HER2/ ERBB2 Immunohistochemical Expression and Copy Number Status in Ovarian Mucinous Tumors.

Primary mucinous ovarian carcinoma (MOC) is a rare ovarian epithelial cancer, which is often refractory to chemotherapy. HER2-targeting therapy is being increasingly considered in gynecologic malignancies. Although there have been limited studies examining the HER2 status of such tumors, the criteria for HER2 expression scoring have not been standardized for MOC as it has for other sites. This study aimed to survey immunohistochemical HER2 expression patterns in MOC and its precursor, mucinous borderline tumor in correlation with fluorescence in situ hybridization (FISH). Immunohistochemistry (IHC) for HER2 was performed on 12 cases of MOC and 15 mucinous borderline tumors, including 7 with intraepithelial carcinoma. HER2 expression was quantified using the gastric/gastroesophageal carcinoma protocol. Cases were considered 3+ if the tumor cells displayed strong complete or basolateral/lateral membranous staining in ≥10% of tumor cells. Cases (2+) had weak to moderate staining in ≥10% of tumor cells. Cases (1+) had faint staining in ≥10% of tumor cells. Cases considered 0 had no staining or faint staining in <10% of tumor cells. HER2 expression was also quantified with the endometrial serous carcinoma protocol, which uses a 30% tumor cell positivity cutoff. FISH for HER2 was performed on all 3+ and 2+ and a subset of 1+ cases. Of the MOC cases, 25% were 3+ and 1 mucinous borderline tumor with intraepithelial carcinoma had 3+ staining. All 3+ IHC MOC cases had >30% basolateral membranous staining. HER2 amplification was confirmed by FISH on all 3+ IHC cases and in one 2+ IHC case of MOC. Up to 25% of mucinous ovarian tumors showed HER2 IHC overexpression with an excellent correlation between IHC and FISH using the HER2 scoring protocol for either gastric/gastroesophageal carcinoma or uterine serous carcinoma.

A Rare PDGFRA Exon 15 Germline Mutation Identified in a Patient With Phenotypic Manifestations Concerning for GIST-Plus Syndrome: A Case Report and Review of Literature.

Molecular alterations in PDGFRA are well-described as drivers of sporadic gastrointestinal stromal tumors (GISTs) and inflammatory fibroid polyps (IFPs). However, a small number of families with germline PDGFRA mutations in exons 12, 14, and 18 have been reported, forming the basis of an autosomal dominant inherited disorder with incomplete penetrance and variable expressivity, now referred to as PDGFRA-mutant syndrome or GIST-plus syndrome. Phenotypic manifestations of this rare syndrome include multiple gastrointestinal GISTS, IFPs, fibrous tumors, and other variable features. Herein, we report the case of a 58-year-old female who presented with a gastric GIST and numerous small intestinal IFPs, found to harbor a previously undescribed germline PDGFRA exon 15 p.G680R mutation. Somatic tumor testing was performed on the GIST, a duodenal IFP, and an ileal IFP utilizing a targeted next-generation sequencing panel, revealing additional and distinct secondary PDGFRA exon 12 somatic mutations in each of the 3 tumors. Our findings raise important considerations regarding mechanisms of tumor development in patients with underlying germline PDGFRA alterations and highlight the potential utility of expanding currently available germline and somatic testing panels to include exons outside the typical hotspot regions.

Current Laboratory Testing Practices for Assessment of ERBB2/HER2 in Endometrial Serous Carcinoma and Colorectal Carcinoma.

