Immunohistochemical analysis of clear cell carcinoma of the gynecologic tract

Targeting DNA Damage Response Pathway in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is one of the major types of ovarian cancer and is of higher relative prevalence in Asians. It also shows higher possibility of resistance to cisplatin-based chemotherapy leading to poor prognosis. This may be attributed to the relative lack of mutations and aberrations in homologous recombination-associated genes, which are crucial in DNA damage response (DDR), such as BRCA1, BRCA2, p53, RAD51, and genes in the Fanconi anemia pathway. On the other hand, OCCC is characterized by a number of genetic defects rendering it vulnerable to DDR-targeting therapy, which is emerging as a potent treatment strategy for various cancer types. Mutations of ARID1A, PIK3CA, PTEN, and catenin beta 1 (CTNNB1), as well as overexpression of transcription factor hepatocyte nuclear factor-1β (HNF-1β), and microsatellite instability are common in OCCC. Of particular note is the loss-of-function mutations in ARID1A, which is found in approximately 50% of OCCC. ARID1A is crucial for processing of DNA double-strand break (DSB) and for sustaining DNA damage signaling, rendering ARID1A-deficient cells prone to impaired DNA damage checkpoint regulation and hence sensitive to poly ADP ribose polymerase (PARP) inhibitors. However, while preclinical studies have demonstrated the possibility to exploit DDR deficiency in OCCC for therapeutic purpose, progress in clinical application is lagging. In this review, we will recapitulate the preclinical studies supporting the potential of DDR targeting in OCCC treatment, with emphasis on the role of ARID1A in DDR. Companion diagnostic tests (CDx) for predicting susceptibility to PARP inhibitors are rapidly being developed for solid tumors including ovarian cancers and may readily be applicable on OCCC. The potential of various available DDR-targeting drugs for treating OCCC by drawing analogies with other solid tumors sharing similar genetic characteristics with OCCC will also be discussed.

Clear cell lesions in pathology: Histomorphologic approach to diagnosis

There has been remarkable progress in the field of surgical pathology; however, histomorphology has remained the most important and essential tool of the surgical pathologist in everyday practice till now. It is surprising that the hematoxylin-eosin (H and E) stain, introduced more than a century ago, has still remained the gold standard stain for histological examination and diagnosis of human diseases. Besides different findings or clues observed in histopathology sections like inclusions, granules, grooving, globules, halo, or clearing, which would enable the pathologist to provide a precise and accurate diagnosis; observation of clear cells is one of the important findings and clue for reporting. It may also sometimes lead to difficulties and delays in establishing the diagnosis. It can be focal or extensive and primary or rarely it may be secondary. Clear cell changes may be observed in many non-neoplastic, benign, or malignant tumors of diverse origin. Clear cell tumors contain a preponderance of clear cells. It can be seen in almost all the organs of human body and can be classified according to location or biological behavior. Commonly seen clear-cell tumors are usually malignant and common organs involved are female genital tract, urogenital tract, head and neck areas, central nervous system, skin, and rarely in bone and soft tissues. For approach to clear cell lesions, one has to decide if the change is artifactual, a mimic of clear cell tumors, or a clear cell tumor in reality. Once the mimics and artifactual/degenerative changes have been ruled out, a tumor either primarily of clear cell origin or showing secondary change has to be decided. The tumor next is to be diagnosed as benign/malignant and epithelial/mesenchymal based on morphology.

Clear cell carcinoma of the urinary bladder: a systematic review

PURPOSE

We conducted a systematic review of the literature on primary clear cell carcinoma (CCC) of the urinary bladder.

METHODS

A literature search using keywords and MeSH terms related to "clear cell carcinoma", "clear cell adenocarcinoma", "mesonephroma" and "urinary bladder" in EMBASE, MEDLINE and Cochrane Central Register of Controlled Trials was performed. A manual search was performed with web-based search engine Google Scholar. Reference lists of the included studies were screened for additional articles. Articles up till 16th July 2020 were retrieved. Observational human studies on primary CCC in urinary bladder with English full-text were included for further analysis.

RESULTS

904 articles were identified and 44 articles were included for further analysis. Data including clinical features, tumour characteristics, treatment and oncological outcomes were reviewed. There were 70 patients (44 females and 26 males) reported in literatures and included in this review. Gross haematuria was the most common presentation (79.7%), followed by irritative urinary symptoms (47.5%). Regarding the histology, tubulocystic pattern is the most common histologic pattern (49.1%), and 52.6% had muscle invasion. Most cases were CK7 (96.6%) and CK20 (88.9%) positive. CA125 (96%) was commonly positive, indicating its potential origin from mullerian duct. Most patients received surgery (95.5%) as primary treatment. However, the oncological outcomes were unsatisfactory with a 2-year survival rate of 60.0%.

CONCLUSION

Clear cell carcinoma is an uncommon subtype of bladder cancer which can be diagnosed by histology and immunohistochemical staining result. The majority of patients presented with muscle invasion and had a poor survival despite aggressive treatment.

A clear cancer cell line (150057) derived from human endometrial carcinoma harbors two novel mutations

BACKGROUND

Cell lines are extremely useful for both basic and clinical research. Thus, establishing endometrial cancer cell lines with malignant histology is important. This study aimed to extensively characterize an endometrial clear cell carcinoma cell line.

METHODS

This cell line, named 150,057, was derived from the endometrial clear cell cancer of a 63-year-old woman. The morphology, chromosomes, chemosensitivity, tumor markers, xenotransplantation characteristics, and cancer-related genes of the cell line were characterized.

RESULTS

This cell line exhibited adequate growth, being passaged more than 70 times. The morphology of the cells was polygonal with a cobblestone-like appearance. Karyotyping of the cell line revealed a hypodiploid chromosomal number. 150057 cells expressed CA19-9 and CA125. The cell line was sensitive to doxorubicin, paclitaxel, carboplatin, and cisplatin. After the cells were transplanted into the subcutaneous region of non-obese diabetic-severe combined immunodeficiency mice, they generated xenograft tumors with similar histology as the original tumor. A total of 59 somatic nucleotide mutations were identified in 25 of the 53 examined tumor suppressor genes and oncogenes. Two novel mutations were found in FGFR3 and ARID1A.

CONCLUSION

We established and characterized an endometrial clear cell carcinoma cell line that may be useful in carcinogenesis and treatment research for endometrial cancer.

Clinicopathologic and Molecular Characteristics of Mesonephric Adenocarcinoma Arising From the Uterine Body

Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract mainly occurring in the uterine cervix. To date, only a few cases of MNAC arising from of the uterine body (UB-MNAC) have been reported. The clinicopathologic and molecular characteristics of UB-MNAC remain unknown. In this study, we investigated the clinical, histopathologic, immunohistochemical, and genetic features of UB-MNAC. In total, 11 cases were included. Six patients developed metastatic disease, most commonly in lungs (5/6). Histopathologically, UB-MNAC was characterized by an admixture of tubular, glandular, papillary, retiform, glomeruloid, sex cord-like, and comedonecrosis-like architectural patterns. Three adverse pathologic characteristics, including advanced International Federation of Gynecology and Obstetrics stage, high mitotic activity, and presence of lymphovascular the invasion, were independent factors predicting the development of metastasis. All cases were positive for GATA-binding protein 3 and paired box 2 expression and showed wild-type p53, patchy p16, and preserved PTEN expression, as indicated by immunohistochemistry. Next-generation sequencing using 12 samples (11 primary tumors and 1 metastatic tumor) revealed 42 single nucleotide variations in 16 genes, mostly in KRAS (10/12) and ARID1A (9/12). Copy number variation was found in 16 genomic regions, and consisted of 57 gains and 10 losses, with 1q gain (11/12) being the most prevalent. In conclusion, UB-MNAC displays an aggressive biological behavior, with a tendency to metastasize to the lungs. Adverse pathologic characteristics reflect the aggressive nature of UB-MNAC. Distinct molecular features of UB-MNAC include frequent somatic mutations of KRAS and ARID1A and gain of 1q.

Contemporary management of uterine clear cell carcinoma: A Society of Gynecologic Oncology (SGO) review and recommendation

Uterine clear cell cancer (UCCC) is a rare but aggressive disease. Due to its rarity, large, prospective studies focused on UCCC are exceedingly difficult therefore available data are generally from small, retrospective studies. There is also pertinent information from subsection analysis of larger studies that include UCCC and other histotypes. In 2009, the clinical practice committee of the Society of Gynecologic Oncology (SGO) published a review on UCCC aimed at guiding management. Since that publication, there have been developments which are relevant to UCCC, these include availability of data from landmark trials regarding adjuvant therapy, increasing utilization of sentinel lymph node approach and availability of immunotherapy as a treatment option. This SGO review is updated with all relevant, published information since 2009 considered clinically important for management of UCCC. In addition, it follows the new SGO's style for this type of publication which includes utilization of the question and answer format.

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

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

High-grade Endometrial Carcinomas: Morphologic and Immunohistochemical Features, Diagnostic Challenges and Recommendations

This review of challenging diagnostic issues concerning high-grade endometrial carcinomas is derived from the authors' review of the literature followed by discussions at the Endometrial Cancer Workshop sponsored by the International Society of Gynecological Pathologists in 2016. Recommendations presented are evidence-based, insofar as this is possible, given that the levels of evidence are weak or moderate due to small sample sizes and nonuniform diagnostic criteria used in many studies. High-grade endometrioid carcinomas include FIGO grade 3 endometrioid carcinomas, serous carcinomas, clear cell carcinomas, undifferentiated carcinomas, and carcinosarcomas. FIGO grade 3 endometrioid carcinoma is diagnosed when an endometrioid carcinoma exhibits >50% solid architecture (excluding squamous areas), or when an architecturally FIGO grade 2 endometrioid carcinoma exhibits marked cytologic atypia, provided that a glandular variant of serous carcinoma has been excluded. The most useful immunohistochemical studies to make the distinction between these 2 histotypes are p53, p16, DNA mismatch repair proteins, PTEN, and ARID1A. Endometrial clear cell carcinomas must display prototypical architectural and cytologic features for diagnosis. Immunohistochemical stains, including, Napsin A and p504s can be used as ancillary diagnostic tools; p53 expression is aberrant in a minority of clear cell carcinomas. Of note, clear cells are found in all types of high-grade endometrial carcinomas, leading to a tendency to overdiagnose clear cell carcinoma. Undifferentiated carcinoma (which when associated with a component of low-grade endometrioid carcinoma is termed "dedifferentiated carcinoma") is composed of sheets of monotonous, typically dyscohesive cells, which can have a rhabdoid appearance; they often exhibit limited expression of cytokeratins and epithelial membrane antigen, are usually negative for PAX8 and hormone receptors, lack membranous e-cadherin and commonly demonstrate loss of expression of DNA mismatch repair proteins and SWI-SNF chromatin remodeling proteins. Carcinosarcomas must show unequivocal morphologic evidence of malignant epithelial and mesenchymal differentiation.

Primary Clear Cell Adenocarcinoma of the Cervix: A Clinical Analysis of 18 Cases without Exposure to Diethylstilbestrol

OBJECTIVES

Cervical clear cell adenocarcinoma (CCAC) is a rare malignant tumor with independent biological behavior in the female reproductive system. In this report, we collect the clinical and histopathological characteristics of 18 CCAC patients without exposure to diethylstilbestrol (DES) and conduct relevant clinical analysis.

METHODS

We retrospectively analyzed the clinical data of 18 patients with CCAC who were diagnosed and treated from January 2009 to August 2017 in the Second Hospital of Jilin University.

