Gigaxonin Suppresses Epithelial-to-Mesenchymal Transition of Human Cancer Through Downregulation of Snail.

Gigaxonin is an E3 ubiquitin ligase that plays a role in cytoskeletal stability. Its role in cancer is not yet clearly understood. Our previous studies of head and neck cancer had identified gigaxonin interacting with p16 for NFκB ubiquitination. To explore its role in cancer cell growth suppression, we analyzed normal and tumor DNA from cervical and head and neck cancers. There was a higher frequency of exon 8 SNP (c.1293 C>T, rs2608555) in the tumor (46% vs. 25% normal, P = 0.011) pointing to a relationship to cancer. Comparison of primary tumor with recurrence and metastasis did not reveal a statistical significance. Two cervical cancer cell lines, ME180 and HT3 harboring exon 8 SNP and showing T allele expression correlated with higher gigaxonin expression, reduced in vitro cell growth and enhanced cisplatin sensitivity in comparison with C allele expressing cancer cell lines. Loss of gigaxonin expression in ME180 cells through CRISPR-Cas9 or siRNA led to aggressive cancer cell growth including increased migration and Matrigel invasion. The in vitro cell growth phenotypes were reversed with re-expression of gigaxonin. Suppression of cell growth correlated with reduced Snail and increased e-cadherin expression. Mouse tail vein injection studies showed increased lung metastasis of cells with low gigaxonin expression and reduced metastasis with reexpression of gigaxonin. We have found an association between C allele expression and RNA instability and absence of multimeric protein formation. From our results, we conclude that gigaxonin expression is associated with suppression of epithelial-mesenchymal transition through inhibition of Snail. SIGNIFICANCE: Our results suggest that GAN gene exon 8 SNP T allele expression correlates with higher gigaxonin expression and suppression of aggressive cancer cell growth. There is downregulation of Snail and upregulation of e-cadherin through NFκB ubiquitination. We hypothesize that exon 8 T allele and gigaxonin expression could serve as diagnostic markers of suppression of aggressive growth of head and neck cancer.

Accuracy of frozen section remote subspecialty consultation using real-time telepathology and whole-slide imaging in gynecologic cases.

OBJECTIVES: Intrapathology consultation is recommended for complex cases during frozen section (FS) as routine practice. In our institution, solicited second opinions were traditionally provided by in-person consultation (IPC). Whole-slide imaging (WSI) was implemented in 2018 as an alternative but replaced by videoconferencing in 2020. Here, we assess the accuracy of remote FS consultation using these digital modalities vs IPC. METHODS: Gynecologic FS cases over a 4-year period overseen by 2 intraoperative consultants were grouped by consultation method: (1) IPC, (2) WSI, and (3) videoconferencing. Accuracy was determined by concordance between the FS and final report diagnoses. Turnaround time between the 3 groups was analyzed using SPSS statistical software (IBM). RESULTS: Using WSI and videoconferencing, 100% concordance was observed, while the IPC group had a 98.5% concordance rate. Videoconferencing, however, showed longer turnaround times (mean, 45.59 minutes) than IPC (mean, 33.36 minutes). Although turnaround time positively correlated with the number of FS specimens, blocks, and H&E slides per case, no statistically significant differences in the number of specimens, blocks, and H&E slides generated were found among the consultation methods. CONCLUSIONS: Even though turnaround time using videoconferencing is longer, the accuracy of WSI and videoconferencing for remote FS consultation is equivalent to IPC. It is therefore a safe method for conducting intrapathology FS consultation in challenging surgical cases.

Profiling ovarian cancer tumor and microenvironment during disease progression for cell-based immunotherapy design.

Ovarian cancer (OC) is highly lethal due to late detection and frequent recurrence. Initial treatments, comprising surgery and chemotherapy, lead to disease remission but are invariably associated with subsequent relapse. The identification of novel therapies and an improved understanding of the molecular and cellular characteristics of OC are urgently needed. Here, we conducted a comprehensive analysis of primary tumor cells and their microenvironment from 16 chemonaive and 10 recurrent OC patient samples. Profiling OC tumor biomarkers allowed for the identification of potential molecular targets for developing immunotherapies, while profiling the microenvironment yielded insights into its cellular composition and property changes between chemonaive and recurrent samples. Notably, we identified CD1d as a biomarker of the OC microenvironment and demonstrated its targeting by invariant natural killer T (iNKT) cells. Overall, our study presents a comprehensive immuno-profiling of OC tumor and microenvironment during disease progression, guiding the development of immunotherapies for OC treatment, especially for recurrent disease.

