Uterine Carcinosarcomas: Clinical, Histopathologic and Immunohistochemical Characteristics

Uterine carcinosarcomas: A case series of 9 cases from a low-income country

RATIONALE

Uterine carcinosarcomas (UCS) are rare aggressive biphasic tumors classified as a subtype of high-grade uterine carcinomas. However, these tumors have particular histopathological features and clinical behavior with worse prognosis than high-grade uterine carcinomas.

PATIENT CONCERNS

The incidence of UCS is increasing and more studies are required to elucidate their clinical and histopathological characteristics. Herein, we report clinicopathological features of 9 cases of UCS in a low-income country.

DIAGNOSES

We retrospectively collected all cases of UCS at our Pathology Department over a period of 4 years. The diagnosis was performed on formalin-fixed, paraffin-embedded and hematoxylin and eosin-stained surgical specimens.

INTERVENTIONS

Nine surgically treated cases of UCS have been registered, representing 12.67% of all uterine malignancies with a mean age of 58.88 years (range: 50-65 years). Abdominal pain and metrorrhagia were the main clinical presentations. The epithelial component of UCS was often a serous carcinoma (66.66%) and patients presented with large tumors (mean size of 9.24 cm, range of 5-19 cm), with advanced FIGO stages (stages III-IV) in 5/9 patients (55.55%).

OUTCOMES

Follow-up data were available in 5/9 patients among which only 2 were alive 2 and 25 months after the surgical treatment (overall survival of 40%).

LESSONS

UCS are rare and aggressive uterine tumors with very poor prognosis especially in low-income countries.

Comparative analysis of EZH2, p16 and p53 expression in uterine carcinosarcomas

Introduction: The role of p16 and p53 immunohistochemistry in the diagnosis of rare and aggressive uterine carcinosarcoma (UCS) has been well established. However, enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and a member of the polycomb group family is a relatively new biomarker, with limited published data on its significance in this tumor type. The goal of this study was to examine EZH2 expression in UCS and its components, in correlation with morphological features, and p16 and p53 staining patterns. Methods: Twenty-eight UCSs were included in the study. EZH2, p16 and p53 immunoreactivity were assessed independently by two pathologists in both tumor components (epithelial and mesenchymal). EZH2 and p16 immunostains were scored semiquantitatively: based on the percentage and intensity of tumor cell staining a binary staining index ("high- or low-expressing") was calculated. The p53 staining pattern was evaluated as wild-type or aberrant (diffuse nuclear, null, or cytoplasmic expression). Statistical tests were used to evaluate the correlation between staining patterns for all three markers and the different tumor components and histotypes. Results: High EZH2 and p16 expression and aberrant p53 patterns were present in 89.3% 78.6% and 85.7% of the epithelial component and in 78.6%, 62.5% and 82.1% of the mesenchymal component, respectively. Differences among these expression rates were not found to be significant (p > 0.05). Regarding the epithelial component, aberrant p53 pattern was found to be significantly (p = 0.0474) more frequent in the serous (100%) than in endometrioid (66.6%) histotypes. Within the mesenchymal component, p53 null expression pattern occurred significantly (p = 0.0257) more frequently in heterologous sarcoma components (71.4%) compared to the homologous histotype (18.8%). Conclusion: In conclusion, EZH2, p16 and p53 seem to play a universal role in the pathogenesis of UCS; however, a distinctive pattern of p53 expression appears to exist between the serous and endometrioid carcinoma components and also between the homologous and heterologous sarcoma components.

The prognostic significance of the heterologous component in uterine carcinosarcomas

OBJECTIVE

Uterine carcinosarcomas are aggressive, rare biphasic tumors with malignant epithelial and malignant sarcomatous components. The prognostic significance of the presence of extrauterine sarcoma (heterologous component) is controversial. Therefore, the aim of this study was to investigate the effect of heterologous components in uterine carcinosarcomas on disease-free survival, overall survival, and other prognostic factors.

