusely immunostained for p53; thus, possible recurrence of SEIC was suspected. Tumor DNAs were microdissected from the uterine and peritoneal lesions and p53 mutation analysis was done. SEIC and peritoneal carcinomas had distinct p53 mutations that were mutually exclusive.

Conclusions

The present case raised a concern about the difficulty of histologic staging for SEICs. Although SEICs confined to the uterine endometrium in most cases predict a good prognosis, microscopic metastasis to the peritoneum may not be detectable at hysterectomy. If secondary malignancies of a serous phenotype develop years later, comprehensive reexamination of SEIC is mandated, with the help of DNA analysis.

Practical issues related to uterine pathology: staging, frozen section, artifacts, and Lynch syndrome

This review covers three areas in endometrial tumor pathology: International Federation of Gynecology and Obstetrics (FIGO) staging, the use of frozen section, and Lynch syndrome. The section on FIGO staging will emphasize problems that practicing pathologists often confront, such as measuring the depth of myometrial invasion, assessing for the presence of cervical stromal invasion, detecting low-volume lymph node metastases, and recognizing synchronous endometrial and ovarian tumors and artifacts. The frozen section portion of this review will focus on the performance characteristics of intraoperative examination of the uterus to determine tumor grade and depth of myometrial invasion, including suggestions for alternative methods. The last portion of this review will provide an overview of Lynch syndrome and a discussion of the rationale and methods of screening for Lynch syndrome.

Practical issues in the diagnosis of serous carcinoma of the endometrium

Serous carcinoma (SC) represents ~10% of endometrial carcinomas, but is responsible for almost 40% of cancer deaths. This article reviews the main pathological features, differential diagnosis, and the usefulness of molecular pathology and immunohistochemistry in its diagnosis. Most helpful features for the diagnosis include: irregularly shaped and sized papillae, slit-like spaces, cell stratification and budding, highly atypical cells, architectural and cytological discordance in pseudoglandular tumors, as well as lack of endometrioid features. SC shows typically a predominant papillary growth, which is also found in some subtypes of endometrioid carcinoma of the endometrium (EEC). Distinction is easy when attention is paid to the presence of diffuse marked nuclear pleomorphism, but also to the complex papillary architecture. SC may also show a solid or pseudoglandular patterns, and in these cases differential diagnosis may be difficult with EEC grade 3. Moreover, a high proportion of SC may exhibit clear cells, and, thus, may be confused with clear cell carcinoma. Finally, it is sometimes difficult to distinguish mixed SC-EEC, from SC that combines papillary and pseudoglandular growths. Although there is not a single immunohistochemical marker for distinguishing SC from its mimickers, some antibodies are useful (p53, p16, IMP2, and IMP3), particularly when used in combination. Diagnosis of SC may be even more problematic in small biopsies; a diagnosis of high-grade endometrial carcinoma, SC component can not be excluded, is acceptable as a managerial approach, so it could be taken into account at the time of final surgery.

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.

The frequency and significance of WT-1 expression in serous endometrial carcinoma

Serous endometrial carcinoma is an aggressive type of endometrial carcinoma. Wilms tumor gene 1 (WT-1) is commonly expressed in ovarian serous carcinomas and considered a diagnostic marker of these tumors. However, it is generally believed that WT-1 is rarely expressed by endometrial serous carcinoma. The aim of this study was to evaluate the frequency and significance of WT-1 expression in endometrial serous carcinoma. We studied the expression of WT-1 in formalin-fixed, paraffin-embedded tumor sections from 77 cases of endometrial serous carcinoma. Thirty-four tumors showed positive expression for WT-1 (44%). There was a statistically significant association between the presence of WT-1 expression and disease-free survival (DFS), where patients with tumors expressing WT-1 had a shorter DFS compared with those with no WT-1 expression (P = .031; median DFS, 15 and 38 months, respectively). By multivariate Cox regression analysis, DFS was independent from other clinicopathological data (tumor stage, presence of lymphovascular space invasion, cervical involvement, and extrauterine spread), indicating that WT-1 expression is independently associated with DFS. Our study shows that WT-1 is expressed in a considerable percentage of endometrial serous carcinomas, suggesting a role for WT-1 in the pathology of these tumors. This has therapeutic significance, as WT-1 is an emerging target for immunotherapy. Moreover, our results show that WT-1 has prognostic value, being predictive of DFS. As a potential prognostic marker and therapeutic target, we recommend that WT-1 expression should be included in histopathologic reports of endometrial serous carcinoma.