Androgen receptor and its correlation with estrogen and progesterone receptors, aimed for identification of cases for future anti-androgen therapy in endometrial cancers.

INTRODUCTION: The expression of androgen receptor (AR) is not commonly tested or studied in uterine cancers, unlike estrogen receptor (ER) and progesterone receptor (PR) which are positive in most endometrial carcinomas. In this series, we evaluated the expression of AR and its comparison to ER and PR in different types of endometrial cancers and have reviewed the literature. MATERIALS AND METHODS: The status of AR, ER, and PR expression were evaluated in 71 cases which were categorized into endometrial endometrioid cancer (EEC), non-endometrioid endometrial cancers (NEEC), and metastatic carcinomas of endometrium. Expression of the receptors were compared to each other as well as to mismatch repair proteins (MMR), p53, and body mass index (BMI) using Fisher's Exact test in the StatPlus software. RESULTS: In EECs, the positivity was 97% for all the three receptors. In NEEC, positivity rates were 68%, 48%, and 35% for AR, ER, and PR respectively. In Metastatic carcinomas, AR and ER positivity was seen in 100% while PR was positive in 75% of the cases. In all cancers, the rates were 17% (11/66) for MMR loss, 57% (30/53) for p53 aberrant expression, and 76% (54/71) for the patients with BMI of ≥ 25 (kg/m2). CONCLUSION: AR is expressed in a high percentage of endometrial cancers. Its significance is more evident in high-grade NEEC where ER and PR may not be expressed. These findings warrant further evaluation of AR expression and candidacy of this pathway as a potential therapeutic target in endometrial cancers.

"Copy number alteration" as the sole molecular finding of a Thyroseq test is more commonly seen in Hurthle cell neoplasms.

BACKGROUND: To better understand the molecular alterations associated with Hurthle cell lesions of the thyroid, we retrospectively reviewed the association of clonal DNA copy number alterations (CNAs) with fine needle aspiration (FNA) cytomorphology and surgical follow-up. METHODS: Hurthle cell type (HCT) and non-Hurthle cell type (NHCT) thyroid FNAs that were classified according to the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) as atypia of undetermined significance (AUS) and suspicious for a follicular neoplasm (SFN) with corresponding molecular testing performed by ThyroSeq v3 genomic classifier were compared to surgical follow-up. RESULTS: A total of 54 thyroid FNA cases were identified, distributed among the following categories: AUS-HCT (n = 15, 27.8%), SFN-HCT (n = 11, 20.4%), AUS-NHCT (n = 19, 35.2%), and SFN-NHCT (n = 9, 16.6%). The lesions classified as AUS-HCT and SFN-HCT showed a higher prevalence of CNAs (n = 10/26; 38.5%) compared to their NHCT counterparts (n = 3/28; 10.7%) (p < .03). Of the 42 patients (77.8%) with surgical follow-up, CNAs were more often seen in benign (n = 10/26, 38.5%) than malignant conditions (n = 1/16, 6.3%) (p < .03). CNAs were encountered in more lesions with Hurthle cell features on histologic examination (n = 8/14, 57.1%) than those without (n = 3/28, 10.7%) (p < .002). The presence of CNAs alone was seen only in benign adenomas and more commonly with Hurthle cell features (n = 5/7, 71.4%). CONCLUSION: In this study, CNAs were associated with Hurthle cell morphology on thyroid FNA and benign adenomas upon surgical follow-up. Therefore, if the only finding of a positive ThyroSeq v3 GC result is a CNA, conservative management can be considered if clinically indicated.

Use of platinum-based chemotherapy and pembrolizumab to treat squamous cell carcinoma arising in a mature teratoma of the ovary in a pre-menopausal woman with negative response: A case report.