METHODS

Clinical and histopathological data from patients treated for uterine carcinosarcoma in a tertiary cancer center in Turkey between July 2000 and January 2020 were collected. Independent risk factors affecting overall survival and disease-free survival were analyzed by univariate and multivariate Cox regression analyses.

RESULTS

A total of 98 patients were identified. The median follow-up was 21.8 (1.2-233.1) months. In the multivariate analysis, the median overall survival and disease-free survival were 23.8 and 20.7 months in those with homologous mesenchymal components and 17.6 and 9.7 months in those with heterologous mesenchymal components, respectively. It was found that the presence of heterologous mesenchymal components significantly reduced both overall survival and disease-free survival (odds ratio [OR], 2.861; 95% confidence interval [CI] 1.196-6.841; p=0.018 and OR, 3.697; 95%CI 1.572-8.695; p=0.003, respectively). In addition, both lymphadenectomy and adjuvant radiotherapy were found to significantly increase overall survival and disease-free survival. Age was found to increase only disease-free survival.

CONCLUSION

The results obtained in this study showed that the presence of heterologous components in uterine carcinosarcoma is a prognostic factor that adversely affects both overall survival and disease-free survival. Lymphadenectomy and adjuvant radiotherapy have beneficial effects on both overall survival and disease-free survival.

Is the sarcomatous component (homologous vs heterologous) the prognostic "driving force" in early-stage uterine carcinosarcomas? A retrospective multicenter study

PURPOSE

Uterine carcinosarcomas (UCSs) are aggressive biphasic malignancies, with a carcinomatous/epithelial component and a sarcomatous/mesenchymal counterpart. The aim of this study was to evaluate the impact of the sarcomatous component (homologous vs heterologous) on the overall survival (OS) and progression-free survival (PFS).

METHODS

This is a multicenter observational retrospective study conducted in patients with stage I and II UCSs.

RESULTS

Ninety-five women with histological diagnosis of early-stage UCSs were retrieved: 60 (63.2%) had tumors with homologous sarcomatous components, and 35 (36.8%) with heterologous. At univariate analysis, a stromal invasion ≥ 50%, the presence of clear cell, serous or undifferentiated carcinomatous component, the heterologous sarcomatous component and FIGO stage IB and II were shown to be variables with a statistically significant negative impact on PFS. Similarly, a depth of invasion ≥ 50%, the heterologous sarcomatous component and FIGO stage IB and II were statistically negative prognostic factors also concerning OS. At multivariate analysis, only the heterologous sarcomatous component was confirmed to be a statistically significant negative prognostic factor both on PFS (HR 2.362, 95% CI 1.207-4.623, p value = 0.012) and on OS (HR 1.950, 95% CI 1.032-3.684, p = 0.040).

CONCLUSION

Carcinomatous and sarcomatous components both played a role in tumor progression and patients' survival. However, only the sarcomatous component retained a statistical significance at the multivariable model suggesting its preeminent prognostic role in early-stage UCSs.

Utility of p16/Ki67 double immunocytochemistry for detection of cervical adenocarcinoma

BACKGROUND

Although the incidence of cervical adenocarcinoma has consistently increased, especially among young women, there is no established best means for screening. This study evaluated the screening efficacy of CINtec PLUS (CINtec; p16/Ki67 double immunocytochemistry) expression in cervical glandular cells.

METHODS

Cervical cytology was examined using abnormal glandular cells. The CINtec status of 100 samples with corresponding surgically resected specimens and 11 samples that exhibited negative results for intraepithelial lesion or malignancy at follow-up was analyzed. Additionally, 31 negative samples containing benign glandular cells were included.

RESULTS

Of the 142 samples, CINtec status was diffusely positive in 74, focally positive in 24, and negative in 44. The 74 diffusely positive samples included 70 adenocarcinomas (62 cervical, seven uterine, and one ovarian) and four cases of high-grade cervical intraepithelial neoplasia. The 24 focally positive samples included 15 adenocarcinomas (seven cervical, seven uterine, and one fallopian tube) and nine without malignancy. The 44 negative samples included nine adenocarcinomas (five uterine and four cervical) and 35 without malignancy. The sensitivity, specificity, positive predictive value, and negative predictive value of the CINtec diffusely or focally positive cases for cervical adenocarcinomas were 94.5%, 58.0%, 70.4%, and 90.9%, respectively. In CINtec diffusely positive cases, the respective values were 84.9%, 82.6%, 83.8%, and 83.8%, and in women aged ≤39 years the values were 90.6%, 89.5%, 93.5%, and 85.0%, respectively.

CONCLUSIONS

CINtec may support efficient detection of cervical adenocarcinomas.

Inter‑component immunohistochemical assessment of proliferative markers in uterine carcinosarcoma

In the scientific literature, a selected number of reports have investigated the impact of proliferative activity on the development and progression of uterine carcinosarcomas (UC). The aim of the present retrospective study was to compare the immunohistochemical proliferation markers [Ki67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 3 (MCM3), and topoisomerase IIα (topoIIα)] assessment in both components of UC. A total of 30 paraffin-embedded slides of UCs, obtained from patients who underwent surgery between January 1, 2006, and December 31, 2020, were analyzed. Medical records and clinicopathological data of patients were reviewed. Formalin-fixed, paraffin-embedded tissue sections were immunostained with monoclonal antibodies against Ki67, PCNA, MCM3 and topoIIα. Ki67-positive nuclear immunoreactivity was reported in 20 (67%) and 16 (53%) UC carcinomatous and sarcomatous components, respectively. In the epithelial component, Ki67 positive staining was related to the International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.025), and histological grade (G1 vs. G2/G3, P=0.031). Nuclear PCNA reactivity was observed in 18 (60%) and 16 (53%) carcinomatous and sarcomatous components, respectively. Notably, all four cases with omental metastases were PCNA-positive, and a relationship between staining pattern and the existence of metastases was of significant value (P=0.018). MCM3-positive nuclear staining was found nearly twice as high in the carcinomatous (n=19; 63%), compared with the sarcomatous (n=11; 37%) component, respectively, and MCM3 expression in the epithelial component was related to clinical stage (P=0.030), and the existence of omental metastasis (P=0.012). In addition, out of the 30 UCs, 17 (57%) and 13 (43%) showed topoIIα positivity in the carcinomatous and sarcomatous UC components, respectively. A significant relationship between protein immunoreactivity and FIGO stage (P=0.049), and omental metastasis (P=0.026) was revealed to exist. However, no significant differences between expression of proliferation markers and clinicopathological features in the sarcomatous UC component were identified. Finally, a significant correlation between each protein immunohistochemical staining was demonstrated, particularly in the sarcomatous UC component. Collectively, a combined analysis of Ki67, PCNA, MCM3, and topoIIα may provide more detailed information of cell-cycle alterations determining the heterogeneity of uterine carcinosarcomas.

The role of multimodal adjuvant therapy for FIGO I-II carcinosarcoma of the uterus: a systematic review

The uterine carcinosarcoma (UCS) is a rare entity with poor prognosis. Treatment of FIGO I-II UCS usually consists of surgery with or without adjuvant treatment. Due to the high metastatic potential, aggressive combined modality adjuvant treatment approaches, consisting of chemo- and radiotherapy, have been of interest. Our systematic review aims to compare survival, disease control and toxicity profiles in patients receiving adjuvant chemoradiation to other adjuvant strategies (e.g.observation, chemotherapy or radiotherapy). A total of ten studies were included for a combined cohort size of 6,520 patients. Generally, the studies showed a trend towards improved disease control and survival in patients undergoing adjuvant multimodal treatment, although statistical significance was often not reached. Selection bias and non-randomized treatment allocation pose serious challenges to extrapolate these outcomes to clinical practice. We recommend additional prospective research on the role of adjuvant chemoradiation in FIGO I-II UCS.