CONTEXT.­: Therapy targeted at human epidermal growth factor receptor 2 (HER2; also known as ERBB2) was used initially for breast and gastroesophageal carcinoma and has more recently been adopted for endometrial serous carcinoma (ESC) and colorectal carcinoma (CRC). There is evidence that predictive biomarker testing algorithms for HER2 must be tumor type specific and that an algorithm validated for one tumor type cannot be applied to another. OBJECTIVE.­: To describe current laboratory practices for HER2 assessment in ESC and CRC. DESIGN.­: We surveyed laboratories participating in the 2021 College of American Pathologists (CAP) HER2 immunohistochemistry proficiency testing program. RESULTS.­: The survey was distributed to 1548 laboratories and returned by 1195, of which 83.5% (998) were in the United States. For ESC, 24.0% (287) of laboratories reported performing in-house testing for HER2 by immunohistochemical staining and/or in situ hybridization; of these, 44.3% (127) performed it reflexively on all cases of ESC. The most common criterion for evaluating HER2 was the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma (69.0%; 194 of 281), whereas only 16.0% (45) of laboratories used guidelines specific to ESC. For CRC, 20.2% (239 of 1185) of laboratories performed in-house HER2 testing, and 82.0% of these (196) did the test only at the clinician's request. A plurality (49.4%; 115 of 233) used gastroesophageal cancer guidelines when scoring CRC, 30.0% (70) used the CRC scoring system from the HERACLES trial, and 16.3% (38) used the American Society of Clinical Oncology/CAP 2018 guideline for breast carcinoma. CONCLUSIONS.­: Laboratories vary in their approach to HER2 testing in ESC and CRC. Most laboratories did not report using tumor type-specific recommendations for HER2 interpretation. The lack of standardization could present a challenge to evidence-based practice when considering targeted therapy for these diseases.

Neoplastic Cellularity Assessment in Molecular Testing.

CONTEXT.­: Neoplastic cellularity assessment has become an essential component of molecular oncology testing; however, there are currently no best practice recommendations or guidelines for this potentially variable step in the testing process. OBJECTIVE.­: To describe the domestic and international practices of neoplastic cellularity assessment and to determine how variations in laboratory practices affect neoplastic cellularity assessment accuracy. DESIGN.­: Data were derived from 57 US and international laboratories that participated in the 2019 College of American Pathologists Neoplastic Cellularity Proficiency Testing Survey (NEO-B 2019). NEO-B 2019 included 29 laboratory practice questions and 5 images exhibiting challenging histologic features. Participants assessed the neoplastic cellularity of hematoxylin-eosin-stained digital images, and results were compared to a criterion standard derived from a manual cell count. RESULTS.­: The survey responses showed variations in the laboratory practices for the assessment of neoplastic cellularity, including the definition of neoplastic cellularity, assessment methodology, counting practices, and quality assurance practices. In some instances, variation in laboratory practice affected neoplastic cellularity assessment performance. CONCLUSIONS.­: The results highlight the need for a consensus definition and improved standardization of the assessment of neoplastic cellularity. We put forth an initial set of best practice recommendations to begin the process of standardizing neoplastic cellularity assessment.

Improving the quality of care for patients with advanced epithelial ovarian cancer: Program components, implementation barriers, and recommendations.

The high lethality of ovarian cancer in the United States and associated complexities of the patient journey across the cancer care continuum warrant an assessment of current practices and barriers to quality care in the United States. The objectives of this study were to identify and assess key components in the provision of high-quality care delivery for patients with ovarian cancer, identify challenges in the implementation of best practices, and develop corresponding quality-related recommendations to guide multidisciplinary ovarian cancer programs and practices. This multiphase ovarian cancer quality-care initiative was guided by a multidisciplinary expert steering committee, including gynecologic oncologists, pathologists, a genetic counselor, a nurse navigator, social workers, and cancer center administrators. Key partnerships were also established. A collaborative approach was adopted to develop comprehensive recommendations by identifying ideal quality-of-care program components in advanced epithelial ovarian cancer management. The core program components included: care coordination and patient education, prevention and screening, diagnosis and initial management, treatment planning, disease surveillance, equity in care, and quality of life. Quality-directed recommendations were developed across 7 core program components, with a focus on ensuring high-quality ovarian cancer care delivery for patients through improved patient education and engagement by addressing unmet medical and supportive care needs. Implementation challenges were described, and key recommendations to overcome barriers were provided. The recommendations emerging from this initiative can serve as a comprehensive resource guide for multidisciplinary cancer practices, providers, and other stakeholders working to provide quality-directed cancer care for patients diagnosed with ovarian cancer and their families.

A point mutation in the photosystem I P700 chlorophyll a apoprotein A1 gene confers variegation in Helianthus annuus L.