Squamous cell carcinoma of the ovary (SCC) is a rare and aggressive disease and optimal treatment is unknown. Here we report the case of a 29- year-old woman who presented with abdominal pain and was ultimately found to have a multi-septate, gas containing pelvic mass with mixed fat, soft tissue, and calcified components concerning for a ruptured teratoma with fistulization to the distal ileum and cecum on imaging. Operative findings included a 20 cm pelvic mass arising from the right ovary with frank invasion into the ileum and cecum and dense adhesion to the anterior abdominal wall on surgical exploration. Pathologic specimens were remarkable for stage IIIC SCC of the ovary arising in a mature teratoma, with a tumor proportion score of 40%. She progressed on first line treatment with cisplatin, paclitaxel and pembrolizumab as well as second line treatment with gemcitabine and vinorelbine. She died nine months after her initial diagnosis.

Clinical history of female-to-male transgender patients is needed to avoid misinterpretation of cervical Papanicolaou tests.

OBJECTIVE: Cervical cancer screening is as important in female-to-male transgender (FTMT) patients as it is in cisgender female patients. The aim of this study was to examine the impact of clinical information regarding gender identity and testosterone therapy on the cytological interpretations. METHODS: A list of FTMT patients and cisgender female patients who had received a cervical Papanicolaou (Pap) test for cancer screening was obtained. The cytological diagnoses, rendered at the time of collection, were recorded. A retrospective slide review with knowledge of the pertinent clinical information, including testosterone therapy status, was performed. The data sets were statistically compared. RESULTS: Of 122 cervical Pap tests in 111 FTMT individuals, 23 (19%) had surgical follow-ups; 73 (60%) had HPV testing, of which 12 (16%) were positive for high-risk strains; and 79 (65%) were known to be receiving testosterone. On the "original" review, 12 (9.8%) tests were diagnosed as unsatisfactory. Seventy-one (58%) Pap tests were initially diagnosed as negative for intraepithelial lesion or malignancy (NILM) without atrophy and 32 (26%) with atrophy. Seven (5.7%) of the tests were initially diagnosed as abnormal. On the "retrospective" review, the rate of unsatisfactory tests remained the same, and atrophy was observed in 76 (62%) tests. The number of abnormal tests was reduced to 4 (3.3%) after the retrospective review. Almost all comparative studies returned a P-value of ≤0.05. CONCLUSION: Our findings indicate that clinical information regarding whether a subject is transgender and/or is receiving testosterone therapy is crucial to avoiding Pap test overcalls.

Expression of immune checkpoint regulators, programmed death-ligand 1 (PD-L1/PD-1), cytotoxic T lymphocyte antigen 4 (CTLA-4), and indolaimine-2, 3-deoxygenase (IDO) in uterine mesenchymal tumors.

BACKGROUND: Immune checkpoints including programmed death-ligand 1/programmed death-1/ (PD-L1/PD-1), cytotoxic T lymphocyte antigen 4 (CTLA-4), and indolaimine-2, 3-deoxygenase (IDO) have recently emerged as effective candidates for treatment against a range of human malignancies. We have investigated their expression in the uterine mesenchymal tumors. METHODS: Sixty-eight mesenchymal tumors were categorized into 6 diagnostic groups. We assessed PD-L1, PD-1, CTLA-4, and IDO expression on paraffin embedded tissue blocks of the uterine tumors using the respective antibodies. Immunohistochemical (IHC) stains were classified as positive when the reactions were present in at least 1% of the cell membranes for PD-L1/PD-1 or in cytoplasm for CTLA-4 and IDO, regardless of intensity. Student's t-test and McNemar's chi-square tests were carried out to analyze the results. RESULTS: The mesenchymal neoplasms had expressed the immune checkpoints in the tumor and/or the lymphoid cells at the rate of 49% and 54% respectively. The tumor cells were positive in 10 (18%, PD-L1), 0 (0%, PD-1), 18 (32%, CTLA-4), and 13 (23%, IDO) cases while the infiltrating lymphoid cells were positive in 10 (18%, PD-L1), 23 (40%, PD-1), 18 (32%, CTLA-4), and 13 (23%, IDO) cases. Overall, comparison of paired tumor vs lymphoid cells resulted in p-values of ≤ 0.04. CONCLUSIONS: Nearly 50% of the uterine tumors express at least one of the immune checkpoints in tumor and/or the infiltrating lymphoid cells. However, expression of the proteins in the two cellular components are mutually exclusive. Namely, when tumor cells express an immune checkpoint, the infiltrating lymphoid cells do not, and vice versa. Since the leiomyosarcomas are reportedly resistant to the immunotherapy when PD-L1 is expressed in the tumor cells, it can be posited that presence of the IHC positive lymphoid cells may be a better indicator of response to the treatment.

Efficacy of birinapant in combination with carboplatin in targeting platinum­resistant epithelial ovarian cancers.

Patients diagnosed with epithelial ovarian cancers (EOCs) often suffer from disease relapse associated with the emergence of resistance to standard platinum­based chemotherapy. Treatment of patients with chemo­resistant disease remains a clinical challenge. One mechanism of chemoresistance includes overexpression of pro­survival proteins called inhibitors of apoptosis (IAP) which enable cancer cells to evade apoptosis. Due to their anti­apoptotic activity, association with poor prognosis, and correlation with therapy resistance in multiple malignancies, IAP proteins have become an attractive target for development of anticancer therapeutics. Second mitochondrial activator of caspase (SMAC) mimetics are the most widely used IAP antagonists currently being tested in clinical trials as a monotherapy and in combination with different chemotherapeutic drugs to target different types of cancer. In the present study, the antitumor efficacy of combination therapy with birinapant, a bivalent SMAC mimetic compound, and carboplatin to target platinum­resistant EOC cells was investigated. A 3D organoid bioassay was utilized to test the efficacy of the combination therapy in a panel of 7 EOC cell lines and 10 platinum­resistant primary patient tumor samples. Findings from the in vitro studies demonstrated that the birinapant and carboplatin combination was effective in targeting a subset of ovarian cancer cell lines and platinum­resistant primary patient tumor samples. This combination therapy was also effective in vitro and in vivo in targeting a platinum­resistant patient­derived xenograft (PDX) model established from one of the patient tumors tested. Overall, our study demonstrated that birinapant and carboplatin combination could target a subset of platinum­resistant ovarian cancers and also highlights the potential of the 3D organoid bioassay as a preclinical tool to assess the response to chemotherapy or targeted therapies in ovarian cancer.

Expression of immune checkpoint regulators, cytotoxic T lymphocyte antigen 4 (CTLA-4), and CD137 in cervical carcinoma.

Immune checkpoint inhibitors have a significant role in oncology. One of these immune checkpoints is cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Inhibition of the CTLA-4 pathway has already led to the FDA approval of Ipilimumab (anti-CTLA-4), a targeted therapy for melanoma and other malignancies. CD137 is an inducible, costimulatory receptor of the tissue-necrosis-factor-receptor superfamily expressed on the activated immune cells. Clinical trials have also been set for anti-CD137 in several malignancies. We assessed CTLA-4 and CD137 expression on a tissue microarray (TMA) comprising of 99 core tissues which included normal, non-neoplastic, and neoplastic cervical lesions. When detected as strong granular cytoplasmic reaction in the epithelial cells, CTLA-4 expression was scored as positive. For CD137, the results were recorded based on the presence or absence of staining reaction on the cell membranes of the lymphoplasmacytic infiltrates. Overall, CTLA-4 was positive in 30% (30/100) of the cervical malignancies. Sub-categorically, 20% of invasive endocervical adenocarcinomas, 63% of adenosquamous carcinomas, and 31% of squamous cell carcinomas were positive for CTLA-4 with a tendency toward lower grade squamous cell carcinomas (SCCs). CD137 was positive in 100% lymphoplasmacytic infiltrates of endocervical adenocarcinomas, 90.5% of SCCs, and 87.5% of adenosquamous carcinomas. This study has found a significant expression of CTLA-4 in cervical cancer cells and CD137 positivity of lymphoplasmacytic infiltrates with potential for future targeted immunotherapy.

p16 is superior to Stathmin-1 and HSP27 in identifying cervical dysplasia.

BACKGROUND: The aim of this study was to determine how Stathmin-1 and Heat Shock Protein 27 (HSP27) can be used as adjunctive biomarkers to differentiate high-grade dysplasia from benign/reactive lesions in cervical tissues. In addition, we aimed to see if any of these markers can differentiate endometrial from endocervical adenocarcinomas. METHODS: Fifty cases including benign cervical tissue, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ of the endocervix, invasive endocervical adenocarcinoma, and endometrial adenocarcinoma were selected. Stathmin-1 and HSP27 immunohistochemistry (IHC) were performed for each case and the results were compared to the previously available p16 IHC stains. RESULTS: p16 stained positively in 100% of HSIL, endocervical adenocarcinoma in situ, and invasive endocervical cases. Stathmin-1 stained positively in 43% of HSIL and 90% of endocervical adenocarcinoma in situ and all invasive endocervical cases. Stathmin-1 and p16 were negative in all benign cervical samples. Stathmin-1, HSP27, and p16 stained 100% of LSIL cases. HSP27 stained indiscriminately, including 100% of benign cervical tissue. 87% of the endometrial adenocarcinomas stained positively for p16, Stathmin-1, and HSP27. CONCLUSION: p16 remains superior to both Stathmin-1 and HSP27 in differentiating dysplasia from benign, reactive changes of the cervix.

A rare case of vulvar extraskeletal myxoid chondrosarcoma: mimics and diagnostic clues.

Only 14 cases of extraskeletal myxoid chondrosarcoma (EMC) of the vulva have been documented in the literature. We report a case of a 63-year-old woman with EMC of the vulva confirmed by both EWSR1 and NR4A3 fluorescence in situ hybridization, the latter of which is a more specific probe for this entity. The unusual location of this tumor of prominent myxoid morphology gave rise to a wide differential diagnosis, which necessitated thorough histologic evaluation and confirmatory ancillary testing in the form of immunohistochemistry and cytogenetic studies. This article aims to review extraskeletal myxoid chondrosarcoma of the vulva and various diagnostic clues to help differentiate it from its histologic mimics. This is the fifth case of vulvar EMC in the literature with confirmation of a NR4A3 gene rearrangement.

ALDH1 expression predicts progression of premalignant lesions to cancer in Type I endometrial carcinomas.

In type 1 endometrial cancer, unopposed estrogen stimulation is thought to lead to endometrial hyperplasia which precedes malignant progression. Recent data from our group and others suggest that ALDH activity mediates stemness in endometrial cancer, but while aldehyde dehydrogenase 1 (ALDH1) has been suggested as a putative cancer stem cell marker in several cancer types, its clinical and prognostic value in endometrial cancer remains debated. The aim of this study was to investigate the clinical value of ALDH1 expression in endometrial hyperplasia and to determine its ability to predict progression to endometrial cancer. Interrogation of the TCGA database revealed upregulation of several isoforms in endometrial cancer, of which the ALDH1 isoforms collectively constituted the largest group. To translate its expression, a tissue microarray was previously constructed which contained a wide sampling of benign and malignant endometrial samples. The array contained a metachronous cohort of samples from individuals who either developed or did not develop endometrial cancer. Immunohistochemical staining was used to determine the intensity and frequency of ALDH1 expression. While benign proliferative and secretory endometrium showed very low levels of ALDH1, slightly higher expression was observed within the stratum basalis. In disease progression, cytoplasmic ALDH1 expression showed a step-wise increase between endometrial hyperplasia, atypical hyperplasia, and endometrial cancer. ALDH1 was also shown to be an early predictor of EC development, suggesting that it can serve as an independent prognostic indicator of patients with endometrial hyperplasia with or without atypia who would progress to cancer (p = 0.012).

Comparison of Afirma Gene Expression Classifier with Gene Sequencing Classifier in indeterminate thyroid nodules: A single-institutional experience.

INTRODUCTION: The Afirma test has been used in the diagnosis of cytologically indeterminate thyroid nodules to reduce diagnostic uncertainty and unnecessary surgeries. Gene Sequencing Classifier (GSC) was developed to improve the positive predictive value and overall test performance of Gene Expression Classifier (GEC). Here we present our experience comparing the performance of first-generation assay of Afirma (GEC) with the new assay (GSC). METHODS: Retrospective analysis was performed on all Bethesda III and IV cytology thyroid nodules tested with GEC and GSC. Test performance was evaluated by surgical pathology outcomes. RESULTS: In total, 167 cases were tested with GEC, of which 49% were reported as benign. Fourteen cases had surgical follow-up with 11 benign, one non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and two malignant diagnoses. Of the 167 cases, 51% had suspicious GEC result. Fifty-seven of these suspicious GEC cases had surgical follow-up with 28 benign, nine NIFTP and 20 malignant histology. There 133 cases tested with GSC, of which 61% were reported as benign. Ten cases had surgical follow-up, all of which showed benign results and 32% of the cases were tested as suspicious. Thirty-six cases with suspicious GSC had surgical follow-up. Fourteen of them had benign, five NIFTP, and 17 malignant surgical pathology. Based on molecular testing, surgical resection could have been be prevented 61% with GSC, compared to 49% with GEC test. CONCLUSION: Our experience shows that GSC has a better test performance than GEC. Also, our data support that GSC identify more cases as benign and reduces the number of unnecessary surgeries compared to GEC.

Tumor necrosis factor receptor signaling modulates carcinogenesis in a mouse model of breast cancer.

Pro-inflammatory conditions have long been associated with mammary carcinogenesis and breast cancer progression. The underlying mechanisms are incompletely understood but signaling of pro-inflammatory cytokine TNFα through its receptors TNFR1 and TNFR2 is a major mediator of inflammation in both obesity and in the response of tissues to radiation, 2 known risk factors for the development of breast cancer. Here, we demonstrated the loss of one TNFR2 allele led to ductal hyperplasia in the mammary gland with increased numbers of mammary epithelial stem cell and terminal end buds. Furthermore, loss of one TNFR2 allele increased the incidence of breast cancer in MMTV-Wnt1 mice and resulted in tumors with a more aggressive phenotype and metastatic potential. The underlying mechanisms include a preferential activation of canonical NF-κB signaling pathway and autocrine production of TNFα. Analysis of the TCGA dataset indicated inferior overall survival for patients with down-regulated TNFR2 expression. These findings unravel the imbalances in TNFR signaling promote the development and progression of breast cancer, indicating that selective agonists of TNFR2 could potentially modulate the risk for breast cancer in high-risk populations.

A rare case of vulvar extraskeletal myxoid chondrosarcoma: mimics and diagnostic clues

Only 14 cases of extraskeletal myxoid chondrosarcoma (EMC) of the vulva have been documented in the literature. We report a case of a 63-year-old woman with EMC of the vulva confirmed by both EWSR1 and NR4A3 fluorescence in situ hybridization, the latter of which is a more specific probe for this entity. The unusual location of this tumor of prominent myxoid morphology gave rise to a wide differential diagnosis, which necessitated thorough histologic evaluation and confirmatory ancillary testing in the form of immunohistochemistry and cytogenetic studies. This article aims to review extraskeletal myxoid chondrosarcoma of the vulva and various diagnostic clues to help differentiate it from its histologic mimics. This is the fifth case of vulvar EMC in the literature with confirmation of a NR4A3 gene rearrangement.

Rare occurrence of uterine arteriovenous malformation clinically mimicking a malignant growth: A critical reminder for pathologists.

Arteriovenous malformation (AVM) is a rare lesion in the uterus, which can lead to abnormal uterine bleeding. While AVM has been described in other organs in the literature, there is a paucity of pathology reports of the AVM in uterus. On gross examination, the uterus was markedly enlarged and partly distorted with a pedunculated solid mass, which on the cut surface showed multiple well-circumscribed hemorrhagic cysts ranging from 0.1 to 4.0 cm in size. Microscopically, they were malformed dilated vascular structures containing organized thrombi. We present this case of uterine AVM with gross and microscopic findings, which can serve as a crucial reminder for pathologists to keep in the differential diagnoses as a potential cause of abnormal uterine bleeding.

The uterine pathological features associated with sentinel lymph node metastasis in endometrial carcinomas.

BACKGROUND: In recent years, sentinel lymph node excision and ultrastaging have been performed in endometrial carcinomas to obtain information about lymph node status, avoiding unnecessary complete pelvic and paraaortic lymphadenectomy. The purpose of this retrospective study was to provide a comprehensive evaluation of the pathological features of endometrial carcinomas and their significance in association with sentinel lymph node involvement. METHODS: Patients with endometrial carcinomas, preceded by sentinel lymph node mapping, were classified into Group-I and Group-II with negative and positive involvement, respectively. The pathological features, associated with sentinel lymph node involvement, were statistically analyzed, including determination of test performance parameters. RESULTS: Among 70 patients who had undergone hysterectomy and sentinel lymph node excision, 61 had carcinoma and 9 had atypical hyperplasia. There were 50 patients in Group-I and 10 in Group-II. In Group-II, the significant pathological features were: 1) lower uterine segment involvement (100%), 2) an average tumor size of ≥5 CM, 3) lymphovascular invasion (50%), 4) cervical stromal invasion (40%), and 5) depth of myometrial invasion of ≥50% (50%). The incidences of these pathological features were significantly less in Group-I. Statistical analyses singled out "lower uterine segment involvement" as the most important feature. CONCLUSIONS: We have identified five pathological features which are associated with sentinel lymph node involvement. Since lower uterine segment involvement has occurred in all cases of the Group-II cohort, we recommend FIGO and other organizations that determine staging rules should consider whether tumors that involve the lower uterine segment should be staged as higher than "1a", if the findings in this small series are confirmed by other studies. The results of this study may guide pathologists and oncologists in the diagnostic and therapeutic approaches to management of endometrial carcinomas.

Evaluation of MTAP immunohistochemistry loss of expression in ovarian serous borderline tumors as a potential marker for prognosis and progression.

INTRODUCTION: Serous borderline tumors (SBT) are the most common subtype of ovarian borderline tumors with excellent clinical course. However, they can recur or progress to low-grade serous carcinoma (LGSC) in a small proportion of the cases. Beside BRAF and KRAS mutations, copy number alterations (CNA), particularly loss of chromosome 9p21 locus which results in deletion of genes CDKN2A and MTAP, have been suggested to be involved in disease progression. MTAP immunohistochemistry recently has been introduced for mesothelioma as a reliable surrogate marker for the homozygous deletion of chromosome 9p21 locus. Therefore, in the current study, we aimed to evaluate the MTAP loss of expression in serous borderline tumors and low-grade serous carcinomas to identify if it can be used as a marker for prognosis and progression. METHOD: Eighty-four total cases of ovarian serous lesions, including 21 cases of serous cystadenomas, 21 cases of serous borderline tumors, 12 cases of low-grade serous carcinomas and 30 cases of high-grade serous carcinomas were selected. MTAP immunohistochemistry was performed on the representative blocks and cytoplasmic staining was used for interpretation. The cases were labeled as positive (retained) if MTAP showed cytoplasmic granular staining and negative (loss of expression) if negative cytoplasmic staining was observed in the presence of positive internal control. RESULT: Ten of 21 cases of serous borderline tumors showed loss of MTAP expression (48%). Among those, 7 cases were bilateral, 2 cases had micropapillary features, one case had supraclavicular and cervical lymph node involvement by serous borderline tumor and 2 cases had progression to low-grade serous carcinoma, including one of micropapillary tumors. Also 8 out of 12 cases of LGSCs showed MTAP loss of expression (66%). Only 4 of 30 cases of high-grade serous carcinomas (13%) and none of the serous cystadenoma cases showed loss of expression of MTAP. CONCLUSION: To our knowledge, this is the first description of MTAP immunohistochemistry in serous borderline tumors and low-grade serous carcinomas. Our study was limited due to small sample size. However, it showed an association between MTAP loss of expression and adverse clinical behavior in ovarian serous borderline tumors. This supports the role for further investigations in larger series to evaluate the role of MTAP stain as a prognostic marker in these neoplasms.