Sinonasal carcinosarcoma with cartilaginous and rhabdomyoblastic components: A previously undescribed entity

Carcinosarcomas are rare, aggressive tumors seldom found in the sinonasal region. They classically consist of sarcomatous spindle cell and carcinomatous squamous cell elements. A 61-year-old woman presented reporting right-sided nasal discharge and obstruction. Examination demonstrated a large right-sided nasal mass, from which a biopsy was taken. Computed tomography and magnetic resonance imaging revealed a mass arising from the maxillary antrum and extending into the nasal cavity, ethmoid air cells, and frontal sinus. Right total maxillectomy with resection of the nasal tumour component was performed. Histological analysis demonstrated a high-grade malignancy with features consistent with carcinosarcoma with cartilaginous and rhabdomyoblastic elements, a histologic pattern that has not previously been described at this site. Magnetic resonance imaging 5 weeks postoperatively showed sizeable recurrence. Adjuvant chemotherapy and radiotherapy were commenced to excellent effect. Carcinosarcomas, though very rare at sinonasal sites, should be considered if biopsy demonstrates undifferentiated high-grade neoplasm with cytokeratin expression. These tumors require aggressive multimodal therapy for optimal outcomes.

Carcinosarcoma arising from high-grade serous carcinoma of the ovary without estrogen receptor, WT-1, and PAX8 immunoreactivity

OBJECTIVE

We encountered a case of high-grade serous carcinoma (HGSC) of the ovary which recurred as carcinosarcoma of the sigmoid colon. Tumor cells of both the primary carcinoma and the secondary carcinosarcoma were negative for estrogen receptor (ER), WT-1, and PAX8. It is well known that most ovarian carcinomas arising from the Müllerian duct are immunoreactive for these biologic parameters. To our knowledge, this is the first case report that provides the results of immunohistochemical analysis of WT-1 and PAX8 for a primary carcinoma and recurrent carcinosarcoma.

CASE REPORT

A 61-year-old woman had an advanced right ovarian HGSC. After a primary debulking surgery (hysterectomy, bilateral salpingo-oophorectomy and omentectomy) and adjuvant chemotherapy, complete remission was achieved. However, four and a half years later, a tumor arising beside the sigmoid colon was detected. A tumorectomy was performed through combined partial resection of the ileum and sigmoid colon. Microscopically, the tumor was diagnosed as carcinosarcoma of the sigmoid colon, which had originated from HGSC of the ovary. Interestingly, the malignant cells of the primary carcinoma and epithelial components of the recurrent carcinosarcoma were negative for ER, WT-1, and PAX8. These immunohistochemical features were unusual. Three cycles of chemotherapy with the previously used regimen and three additional cycles of doxorubicin and ifosfamide combination chemotherapy were administered. Currently, 3 years after the final chemotherapy was administered, the patient remains healthy.

CONCLUSION

HGSC of the ovary can recur as carcinosarcoma. Tumor cells of the primary HGSC without ER, WT-1, and PAX8 expression may have dedifferentiated and recurred as carcinosarcoma.

Molecular Evaluation of Endometrial Dedifferentiated Carcinoma, Endometrioid Carcinoma, Carcinosarcoma, and Serous Carcinoma Using a Custom-Made Small Cancer Panel

It is often difficult to histologically differentiate among endometrial dedifferentiated carcinoma (DC), endometrioid carcinoma (EC), serous carcinoma (SC), and carcinosarcoma (CS) due to the presence of solid components. In this study, we aimed to categorize these carcinomas according to The Cancer Genome Atlas (TCGA) classification using a small custom-made cancer genome panel (56 genes and 17 microsatellite regions) for integrated molecular diagnosis. A total of 36 endometrial cancer cases with solid components were assessed using IHC, next-generation sequencing (NGS), and the custom-made panel. Among 19 EC cases, six were categorized as MMR-deficient (MMR-d) and eight were classified as having a nonspecific molecular profile. Three EC cases were classified as POLE mutation (POLEmut)-type, which had a very high tumor mutation burden (TMB) and low microsatellite instability (MSI). Increased TMB and MSI were observed in all three DC cases, classified as MMR-d with mutations in MLH1 and POLD1. Except for one case classified as MMR-d, all SC cases exhibited TP53 mutations and were classified as p53 mutation-type. SC cases also exhibited amplification of CCND1, CCNE1, and MYC. CS cases were classified as three TCGA types other than the POLEmut-type. The IHC results for p53 and ARID1A were almost consistent with their mutation status. NGS analysis using a small panel enables categorization of endometrial cancers with solid proliferation according to TCGA classification. As TCGA molecular classification does not consider histological findings, an integrated analytical procedure including IHC and NGS may be a practical diagnostic tool for endometrial cancers.

Corded and Hyalinized and Spindled Endometrioid Endometrial Carcinoma: A Clinicopathologic and Molecular Analysis of 9 Tumors Based on the TCGA Classifier

Corded and hyalinized and spindled carcinomas are rare variants of endometrioid carcinoma (EC) characterized by cords of low-grade epithelial cells (±spindle cells) within a hyalinized stroma or spindled epithelial cells, respectively, that merge with conventional low-grade EC. Due to their "biphasic" morphology, these tumors are often misdiagnosed as carcinosarcoma. The clinicopathologic features including mismatch repair protein (PMS2 and MSH6) and p53 immunohistochemical expression and POLE mutational status of 9 corded and hyalinized and spindled endometrial ECs were evaluated and classified into The Cancer Genome Atlas (TCGA) based molecular subgroups. Beta-catenin immunohistochemistry was performed as a surrogate for CTNNB1 mutational status. The mean age at diagnosis was 49 years (range: 34 to 68 y) with staging information available for 6 patients: stage IA (n=1), stage IB (n=1), stage II (n=2), stage IIIA (n=1), stage IIIC1 (n=1). A prominent corded and hyalinized component was present in 7 ECs comprising 15% to 80% of the tumor with a minor (5% to 15%) spindled morphology in 5. Two additional tumors were composed of a low-grade spindled component comprising 25% to 30% of the neoplasm. Tumors were grade 1 (n=3), grade 2 (n=5), and grade 2 to 3 (n=1) and squamous differentiation was identified in 8/9. All tumors had preserved expression of mismatch repair proteins with 8 showing a p53 wild-type phenotype including the grade 2 to 3 EC; 1 grade 2, stage IB tumor exhibited a mutant pattern of expression. All (n=7) but 1 tumor demonstrated nuclear beta-catenin expression in the glandular, squamous, and corded or spindled components. POLE exonuclease domain mutations were absent in all tumors. Based on our findings, corded and hyalinized EC and EC with spindle cells are usually low grade, low stage, and present at a younger age and exhibit squamous differentiation at an increased frequency compared to typical EC. Unlike carcinosarcomas, which frequently harbor TP53 mutations, these tumors usually exhibit wild-type p53 and nuclear beta-catenin expression, indicative of underlying CTNNB1 mutations. According to the TCGA subgroups of endometrial carcinoma, the majority of corded and hyalinized and spindled EC appear to fall into the copy number low ("no specific molecular profile") subgroup.