KEY MESSAGE: Even a point mutation in the psaA gene mediates chlorophyll deficiency. The role of the plastid signal may perform the redox state of the compounds on the acceptor-side of PSI. Two extranuclear variegated mutants of sunflower, Var1 and Var33, were investigated. The yellow sectors of both mutants were characterized by an extremely low chlorophyll and carotenoid content, as well as poorly developed, unstacked thylakoid membranes. A full-genome sequencing of the cpDNA revealed mutations in the psaA gene in both Var1 and Var33. The cpDNA from the yellow sectors of Var1 differs from those in the wild type by only a single, non-synonymous substitution (Gly734Glu) in the psaA gene, which encodes a subunit of photosystem (PS) I. In the cpDNA from the yellow sectors of Var33, the single-nucleotide insertion in the psaA gene was revealed, leading to frameshift at the 580 amino acid position. Analysis of the photosynthetic electron transport demonstrated an inhibition of the PSI and PSII activities in the yellow tissues of the mutant plants. It has been suggested that mutations in the psaA gene of both Var1 and Var33 led to the disruption of PSI. Due to the non-functional PSI, photosynthetic electron transport is blocked, which, in turn, leads to photodamage of PSII. These data are confirmed by immunoblotting analysis, which showed a significant reduction in PsbA in the yellow leaf sectors, but not PsaA. The expression of chloroplast and nuclear genes encoding the PSI subunits (psaA, psaB, and PSAN), the PSII subunits (psbA, psbB, and PSBW), the antenna proteins (LHCA1, LHCB1, and LHCB4), the ribulose 1.5-bisphosphate carboxylase subunits (rbcL and RbcS), and enzymes of chlorophyll biosynthesis were down-regulated in the yellow leaf tissue. The extremely reduced transcriptional activity of the two protochlorophyllide oxidoreductase (POR) genes involved in chlorophyll biosynthesis is noteworthy. The disruption of NADPH synthesis, due to the non-functional PSI, probably led to a significant reduction in NADPH-protochlorophyllide oxidoreductase in the yellow sectors of Var1 and Var33. A dramatic decrease in chlorophyllide was shown in the yellow sectors. A reduction in NADPH-protochlorophyllide oxidoreductase, along with photodegradation, has been suggested as a result of chlorophyll deficiency.

International Society of Gynecological Pathologists (ISGyP) Endometrial Cancer Project: Guidelines From the Special Techniques and Ancillary Studies Group.

The aim of this article is to propose guidelines and recommendations in problematic areas in pathologic reporting of endometrial carcinoma (EC) regarding special techniques and ancillary studies. An organizing committee designed a comprehensive survey with different questions related to pathologic features, diagnosis, and prognosis of EC that was sent to all members of the International Society of Gynecological Pathologists. The special techniques/ancillary studies group received 4 different questions to be addressed. Five members of the group reviewed the literature and came up with recommendations and an accompanying text which were discussed and agreed upon by all members of the group. Twelve different recommendations are made. They address the value of immunohistochemistry, ploidy, and molecular analysis for assessing prognosis in EC, the value of steroid hormone receptor analysis to predict response to hormone therapy, and parameters regarding applying immunohistochemistry and molecular tests for assessing mismatch deficiency in EC.

Distinct Biological Types of Ocular Adnexal Sebaceous Carcinoma: HPV-Driven and Virus-Negative Tumors Arise through Nonoverlapping Molecular-Genetic Alterations.

PURPOSE: Ocular adnexal (OA) sebaceous carcinoma is an aggressive malignancy of the eyelid and ocular adnexa that frequently recurs and metastasizes, and effective therapies beyond surgical excision are lacking. There remains a critical need to define the molecular-genetic drivers of the disease to understand carcinomagenesis and progression and to devise novel treatment strategies. EXPERIMENTAL DESIGN: We present next-generation sequencing of a targeted panel of cancer-associated genes in 42 and whole transcriptome RNA sequencing from eight OA sebaceous carcinomas from 29 patients. RESULTS: We delineate two potentially distinct molecular-genetic subtypes of OA sebaceous carcinoma. The first is defined by somatic mutations impacting TP53 and/or RB1 [20/29 (70%) patients, including 10 patients whose primary tumors contained coexisting TP53 and RB1 mutations] with frequent concomitant mutations affecting NOTCH genes. These tumors arise in older patients and show frequent local recurrence. The second subtype [9/29 (31%) patients] lacks mutations affecting TP53, RB1, or NOTCH family members, but in 44% (4/9) of these tumors, RNA sequencing and in situ hybridization studies confirm transcriptionally active high-risk human papillomavirus. These tumors arise in younger patients and have not shown local recurrence. CONCLUSIONS: Together, our findings establish a potential molecular-genetic framework by which to understand the development and progression of OA sebaceous carcinoma and provide key molecular-genetic insights to direct the design of novel therapeutic interventions.