RESULTS

A total of 18 patients were enrolled. The age of patients ranged from 37 to 74 years with the peak incidence between 45 and 55 years. The median age was 53 years. The most common symptom was vaginal bleeding (66.7%, 12/18). The most common type of lesion was the endocervical type (66.7%, 12/18). The negative rate of human papillomavirus (HPV) examination was 88.9% (8/9). Based on the staging criteria of the International Federation of Gynecology and Obstetrics (FIGO) cervical cancer clinical stage in 2018, 55.6% patients were stage I (n=10), 16.7% were stage II (n=3), 22.2% were stage III (n=4), and 5.6% were stage IV (n=1). Seventeen patients underwent surgery; 64.7% (11/17) of cases showed infiltration of the entire layer of the cervix, pelvic lymph node (PLN) metastasis was observed in 4 patients (26.7%, 4/15), endometrium metastasis was observed in 4 patients (25%, 4/16), and 13 patients (72.2%, 13/18) were diagnosed at an early stage (stage IB1-IIA2). Fifteen patients' immunohistochemistry indicated that napsin A, CK7, CK (AE1/AE3), and PAX-8 were positive, and p53, p16, ER, and vimentin were expressed to different degrees. Follow-up data were obtained in 13 patients (72.2%, 13/18). One patient died of recurrence 5 months after surgery, and the other patients' progression-free survival (PFS) ranged from 9 to 59 months. Tumor size (>4 cm), tumor stage (FIGO IIA2-IV), PLN, and endometrium metastasis had negative effects on PFS (P < 0.05).

CONCLUSIONS

CCAC is a highly invasive malignant tumor, whose pathogenesis may not be associated with HPV infection. Radical hysterectomy combined with chemotherapy (paclitaxel + platinum) has the ideal short-term curative effect. In the future, larger samples of clinical data are required to confirm these insights.

Unsupervised Clustering of Immunohistochemical Markers to Define High-Risk Endometrial Cancer

Considerable heterogeneity exists in outcomes of early endometrial cancer (EC) according to the type but also the histological grading. Our goal was to describe the immunohistochemical profiles of type I EC according to grades and type II EC, to identify groups of interacting proteins using principal component analysis (PCA) and unsupervised clustering. We studied 13 immunohistochemical markers (steroid receptors, pro/anti-apoptotic proteins, metalloproteinases (MMP) and tissue inhibitor of metalloproteinase (TIMP), and CD44 isoforms known for their role in endometrial pathology. Co-expressed proteins associated with the type, grade and outcome of EC were determined by PCA and unsupervised clustering. PCA identified three functional groups of proteins from 43 tissue samples (38 type I and 5 type II EC): the first was characterized by p53 expression; the second by MMPs, bcl-2, PR B and CD44v6; and the third by ER alpha, PR A, TIMP-2 and CD44v3. Unsupervised clustering found two main clusters of proteins, with both type I grade 3 and type II EC exhibiting the same cluster profile. PCA and unsupervised clustering of immunohistochemical markers in EC contribute to a better comprehension and classification of the disease.

Endometrial Carcinomas With Clear Cells: A Study of a Heterogeneous Group of Tumors Including Interobserver Variability, Mutation Analysis, and Immunohistochemistry With HNF-1β

Endometrial clear cell carcinoma (CC) is an uncommon tumor and often carries a poor prognosis. It has histologic features that overlap with other endometrial carcinomas and is frequently misclassified. Accurate classification is crucial, however, to improve treatment options. The objectives of this study were (1) to assess diagnostic interobserver variability among 5 gynecologic pathologists for tumors originally diagnosed as CC or with a component of CC (n=44); (2) to determine the utility of immunohistochemical markers estrogen receptor and HNF-1β; and (3) to detect mutations in select genes. Clinical data and morphologic features were also recorded. Agreement among reviewers was only moderate: only 46% of the original CC remained classified as such. After reclassification, estrogen receptor was positive in 8% of CC, 67% of endometrioid carcinomas (EC), and 47% of serous carcinomas (SC). Sensitivities of HNF-1β in CC, SC, and EC were 62%, 27%, and 17%, respectively, whereas specificity for CC versus EC or SC was 78%. Mutations in PIK3CA, PIK3R1, PTEN, KRAS, and NRAS were detected in 41% of 37 cases that had adequate material for study. At least 1 mutation was identified in 33% of CC, 67% of EC, and 33% of SC. This group of patients had poor outcomes: 72% of the patients with follow-up information had died of disease. In summary, this study suggests that the current pool of CC is a heterogeneous group of tumors from the morphologic, immunophenotypic, and molecular point of views and that only a percentage of them represent true CC.

The association between reproductive and hormonal factors and ovarian cancer by estrogen-α and progesterone receptor status

OBJECTIVE

We assessed the association between reproductive and hormonal factors and ovarian cancer incidence characterized by estrogen receptor-α (ERα) and progesterone receptor (PR) status.

METHODS

Tissue microarrays were used to assess ERα and PR expression among 197 Nurses' Health Study (NHS), 42 NHSII and 76 New England Case-Control Study (NECC) ovarian cancer cases. NHS/NHSII cases were matched to up to 4 controls (n=954) on diagnosis date and birth year. NECC controls (n=725) were frequency matched on age. Cases were considered receptor positive if ≥1% of tumor cells stained positive. Associations by ERα and PR status were assessed using polytomous logistic regression. p-Value for heterogeneity was calculated using a likelihood ratio test.

RESULTS

45% of ovarian tumors were PR(+), 78% were ERα(+) and 45% were ERα(+)/PR(+), while 22% were ERα(-)/PR(-). Postmenopausal status was associated with an increased risk of PR(-) tumors (OR: 2.07; 95%CI: 1.15-3.75; p-heterogeneity=0.01) and age at natural menopause was inversely associated with PR(-) tumors (OR, per 5years: 0.77; 95%CI: 0.61-0.96; p-het=0.01). Increasing duration of postmenopause was differentially associated by PR status (p-het=0.0009). Number of children and tubal ligation were more strongly associated with ERα(-) versus ERα(+) tumors (p-het=0.002 and 0.05, respectively). No differential associations were observed for oral contraceptive or hormone therapy use.