Mismatch Repair Deficiency in Uterine Carcinosarcoma: A Multi-institution Retrospective Review

Immunohistochemistry (IHC) for mismatch repair (MMR) proteins is recommended in endometrial carcinomas as a screening test for Lynch syndrome, and mismatch repair deficiency (MMRd) is reported in ∼30% of cases. However, few studies have evaluated the rate of MMR loss in uterine carcinosarcomas. A 5-year retrospective database search of uterine carcinosarcomas was performed at 3 academic institutions. The histologic diagnoses, type of carcinoma present, and MMR IHC interpretations were confirmed by a gynecologic pathologist. One hundred three cases of uterine carcinosarcomas with available MMR IHC results were identified. Ninety-nine cases (96%) showed intact expression and 4 cases (4%) showed loss of MLH1/PMS2. All MMRd carcinosarcomas identified in this series had an endometrioid carcinomatous component and wild-type p53 expression. In contrast, the majority of MMR intact carcinosarcomas had a serous morphology and aberrant p53 expression. Three additional cases initially diagnosed as carcinosarcoma also revealed MMRd; however, given the lack of clear mesenchymal differentiation, these cases were reclassified as dedifferentiated endometrial carcinomas and were subsequently excluded from the carcinosarcoma category. No cases of Lynch syndrome were identified among carcinosarcoma patients, as all 4 MMRd cases were due to somatic MLH1 hypermethylation. In summary, we found that the rate of MMRd is markedly lower in uterine carcinosarcoma when compared with endometrial carcinoma. In the setting of MMR loss, a diagnosis of dedifferentiated carcinoma should be considered as almost half of the MMRd tumors which were called carcinosarcomas initially were reclassified as dedifferentiated on review. However, given the interobserver variability in the classification of carcinosarcoma versus dedifferentiated carcinoma a universal screening approach that includes uterine carcinosarcoma is still recommended.

TCGA Classification of Endometrial Cancer: the Place of Carcinosarcoma

In 2013, The Cancer Genome Atlas (TCGA) Research Network found four novel prognostic subgroups of endometrial carcinoma: POLE/ultramutated (POLE), microsatellite-instable/hypermutated (MSI), copy-number-low/TP53-wild-type (CNL), and copy-number-highTP53-mutant (CNH). However, poor is known regarding uncommon histotypes of endometrial cancer. We aimed to assess the genetic profile of uterine carcinosarcoma (UCS) on the light of these findings. A systematic review and meta-analysis was performed through electronic databases searching (up to July 2019). All studies assessing UCS series for the TCGA classification were included. For each TCGA subgroup, pooled prevalence on the total UCS number was calculated. Four studies with 231 patients were included. Pooled prevalence of the TCGA subgroups were: 5.3% for the POLE subgroup, 7.3% for the MSI subgroup, 73.9% for the CNH subgroup, 13.5% for the CNL subgroup. The CNH subgroup predominates in UCS, while subgroups with high mutational load (POLE and MSI) are less common. UCS appears as a preferential evolution of CNH carcinomas.

Landscape of Immune Checkpoint Inhibition in Carcinosarcoma (MMMT): Analysis of IDO-1, PD-L1 and PD-1

BACKGROUND

Carcinosarcoma (CS) or malignant mixed Müllerian tumor (MMMT), is a rare malignant biphasic tumor, which contains both a malignant epithelial and mesenchymal component. That being said, they have an aggressive clinical course. Given that immune checkpoint inhibitors have mustered significant excitement in the oncology world - immunotherapy could offer significant promise to this poor prognostic cancer subtype. A total of 75 carcinosarcoma cases were identified in our institutional database from 2010 to 2019 and immunohistochemistry for PD-L1, PD-1 and IDO-1 was performed. Out of the 75 patients, 65(87 %) demonstrated >1 % PD-1 expression and 50(67 %) expressed >1 % PD-L1 in either the tumoral and immune stromal components. 29 (39 %) cases demonstrated >20 % PD-1 expression and 14 (19 %) cases expressed >20 % PD-L1. 41(55 %) cases demonstrating co-expression of PD-1 and PD-L1. For IDO-1 64 (85 %) patients showed at least >5 %, while 34 (45 %) showed staining above 20 %. 45 patients (60 %) showed co-expression of IDO-1 and PD-L1, while 59 (79 %) patients had co-expression of IDO and PD-1 above 5 and 1 % respectively. Regarding clinicopathologcial features; older patients (> 65) were more likely to express PD-L1 (>1 %) and IDO-1 (>20 %). For tumor size, IDO-1 expression (>5 %), along with PD-1/IDO-1 Co-expression (>1/5 %), was associated with larger tumor size (>5cm). For myometrial invasion, CSs with >50 % invasion were more likely to express IDO-1 (>20 %) and PD-1/IDO-1 (>1/5 %). Ultimately, the effect of IDO-1, PD-1 and PD-L1 on the clinical profile may be less important than its potential use as a immunotherapeutic, where safe and effective corresponding drugs could be used to treat particular patient populations. Future clinical trials are needed to decipher the association between immune check point inhibitor expression and therapeutic response. This is the only way to definitively prove immune checkpoint immunohistochemistry as predictive biomarkers in this cancer subtype.