Gene Expression Analysis Identifies Novel Targets for Cervical Cancer Therapy.

Although there has been significant progress in prevention and treatment of cervical cancer, this malignancy is still a leading cause of cancer death for women. Anti-angiogenesis and immunotherapy approaches have been providing survival benefits, however, response rates and durability of response need to be improved. There is a clear need for combination therapies that increase effectiveness of these agents and further improve patient outcome. Previous studies have largely focused on gene expression and molecular pathways in untreated cervix cancer. The goal of this study was to evaluate cancer-specific molecular pathways and their correlation with tumor immune profile in recurrent cervical cancer. Tumor and adjacent normal tissues were used to identify potential combination therapy targets. We found that DNA damage repair pathway genes were significantly overexpressed in the tumor. Based on our results and other recent investigations, we suggest that combination immune checkpoint and PARP inhibitor therapy is a high priority consideration for patients with recurrent, previously treated cervical cancer. We also show that multiple epithelial-mesenchymal transition-related genes, including MAP2K4, ID2, JAK1, FGF2, PIK3R1, AKT3, FGF13, and STAT3 may be potential targets. Interestingly, high-throughput analysis of Cancer Genome Atlas data identified distinct targets, including Fatty acid synthase FASN and Matrix Metallopeptidase 1 MMP1 as novel, promising combination therapy partners.

Challenges in next generation sequencing analysis of somatic mutations in transplant patients.

Analysis of somatic mutations in solid tumors and hematologic malignancies using targeted next generation sequencing (NGS)-based assays has become part of routine oncology practice as well as clinical trials. The use of paired tumor-normal DNA samples increases confidence of somatic calls. NGS assays that utilize unique patient identifiers (SNP IDs) allow further comparison of samples within a run or paired tumor/normal samples. The sources of germline DNA include peripheral blood (PB) and formalin-fixed paraffin-embedded tissue (FFPE). However, the source of normal can be problematic, especially in transplant setting. Herein, we report two cases of NGS-based molecular testing in a patient with mycosis fungoides treated with stem cell transplant [SCT] (Pt1) and a patient with lung adenocarcinoma who previously had acute leukemia cured by SCT. These cases highlight the importance of selecting an appropriate normal sample for excluding germline polymorphisms during somatic mutation testing. Initial analyses that included concurrent PB sample failed to filter known germline polymorphisms. Repeat analyses using pre-transplant PB/bone marrow allowed for the successful subtraction of germline variants. Somatic mutations in PTEN and ERBB4 (Pt1) and CDKN2A, KRAS, KDR, and TP53 (Pt2) were reported with confidence. Selection of an appropriate source of germline DNA for NGS-based somatic mutation testing for patients with SCT transplant can be challenging. Particular attention to the clinical history is crucial for accurate interpretation and reporting.

Early and consistent overexpression of ADRM1 in ovarian high-grade serous carcinoma.

BACKGROUND: Ovarian carcinoma is highly dependent on the ubiquitin proteasome system (UPS), but its clinical response to treatment with the proteasome inhibitor bortezomib has been disappointing. This has driven exploration of alternate approaches to target the UPS in ovarian cancer. Recently, proteasome inhibitors targeting the 19S regulatory particle-associated RPN13 protein have been described, such as RA190. RPN13, which is encoded by ADRM1, facilitates the recognition by the proteasome of its polyubiquinated substrates. Inhibition of RPN13 produces a rapid, toxic accumulation of polyubiquitinated proteins in ovarian and other cancer cells, triggering apoptosis. Here, we sought to determine if RPN13 is available as a target in precursors of ovarian/fallopian tube cancer as well as all advanced cases, and the impact of increased ADRM1 gene copy number on sensitivity of ovarian cancer to RA190. METHODS: ADRM1 mRNA was quantified by RNAscope in situ hybridization and RPN13 protein detected by immunohistochemistry in high grade serous carcinoma (HGSC) of the ovary and serous tubal intraepithelial carcinoma (STIC). Amplification of ADRM1 and sensitivity to RA190 were determined in ovarian cancer cell lines. RESULTS: Here, we demonstrate that expression of ADRM1mRNA is significantly elevated in STIC and HGSC as compared to normal fallopian tube epithelium. ADRM1 mRNA and RPN13 were ubiquitously and robustly expressed in ovarian carcinoma tissue and cell lines. No correlation was found between ADRM1 amplification and sensitivity of ovarian cancer cell lines to RA190, but all were susceptible. CONCLUSIONS: RPN13 can potentially be targeted by RA190 in both in situ and metastatic ovarian carcinoma. Ovarian cancer cell lines are sensitive to RA190 regardless of whether the ADRM1 gene is amplified.

