Epithelial-myoepithelial carcinoma (EMC) can be a challenging diagnosis due to a lack of obvious invasion and bland cytology. We report an unusual case of a low-grade EMC with prominent fibrous stroma, an extensive solid-oncocytic differentiation and limited areas of morphological clearly identifiable characteristic biphasic (tubular) differentiation, clear cells and PAS-positive secretions/calcifications. Both areas were investigated by next generation sequencing (Oncomine comprehensive assay) and revealed a typical concordant HRAS p.Q61R mutation. An additional heterogeneous ARID1A (p.E672*) terminating mutation with loss of heterozygosity, which could be visualized predominantly in the solid-oncocytic differentiation by immunohistochemical loss of ARID1A protein expression, was found. This is the first case of an EMC of the salivary gland to be described with two separate tumor clones involving concordant HRAS and heterogeneous ARID1A mutations. The latter seem to be a "second hit" and was predominantly found in the solid-oncocytic differentiation, suggesting a potential morpho-molecular association.

• Keywords
• ARID1A, Epithelial myoepithelial carcinoma, HRAS, Heterogeneous, Oncocytic, Salivary gland, Solid,
• MeSH
• DNA-Binding Proteins genetics   MeSH
• Carcinoma genetics   pathology   MeSH
• Humans MeSH
• Mutation MeSH
• Myoepithelioma genetics   pathology   MeSH
• Neoplasms, Glandular and Epithelial genetics   pathology   MeSH
• Parotid Neoplasms genetics   pathology   MeSH
• Proto-Oncogene Proteins p21(ras) genetics   MeSH
• Aged MeSH
• Transcription Factors genetics   MeSH
• Check Tag
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH
• Names of Substances
• ARID1A protein, human MeSH Browser
• DNA-Binding Proteins MeSH
• HRAS protein, human MeSH Browser
• Proto-Oncogene Proteins p21(ras) MeSH
• Transcription Factors MeSH

Glioblastoma (GBM) is regarded as an aggressive brain tumor that rarely develops extracranial metastases. Despite well-investigated molecular alterations in GBM, there is a limited understanding of these associated with the metastatic potential. We herein present a case report of a 43-year-old woman with frontal GBM with primitive neuronal component who underwent gross total resection followed by chemoradiation. Five months after surgery, the patient was diagnosed with an intraspinal GBM metastasis. Next-generation sequencing analysis of both the primary and metastatic GBM tissues was performed using the Illumina TruSight Tumor 170 assay. The number of single nucleotide variants observed in the metastatic sample was more than two times higher. Mutations in TP53, PTEN, and RB1 found in the primary and metastatic tissue samples indicated the mesenchymal molecular GBM subtype. Among others, there were two inactivating mutations (Arg1026Ile, Trp1831Ter) detected in the NF1 gene, two novel NOTCH3 variants of unknown significance predicted to be damaging (Pro1505Thr, Cys1099Tyr), one novel ARID1A variant of unknown significance (Arg1046Ser), and one gene fusion of unknown significance, EIF2B5-KIF5B, in the metastatic sample. Based on the literature evidence, the alterations of NF1, NOTCH3, and ARID1A could explain, at least in part, the acquired invasiveness and metastatic potential in this particular GBM case.

• Keywords
• ARID1A, NF1, NOTCH3, glioblastoma, metastasis, mutation,
• Publication type
• Journal Article MeSH
• Case Reports MeSH

Loss of the SWI/SNF chromatin remodeling complex has been recently implicated in the pathogenesis of dedifferentiated carcinomas from different organs, but its possible role in undifferentiated urothelial carcinoma (UC) has not been studied to date. In this study, we analyzed by immunohistochemistry 14 undifferentiated UCs (11 from bladder and 3 from renal pelvis) with a nondescript anaplastic or rhabdoid morphology, using commercially available antibodies against the SWI/SNF components SMARCB1 (INI1), SMARCA2, SMARCA4, SMARCC1, SMARCC2, and ARID1A. Patients were eight females and six males aged 40 to 84 years (median, 65). All tumors were muscle-invasive (9 were T3-4). A conventional UC component was seen in eight cases and varied from in situ to papillary. The undifferentiated component comprised 60-100 % of the tumors. Histologically, most tumors showed diffuse dyscohesive or pseudoalveolar growth of variably sized cells with frequent rhabdoid features. Transition from conventional to undifferentiated UC was abrupt, except in one case. The undifferentiated component almost always expressed pan-cytokeratin AE1/AE3 (13/14) and variably vimentin (8/14) and GATA3 (9/14). Complete loss of at least one SWI/SNF subunit limited to the undifferentiated component was detected in 10/14 cases (71 %). SMARCA2 was most frequently lost (six) followed by ARID1A (four), SMARCB1/INI1 (two), SMARCA4 (one), and SMARCC1 (one). This is the first study exploring SWI/SNF expression in undifferentiated UC of the urinary tract. Our results are in line with recent studies reporting involvement of the SWI/SNF complex in the dedifferentiation process of a variety of epithelial neoplasms in different organs, including the urinary tract, and association with aggressive clinical course.

• Keywords
• ARID1A, Renal pelvis, Rhabdoid carcinoma, SMARCA2, SMARCB1, SWI/SNF, Undifferentiated carcinoma, Urinary bladder, Urothelial carcinoma,
• MeSH
• DNA-Binding Proteins MeSH
• DNA Helicases metabolism   MeSH
• Adult MeSH
• SMARCB1 Protein metabolism   MeSH
• Immunohistochemistry methods   MeSH
• Nuclear Proteins metabolism   MeSH
• Carcinoma, Transitional Cell metabolism   pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Urinary Tract metabolism   pathology   MeSH
• Rhabdoid Tumor diagnosis   metabolism   pathology   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Transcription Factors metabolism   MeSH
• Urologic Neoplasms diagnosis   metabolism   pathology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• ARID1A protein, human MeSH Browser
• DNA-Binding Proteins MeSH
• DNA Helicases MeSH
• SMARCB1 Protein MeSH
• Nuclear Proteins MeSH
• SMARCA2 protein, human MeSH Browser
• SMARCA4 protein, human MeSH Browser
• SMARCB1 protein, human MeSH Browser
• SMARCC1 protein, human MeSH Browser
• Transcription Factors MeSH

Fumarate hydratase-deficient renal cell carcinoma (FH-RCC) is a rare, aggressive RCC type, originally described in the setting of hereditary leiomyomatosis and RCC syndrome, which is defined by germline FH gene inactivation. Inactivation of components of the switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex is involved in renal medullary carcinoma (SMARCB1/INI1 loss), clear cell RCC (PBRM1 loss), and subsets of dedifferentiated RCC of clear cell, chromophobe, and papillary types (loss of different SWI/SNF components). FH-RCC and SWI/SNF-deficient RCC share anaplastic nuclear features and highly aggressive course. We analyzed 32 FH-RCCs from 28 patients using 7 commercially available SWI/SNF antibodies (SMARCB1/INI1, SMARCA2, SMARCA4, SMARCC1, SMARCC2, PBRM1, and ARID1A). Variable loss of SMARCB1, ARID1A, and SMARCC1 was observed in 1 of 31, 2 of 31, and 1 of 29 evaluable cases, respectively; 3 of these 4 SWI/SNF-deficient tumors had confirmed FH mutations. No correlation of SWI/SNF loss with solid or sarcomatoid features was observed. Two tumors with SMARCB1 and ARID1A deficiency had available SWI/SNF molecular data; both lacked SMARCB1 and ARID1A mutations. The remaining 5 SWI/SNF components were intact in all cases. Especially PBRM1 seems not to be involved in the pathogenesis or progression of FH-RCC. Our data showed that a subset of FH-RCC (12%) have a variable loss of SWI/SNF complex subunits, likely as secondary genetic events. This should not be confused with SWI/SNF-deficient RCC of other types. Evaluation of FH and SWI/SNF together with comprehensive molecular genetic profiling is needed to explore possible prognostic implications of FH/SWI-SNF double deficiency and to better understand the somatic mutation landscape in high-grade RCC.

• Keywords
• ARID1A, Fumarate hydratase, HLRCC, INI1, Renal cell carcinoma, SMARCB1, SWI/SNF complex,
• MeSH
• Chromosomal Proteins, Non-Histone metabolism   MeSH
• DNA-Binding Proteins MeSH
• DNA Helicases genetics   metabolism   MeSH
• Adult MeSH
• Fumarate Hydratase deficiency   MeSH
• Immunohistochemistry methods   MeSH
• Nuclear Proteins genetics   metabolism   MeSH
• Carcinoma, Renal Cell genetics   pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Mutation genetics   MeSH
• Kidney Neoplasms genetics   pathology   MeSH
• Aged MeSH
• Transcription Factors genetics   metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chromosomal Proteins, Non-Histone MeSH
• DNA-Binding Proteins MeSH
• DNA Helicases MeSH
• Fumarate Hydratase MeSH
• Nuclear Proteins MeSH
• PBRM1 protein, human MeSH Browser
• SMARCA2 protein, human MeSH Browser
• SMARCA4 protein, human MeSH Browser
• SMARCC1 protein, human MeSH Browser
• SMARCC2 protein, human MeSH Browser
• Transcription Factors MeSH

Undifferentiated (anaplastic) and rhabdoid cell features are increasingly recognized as adverse prognostic findings in renal cell carcinoma (RCC), but their molecular pathogenesis has not been studied sufficiently. Recent studies identified alterations in the Switch Sucrose nonfermentable (SWI/SNF) chromatin remodeling complex as molecular mechanisms underlying dedifferentiation and rhabdoid features in carcinomas of different organs. We herein have analyzed 32 undifferentiated RCCs having in common an undifferentiated (anaplastic) phenotype, prominent rhabdoid features, or both, irrespective of the presence or absence of conventional RCC component. Cases were stained with 6 SWI/SNF pathway members (SMARCB1, SMARCA2, SMARCA4, ARID1A, SMARCC1, and SMARCC2) in addition to conventional RCC markers. Patients were 20 males and 12 females aged 32 to 85 years (mean, 59). A total of 22/27 patients with known stage presented with ≥pT3. A differentiated component varying from microscopic to major component was detected in 20/32 cases (16 clear cell and 2 cases each chromophobe and papillary RCC). The undifferentiated component varied from rhabdoid dyscohesive cells to large epithelioid to small monotonous anaplastic cells. Variable loss of at least 1 SWI/SNF complex subunit was noted in the undifferentiated/rhabdoid component of 21/32 cases (65%) compared with intact or reduced expression in the differentiated component. A total of 15/17 patients (88%) with follow-up died of metastatic disease (mostly within 1 y). Only 2 patients were disease free at last follow-up (1 and 6 y). No difference in survival, age distribution, or sex was observed between the SWI/SNF-deficient and the SWI/SNF-intact group. This is the first study exploring the role of SWI/SNF deficiency as a potential mechanism underlying undifferentiated and rhabdoid phenotype in RCC. Our results highlight the association between the aggressive rhabdoid phenotype and the SWI/SNF complex deficiency, consistent with studies on similar neoplasms in other organs. Thorough sampling of such tumors that are usually huge and locally advanced is necessary for recognizing the clone of origin and hence for proper subtyping and also for differentiating them from undifferentiated urothelial carcinoma.

• MeSH
• Cell Dedifferentiation MeSH
• DNA-Binding Proteins MeSH
• DNA Helicases analysis   metabolism   MeSH
• Adult MeSH
• Phenotype MeSH
• Immunohistochemistry MeSH
• Nuclear Proteins analysis   metabolism   MeSH
• Carcinoma, Renal Cell pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Kidney Neoplasms pathology   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Transcription Factors analysis   metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• ARID1A protein, human MeSH Browser
• DNA-Binding Proteins MeSH
• DNA Helicases MeSH
• Nuclear Proteins MeSH
• SMARCA2 protein, human MeSH Browser
• SMARCA4 protein, human MeSH Browser
• SMARCC1 protein, human MeSH Browser
• SMARCC2 protein, human MeSH Browser
• Transcription Factors MeSH

The osa gene of Drosophila melanogaster encodes a nuclear protein that is a component of the Brahma chromatin-remodeling complex. Osa is required for embryonic segmentation, development of the notum and wing margin, and photoreceptor differentiation. In these tissues, osa mutations have effects opposite to those caused by wingless (wg) mutations, suggesting that osa functions as an antagonist of wg signaling. Here we describe the cloning and characterization of mammalian orthologues of osa. Three evolutionarily conserved domains were identified in Osa family members: the N-terminal Bright domain and C-terminally located Osa homology domains 1 and 2. RNase protection analysis indicates a widespread expression of the Osa1 gene during mouse development, in adult tissues, and in cultured cell lines. The Osa1 gene was localized to mouse chromosome 4, within the region syntenic to chromosomal position 1p35-p36 of its human counterpart. We present evidence that the OSA1 product is localized in the nucleus and associates with human Brahma complex, which suggests evolutionarily conserved function for Osa in gene regulation between mammals and Drosophila.

• MeSH
• Alternative Splicing MeSH
• Cell Nucleus metabolism   MeSH
• Cell Line MeSH
• Chromatin physiology   MeSH
• DNA-Binding Proteins genetics   MeSH
• Drosophila melanogaster MeSH
• Transcription, Genetic MeSH
• Nuclear Proteins genetics   MeSH
• Conserved Sequence MeSH
• Humans MeSH
• Chromosomes, Human, Pair 1 MeSH
• Evolution, Molecular MeSH
• Molecular Sequence Data MeSH
• Mice MeSH
• Drosophila Proteins * MeSH
• Regulatory Sequences, Nucleic Acid MeSH
• Amino Acid Sequence MeSH
• Sequence Alignment MeSH
• Transcription Factors MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Arid1a protein, mouse MeSH Browser
• ARID1B protein, human MeSH Browser
• Chromatin MeSH
• DNA-Binding Proteins MeSH
• Nuclear Proteins MeSH
• osa protein, Drosophila MeSH Browser
• Drosophila Proteins * MeSH
• Transcription Factors MeSH

Undifferentiated gastrointestinal tract carcinomas are rare highly aggressive neoplasms with frequent but not obligatory rhabdoid features. Recent studies showed loss of SMARCB1 (INI1), a core subunit of the SWI/SNF chromatin remodeling complex, in 50% of tested cases. However, the molecular pathways underlying histologically similar but SMARCB1-intact cases are unknown. We herein analyzed 13 cases for expression of 4 SWI/SNF complex subunits SMARCB1, SMARCA2, SMARCA4, and ARID1A and the mismatch-repair proteins MLH1, MSH2, MSH6, and PMS2 by immunohistochemistry. Patients included 12 men and 1 woman aged 32 to 81 years (median, 57 y). Site of origin was colon (5), small bowel (2), stomach (3), small+large intestine (1), small intestine+ampulla of Vater (1), and esophagogastric junction (1). All tumors showed anaplastic large to medium-sized cells with variable rhabdoid features, pleomorphic giant cells, and, rarely, spindle cell foci. Abortive gland formation was seen in 3 cases and bona fide glandular component in 1 case. Most cases strongly expressed vimentin and variably pancytokeratin. In total, 12/13 cases (92%) showed loss of at least 1 SWI/SNF component. Loss of SMARCB1 (5/13), SMARCA2 (10/13), SMARCA4 (2/13), and ARID1A (2/13) was observed either in combination or isolated. SMARCA2 loss was isolated in 5 cases and coexisted with lost SMARCB1 in 5 cases (all 5 SMARCB1-deficient tumors showed loss of SMARCA2 as well). Co-inactivation of SMARCB1 and SMARCA4 or of SMARCA2 and SMARCA4 was not observed. Two mismatch-repair-deficient cases (MLH1/PMS2) showed concurrent loss of SMARCB1, SMARCA2, and (one of them) ARID1A. This study illustrates for the first time loss of different components of the SWI/SNF complex other than SMARCB1 in undifferentiated gastrointestinal carcinomas including novel SMARCA4-deficient and SMARCA2-deficient cases. Our results underline the close link between SWI/SNF deficiency and the aggressive rhabdoid phenotype. Frequent loss of SMARCA2 possibly points to fragility/vulnerability of the SWI/SNF complex as a consequence of lost core subunit SMARCB1. The exact molecular mechanisms underlying co-inactivation of different SWI/SNF subunits merit further investigations.