CONCLUSIONS

Postmenopausal women have an increased risk of developing PR(-) ovarian tumors compared to premenopausal women. The associations observed for ovarian cancer differ from those seen for breast cancer suggesting that the biology for tumor development through ERα and PR pathways may differ.

Vaginal clear cell carcinoma in a Japanese Black cow

During artificial insemination of an 18-year-old female Japanese Black cow, a mass that was of a hen’s egg size was found in the vagina. On necropsy, the firm mass, measuring approximately 3.5 × 3.5 × 3.0 cm, was located at the superior region of the vagina. The cut surface of the mass was gray-white in color with occasional necrotic or hemorrhagic areas. Histologically, the mass was composed of tumor cells arranged in solid nests of various sizes with an occasional tubular structure separated by a delicate fibrovascular stroma. The tumor cells had a hypochromatic nucleus and abundant, faintly eosinophilic cytoplasm. The tumor cells contained diastase-sensitive periodic acid-Schiff positive granules. Immunohistochemically, tumor cells were positive for cytokeratin AE1/AE3, CAM5.2 and carcinoembryonic antigen, but not for vimentin, p63, estrogen receptor-α, progesterone receptor, α-smooth muscle actin, neuron-specific enolase, S-100 protein and chromogranin A. On the basis of these findings, the tumor was diagnosed as a clear cell carcinoma of the vagina.

Are clear cell carcinomas of the ovary and endometrium phenotypically identical? A proteomic analysis

Phenotypic differences between otherwise similar tumors arising from different gynecologic locations may be highly significant in understanding the underlying driver molecular events at each site and may potentially offer insights into differential responses to treatment. In this study, the authors sought to identify and quantify phenotypic differences between ovarian clear cell carcinoma (OCCC) and endometrial clear cell carcinoma (ECCC) using a proteomic approach. Tissue microarrays were constructed from tumor samples of 108 patients (54 ECCCs and 54 OCCCs). Formalin-fixed samples on microarray slides were analyzed by matrix-assisted laser desorption/ionization mass spectrometry, and 730 spectral peaks were generated from the combined data set. A linear mixed-effect model with random intercept was used to generate 93 (12.7%) peaks that were significantly different between OCCCs and ECCCs at the fold cutoffs of 1.5 and 0.667 and an adjusted P value cutoff of 1.0 × 10(-10). Liquid chromatography-tandem mass spectrometry was performed on selected cores from each group, and peptides identified therefrom were compared with lists of statistically significant peaks from the aforementioned linear mixed-effects model to find matches within 0.2 Da. A total of 53 candidate proteins were thus identified as being differentially expressed in OCCCs and ECCCs, 45 (85%) of which were expressed at higher levels in ECCCs than OCCCs. These proteins were functionally diverse and did not highlight a clearly dominant cellular theme or molecular pathway. Although ECCCs and OCCCs are very similar, some phenotypic differences are demonstrable. Additional studies of these differentially expressed proteins may ultimately clarify the significance of these differences.

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

Context

Immunohistochemistry has assumed an increasing role in the identification and characterization of gynecologic disorders including lesions with deceptively bland morphology, uncommon and underdiagnosed neoplasms, and neoplasms with specific genetic alterations associated with overexpression or loss of expression of specific proteins. The diagnostic accuracy has been significantly improved owing to the discovery and increasing experience with the tumor-associated biomarkers, and the increasing demand for precise tumor classification to assess suitability for the expanding therapeutic modalities including clinical trials.

Objective

To differentiate lesions of the gynecologic tract through the use of effective immunohistochemical panels.

Data Sources

Literature review and authors' personal practice experience.

Conclusions

The application of diagnostic and prognostic immunohistochemical panels has enabled pathologists to better guide therapeutic decisions and to better predict the clinical outcome. It is now well established that the use of ancillary testing, including immunohistochemistry, has a significant power in the identification, differentiation, and classification of reactive, premalignant, and malignant gynecologic disorders. This article discusses the utilities and pitfalls of the commonly used immunohistochemical markers in the context of overlapping morphologic features encountered in the uterus, ovaries, and fallopian tubes.

HNF-1β in ovarian carcinomas with serous and clear cell change

Many ovarian tumors, including high-grade serous carcinoma (HGSC), show clear cell change. Accurate diagnosis is important, however, as ovarian clear cell carcinoma (OCCC) is known to be less responsive to traditional types of ovarian cancer chemotherapies. In a previous study, the clinical, morphologic, and immunohistochemical features of 32 ovarian carcinomas, which had been previously diagnosed as pure OCCC (n=11), pure HGSC (n=11), and mixed serous and clear cell (MSC) (n=10), were analyzed. The immunoreactivities of WT1, ER, and p53, as well as the mitotic indices and stages of presentation of the MSC, were similar to those of HGSC. It was consequently concluded that MSC represented HGSC with clear cell change. Hepatocyte nuclear factor-1β (HNF-1β) is a relatively new immunohistochemical marker that has been shown to be rather sensitive and specific for OCCC. We thus sought to evaluate this marker in this specific group of tumors. One block each of pure HGSC and pure OCCC were stained with HNF-1β. In the cases of MSC, 2 blocks were stained when the serous and clear cell components were not present on the same slide. None (0/11) of the pure HGSC showed immunoreactivity for HNF-1β, whereas all (11/11) of the pure OCCC were positive. In the cases of MSC, both the serous and clear cell components were negative for HNF-1β. HNF-1β seems to be a sensitive and specific marker for OCCC and is not expressed in HGSC with clear cell change. The pattern of immunoreactivity of HNF-1β in tumors with both serous and clear cell change supports the conclusion that MSC are HGSC with clear cells.

ER+ /PR+ /TFF3+ /IMP3- immunoprofile distinguishes endometrioid from serous and clear cell carcinomas of the endometrium: a study of 401 cases

AIMS

Differentiating endometrioid adenocarcinoma (EAC) from uterine serous carcinoma (USC) and clear cell carcinoma (CCC) of the endometrium can be challenging. We undertook an immunohistochemical study to address this issue.

METHODS AND RESULTS

We evaluated 401 endometrial carcinomas cases by using four immunomarkers - oestrogen receptor (ER), progesterone receptor (PR), insulin-like growth factor II mRNA - binding protein 3 (IMP3), and intestinal trefoil factor 3 (TFF3)-on a tissue microarray. The cases included 311 EACs (G1, 146; G2, 104; and G3, 61), 69 USCs, and 21 CCCs. ER, PR and TFF3 were most frequently expressed in EACs (P < 0.001), and IMP3 was more frequently expressed in USCs and CCCs (P < 0.001). ER(+) /PR(+) /TFF3(+) /IMP3(-) was the best marker combination associated with EAC [exact odds ratio (OR) 112; 95% confidence interval (CI) 19-∞; P < 0.0001]. This marker combination remained very reliable after adjustment for tumour grade (exact OR 19.2; 95% CI 3-∞; P = 0.0004). Because distinguishing EAC G3 from USC and CCC on the basis of morphology may be difficult, the use of immunomarkers to improve reproducibility is highly recommended. We found the ER(+) /PR(+) /TFF3(+) /IMP3(-) immunoprofile to be the best combination for confirming a diagnosis of endometrioid adenocarcinoma (exact OR 19.2; 95% CI 3-∞; P = 0.0004).

CONCLUSIONS

We recommend using an ER/PR/TFF3/IMP3 immunohistochemical panel in selected cases of endometrial carcinoma where the differential diagnosis is challenging.

In vitro model of stromal and epithelial immortalized endometriotic cells

Endometriosis is a relatively common chronic gynecologic disorder that usually presents with chronic pelvic pain or infertility. It results from implantation of endometrial tissue outside the uterine cavity. Despite its frequency and its impact on quality of life, the understanding of pathogenesis of endometriosis remains incomplete and its treatment remains controversial. In this work, we established a suitable in vitro model system of immortalized human endometriotic cell line taking advantage of the human telomerase reverse transcriptase. The results demonstrate that these cells retain the natural characteristics of endometrial cells in term of phenotype and of functional expression of estrogen and progesterone receptors, without chromosomal abnormalities. In conclusion, these cells are potentially useful as an experimental model to investigate endometriosis biology.

Clear cell carcinoma of the female genital tract (not everything is as clear as it seems)

Clear cell carcinoma has a storied history in the female genital tract. From the initial designation of ovarian clear cell adenocarcinoma as "mesonephroma" to the linkage between vaginal clear cell carcinoma and diethylstilbestrol exposure in utero, gynecologic tract clear cell tumors have puzzled investigators, posed therapeutic dilemmas for oncologists, and otherwise presented major differential diagnostic challenges for pathologists. One of the most common errors in gynecologic pathology is misdiagnosis of clear cell carcinoma, on both frozen section and permanent section. Given the poor response to platinum-based chemotherapy for advanced-stage disease and increased risk of thromboembolism, accurate diagnosis of clear cell carcinoma is important in the female genital tract. This review (1) presents the clinical and pathologic features of female genital tract clear cell carcinomas; (2) highlights recent molecular developments; (3) identifies areas of potential diagnostic confusion; and (4) presents solutions for these diagnostic problems where they exist.

Does the Loss of ARID1A (BAF-250a) Expression in Endometrial Clear Cell Carcinomas Have Any Clinicopathologic Significance? A Pilot Assessment

SWI/SNF chromatin-modification complexes use the energy of ATP hydrolysis to remodel nucleosomes and to affect transcription and several cellular processes. Accordingly, their loss of function has been associated with malignant transformation. ARID1A (the expression of whose product, BAF250a, a key complex component, is lost when mutated) has recently been identified as a tumor suppressor gene that is mutated in 46-57% of ovarian clear cell carcinoma (CCC). The purposes of this study are to assess the frequency of loss of BAF250a expression in endometrial CCC and whether this loss has any discernable clinicopathologic implications. 34 endometrial carcinomas with a CCC component (including 22 pure CCC, 8 mixed carcinomas with a 10% CCC component, and 4 carcinosarcomas with a CCC epithelial component), were evaluated by immunohistochemistry using a monoclonal antibody directed against the human BAF250a protein. 5 (22.7%) of the 22 pure CCC were entirely BAF250a negative, whereas the remainder showed diffuse immunoreactivity. None of 4 carcinosarcomas and only 1 (12.5%) of the 8 mixed carcinomas were BAF250a negative. There was no discernable relationship between BAF250a immunoreactivity status and tumor architectural patterns (solid, papillary or tubulocystic areas) or cell type (flat, hobnail or polygonal). Of the 22 patients with pure CCC, 14, 2, 3, and 3 were International Federation of Gynecology and Obstetrics stages 1, II, III and IV respectively. Interestingly, all 5 BAF250a negative cases were late stage [stages III or IV] as compared with 1 of 17 BAF250a positive cases (p=0.0002). Thus, 83% (5/6) of all late stage cases were BAF250a [-], as compared with 0 (0%) of the 16 early stage (I or II) cases (p=.0002). BAF250a negative and positive cases did not show any statistically significant difference regarding patient age and frequency of lymphovascular invasion or myometrial invasion. As may be anticipated from the concentration of late stage cases in the BAF250a negative group, patient outcomes were worsened in that group on univariate analysis. In conclusion, we found in this pilot assessment that 22.7% of endometrial CCC displays complete loss of BAF250a expression. There was a disproportionate concentration of BAF250a negative cases in the late stage group, with the attendant possibility of an associated worsened prognosis for those CCC patients whose tumors are BAF250a negative. These preliminary findings suggest the need for larger analyses to evaluate the prognostic significance, if any, of the loss of BAF250a expression in this rare histotype of endometrial cancer.