Wilms' tumor gene 1 immunotherapy in pelvic gynecological malignancies

Pelvic gynecological malignancies account for 6% of all cancers. In the relapsed state, classical treatments are limited. There is an urgent need for new and personalized treatment. Wilms' tumor gene 1 (WT1) is the most important tumor-associated antigen. Although highly present in gynecological tumors, active immunotherapy against it is still underexplored. This review gives an insight into the importance of WT1 in pelvic gynecological malignancies and the first taken steps into the world of WT1 immunotherapy.

Use of immunohistochemistry in the diagnosis of miscellaneous and metastatic tumors of the uterine corpus and cervix

Uncommon tumors in the uterus present diagnostic challenges. In some cases, the tumor subtype is usually seen outside the gynecologic tract and the possibility of a uterine primary is not considered. In other cases, histologic overlap with more common uterine tumors leads to potential misdiagnosis. Finally, metastatic carcinoma may involve the uterus and cervix. Rarely, symptoms related to the uterine metastasis may precede diagnosis of an extrauterine primary. Without the proper clinical context, the possibility of a missed diagnosis is increased. One must first be aware of these possibilities, but immunoperoxidase studies are often necessary to confirm the diagnosis. In this review, unusual and metastatic tumors involving the uterine corpus and cervix and immunoperoxidase studies used to diagnosis such tumors are discussed.

Primary peritoneal cancer in Lynch syndrome: a clinical-pathologic report of a case and analysis of the literature

Lynch syndrome is a genetic disease, caused by a germ-line mutation in a mismatch repair gene, related to an increased risk of developing colorectal and extracolonic cancer. Despite that, the incidence of primary peritoneal cancer after adnexectomy remains unknown. We here report a case of primary peritoneal cancer in a woman affected by Lynch syndrome who underwent hysterectomy+salpingo-oophorectomy for endometrial cancer 13 yr before. Morphology and immunophenotype allowed to differentiate peritoneal malignancy from the previously diagnosed endometrial carcinoma. Physicians should be aware of the potential risk of primary peritoneal cancer in women affected by Lynch syndrome, despite previous prophylactic surgery.

The occurrence of endometriosis with ovarian carcinomas is not purely coincidental

OBJECTIVE

To explore the association between epithelial ovarian cancer (EOC) and common benign gynecological disorders.

STUDY DESIGN

The medical records of 226 patients with EOC treated at Peking Union Medical College Hospital between March 2011 and March 2012 were reviewed. Histological evaluations had been performed to determine the presence of coexisting pelvic endometriosis (n=17), uterine leiomyoma (n=66), adenomyosis (n=22), or endometrial polyps (n=17).

RESULTS

Coexistence of endometriosis occurred in 35.3% and 36.4% of cases of the clear cell and endometrioid subtypes of EOC histology, respectively. Endometriosis was more likely associated with clear cell or endometrioid ovarian carcinoma, but less likely with high grade serous cancer. No differences were observed in the concurrence of uterine myoma, adenomyosis or endometrial polyps among the different subtypes of EOC.

CONCLUSIONS

In contrast to other common benign gynecological disorders, endometriosis showed close relationships with the clear cell and endometrioid subtypes of EOC specifically.

The significance of Wilms Tumor Gene (WT1) and p53 expression in curettage specimens of patients with endometrial carcinomas

In this retrospective experimental study, we assessed the immunohistochemical expression of Wilms Tumor Gene (WT1) and p53 in endometrial biopsies of patients with endometrial cancer, and correlated their expression with the final pathological findings. Sixty-two patients with primary endometrial cancer who underwent surgical treatment were investigated. Immunohistochemical expression of Wilms Tumor Gene (WT1) and p53 was assessed in curettage specimens, and the final pathology reports from hysterectomy specimens were reviewed. The expression of these markers seems to play a role in curettage specimens as they correlate with the final tumor characteristics of hysterectomy specimens. Five out of sixty-two endometrial cancer specimens (8.1%) were WT1-positive, and 21 specimens (33.9%) were P53-positive. Positive expression of WT1 and P53 was significantly associated with the non-endometrioid type (p value of 0.019 and 0.005, respectively). Positive WT1 expression was significantly associated with high grade lesions, deep myometrial invasion, and advanced stage disease. Moreover, a statistically significant inverse relationship was observed between the positivity of WT1 and P53, and the positivity of ER and PR. We think that examination for WT1 and p53 in curettage specimens might help to predict the final pathological diagnosis in patients with endometrial cancer. This might be useful for the identification of high risk groups and, therefore, of candidates for more radical surgery.

Application of Immunohistochemistry and Molecular Diagnostics to Clinically Relevant Problems in Endometrial Cancer Bojana Djordjevic, Shannon Westin, Russell R. Broaddus

A number of different clinical scenarios are presented in which lab-based analyses beyond the usual diagnosis based on light microscopic examination of H&E stained slides - immunohistochemistry and PCR-based assays such as sequencing, mutation testing, microsatellite instability analysis, and determination of MLH1 methylation - are most helpful for guiding diagnosis and treatment of endometrial cancer. The central goal of this information is to provide a practical guide of key current and emerging issues in diagnostic endometrial cancer pathology that require the use of ancillary laboratory techniques, such as immunohistochemistry and molecular testing. The authors present the common diagnostic problems in endometrial carcinoma pathology, types of endometrial carcinoma, description of tissue testing and markers, pathological features, and targeted therapy.

Ovarian cancer stroma: pathophysiology and the roles in cancer development

Ovarian cancer represents one of the cancers with the worst prognostic in adult women. More than half of the patients who present with clinical signs such as abdominal bloating and a feeling of fullness already show advanced stages. The majority of ovarian cancers grow as cystic masses, and cancer cells easily spread into the pelvic cavity once the cysts rupture or leak. When the ovarian cancer cells disseminate into the peritoneal cavity, metastatic nests may grow in the cul-de-sac, and in more advanced stages, the peritoneal surfaces of the upper abdomen become the next largest soil for cancer progression. Ascites is also produced frequently in ovarian cancers, which facilitates distant metastasis. Clinicopathologic, epidemiologic and molecular studies on ovarian cancers have improved our understanding and therapeutic approaches, but still further efforts are required to reduce the risks in the patients who are predisposed to this lethal disease and the mortality of the patients in advanced stages. Among various molecules involved in ovarian carcinogenesis, special genes such as TP53, BRCA1 and BRCA2 have been well investigated. These genes are widely accepted as the predisposing factors that trigger malignant transformation of the epithelial cells of the ovary. In addition, adnexal inflammatory conditions such as chronic salpingitis and ovarian endometriosis have been great research interests in the context of carcinogenic background of ovarian cancers. In this review, I discuss the roles of stromal cells and inflammatory factors in the carcinogenesis and progression of ovarian cancers.

WT1 expression in the female genital tract

The Wilms tumor gene 1 (WT1) has been reported in normal tissues and many neoplasms of the female genital tract. This review discusses WT1 expression in the female genital tract and its potential utility in the differential diagnosis of neoplasms that occur at this location. WT1 is of value in the differential diagnosis of synchronous serous carcinomas arising in the ovary/fallopian tube/peritoneum and endometrium, as strong WT1 positivity in both tumors points toward an extrauterine origin. In addition, WT1 can be used to distinguish sex cord stromal tumors (WT1 positive) from endometrioid carcinomas (OECs). WT1 expression is not helpful in the differential diagnosis of ovarian serous carcinomas (OSCs) and transitional carcinomas, as both are typically positive and has limited value in the distinction of serous tumors arising in the ovary/fallopian tube/peritoneum from mesotheliomas. WT1 is also not helpful to differentiate small cell carcinoma of hypercalcemic type from juvenile granulosa cell tumor, a common diagnostic problem. Intra-abdominal desmoplastic round cell tumor reacts to WT1 (C-terminal) in contrast to all other tumors discussed which helps to separate this rare tumor from most other small round cell tumors that may involve, primarily or secondarily, the ovary with the exception of small cell carcinoma of hypercalcemic type that typically reacts with the N-terminal of WT1.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

Metastatic Neoplasms Involving the Ovary

In this review, ovarian metastatic carcinomas from various sites, as well as other neoplasms secondarily involving the ovary, are discussed. As well as describing the morphology, the value of immunohistochemistry in distinguishing between primary and metastatic neoplasms in the ovary is discussed. While immunohistochemistry has a valuable role to play and is paramount in some cases, the results should be interpreted with caution and with regard to the clinical picture and gross and microscopic pathologic findings.

High-Grade Endometrial Carcinomas

High-grade endometrial carcinomas are a heterogeneous group of clinically aggressive tumors. They include FIGO grade 3 endometrioid carcinoma, serous carcinoma, clear cell carcinoma, undifferentiated carcinoma, and malignant mixed Müllerian tumor (MMMT). Epidemiologic, genetic, biologic prognostic and morphologic differences between these entities are striking in prototypic cases, yet substantial overlap exists and diagnostic criteria and therapeutic approaches that account for the group's diversity are currently insufficient. FIGO grade 3 endometrioid carcinoma demonstrates solid, trabecular or nested growth and may resemble poorly differentiated squamous cell carcinoma. Endometrioid glandular differentiation is usually focally present. Serous carcinoma usually displays papillary architecture but glandular and solid patterns may predominate. Tumor cells typically display diffuse and severe atypia. Clear cell carcinoma should be diagnosed by recognizing characteristic papillary or tubulocystic architecture with cuboidal tumor cells showing atypical but uniform nuclei. Cells with clear cytoplasm are frequently but not always present. On the other hand, clear cells may be encountered in endometrioid and serous carcinomas. Immunohistochemical stains for p53, p16, ER, PR, mib-1, hepatocyte nuclear factor 1β and pan-cytokeratin can be helpful in classifying these high-grade carcinomas. They should be used in concert with thorough morphologic examination, as part of a rational panel of markers and only in specific circumstances. Although these tumors may appear clinically and even morphologically similar, demographic and epidemiologic features as well as patterns of spread and treatment modalities differ.

A pathologist's road map to benign, precancerous, and malignant intraepithelial proliferations in the fallopian tube

The fallopian tube has recently emerged as an important site of origin for not only early serous cancer in women with inherited mutations in BRCA1/BRCA2 but as a source of many pelvic serous carcinomas. With this increased attention has come the inevitable need to sort out what epithelial abnormalities are clinically important and how they should be reported by the practicing pathologist. This review addresses 4 categories of tubal epithelial change: (1) metaplasias; (2) nonmalignant atypias; (3) potential precursors, including secretory cell outgrowths and p53 signatures; and (4) tubal intraepithelial carcinomas. A modified protocol for sectioning the fallopian tube (SEE-FIM) is discussed and each of the above topics is covered in the context of its differential diagnosis and recommendations for reporting are included. Finally, the rationale for close inspection of the tube, both in presumed benign and malignant disease, is discussed, with reference to an ongoing multi-institutional web-based project (Pelvic-ovarian Cancer Interception project).

WT1 expression in endometrioid ovarian carcinoma with and without associated endometriosis

AIMS

To determine how frequently endometrioid ovarian carcinomas (EOC) express WT1 protein, and to correlate the results with the presence of endometriosis and p53 immunoreactivity.

METHODS

Forty-one grade 1-2 EOC were stained immunohistochemically for WT1 and p53 proteins. Twenty-one tumours were associated with endometriosis and 20 cases lacked such an association. WT1 expression in the tumour cell nuclei and/or cytoplasm was recorded. Nuclear p53 staining was assessed as diffuse (>50% cells positive), focal, or negative.

RESULTS

Four of the 20 (20%) tumours in the endometriosis negative group showed nuclear WT1 staining, while none of the endometriosis-associated EOC was positive (p < 0.05). Two of the immunoreactive cases exhibited sertoliform/sex cord-like patterns. Focal cytoplasmic WT1 labelling was present in seven EOC, three of which showed sertoliform, spindle cell or corded and hyaline patterns. There was no correlation between WT1 expression and p53 immunoreactivity.

CONCLUSIONS

Nuclear WT1 expression is present in a minority of EOC and this should be considered if immunohistochemistry is used as an adjunct in sub-typing ovarian carcinomas. The negative correlation of WT1 staining with endometriosis supports the possibility that some EOC, including unusual histological variants, arise from the ovarian surface epithelium. Further studies of EOC should document any association with endometriosis.

Clinical aspects of uterine papillary serous carcinoma

PURPOSE OF REVIEW

We review the demographic and clinicopathologic characteristics, and prognosis of women diagnosed with uterine papillary serous carcinoma, with a focus on clinical management.

RECENT FINDINGS

Pathologic evaluation of postmenopausal bleeding is preferred for patients who fit the profile of a high-risk endometrial cancer such as uterine papillary serous carcinoma. Women diagnosed with endometrial cancer who fit this profile and all women with uterine papillary serous carcinoma should undergo comprehensive surgical staging and aggressive cytoreduction of extrauterine disease. Adjuvant therapy remains controversial. Several recent investigations reported on the potential benefit of adjuvant chemotherapy, with many recommending additional loco-regional radiation.

SUMMARY

Despite the lack of randomized trials on uterine papillary serous carcinoma, several recent reports have provided insight into the diagnosis, surgical management, and adjuvant treatment of this high-risk endometrial cancer.

Diagnostic Utility of WT1 Immunostaining in Ovarian Sertoli Cell Tumor

WT1, the Wilms tumor gene product, can be expressed in various tumors from different anatomic sites, including some types of ovarian tumors. Regarding the latter, most studies have focused on surface epithelial-stromal tumors in which serous carcinomas are usually positive and endometrioid carcinomas are negative. Very few studies have specifically investigated this marker in ovarian sex cord-stromal tumors; however, limited data in the literature suggest that WT1 may be frequently expressed in sex cord-stromal tumors. As pure Sertoli cell tumor can be in the histologic differential diagnosis of endometrioid tumors (particularly borderline tumor and carcinoma) and carcinoid, immunostaining for WT1 might be of diagnostic value. Immunohistochemical staining for WT1 was performed in 108 ovarian tumors: pure Sertoli cell tumor (n=26), endometrioid borderline tumor (n=25), classic well-differentiated endometrioid carcinoma (n=23), sertoliform endometrioid carcinoma (n=12), and carcinoid (n=22). Additionally, inhibin and calretinin immunostaining were performed in all cases of Sertoli cell tumor for purposes of comparing expression with WT1. Extent of immunostaining was scored on a 0 to 4+ semiquantitative scale, and immunohistochemical composite scores based on a combination of extent and intensity of immunostaining were calculated in positive cases (possible range, 1 to 12). Nuclear expression of WT1 was present in 96% of Sertoli cell tumors, 16% of endometrioid borderline tumors, 13% of classic well-differentiated endometrioid carcinomas, 25% of sertoliform endometrioid carcinomas, and 0% of carcinoids. In Sertoli cell tumors, expression was diffuse (>50% of positive cells) in all positive cases. When positive in the non-Sertoli cell tumors, the extent of expression tended to be focal to patchy (50% or less positive cells). In Sertoli cell tumors, inhibin and calretinin were expressed in 96% and 54% of cases, respectively. The extent of expression of inhibin tended to be diffuse, similar to WT1; however, the extent of immunostaining for calretinin tended to be focal to patchy. The immunohistochemical composite scores for WT1, inhibin, and calretinin were 11.2, 7.6, and 4.8, respectively. Coordinate patterns for the extent of expression of WT1, inhibin, and calretinin in pure Sertoli cell tumor showed that all 3 markers were positive in 54% of cases; however, 42% were positive for WT1 and inhibin but negative for calretinin. In cases positive for both WT1 and inhibin, expression of both markers was diffuse in 84% of cases, but WT1 was diffuse while inhibin was focal to patchy in 16% of cases. We conclude that ovarian Sertoli cell tumor should be added to the growing list of WT1-positive tumors. This marker is useful for the distinction of Sertoli cell tumor from endometrioid tumors and carcinoid. The diagnostic utility of WT1 in Sertoli cell tumor is similar to inhibin but better than that of calretinin.

Minimal uterine serous carcinoma: current concepts in diagnosis and prognosis

Uterine serous carcinoma (USC) is an aggressive type of endometrial cancer with a propensity to have extra-uterine spread at diagnosis, in some cases despite limited involvement of the uterus. Serous endometrial intra-epithelial carcinoma (EIC) is a recently recognised entity with the same cytological features and p53 mutations as USC, but it does not demonstrate stromal or myometrial invasion. In addition to representing the putative precursor to USC, the pure form of serous EIC may also be associated with extra-uterine tumour at the time of diagnosis and with risk for recurrence, spread, and eventual death from tumour. Current evidence indicates that serous EIC is a form of minimal USC with behaviour that is stage dependent, thereby necessitating complete surgical staging despite limited disease in the uterus. We review the diagnostic criteria for minimal USC, pitfalls in the differential diagnosis, and discuss a practical approach to evaluating biopsies, polypectomies, or hysterectomies containing minimal USC.

The management of serous papillary uterine cancer

PURPOSE OF REVIEW

Uterine papillary serous cancer is an extremely aggressive cancer, the optimum management of which is still being determined. It is important to understand advances that have been made in 2005 regarding the molecular biology, diagnosis, and management of this deadly disease.

RECENT FINDINGS

The main themes in the literature regarding uterine papillary serous cancer are that a potential precursor lesion, serous endometrial intraepithelial carcinoma, has been recognized as an early form of the disease. A variety of molecular biologically important markers have now been identified, including p53, HER2/neu, IL-6, kallikrein 6, and claudin-4, some of which may be susceptible to molecularly targeted therapy. Systematic surgical staging is necessary before additional therapy is recommended. Stage I uterine papillary serous cancer requires aggressive treatment, including surgery, chemotherapy, and radiation therapy for successful treatment. The most effective management of advanced stage disease remains to be resolved.

SUMMARY

Serous endometrial intraepithelial carcinoma should be treated as a form of uterine papillary serous cancer. Multimodality therapy is required for the successful management of early stage uterine papillary serous cancer. Advanced disease is often unresponsive to conventional therapy. Molecularly targeted therapies are now being introduced into the management of this disease.