Fbxw7 is a driver of uterine carcinosarcoma by promoting epithelial-mesenchymal transition

Uterine carcinosarcoma (UCS) is an aggressive endometrial cancer variant distinguished from endometrial adenocarcinoma (EC) by admixed malignant epithelial and mesenchymal components (carcinoma and sarcoma). The molecular events underlying UCS are enigmatic, as cancer gene mutations are generally shared among UCS/EC. We take advantage of genetic approaches in mice to show that inactivation of Fbxw7 and Pten results in UCS through spontaneous acquisition of mutations in a third gene (Tp53), arguing for strong biological selection and synergism in UCS. We used this UCS model including tumor-derived cell lines to show that Fbxw7 loss drives epithelial–mesenchymal transition, explaining Fbxw7’s role in UCS. This model system argues that simultaneous genetic defects in 3 distinct pathways (Fbxw7, Pten/PI3K, Tp53) converge in UCS genesis.

Uterine carcinosarcoma is an aggressive variant of endometrial carcinoma characterized by unusual histologic features including discrete malignant epithelial and mesenchymal components (carcinoma and sarcoma). Recent studies have confirmed a monoclonal origin, and comprehensive genomic characterizations have identified mutations such as Tp53 and Pten. However, the biological origins and specific combination of driver events underpinning uterine carcinosarcoma have remained mysterious. Here, we explored the role of the tumor suppressor Fbxw7 in endometrial cancer through defined genetic model systems. Inactivation of Fbxw7 and Pten resulted in the formation of precancerous lesions (endometrioid intraepithelial neoplasia) and well-differentiated endometrioid adenocarcinomas. Surprisingly, all adenocarcinomas eventually developed into definitive uterine carcinosarcomas with carcinomatous and sarcomatous elements including heterologous differentiation, yielding a faithful genetically engineered model of this cancer type. Genomic analysis showed that most tumors spontaneously acquired Trp53 mutations, pointing to a triad of pathways (p53, PI3K, and Fbxw7) as the critical combination underpinning uterine carcinosarcoma, and to Fbxw7 as a key driver of this enigmatic endometrial cancer type. Lineage tracing provided formal genetic proof that the uterine carcinosarcoma cell of origin is an endometrial epithelial cell that subsequently undergoes a prominent epithelial–mesenchymal transition underlying the attainment of a highly invasive phenotype specifically driven by Fbxw7.

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.

The Effect of Fucoidan, a Potential New, Natural, Anti-Neoplastic Agent on Uterine Sarcomas and Carcinosarcoma Cell Lines: ENITEC Collaborative Study

The aim of the study was to assess the activity of fucoidan on the uterine sarcomas (MES-SA and ESS-1) and carcinosarcoma cell lines (SK-UT-1 and SK-UT-1B) and its toxicity on the human skin fibroblasts (HSF). Two uterine sarcomas and two carcinosarcoma cell lines were examined, as a control HSF were used. Cell viability was assessed with MTT test, apoptosis with caspase-3 activity and cell cycle by assessment of DNA synthesis. Fucoidan significantly decreases cell viability in SK-UT-1, SK-UT-1B, and ESS-1 cell lines, such effect was not observed in MES-SA. Fucoidan was not substantially affecting proliferation among normal cells. The tested agent induced apoptosis in all cell cultures used in the experiment. Fucoidan affects cell cycle of all tested cell lines except MES-SA by increasing percentage of cells in G0/sub-G1/G1 phase. Fucoidan do not only affect proliferation but induces apoptosis in selected uterine sarcoma and carcinosarcoma cell lines, so it has potential to be used as cytotoxic agent. Fucoidan seems to be promising anti-cancer agent for endometrial stromal sarcoma and carcinosarcoma.

Uterine carcinosarcoma (malignant mixed Müllerian tumor): case report in a goat and literature review

Carcinosarcomas are biphasic malignant tumors composed of 2 distinct neoplastic cell populations, epithelial cells and mesenchymal cells. A 13-y-old, female, mixed-breed goat was presented with a 1-wk history of anuria and lethargy. Transabdominal ultrasonography showed an irregular and heterogeneous structure in the region of the bladder and uterus and changes in the echogenicity of both kidneys. Given the poor prognosis, euthanasia was elected. Autopsy revealed a large mass within the uterine cervix and confirmed the changes in the urinary tract. Histopathology and immunohistochemistry revealed a mixed, anti-cytokeratin AE1/AE3-positive epithelial, and vimentin-positive mesenchymal neoplasm consistent with a homologous carcinosarcoma, also called malignant mixed Müllerian tumor, with areas of double-labeling. We highlight the complexity of the diagnosis of uterine neoplasms in domestic animals and in goats in particular.

Are the uterine serous carcinomas underdiagnosed? Histomorphologic and immunohistochemical correlates and clinical follow up in high-grade endometrial carcinomas initially diagnosed as high-grade endometrioid carcinoma

Histologic subclassification of high-grade endometrial carcinomas can sometimes be a diagnostic challenge when based on histomorphology alone. Here we utilized immunohistochemical markers to determine the immunophenotype in histologically ambiguous high-grade endometrial carcinomas that were initially diagnosed as pure or mixed high-grade endometrioid carcinoma, aiming to determine the utility of selected immunohistochemical panel in accurate classification of these distinct tumor types, while correlating these findings with the clinical outcome. A total of 43 high-grade endometrial carcinoma cases initially classified as pure high-grade endometrioid carcinoma (n=32), mixed high-grade endometrioid carcinoma/serous carcinoma (n=9) and mixed high-grade endometrioid carcinoma/clear cell carcinoma (n=2) were retrospectively stained with a panel of immunostains, including antibodies for p53, p16, estrogen receptor, and mammaglobin. Clinical follow-up data were obtained, and stage-to-stage disease outcomes were compared for different tumor types. Based on aberrant staining for p53 and p16, 17/43 (40%) of the high-grade endometrial carcinoma cases initially diagnosed as high-grade endometrioid carcinoma were re-classified as serous carcinoma. All 17 cases showed negative staining for mammaglobin, while estrogen receptor was positive in only 6 (35%) cases. The remaining 26 cases of high-grade endometrioid carcinoma showed wild-type staining for p53 in 25 (96%) cases, patchy staining for p16 in 20 (77%) cases, and were positive for mammaglobin and estrogen receptor in 8 (31%) and 19 (73%) cases, respectively, thus the initial diagnosis of high-grade endometrioid carcinoma was confirmed in these cases. In addition, the patients with re-classified serous carcinoma had advanced clinical stages at diagnosis and poorer overall survival on clinical follow-up compared to that of the remaining 26 high-grade endometrioid carcinoma cases. These results indicate that selected immunohistochemical panel, including p53, p16, and mammaglobin can be helpful in reaching accurate diagnosis in cases of histomorphologically ambiguous endometrial carcinomas, and can assist in providing guidance for appropriate therapeutic options for the patients.