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).

Endometrial clear cell adenocarcinoma diagnosed by endometrial cytological examination: two cases report

In contrast to endometrioid endometrial adenocarcinoma (EA), endometrial clear cell adenocarcinoma (ECCA) is rare and shows a clinically aggressive potential, resulting in a poor prognosis. Therefore, the early diagnosis of ECCA is crucial for the treatment of patients bearing the tumor. Here, we report two cases of ECCA diagnosed by cytological examination. Case 1 was a 67-year-old female, while case 2 was a 68-year-old female. In both cases, tumors of the corpus uteri were identified, and they were diagnosed as ECCA on cytological examination with specimens derived from endometrial brushing. The diagnosis was confirmed by the histological examination of the surgical specimens.

Hepatocyte nuclear factor-1β expression in clear cell adenocarcinomas of the bladder and urethra: diagnostic utility and implications for histogenesis

The histogenesis of clear cell adenocarcinoma of the bladder/urethra is uncertain. Hepatocyte nuclear factor-1β is a homeodomain protein that has been reported to be frequently overexpressed in ovarian clear cell adenocarcinoma in comparison with rare or no expression in other types of epithelial ovarian tumors. We assessed the expression of hepatocyte nuclear factor-1β in a series of 18 clear cell adenocarcinomas of the bladder and urethra and compared it with that of invasive high-grade transitional/urothelial carcinoma (n = 35); adenocarcinomas of the bladder, urethra, and paraurethral glands (n = 21); as well as nephrogenic adenomas of the bladder (n = 8). Staining intensity and extent were evaluated using a 4-tiered grading system (0-3). A case was considered positive for hepatocyte nuclear factor-1β if 10% or more of tumor cells showed at least weak nuclear staining or if any moderate or strong nuclear staining was observed. All 18 clear cell adenocarcinomas exhibited nuclear staining in at least 50% of tumor cells (16 strong, 1 moderate, and 1 weak with focal strong nuclear staining) in comparison with positive nuclear staining (moderate) in 1 of 21 bladder adenocarcinoma, 1 of 35 invasive high-grade transitional/urothelial carcinoma (weak to moderate staining), and 2 of 8 nephrogenic adenomas (1 weak and 1 moderate to strong staining). We concluded that hepatocyte nuclear factor-1β is a useful marker in differentiating clear cell adenocarcinomas of the bladder/urethra from invasive high-grade transitional/urothelial carcinoma and other types of bladder adenocarcinomas and to a lesser extent from nephrogenic adenomas. Hepatocyte nuclear factor-1β is of no diagnostic utility in discriminating primary bladder/urethral clear cell adenocarcinomas from metastatic clear cell adenocarcinomas of the female genital tract to the bladder/urethra. From a histogenesis standpoint, although the expression of hepatocyte nuclear factor-1β in both gynecologic and urologic tract clear cell adenocarcinomas may point to a Müllerian derivation/differentiation, this immunohistochemical evidence is insufficient to completely exclude an urothelial association.

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.

Neoplastic Lesions of the Cervix

This review presents a discussion of the gross and microscopic features, diagnosis, differential diagnosis, and prognosis of neoplastic lesions of the cervix. Biomarkers are discussed for each entity presented - cervical intraepithelial neoplasia, squamous carcinoma, glandular neoplasms, adenocarcinoma in situ, adenosquamous carcinoma, and others.

Mesothelial neoplasms presenting as, and mimicking, ovarian cancer

Mesotheliomas of the abdominal cavity are rare tumors that primarily involve the peritoneum, mesentery, and omentum. The involvement of the viscera is usually secondary to bulky and extensive serosal disease. We describe 7 cases of mesothelioma in which the initial manifestation was that of an ovarian mass. All patients underwent surgery with a primary diagnosis of ovarian cancer. Clinical histories, gross features, and histology slides were reviewed. Immunostains were performed on all cases and electron microscopy was performed in 2 cases. The patients ranged in age from 22 to 52 years and the lesions ranged in size from 3.8 to 9 cm. Of the 7 cases, 4 were predominantly cystic and 3 were solid. Histologically, all cystic tumors were multicystic mesothelioma, whereas the 3 solid tumors were diffuse malignant mesotheliomas. One patient had a borderline mucinous tumor with the mesothelioma occurring as a mural nodule, an association not described earlier. The oldest patient in this series had a diffuse malignant mesothelioma of the peritoneum with predominant ovarian surface involvement. Mesothelial neoplasms can present as ovarian masses in young women. Awareness of this presentation is important to establish appropriate management.

Ovarian clear cell adenofibromatous tumor of borderline malignancy associated with high levels of carbohydrate antigen 19-9

This report presents a case of ovarian clear cell adenofibromatous tumor of borderline malignancy, which is a rare variant of an ovarian epithelial tumor associated with high levels of carbohydrate antigen 19-9 (CA19-9). A 79-year-old female with a large pelvic tumor underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy; her pre-operative serum CA19-9 level was 780 IU/mL. The diameter of the elastic hard ovarian tumor was 17 cm. Microscopically, many tubular glands lay in an abundant fibrocollagenous stroma. Most of the glands were lined with flattened cells or cuboidal clear cells with large nuclei, but in a small area there were small crowded glands. The epithelium of the glands, in which stratification occurred over three layers, had clear cytoplasmic regions and enlarged nuclei with prominent nucleoli. CA19-9 was immunohistochemically positive in the epithelial cells. The final diagnosis was ovarian clear cell adenofibromatous tumor of borderline malignancy, stage Ia. Postoperatively, her serum CA19-9 level decreased to the normal limit.

The use of immunohistochemistry in the diagnosis of metastatic clear cell renal cell carcinoma: a review of PAX-8, PAX-2, hKIM-1, RCCma, and CD10

The diagnosis of metastatic clear cell renal cell carcinoma may be difficult in some cases, particularly in the small image-guided biopsies that are becoming more common. As targeted therapies for renal cell carcinoma are now standard treatment, the recognition and diagnosis of renal cell carcinoma has become even more critical. Many adjunctive immunohistochemical markers of renal epithelial lineage such as CD10 and RCCma have been proposed as aids in the diagnosis of metastatic renal cell carcinoma, but low specificities often limit their utility. More recently described markers (PAX-2, PAX-8, human kidney injury molecule-1, hepatocyte nuclear factor-1-β, and carbonic anhydrase-IX) offer the potential for greater sensitivity and specificity in this diagnostic setting; however, knowledge of their expected staining in other neoplasms and tissues is critical for appropriate use. In this review, we discuss the most widely used immunohistochemical markers of renal lineage with an emphasis on their sensitivity and specificity for metastatic clear cell renal cell carcinoma. Subsequently, we present a variety of organ-specific differential diagnostic scenarios in which metastatic clear cell renal cell carcinoma might be considered and we propose immunopanels for use in each situation.

Ovarian clear cell carcinoma arising in a mucinous cystadenoma

Here we report a rare case of ovarian clear cell carcinoma (CC) arising in a mucinous cystadenoma. A 59-year-old woman presented with a dull pain at the left inguinal area. She was found to have a left ovarian cyst measuring 4.7 cm and underwent a salpingo-oophorectomy. The unilocular cyst contained thick mucin, lacking any solid components. Histopathologically, most of the cyst wall was lined with a single layer of tall columnar cells with basophilic mucin. Within limited areas, small glands consisting of clear cytoplasm aggregated and intermingled with or partially transitioned to the mucinous glands. The clear cell components had adenofibroma-like features devoid of significant nuclear atypia or stromal invasion, including distinctive foci of CC with a hobnail appearance and hyperchromatic nuclei surrounded by desmoplastic or hyalinized stroma. Immunohistochemically, both mucinous and clear cells were positive for estrogen receptor. Hepatocyte nuclear factor-1beta and laminin were positive in all of the clear cell components, in contrast to a consistent lack of staining in the mucinous epithelium. An eleven-month follow-up revealed no recurrence or metastasis. This case was considered as an early manifestation of ovarian CC arising in a mucinous cystadenoma in the absence of demonstrable endometriosis.

Relationship between epidemiologic risk factors and hormone receptor expression in ovarian cancer: results from the Nurses' Health Study

Hormone receptor expression in tumors may offer etiologic information for ovarian cancer, particularly in light of known associations with hormonal and reproductive risk factors. Tissue microarrays constructed from 157 paraffin-embedded blocks of epithelial ovarian tumors collected from participants in the Nurses' Health Study were stained for estrogen receptor-alpha (ERalpha) and progesterone receptor (PR). We examined receptor expression by invasion, grade, and histologic subtype. Multivariate unconditional logistic regression was used to evaluate whether hormonal, reproductive, and anthropometric risk factors were differentially associated with the risk of developing receptor-positive or receptor-negative ovarian tumors compared with controls. PR-expressing tumors were less likely to be invasive (P = 0.05) and more likely to be of a lower grade (P < 0.001) and stage (P = 0.007) compared with PR- tumors. ERalpha status was not associated with any pathologic features of the tumor (P > 0.34). Increasing age, being postmenopausal, and postmenopausal hormone use were associated with an increased risk of developing ERalpha+, but not ERalpha- (P(heterogeneity) = 0.001, 0.06, and 0.06, respectively) and PR-, but not PR+, tumors (P(heterogeneity) = 0.08, 0.003, and 0.40, respectively), whereas height was only associated with the risk of developing PR- disease (P(heterogeneity) = 0.08). There were no clear risk differentials with OC use, parity, body mass index, or physical activity. Reproductive and hormonal risk factors are associated with subgroups of ovarian cancer defined by histologic subtype or ERalpha and PR status. These finding support specific models of hormone mediated triggers of ovarian cancer.

Validation of tissue microarray technology in ovarian cancer: results from the Nurses' Health Study

BACKGROUND

Tissue microarrays (TMAs) allow high-throughput evaluation of protein expression from archived tissue samples. We identified characteristics specific to ovarian cancer that may influence TMA interpretation.

METHODS

TMAs were constructed using triplicate core samples from 174 epithelial ovarian cancers. Stains for p53, Ki-67, estrogen receptor-alpha, progesterone receptor, Her-2, WT-1, cytokeratin 7, and cytokeratin 20 were evaluated by intraclass correlation coefficients, Spearman correlation coefficients, the effect of sample age, and tumor histology on the ability to score the cores, and inter-rater reliability.

RESULTS

The interclass correlation coefficient and the mean Spearman correlation coefficients among 3 cores were > or = 0.91 and 0.87, respectively. Tissue age and tumor histology were not predictive of an inability to evaluate stains, but borderline tumors had a 2 to 4-fold increase in the risk of having uninterpretable cores over invasive tumors. There was moderate to substantial concordance between the two pathologists for estrogen receptor-alpha [Cohen's Kappa (kappa), 0.79] and Ki-67 (kappa, 0.52). The prevalence of positive staining cells by histologic type was comparable with previous studies.

CONCLUSION

TMA is a valid method for evaluating antigen expression in invasive ovarian cancer but should be used with caution for borderline tumors. We suggest several methods of quality control based on intercore comparisons and show that some antigens may be affected by age of the samples.