Interobserver Reproducibility Among Gynecologic Pathologists in Diagnosing Heterologous Osteosarcomatous Component in Gynecologic Tract Carcinosarcomas.

Distinguishing hyalinized stroma from osteoid production by a heterologous osteosarcomatous component can be challenging in gynecologic tract carcinosarcomas. As heterologous components in a carcinosarcoma may have prognostic and therapeutic implications, it is important that these are recognized. This study examines interobserver reproducibility among gynecologic pathologists in the diagnosis of osteosarcomatous components, and its correlation with expression of the novel antibody SATB2 (marker of osteoblastic differentiation) in these osteosarcomatous foci. Digital H&E images from 20 gynecologic tract carcinosarcomas were reviewed by 22 gynecologic pathologists with a request to determine the presence or absence of an osteosarcomatous component. The 20 preselected cases included areas of classic heterologous osteosarcoma (malignant cells producing osteoid; n=10) and osteosarcoma mimics (malignant cells with admixed nonosteoid matrix; n=10). Interobserver agreement was evaluated and SATB2 scored on all 20 cases and compared with the original diagnoses. Moderate agreement (Fleiss' κ=0.483) was identified for the 22 raters scoring the 20 cases with a median sensitivity of 7/10 and a median specificity of 9/10 for the diagnosis of osteosarcoma. SATB2 showed 100% sensitivity (10/10) and 60% (6/10) specificity in discriminating classic osteosarcoma from osteosarcoma mimics. Utilizing negative SATB2 as a surrogate marker to exclude osteosarcoma, 73% (16/22) of the reviewers would have downgraded at least 1 case to not contain an osteosarcomatous component (range, 1-6 cases, median 1 case). Gynecologic pathologists demonstrate only a moderate level of agreement in the diagnosis of heterologous osteosarcoma based on morphologic grounds. In such instances, a negative SATB2 staining may assist in increasing accuracy in the diagnosis of an osteosarcomatous component.

Potential immunotherapy targets in recurrent cervical cancer.

OBJECTIVE: Our objective was to characterize the intra and peritumoral immune profile in recurrent cervical cancers to identify rational immunotherapy targets. METHODS: Archival pelvic exenteration specimens were examined using a validated multiplex immuno-fluorescent panel of antibodies against cluster of differentiation 8 (CD8), cluster of differentiation 68 (CD68), forkhead box P3 (FoxP3), programmed cell death protein 1 (PD1), and programmed death-ligand 1 (PD-L1, N=28). Clinical data were abstracted from the electronic medical record. RESULTS: Cytotoxic T cells, macrophages, and regulatory T cells were found in higher densities in peritumoral stroma (CD8+ density 497.7 vs 83.5, p<0.0001, CD68+ density 345.0 vs 196.7, p=0.04, FoxP3+ density 214.5 vs 35.6, p<0.0001). Antigen experienced T cells (PD1+) were higher in peritumoral compared to tumor tissue (median normalized fluorescence intensity 0.05 vs 0.0085, p<0.001). Although there was a higher median density of intratumoral cytotoxic T cells and macrophages compared to regulatory T cells (median density CD8+ 83.5 vs 35.6, p<0.05, median density 196.7 vs 35.6, p<0.05), the presence of macrophages correlated with the presence of regulatory T cells in tumors (r=0.58, p=0.001). CONCLUSIONS: While cytotoxic T cells are present in tumor tissue to varying degrees, their density is lower than in peritumoral stroma, suggesting intratumoral exclusion or destruction of T cells. Higher densities of intratumoral macrophages compared to regulatory T cells suggest macrophages may be important contributors to the immunosuppressive tumor environment. Future directions for combination therapy include altering T cell trafficking and targeting tumor associated macrophages (TAMs) to enhance intratumoral activated T cell density and effect a more robust immune response.

Primary Glial and Neuronal Tumors of the Ovary or Peritoneum: A Clinicopathologic Study of 11 Cases.

Primary glial and neuronal tumors of the ovary or peritoneum are rare neuroectodermal-type tumors similar to their counterparts in the central nervous system. We retrospectively reviewed 11 cases. These cases included 4 ependymomas, 6 astrocytic tumors, and 1 neurocytoma. Patients' age ranged from 9 to 50 years (mean, 26 y; median, 24 y). All ependymal tumors with detailed clinical history (n=3) were not associated with any other ovarian neoplasm. In contrast, all astrocytic tumors were associated with immature teratoma (n=4), mature cystic teratoma (n=1), or mixed germ cell tumor (n=1). The neurocytoma arose in association with mature teratomatous components in a patient with a history of treated mixed germ cell tumor. Immunohistochemical staining showed that 7 of 7 ependymal and astrocytic tumors (100%) were positive for glial fibrillary acidic protein, and 2 of 2 ependymomas (100%) were positive for both estrogen and progesterone receptors. The neurocytoma was positive for synaptophysin and negative for S100 protein, glial fibrillary acidic protein, and SALL4. No IDH1-R132H mutation was detected in 2 of 2 (0%) astrocytomas by immunohistochemistry. Next-generation sequencing was performed on additional 2 ependymomas and 2 astrocytomas but detected no mutations in a panel of 50 genes that included IDH1, IDH2, TP53, PIK3CA, EGFR, BRAF, and PTEN. Follow-up information was available for 8 patients, with the follow-up period ranging from 4 to 59 months (mean, 15 mo; median, 8.5 mo), of which 3 had no evidence of disease and 5 were alive with disease. In conclusion, primary glial and neuronal tumors of the ovary can arise independently or in association with other ovarian germ cell tumor components. Pathologists should be aware of these rare tumors and differentiate them from other ovarian neoplasms. Even though an IDH1 or IDH2 mutation is found in the majority of WHO grade II and III astrocytomas, and in secondary glioblastomas arising from them, such mutations were not identified in our series, suggesting that these tumors are molecularly different from their central nervous system counterparts despite their morphologic and immunophenotypic similarities.

Incidental Serous Tubal Intraepithelial Carcinoma and Non-Neoplastic Conditions of the Fallopian Tubes in Grossly Normal Adnexa: A Clinicopathologic Study of 388 Completely Embedded Cases.

Serous tubal intraepithelial carcinoma (STIC), the putative precursor of the majority of extrauterine high-grade serous carcinomas, has been reported in both high-risk women (those with a germline BRCA mutation, a personal history of breast carcinoma, and/or family history of breast or ovarian carcinoma) and average risk women from the general population. We reviewed grossly normal adnexal specimens from 388 consecutive, unselected women undergoing surgery, including those with germline BRCA mutation (37 patients), personal history of breast cancer or family history of breast/ovarian cancer (74 patients), endometrial cancer (175 patients), and a variety of other conditions (102 patients). Among 111 high-risk cases and 277 non-high-risk cases, 3 STICs were identified (0.8%), all in non-high-risk women (high risk vs. non-high risk: P=not significant). STIC was found in 2 women with nonserous endometrial carcinoma and 1 with complex atypical endometrial hyperplasia. Salpingoliths (mucosal calcifications), found in 9% of high-risk cases, and fimbrial adenofibromas in 9.9% of high-risk cases, were significantly more common in high-risk as compared with non-high-risk women (1.8% and 2.5%, respectively; P<0.007). Mucinous metaplasia was found in 3.1%, salpingitis isthmica nodosa in 3.4%, hemosiderin or pseudoxanthoma cells in 4.9%, and fibrous luminal nodules in 4.1%. None of these latter features differed significantly in the high-risk versus non-high-risk groups. These findings suggest a possible association between STIC and endometrial hyperplasia and carcinoma, and clarify the frequency of non-neoplastic tubal findings in grossly normal fallopian tubes.

Distribution and case-fatality ratios by cell-type for ovarian carcinomas: a 22-year series of 562 patients with uniform current histological classification.

BACKGROUND: Ovarian carcinoma is comprised of several different cell types reflecting different clinicopathologic features. Pathologic criteria for distinguishing cell types have evolved, and therefore non-contemporary literature on ovarian cancer may have limited current relevance. A new dualistic model of pathogenesis that distinguishes type I (endometrioid, mucinous, clear cell and low grade serous carcinomas) from type II (high grade serous carcinomas and carcinosarcomas) tumors has become widely accepted. METHODS: A cohort of 562 patients with invasive ovarian carcinoma from a large community hospital practice was reviewed. Cell type, FIGO stage, mortality and interpathologist diagnostic reproducibility were analyzed. RESULTS: Advanced stage ovarian carcinomas were type II in 86% of cases while low stage tumors were most often type I. Only 1.7% of type II tumors were confirmed to be stage I with comprehensive surgical staging. Type II tumors accounted for 85% of deaths, and clear cell carcinomas, 5% of deaths. Cell type-specific case-fatality ratios for type II tumors were 62% and 79% for high grade serous carcinoma and carcinosarcoma, respectively. For type I tumors, case-fatality ratios were 38%, 36%, 27% and 13% for low grade serous, clear cell, endometrioid and mucinous carcinomas, respectively. The kappa value for diagnostic reproducibility among 3 gynecologic pathologists was 0.83. CONCLUSIONS: Current diagnostic criteria confirm that high grade serous carcinoma and carcinosarcoma account for the vast majority (85%) of ovarian cancer deaths. Cell type designation is highly reproducible among gynecologic pathologists. Type II tumors are rarely stage I (<2%) when comprehensively staged by a gynecologic oncologist.

Molecular alterations of PIK3CA in uterine carcinosarcoma, clear cell, and serous tumors.

OBJECTIVES: Type II endometrial carcinomas-uterine carcinosarcomas or uterine malignant mesodermal mixed tumors (UMMMTs), clear cell carcinomas (UCCs), and uterine serous carcinomas (USCs)-are aggressive malignancies that present with advanced disease and have high mortality rates. PIK3CA mutations are commonly found in endometrial cancers. The objective of the study was to characterize molecular alterations in the PIK3CA gene in these tumors. METHODS: A total of 84 cases (20 UMMMTs, 18 UCCs, and 46 USCs) were selected from the surgical pathology files of Weill Cornell Medical College and Johns Hopkins Hospital. The diagnoses were confirmed by gynecologic pathologists (L.H.E. and A.Y.). DNA was extracted from paraffin-embedded tissue. Polymerase chain reaction was performed for mutational analysis. All the studies were performed in accordance with approved Institutional Review Board protocols. RESULTS: Mutations in the PIK3CA gene were identified in 3 (15%) of 20 UMMMT, 3 (16.7%) of 18 UCC, and 10 (21.7%) of 46 USC cases. We report novel mutations in PIK3CA in uterine carcinosarcoma. CONCLUSIONS: A significant percentage of UMMMTs, UCCs, and USCs have mutations in PIK3CA. Further investigation is needed to develop targeted therapies for these aggressive uterine cancers.

PAX8 expression in uterine adenocarcinomas and mesonephric proliferations.

PAX8 is a useful immunohistochemical marker for the diagnosis of gynecologic tract malignancies. Several studies have described PAX8 expression in a wide variety of epithelial neoplasms, including ovarian and endometrial carcinomas. The goal of this study was to evaluate PAX8 expression in various types of uterine adenocarcinomas and mesonephric proliferations. Ninety-four cases of uterine adenocarcinomas (52 endometrial endometrioid carcinomas, 21 endometrial serous carcinomas, and 21 human papillomavirus-related endocervical carcinomas), 11 cases of benign mesonephric proliferations (remnants/hyperplasia), and normal endometrial and endocervical glandular epithelium in 58 cases were studied. Immunohistochemical staining was performed with the rabbit polyclonal anti-PAX8 antibody. All adenocarcinoma groups demonstrated a high frequency of PAX8 expression but with relatively high variability in the extent of staining among different subtypes. Both serous carcinomas and endometrioid carcinomas were positive in most cases (95% and 96%, respectively), but serous carcinomas displayed a significantly higher level of expression (immunohistochemical composite scores based on combined extent and intensity of expression) compared with endometrioid carcinomas (mean immunohistochemical composite scores: 8.3 vs. 5.3, respectively; P<0.006). Endocervical adenocarcinomas also had a high frequency of PAX8 expression (86% of cases), but the level of expression was significantly less than that of endometrial adenocarcinomas (mean immunohistochemical composite scores: 2.9 vs. 5.3-8.3, respectively; P<0.004). Among benign glandular epithelia, normal endocervical glands exhibited a significantly lower level of expression compared with either normal endometrial glands or benign mesonephric proliferations (mean immunohistochemical composite scores: 2.6 vs. 6.6-11.2, respectively; P<0.0006). We conclude that PAX8 is expressed in the vast majority of uterine adenocarcinomas, including those of both endometrial and endocervical origin, and that the level of expression based on combined extent and intensity is highest in endometrial serous carcinoma and lowest in endocervical adenocarcinoma. However, the high prevalence of PAX8 expression in the various types of uterine adenocarcinomas precludes use of this marker for distinguishing these tumors. In extrauterine sites, PAX8 can serve as a useful marker for adenocarcinomas of uterine origin (also positive in the majority of ovarian carcinomas), being most sensitive for identification of endometrial adenocarcinomas (both serous and endometrioid). The sensitivity for identifying metastatic endocervical adenocarcinomas is likely less and dependent on the degree to which the significantly lower extent of expression in these tumors is maintained in metastatic sites.

PAX8 expression in uterine malignant mesodermal mixed tumor (carcinosarcoma).

PAX8 has emerged as a useful immunohistochemical marker for epithelial neoplasms of gynecologic origin. Expression of PAX8 in uterine malignant mesodermal mixed tumors (MMMT, carcinosarcoma) has not been characterized in detail. The goal of this study is to evaluate PAX8 expression in uterine MMMTs, with particular attention to its distribution in specific tumor components. Thirty-seven cases were studied. PAX8 expression was assessed by immunohistochemistry and scored separately in the epithelial and mesenchymal components of the tumors. The extent of staining was scored based on the estimated percentage of positive tumor cells as 1+: 1% to 25%; 2+: 26% to 50%; 3+: 51% to 75%; 4+: 76% to 100%. The epithelial component expressed PAX8 in all but 1 tumor, with 92% of tumors displaying 3+ and 4+ extent of staining. The mesenchymal component lacked PAX8 expression in 27 cases (73%) with variable expression in the remaining 10 cases. In addition, 12 tumors contained undifferentiated areas that were not readily classifiable as carcinoma or sarcoma based on morphologic features. Of these, 8 (67%) were negative for PAX8, whereas 4 (33%) demonstrated variable extent of expression. Thus, PAX8 is expressed in the carcinomatous components of nearly all uterine MMMTs (97%), with expression in sarcomatous and undifferentiated components being less common and less extensive. The uniform, extensive expression in the carcinomatous components makes PAX8 a useful marker for diagnosis of carcinomatous metastases of uterine MMMT at extrauterine sites. Its infrequent expression in the sarcomatous and undifferentiated components limits its utility in identifying sarcoma-predominant metastases as gynecologic in origin.

Mucoepidermoid carcinoma does not harbor transcriptionally active high risk human papillomavirus even in the absence of the MAML2 translocation.

High risk human papillomavirus (HPV) is firmly established as an important cause of oropharyngeal carcinoma. Recent studies have also implicated HPV as a cause of mucoepidermoid carcinoma (MEC)-a tumor of salivary gland origin that frequently harbors MAML2 translocations. The purpose of this study was to determine the prevalence of transcriptionally active HPV in a large group of MECs and to determine whether HPV infection and the MAML2 translocation are mutually exclusive events. Break-apart fluorescence in situ hybridization for MAML2 was performed on a tissue microarray containing 92 MECs. HPV testing was performed using RNA in situ hybridization targeting high risk HPV mRNA E6/E7 transcripts. Of the 71 MECs that could be evaluated by FISH, 57 (80 %) harbored the MAML2 rearrangement. HPV was not detected in any of the 57 MECs that contained a MAML2 rearrangement, in any of the 14 MECs that did not contain the rearrangement, or in any of the 21 MECs where MAML2 status was unknown. High risk HPV does not appear to play any significant role in the development of MEC. It neither complements nor replaces MAML2 translocation in the tumorigenesis of MEC.