• MeSH
• Chromosomal Proteins, Non-Histone genetics   MeSH
• Neoplastic Syndromes, Hereditary MeSH
• DNA Helicases genetics   MeSH
• Adult MeSH
• Gastrointestinal Neoplasms genetics   pathology   MeSH
• Immunohistochemistry MeSH
• Nuclear Proteins genetics   MeSH
• Carcinoma genetics   pathology   MeSH
• Colorectal Neoplasms MeSH
• Middle Aged MeSH
• Humans MeSH
• Brain Neoplasms MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Transcription Factors genetics   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chromosomal Proteins, Non-Histone MeSH
• DNA Helicases MeSH
• Nuclear Proteins MeSH
• SMARCA2 protein, human MeSH Browser
• SMARCA4 protein, human MeSH Browser
• SWI-SNF-B chromatin-remodeling complex MeSH Browser
• Transcription Factors MeSH

Endometrial carcinomas (EC) of no special molecular profile (NSMP) represent the largest molecular category of EC, comprising a mixture of tumors with different histology and molecular profiles. These facts likely point to different tumor biology, clinical outcomes, and targeted therapy responses within this molecular category. The PIK3CA is currently the only targetable kinase oncoprotein directly implicated in EC carcinogenesis. Investigating a unique single-institution cohort, we attempted to stratify NSMP ECs based on the presence of the PIK3CA pathogenic mutation. Those cases were further analyzed for other well-established-associated oncogenic driver gene mutations. Histological and clinical variables were also correlated in each case. Altogether, 175 ECs were prospectively tested by a limited custom NGS panel containing ARID1A, BCOR, BRCA1, BRCA2, CTNNB1, KRAS, MLH1, MSH2, MSH6, NRAS, PIK3CA, PMS2, POLD1, POLE, PTEN,and TP53 genes. We identified 24 PIK3CA mutated cases in the group of 80 NSMP ECs, with another co-occurring mutation in at least one oncogenic driver gene (CTNNB1, PTEN, ARID1A, KRAS, BCOR, PMS2) in 19 cases. In conclusion, a limited NGS panel can effectively test EC tissue for specific pathogenetically relevant oncogene mutations. The NSMP EC category contains 30% of the PIK3CA mutated cases. Of those, 21% contain the PIK3CA mutation as a sole EC-associated oncogene mutation, while 79% harbor at least one more mutated gene. These findings may inform future healthcare planning and improve the effectiveness of EC patient selection for the PIK3CA-targeted therapy.

• Keywords
• PIK3CA, Copy number low, Endometrial carcinoma, Kinase, Targeted therapy, Theranostics,
• Publication type
• Journal Article MeSH

Dedifferentiated and undifferentiated ovarian carcinomas (DDOC/UDOC) are rare neoplasms defined by the presence of an undifferentiated carcinoma. In this study, we detailed the clinical, pathological, immunohistochemical, and molecular features of a series of DDOC/UDOC. We collected a multi-institutional cohort of 23 DDOC/UDOC and performed immunohistochemistry for core switch/sucrose nonfermentable (SWI/SNF) complex proteins (ARID1A, ARID1B, SMARCA4, and SMARCB1), mismatch repair (MMR) proteins, and p53. Array-based genome-wide DNA methylation and copy number variation analyses were performed on a subset of cases with comparison made to a previously reported cohort of undifferentiated endometrial carcinoma (UDEC), small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), and tubo-ovarian high-grade serous carcinoma (HGSC). The age of all 23 patients with DDOC/UDOC ranged between 22 and 71 years (with an average age of 50 years), and a majority of them presented with extraovarian disease (16/23). Clinical follow-up was available for 19 patients. Except for 2 patients, the remaining 17 patients died from disease, with rapid disease progression resulting in mortality within a year in stage II-IV settings (median disease-specific survival of 3 months). Eighteen of 22 cases with interpretable immunohistochemistry results showed loss of expression of core SWI/SNF protein(s) that are expected to result in SWI/SNF complex inactivation as 10 exhibited coloss of ARID1A and ARID1B, 7 loss of SMARCA4, and 1 loss of SMARCB1. Six of 23 cases were MMR-deficient. Two of 20 cases exhibited mutation-type p53 immunoreactivity. Methylation profiles showed coclustering of DDOC/UDOC with UDEC, which collectively were distinct from SCCOHT and HGSC. However, DDOC/UDOC showed an intermediate degree of copy number variation, which was slightly greater, compared with SCCOHT but much less compared with HGSC. Overall, DDOC/UDOC, like its endometrial counterpart, is highly aggressive and is characterized by frequent inactivation of core SWI/SNF complex proteins and MMR deficiency. Its molecular profile overlaps with UDEC while being distinct from SCCOHT and HGSC.

• Keywords
• ARID1B, SMARCA4, SMARCB1, SWI/SNF, methylation, undifferentiated ovarian carcinoma,
• MeSH
• Neoplastic Syndromes, Hereditary * MeSH
• DNA Helicases genetics   metabolism   MeSH
• Adult MeSH
• Carcinoma, Ovarian Epithelial MeSH
• Nuclear Proteins genetics   MeSH
• Carcinoma * pathology   MeSH
• Colorectal Neoplasms * MeSH
• Middle Aged MeSH
• Humans MeSH
• Carcinoma, Small Cell * MeSH
• Young Adult MeSH
• Biomarkers, Tumor genetics   metabolism   MeSH
• Tumor Suppressor Protein p53 genetics   MeSH
• Endometrial Neoplasms * pathology   MeSH
• Brain Neoplasms * MeSH
• Ovarian Neoplasms * genetics   pathology   MeSH
• Aged MeSH
• Transcription Factors genetics   metabolism   MeSH
• DNA Copy Number Variations MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• DNA Helicases MeSH
• Nuclear Proteins MeSH
• Biomarkers, Tumor MeSH
• Tumor Suppressor Protein p53 MeSH
• SMARCA4 protein, human MeSH Browser
• Transcription Factors MeSH

OBJECTIVE: Molecular classification of endometrial carcinomas (EC) divides these neoplasms into four distinct subgroups defined by a molecular background. Given its proven clinical significance, genetic examination is becoming an integral component of the diagnostic procedure. Recommended diagnostic algorithms comprise molecular genetic testing of the POLE gene, whereas the remaining parameters are examined solely by immunohistochemistry. The aim of this study is to share our experiences with the molecular classification of EC, which has been conducted using immunohistochemistry and next-generation sequencing (NGS) at our department. METHODS: This study includes all cases of EC diagnosed at Šikl's Department of Pathology and Biopticka Laboratory Ltd. from 2020 to the present. All ECs were prospectively examined by immunohistochemistry (MMR, p53), fol lowed by NGS examination using a customized Gyncore panel (including genes POLE, POLD1, MSH2, MSH6, MLH1, PMS2, TP53, PTEN, ARID1A, PIK3CA, PIK3R1, CTNNB1, KRAS, NRAS, BRCA1, BRCA2, BCOR, ERBB2), based on which the ECs were classified into four molecularly distinct groups [POLE mutated EC (type 1), hypermutated (MMR deficient, type 2), EC with no specific molecular profile (type 3), and TP53 mutated ("copy number high", type 4)]. RESULTS: The cohort comprised a total of 270 molecularly classified ECs. Eighteen cases (6.6%) were classified as POLE mutated EC, 85 cases (31.5%) as hypermutated EC (MMR deficient), 137 cases (50.7%) as EC of no specific molecular profile, and 30 cases (11.1%) as TP53 mutated EC. Twelve cases (4.4%) were classified as "multiple classifier" endometrial carcinoma. ECs of no specific molecular profile showed multiple genetic alterations, with the most common mutations being PTEN (44% within the group of NSMP), fol lowed by PIK3CA (30%), ARID1A (21%), and KRAS (9%). CONCLUSION: In comparison with recommended diagnostic algorithms, NGS provides a more reliable classification of EC into particular molecular subgroups. Furthermore, NGS reveals the complex molecular genetic background in individual ECs, which is especially significant within ECs with no specific molecular profile. These data can serve as a springboard for the research of therapeutic programs committed to targeted therapy in this type of tumor.

• Keywords
• Endometrial carcinoma, NGS, endometrium, molecular classification, next generation sequencing,
• MeSH
• Immunohistochemistry MeSH
• Middle Aged MeSH
• Humans MeSH
• Mutation MeSH
• Endometrial Neoplasms * genetics   classification   pathology   diagnosis   MeSH
• High-Throughput Nucleotide Sequencing * methods   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH