Juxtaglomerular cell tumor (JxGCT) is a rare type of renal neoplasm demonstrating morphologic overlap with some mesenchymal tumors such as glomus tumor (GT) and solitary fibrous tumor (SFT). Its oncogenic drivers remain elusive, and only a few cases have been analyzed with modern molecular techniques. In prior studies, loss of chromosomes 9 and 11 appeared to be recurrent. Recently, whole-genome analysis identified alterations involving genes of MAPK-RAS pathway in a subset, but no major pathogenic alterations have been discovered in prior whole transcriptome analyses. Considering the limited understanding of the molecular features of JxGCTs, we sought to assess a collaborative series with a multiomic approach to further define the molecular characteristics of this entity. Fifteen tumors morphologically compatible with JxGCTs were evaluated using immunohistochemistry for renin, single-nucleotide polymorphism array (SNP), low-pass whole-genome sequencing, and RNA sequencing (fusion assay). In addition, methylation analysis comparing JxGCT, GT, and SFT was performed. All cases tested with renin (n=11) showed positive staining. Multiple chromosomal abnormalities were identified in all cases analyzed (n=8), with gains of chromosomes 1p, 10, 17, and 19 and losses of chromosomes 9, 11, and 21 being recurrent. A pathogenic HRAS mutation was identified in one case as part of the SNP array analysis. Thirteen tumors were analyzed by RNA sequencing, with 2 revealing in-frame gene fusions: TFG::GPR128 (interpreted as stochastic) and NAB2::STAT6 . The latter, originally diagnosed as JxGCT, was reclassified as SFT and excluded from the series. No fusions were detected in the remaining 11 cases; of note, no case harbored NOTCH fusions previously described in GT. Genomic methylation analysis showed that JxGCT, GT, and SFT form separate clusters, confirming that JxGCT represents a distinct entity (ie, different from GT). The results of our study show that JxGCTs are a distinct tumor type with a recurrent pattern of chromosomal imbalances that may play a role in oncogenesis, with MAPK-RAS pathway activation being likely a driver in a relatively small subset.

• MeSH
• dospělí MeSH
• epigeneze genetická MeSH
• epigenomika MeSH
• fúze genů * MeSH
• genetická predispozice k nemoci MeSH
• genomika MeSH
• imunohistochemie MeSH
• jednonukleotidový polymorfismus MeSH
• juxtaglomerulární aparát patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA MeSH
• nádorové biomarkery * genetika   MeSH
• nádory ledvin * genetika   patologie   chemie   MeSH
• sekvenování celého genomu MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH

Pathogenic alterations, namely, fusions and amplifications, of the GLI1 gene have been identified in various mesenchymal tumors, including pericytoma with t(7;12), plexiform fibromyxoma, gastroblastoma, and other malignant mesenchymal neoplasms arising in the soft tissues, as well as in various visceral organs. However, only three cases of GLI1-rearranged renal tumors have been reported to date, comprising two low-grade spindle cell tumors with GLI1::FOXO4 fusion along with one GLI1-rearranged case with an unknown fusion partner. In this study, we analyzed three cases with GLI1::FOXO4 fusion and overlapping morphology. One of the cases was reported previously, but an extended clinical and immunohistochemical information is provided. The studied cases occurred in 2 female and 1 male patients aged 35, 55, and 62 years (mean 51 years). All three tumors affected the renal parenchyma and grew as unencapsulated but well-circumscribed solid masses containing occasional entrapped and dilated renal tubules. The tumor cells were organized in cords, nests, or fascicles, had a round to spindled shape, and exhibited only mild nuclear atypia and minimal mitotic activity. They had a sparse eosinophilic to clear cytoplasm and were embedded in myxocollagenous stroma. Immunohistochemically, all cases expressed GLI1 (albeit with variable intensity) and harbored GLI1::FOXO4 fusion. All three patients were treated solely by complete surgical excision. Case 1 was alive with unknown disease status, case 2 was alive without evidence of disease, and case 3 died of unrelated causes. Our study doubles the number of reported cases with GLI1::FOXO4 fusion. The so far absolute predilection of this fusion for renal tumors, coupled with the absence of reports of other GLI1 fusions in tumors of the kidney, might indicate the potential existence of a distinct renal subtype with morphological features similar to other GLI1-altered tumors. All four reported cases had an uneventful follow-up which, together with their low-grade morphological features, suggests that these tumors might have a favorable prognosis.

• MeSH
• dospělí MeSH
• forkhead transkripční faktory * genetika   MeSH
• genová přestavba * MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory ledvin * genetika   patologie   MeSH
• protein Gli1 * genetika   MeSH
• proteiny buněčného cyklu * genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

Uterine sarcomas with KAT6B/A::KANSL1 fusion represent a new entity characterized by bland morphology, commonly with hybrid features of low-grade endometrial stromal sarcoma (LG-ESS) and tumors with smooth muscle differentiation. In our study, we performed a detailed morphological, immunohistochemical, and molecular analysis of 9 cases of these tumors. Six of those had been originally diagnosed as LG-ESS, one as leiomyoma, one as leiomyosarcoma, and the remaining case as sarcoma with the KAT6B/A::KANSL1 fusion. Seven cases showed overlapping features between endometrial stromal and smooth muscle tumors, one case resembled cellular leiomyoma, and one case resembled high-grade endometrial stromal sarcoma. Immunohistochemically, the tumors showed a common expression of smooth muscle markers and endometrial stromal markers. Molecular findings showed the KAT6B/A::KANSL1 fusion in all cases (by NGS and FISH). In addition, mutations affecting genes such as TP53, PDGFRB, NF1, RB1, PTEN, ATM, RB1, FANCD2, and TSC1 were present in all 5 cases with aggressive behavior. One patient with no evidence of disease showed no additional mutations, while another harbored a mutation of a single gene (ERCC3). Of the 8 patients with available follow-up, two died of disease, 3 are currently alive with disease, and 3 have no evidence of disease. The correct recognition of tumors with the KAT6B/A::KANSL1 fusion is essential because despite the bland morphological features of most cases, these tumors have a propensity for aggressive behavior.

• MeSH
• dospělí MeSH
• endometriální stromální sarkom genetika   patologie   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• histonacetyltransferasy genetika   MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory dělohy * patologie   genetika   MeSH
• sarkom genetika   patologie   MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

TFE3 rearrangements characterize histogenetically, topographically, and biologically diverse neoplasms. Besides being a universal defining feature in alveolar soft part sarcoma (ASPS) and clear cell stromal tumor of the lung, TFE3 fusions have been reported in subsets of renal cell carcinoma, perivascular epithelioid cell tumor (PEComa), epithelioid hemangioendothelioma and ossifying fibromyxoid tumors. TFE3 -related neoplasms are rare in the head and neck and may pose diagnostic challenges. We herein describe 22 TFE3 fusion neoplasms affecting 11 males and 11 females aged 4 to 79 years (median, 25) and involving different head and neck sites: sinonasal cavities (n = 8), tongue (n = 4), oral cavity/oropharynx (n = 3), salivary glands (n = 2), orbit (n = 2), and soft tissue or unspecified sites (n = 3). Based on morphology and myomelanocytic immunophenotype, 10 tumors qualified as ASPS, 7 as PEComas (3 melanotic; all sinonasal), and 5 showed intermediate (indeterminate) histology overlapping with ASPS and PEComa. Immunohistochemistry for TFE3 was homogeneously strongly positive in all cases. Targeted RNA sequencing/FISH testing confirmed TFE3 fusions in 14 of 16 successfully tested cases (88%). ASPSCR1 was the most frequent fusion partner in ASPS (4 of 5 cases); one ASPS had a rare VCP::TFE3 fusion. The 6 successfully tested PEComas had known fusion partners as reported in renal cell carcinoma and PEComas ( NONO, PRCC, SFPQ , and PSPC1 ). The indeterminate tumors harbored ASPSCR1::TFE3 (n = 2) and U2AF2::TFE3 (n = 1) fusions, respectively. This large series devoted to TFE3-positive head and neck tumors illustrates the recently proposed morphologic overlap in the spectrum of TFE3 -associated mesenchymal neoplasms. While all PEComas were sinonasal, ASPS was never sinonasal and occurred in diverse head and neck sites with a predilection for the tongue. The indeterminate (PEComa-like) category is molecularly more akin to ASPS but shows different age, sex, and anatomic distribution compared with classic ASPS. We report VCP as a novel fusion partner in ASPS and PSPC1 as a novel TFE3 fusion partner in PEComa (detected in one PEComa). Future studies should shed light on the most appropriate terminological subtyping of these highly overlapping tumors.

• MeSH
• alveolární sarkom měkkých tkání * genetika   patologie   MeSH
• dítě MeSH
• dospělí MeSH
• fenotyp MeSH
• genetická predispozice k nemoci MeSH
• genová přestavba * MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory hlavy a krku * genetika   patologie   chemie   MeSH
• nádory z perivaskulárních epiteloidních buněk * genetika   patologie   chemie   MeSH
• předškolní dítě MeSH
• senioři MeSH
• transkripční faktory BHLH-Zip * genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Malignant glomus tumors are rare tumors of pericytic origin with a propensity to develop in the upper gastrointestinal tract. Hereby we demonstrate a tumor of a 20-year-old man, who presented with dysphagia and an exophytic esophageal mass. Histologic examination of the resected mass revealed a multinodular tumor in the esophageal wall composed of epithelioid cells showing nesting and monomorphic atypia, staghorn vessels and scanty stroma. Immunohistochemically, the neoplastic cells were positive for SMA, and H-caldesmon, while desmin was negative. Collagen IV and laminin decorated a dense intercellular basal membrane meshwork. RNA-sequencing using TruSight RNA Pan-Cancer Panel revealed a CARMN::NOTCH2 fusion, that is a recurrent, frequently described and so far specific genetic alteration in glomus tumors. In spite of the adjuvant chemotherapy regimens, the patient died of disseminated metastatic disease 2 years after the diagnosis. Our patient presentation and the previous reports in the literature highlight the frequently aggressive behavior of glomus tumors arising in the esophagus.