Estrogen receptor gene amplification occurs rarely in ovarian cancer

Amplification of the gene encoding estrogen receptor-alpha occurs in about 20% of breast cancers and is an important mechanism for estrogen receptor overexpression in this tumor type. In ovarian cancer, overexpression of estrogen receptor protein has been described in more than two thirds of cases. To study a potential role of estrogen receptor-alpha gene amplification for estrogen receptor overexpression in ovarian cancer, a tumor tissue microarray containing 428 ovarian cancers was analyzed by fluorescence in situ hybridization for estrogen receptor-alpha gene amplification and immunohistochemistry for estrogen receptor expression. The estrogen receptor-alpha gene status was successfully determined in 243 of 428 arrayed cancers. Estrogen receptor gene amplification was found in 5 of 243 (2%) of tumors. Amplification levels were usually low, with 4-8 estrogen receptor-alpha gene copies. However, one case had a high-level amplification, with more than 30 estrogen receptor-alpha gene copies. All five amplified tumors were estrogen receptor positive, with 3 of 5 tumors showing highest (Allred score, 7-8) estrogen receptor levels. The data demonstrate that estrogen receptor-alpha amplification occurs only rarely in ovarian cancer.

Clear cell adenocarcinoma of urinary bladder and urethra: another urinary tract lesion immunoreactive for P504S

CONTEXT

Clear cell carcinoma of the urinary bladder/ urethra is a rare tumor histologically resembling the neoplasms in the female genital tract. Adequate characterization of this tumor has been hampered by its rarity. alpha-Methylacyl-CoA racemase (AMACR)/P504S has been reported to be positive in prostatic adenocarcinoma, papillary renal cell carcinoma, and gastrointestinal neoplasmas; however, it has never been studied in clear cell carcinoma of the lower urinary tract.

OBJECTIVE

To investigate the immunohistochemical staining profile in 4 primary clear cell carcinomas of the urinary tract, including P504S, which has not been previously evaluated in these tumors.

DESIGN

Four cases of clear cell adenocarcinoma were retrieved from our archives: 2 cases from the urinary bladder (one each from a man and a woman) and 2 cases from the urethra (both from women, 1 in a diverticulum). Immunohistochemistry performed on the cases were P504S, K903, cytokeratin (CK) 7, CK20, CA 125, and p63.

RESULTS

We found that clear cell carcinomas had a distinct immunoreactive profile: strongly positive for P504S, K903, and CK7, and negative for p63. Two cases were also positive for CA 125 and CK20.

CONCLUSION

The immunohistochemical profile of clear cell carcinomas shares some similarity to conventional urothelial carcinoma; however, it deviates from those tumors in being positive for P504S and negative for p63. This staining profile may suggest a nonurothelial origin for these tumors, may serve as a useful tool in the differential diagnosis of this tumor, and may reflect its etiology. Because similar expression of P504S is also seen in nephrogenic adenomas, this marker should not be used to differentiate nephrogenic adenomas from clear cell adenocarcinomas.

Silent venous thromboembolism before treatment in endometrial cancer and the risk factors

Venous thromboembolism (VTE) often occurs after surgery and can even occur before surgery in patients with gynaecological malignancies. We investigated the incidence of VTE before treatment of endometrial cancer and associated risk factors. Plasma D-dimer (DD) levels before initial treatment were examined in 171 consecutive patients with endometrial cancer. Venous ultrasound imaging (VUI) of the lower extremities was performed in patients with DD ⩾1.5 μg ml⁻¹, as the negative predictive value of DD for VTE is extremely high. For patients with deep vein thrombosis (DVT), pulmonary scintigraphy was performed to ascertain the presence of pulmonary thromboembolism (PTE). Risk factors for VTE were analysed using univariate and multivariate analyses for 171 patients. Of these, 37 patients (21.6%) showed DD ⩾1.5 μg ml⁻¹, 17 (9.9%) displayed DVT by VUI and 8 (4.7%) showed PTE on pulmonary scintigraphy. All patients with VTE were asymptomatic. Univariate analysis for various risk factors revealed older age, non-endometrioid histology and several variables of advanced disease as significantly associated with VTE before treatment. Obesity, smoking and diabetes mellitus were not risk factors. Multivariate analysis confirmed extrauterine spread and non-endometrioid histology as independently and significantly associated with risk of VTE. These data suggest that silent or subclinical VTE occurs before treatment in at least around 10% of patients with endometrial cancer. Risk factors for VTE before treatment might not be identical to those after starting treatment.

Clinical implications of the ErbB/epidermal growth factor (EGF) receptor family and its ligands in ovarian cancer

The ERBB or EGF receptor (EGFR) proto-oncogene family, which consists of four structurally-related transmembrane receptors (i.e., EGFR, ErbB2, ErbB3, and ErbB4), plays an etiological role in the molecular pathogenesis of cancer and is a key therapeutic target in many types of cancer, including ovarian cancer. These ErbB/EGF receptor tyrosine kinases play important physiologic roles in cell proliferation, survival, adhesion, motility, invasion, and angiogenesis. It is, therefore, not surprising that gene amplification, genetic mutation, and altered transcription/translation result in aberrant ErbB/EGF receptor expression and/or signal transduction, contributing to the development of malignant transformation. Clinically, the diagnostic, prognostic, and theragnostic significance of any single ErbB receptor and/or ErbB ligand is controversial, but generally, ErbB receptor overexpression has been correlated with poor prognosis and decreased therapeutic responsiveness in ovarian cancer patients. Thus, anticancer agents targeting ErbB/EGF receptors hold great promise for personalized cancer treatment. Yet, challenges remain in designing prospective clinical trials to assess the clinical utility of ErbB receptors and their ligands to diagnose cancer; to predict progression-free and overall survival, therapeutic responsiveness, and disease recurrence; and to monitor treatment responsiveness. Here, we review the tissue expression and serum biomarker studies that have evaluated the diagnostic, prognostic, and theragnostic utility of ErbB/EGF receptors, their circulating soluble isoforms (sEGFR/sErbBs), and their cognate ligands in ovarian cancer patients.