• MeSH
• ezofágus patologie   chirurgie   diagnostické zobrazování   MeSH
• fatální výsledek MeSH
• fúzní onkogenní proteiny * genetika   MeSH
• glomangiom * genetika   patologie   diagnóza   MeSH
• lidé MeSH
• mladý dospělý MeSH
• nádorové biomarkery genetika   analýza   MeSH
• nádory jícnu * patologie   genetika   diagnóza   MeSH
• receptor Notch2 * genetika   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

AIMS: CIC-rearranged sarcomas (CRS) are clinically aggressive undifferentiated round cell sarcomas (URCS), commonly driven by CIC::DUX4. Due to the repetitive nature of DUX4 and the variability of the fusion breakpoints, CIC::DUX4 fusion may be missed by molecular testing. Immunohistochemical (IHC) stains have been studied as surrogates for the CIC::DUX4 fusion. We aim to assess the performance of DUX4 IHC in the work-up of CRS and its expression in non-CRS round cell or epithelioid neoplasms. METHODS AND RESULTS: Cases of molecularly confirmed CRS (n = 48) and non-CRS (n = 105) were included. CRS cases consisted of 35 females and 13 males, with ages ranging from less than 1 year to 67 years (median = 41 years). Among the molecularly confirmed non-CRS cases, C-terminal DUX4 expression was investigated in Ewing sarcomas (38 cases), alveolar rhabdomyosarcomas (18 cases), desmoplastic small round cell tumours (12 cases) and synovial sarcomas (n = five), as well as in non-mesenchymal neoplasms such as SMARCA4/SMARCB1-deficient tumours (n = five), carcinomas of unknown primary (n = three) and haematolymphoid neoplasms (four cases). DUX4 IHC was considered positive when strong nuclear expression was detected in more than 50% of neoplastic cells. When used as a surrogate for the diagnosis of CRS, the sensitivity and specificity of DUX4 IHC was 98 and 100%, respectively. Only one CRS case was negative for DUX4 IHC and harboured a CIC::FOXO4 fusion. CONCLUSIONS: DUX4 IHC is a highly sensitive and specific surrogate marker for the presence of CIC::DUX4 fusion, demonstrating its utility in establishing a diagnosis of CRS.

• MeSH
• dítě MeSH
• dospělí MeSH
• fúzní onkogenní proteiny * genetika   MeSH
• genová přestavba MeSH
• homeodoménové proteiny * metabolismus   genetika   MeSH
• imunohistochemie * MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádorové biomarkery * metabolismus   analýza   genetika   MeSH
• nádory měkkých tkání diagnóza   patologie   genetika   metabolismus   MeSH
• předškolní dítě MeSH
• sarkom * diagnóza   patologie   genetika   metabolismus   MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• Publikační typ
• abstrakt z konference MeSH

Myoepithelial neoplasms of the skin and soft tissue still represent a confusing and somewhat controversial field in pathology as it appears that this category includes several different entities. However, recent studies have suggested that both apocrine mixed tumors (AMT) and cutaneous myoepitheliomas (CM) harbor identical chromosomal rearrangements involving the PLAG1 gene and hence may represent a morphological spectrum. The aim of the present study was to share our institutional experience with these tumors and specifically focus on studying their immunohistochemical and molecular features to further assess their relatedness. Eleven cases of AMT and 7 cases of CM were collected and analyzed using immunohistochemistry (IHC), PLAG1 FISH, and Archer FusionPlex assay. There were 14 male and 4 female patients with ages ranging from 26 to 85 years (median 55.8 years, mean 58.5 years). AMTs were mainly located in the head and neck (n = 10), while CMs were mainly located in the acral sites (n = 5). PLAG1 IHC was diffusely strongly positive in 14/17 (82%) cases, whereas a single case of AMT diffusely expressed HMGA2. Both tumor groups showed PLAG1 gene fusions which were detected in 6/13 analyzable samples (AMT, n = 4 and CM, n = 2), and included TRPS1::PLAG1 (n = 3), NDRG1::PLAG1 (n = 1), CTNNB1::PLAG1 (n = 1) and a novel PXDNL::PLAG1 fusion (n = 1). The remaining 5 cases were negative, 5 were not analyzable and the single case positive for HMGA2 by IHC revealed a potential HMGA2 gene rearrangement. The cases were further studied by FISH, with 12/17 cases showing PLAG1 gene rearrangement (AMT, n = 8 and CM, n = 4). Altogether, 14/18 cases showed PLAG1 gene rearrangement by at least one of the methods. PLAG1 immunohistochemistry had a 92% specificity and sensitivity. Our study provided additional data to suggest that AMT and CM share overlapping morphological and immunohistochemical features as well as molecular background characterized by PLAG1 gene fusions and thus represent a morphological spectrum. In addition, we identified a novel PXDNL::PLAG1 fusion and suggested that rare cases may harbor HMGA2 gene alterations which seem to be mutually exclusive with PLAG1 gene fusions. The relatedness of these tumors to salivary gland myoepithelial neoplasms and distinctness from eccrine mixed tumors and other skin and soft tissue myoepithelial neoplasms with EWSR1/FUS fusions is discussed.

• MeSH
• DNA vazebné proteiny * genetika   MeSH
• dospělí MeSH
• genová přestavba * MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie * MeSH
• lidé středního věku MeSH
• lidé MeSH
• myoepiteliální nádor * genetika   patologie   MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory komplexní a smíšené genetika   patologie   chemie   MeSH
• nádory kůže * genetika   patologie   MeSH
• nádory potních žláz genetika   patologie   MeSH
• protein HMGA2 * genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Assessing the biological behavior of uterine inflammatory myofibroblastic tumors (IMTs) remains challenging. This study evaluated previously proposed risk schemes and features in 9 IMTs (6 indolent, 3 aggressive) by integrating clinicopathological features, immunohistochemistry, and next-generation sequencing (NGS). High-risk features (necrosis, infiltrative growth, nuclear atypia) were present in both groups, with LVSI in 1/3 of aggressive IMTs. Aberrant p16 expression and CDKN2A/2B deletions were noted in 2/3 aggressive cases. All cases harbored ALK fusions, wild-type p53, and lacked pathogenic gene mutations. Aggressive cases harbored arm-level and segmental copy number gains/losses at chr 1, 2, X, and had significantly reduced AR expression. The clinicopathological risk stratification score (CRSS) predicted the biological behavior correctly in cases with complete clinicopathological data (size, mitoses, age, infiltrative growth). Two morcellated cases (one indolent and one aggressive) would have been predicted as low risk based solely on the absence of pathogenic mutations. Hereby, the reliability of the proposed CRSS was confirmed. Aberrant p16 expression predicted malignant behavior in 2/3 aggressive cases. Absence of pathogenic mutations or presence of large scale CNVs does not seem to be a predictor of clinical behavior. Additional studies and NGS analyses of more cases may improve risk stratification for patients with incomplete clinicopathological information and may reveal additional risk stratifiers (such as the suggested large-scale CNVs or AR downregulation) for IMTs.

• MeSH
• dospělí MeSH
• imunohistochemie MeSH
• inhibitor p16 cyklin-dependentní kinasy MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádory dělohy * patologie   genetika   MeSH
• nádory ze svalové tkáně * patologie   genetika   MeSH
• senioři MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Wilms tumour is a common juvenile cancer of the kidney, and its occurrence in adolescence or adulthood is extremely rare, accounting for around 1% of all adult kidney malignancies. Histopathologically, three tissue patterns can be identified, including blastemal, epithelial, and stromal components, while the overall microscopic appearance of an adult-type tumour does not differ from that of its juvenile counterpart. The blastemal predominant Wilms tumours are the most aggressive and have the worst prognosis. The samples must be histopathologically verified before the definitive diagnosis can be made, and immunohistochemistry examination is critical. Wilms tumours are often positive for keratin, vimentin, desmin, actin, and WT1, which distinguishes this type of tumour from other malignancies. WT1 positivity is indicative of the blastemal component of the tumorous tissue and may be completely absent in the mature epithelial and stromal parts. Only three WT1 negative adult-type Wilms tumours have been reported in the literature to this date. However, none of the patients had a blastemal predominant tumour. That is why we would like to present a highly interesting and diagnostically challenging case of a young man who was diagnosed with a tumorous lesion of the left kidney parenchyma. Genetic analysis did not reveal any known fusion genes associated with round cell sarcomas, ruling out this differential diagnosis. This article also includes a literature review on published articles on WT1 negative Wilms tumour in adults and other concerns related to this topic. The main goal of this publication was to emphasise that, while it is a rare entity in general, similar problematic cases can occur in practise, and thus it is important to be aware of this type of tumour when making a differential diagnosis in cases with similar clinical and histopathological features.

• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH