Apart from the lethal midline carcinoma (NUT carcinoma), NUTM1 translocation has also been reported in mesenchymal tumors, but is exceedingly rare. Here, we describe a series of 8 NUTM1 -rearranged sarcomas to further characterize the clinicopathologic features of this emerging entity. This cohort included 2 males and 6 females with age ranging from 24 to 64 years (mean: 51 y; median: 56 y). Tumors occurred in the colon (2), abdomen (2), jejunum (1), esophagus (1), lung (1) and infraorbital region (1). At diagnosis, 6 patients presented with metastatic disease. Tumor size ranged from 1 to 10.5 cm (mean: 6 cm; median: 5.5 cm). Histologically, 4 tumors were composed of primitive small round cells to epithelioid cells intermixed with variable spindle cells, while 3 tumors consisted exclusively of small round cells to epithelioid cells and 1 tumor consisted predominantly of high-grade spindle cells. The neoplastic cells were arranged in solid sheets, nests, or intersecting fascicles. Mitotic activity ranged from 1 to 15/10 HPF (median: 5/10 HPF). Other features included rhabdoid phenotype (4/8), pronounced nuclear convolutions (2/8), prominent stromal hyalinization (2/8), focally myxoid stroma (1/8), foci of osteoclasts (1/8), and necrosis (1/8). By immunohistochemistry, all tumors showed diffuse and strong nuclear staining of NUT protein, with variable expression of pancytokeratin (AE1/AE3) (2/8), CK18 (1/8), CD99 (3/8), NKX2.2 (2/8), cyclin D1 (2/8), desmin (2/8), BCOR (2/8), S100 (1/8), TLE1 (1/8), and synaptophysin (1/8). Seven of 8 tumors demonstrated NUTM1 rearrangement by fluorescence in situ hybridization analysis. RNA-sequencing analysis identified MXD4::NUTM1 (3/7), MXI1::NUTM1 (3/7), and MGA::NUTM1 (1/7) fusions, respectively. DNA-based methylation profiling performed in 2 cases revealed distinct methylation cluster differing from those of NUT carcinoma and undifferentiated small round cell and spindle cell sarcomas. At follow-up (range: 4 to 24 mo), 1 patient experienced recurrence at 8.5 months, 4 patients were alive with metastatic disease (5, 10, 11, and 24 mo after diagnosis), 3 patients remained well with no signs of recurrence or metastasis (4, 6, and 12 mo after diagnosis). Our study further demonstrated that NUTM1 -rearranged sarcoma had a broad range of clinicopathologic spectrum. NUT immunohistochemistry should be included in the diagnostic approach of monotonous undifferentiated small round, epithelioid to high-grade spindle cell malignancies that difficult to classify by conventional means. DNA-based methylation profiling might provide a promising tool in the epigenetic classification of undifferentiated sarcomas.

UNASSIGNED: Ewing sarcoma (ES) are malignant small round cell tumors (MSRCT) characterized by rearrangements of EWSR1 gene. Although gold standard for diagnosis is detection of specific fusion genes by molecular testing, these ancillary tests are costly and only available in limited number of settings. There is a persuasive evidence for reliability of NKX2.2 immunohistochemistry (IHC) as a surrogate marker for EWSR1 gene rearrangement in ES.
UNASSIGNED: The aim of this study is to correlate the NKX2.2 immuno-expression with genetically confirmed ES cases and also to assess the reliability and accuracy of NKX2.2 along with combined positivity of NXX2.2 and CD99 in diagnosing ES and differentiating it from other relevant histological mimics.
UNASSIGNED: The present study is a retrospective study conducted over a period of 6-year duration in a tertiary cancer care center.
UNASSIGNED: We evaluated NKX2.2 immunoexpression in 35 genetically confirmed cases of ES and also in pertaining differential entities (n = 58) of ES including rhabdomyosarcoma (n = 20), lymphoblastic lymphoma (n = 14), Wilms tumor (n = 10), poorly differentiated synovial sarcoma (n = 4), small-cell osteosarcoma (n = 4), neuroblastoma (n = 5), and mesenchymal chondrosarcoma (n = 1). CD99 was performed in the category of MSRCTs showing NKX2.2 positivity to evaluate combined specificity for the diagnosis of ES.
UNASSIGNED: Of the 35 genetically confirmed cases of ES, 29 cases (83%) showed NKX2.2-positive expression (83% sensitivity). Compared to ES, NKX2.2 was positive in only 05% cases (3/58 cases) of non-ES MSRCT. Only two of five cases of neuroblastomas and one case of mesenchymal chondrosarcoma showed NKX2.2 positivity. CD99 positivity was seen in 100% of ES and in the single case of mesenchymal chondrosarcoma. All five cases (100%) of neuroblastoma were negative for CD99.
UNASSIGNED: The presented study, which is the first from an Indian oncology center, showed NKX2.2 IHC is quite reliable in diagnosis of ES in the right clinicopathological context. With remarkable sensitivity and specificity of NKX2.2 IHC for diagnosis of ES, we propose that combined positivity of CD99 and NKX2.2 IHC can obviate or minimize the need of EWSR1 gene rearrangement molecular testing for diagnosis of ES.

Autism spectrum disorders (ASD) is a complex neurodevelopmental disorder that may significantly impact on the affected individual\'s life. Common variation (SNPs) could explain about 50% of ASD heritability. Despite this fact and the large size of the last GWAS meta-analysis, it is believed that hundreds of risk genes in ASD have yet to be discovered. New tools, such as TWAS (Transcriptome Wide Association Studies) which integrate tissue expression and genetic data, are a great approach to identify new ASD susceptibility genes. The main goal of this study is to use UTMOST with the publicly available summary statistics from the largest ASD GWAS meta-analysis as genetic input. In addition, an in silico biological characterization for the novel associated loci was performed. Our results have shown the association of 4 genes at the brain level (CIPC, PINX1, NKX2-2, and PTPRE) and have highlighted the association of NKX2-2, MANBA, ERI1, and MITF at the gastrointestinal level. The gastrointestinal associations are quite relevant given the well-established but unexplored relationship between ASD and gastrointestinal symptoms. Cross-tissue analysis has shown the association of NKX2-2 and BLK. UTMOST-associated genes together with their in silico biological characterization seems to point to different biological mechanisms underlying ASD etiology. Thus, it would not be restricted to brain tissue and it will involve the participation of other body tissues such as the gastrointestinal.

BACKGROUND: Mesenchymal chondrosarcoma is a rare subtype of chondrosarcoma. The tumor has a characteristic bimorphic pattern with areas of poorly differentiated small round cell component and interspersed islands of well differentiated hyaline cartilage. Histological diagnosis of mesenchymal chondrosarcoma is very challenging especially in small biopsies when tumor presents with little cartilaginous component. In such cases, it is very difficult to distinguish mesenchymal chondrosarcoma from other round blue cell tumors like Ewing\'s sarcoma, rhabdomyosarcoma, small cell osteosarcoma and desmoplastic round blue cell tumor. Immunohistochemically, mesenchymal chondrosarcoma stains positive for NKX2.2, CD99, S100 and SOX9. This immunoprofile is non-specific and overlaps with other round blue cell tumors. Till recently, there was no reliable immunohistochemical marker to differentiate mesenchymal chondrosarcoma from other round blue cell tumors. NKX3.1, though widely used as a diagnostic biomarker for prostatic adenocarcinoma, has been recently proposed by Yoshida et al. (2020) as a unique marker of mesenchymal chondrosarcoma and EWSR1-NFATC2 sarcoma.
OBJECTIVE: The aim of our study was to further explore utility of NKX3.1 as a diagnostic marker of mesenchymal chondrosarcoma.
METHODS: We applied NKX3.1 immunohistochemistry to 21 cases of mesenchymal chondrosarcoma and 32 cases of other round blue cell tumors.
RESULTS: 14 out of 21 cases (66.7%) of mesenchymal chondrosarcoma stained positive for NKX3.1 with nuclear expression in small round component. Cartilaginous component was predominantly negative. All other round blue cell tumors showed negative results.
CONCLUSIONS: Based on our study results we suggest that NKX3.1 is a useful immunohistochemical marker in differentiating mesenchymal chondrosarcoma from its histological mimics.

OBJECTIVE: Mesenchymal chondrosarcoma (MC) is characterised typically by a bimorphic microscopic appearance of islands of a well-differentiated cartilaginous component, admixed with a primitive small cell component, which commonly expresses CD99 and NKX2.2. Given the variable relative abundance of each component and histological overlap with other small round cell tumours, the diagnosis can be challenging, especially in a limited sample. A distinctive gene fusion between HEY1 (located in 8q21) and NCOA2 (located in 8q13) was identified in MC, but the downstream molecular events are unknown. NKX3.1 (coding gene located in 8p21.1) was recently reported to be expressed in a small number of MC cases. The purpose of this study was to evaluate the potential diagnostic utility of NKX3.1 immunohistochemistry in MC.
RESULTS: We evaluated sections from 25 cases of MC, including 20 extraskeletal and five osseous. The tumour affected nine females and 16 males, with a median age of 34 years (age range = 7-82 years). Two different rabbit antibodies against NKX3.1 (monoclonal and polyclonal) were used for immunohistochemistry. However, no immunoreactivity was observed with either of the antibodies in all 25 (100%) MC.
CONCLUSIONS: NKX3.1 immunoreactivity was not identified in our cohort. Clonality of the antibody could not explain the negativity.

Ewing sarcoma (EWS) is a pediatric cancer characterized by the EWSR1-FLI1 fusion. We performed a genome-wide association study of 733 EWS cases and 1346 unaffected individuals of European ancestry. Our study replicates previously reported susceptibility loci at 1p36.22, 10q21.3 and 15q15.1, and identifies new loci at 6p25.1, 20p11.22 and 20p11.23. Effect estimates exhibit odds ratios in excess of 1.7, which is high for cancer GWAS, and striking in light of the rarity of EWS cases in familial cancer syndromes. Expression quantitative trait locus (eQTL) analyses identify candidate genes at 6p25.1 (RREB1) and 20p11.23 (KIZ). The 20p11.22 locus is near NKX2-2, a highly overexpressed gene in EWS. Interestingly, most loci reside near GGAA repeat sequences and may disrupt binding of the EWSR1-FLI1 fusion protein. The high locus to case discovery ratio from 733 EWS cases suggests a genetic architecture in which moderate risk SNPs constitute a significant fraction of risk.

OBJECTIVE: Approximately 60-70% of high-grade round-cell sarcomas that lack the Ewing sarcoma breakpoint region 1 (EWSR1) rearrangement harbour a rearrangement of the CIC gene, most commonly CIC-DUX4. Recent studies have established that CIC-rearranged sarcomas constitute a distinct group characterized by recognizable histology and immunoprofiles, such as positivity for ETV4 and WT1 and negativity for NKX2.2. Although these sarcomas are diagnosed increasingly in practice by fluorescence in-situ hybridization (FISH) with CIC break-apart probes, the optimal modality to diagnose these sarcomas has not been determined. In this study, we describe four round-cell sarcomas that showed false-negative results by CIC break-apart FISH assays.
RESULTS: These sarcomas showed characteristic histology of CIC-rearranged sarcomas, and all were immunohistochemically positive for ETV4 and WT1 and negative for NKX2.2. Although FISH showed non-atypical negative signals for CIC rearrangement, high-throughput RNA sequencing identified CIC-DUX4 and its fusion breakpoint in all cases. Their clinical and histological findings, as well as fusion points determined by RNA sequencing, did not differ significantly from those of nine FISH-positive CIC-DUX4 sarcoma cases. We estimated that the FISH false-negative rate for CIC-rearranged sarcomas was 14%. Although neither histology nor immunoprofiles (e.g. ETV4 and WT1) are entirely sensitive or specific for CIC-rearranged sarcomas, the observation that these four cases were identified successfully by such phenotypes suggested their practical utility.
CONCLUSIONS: CIC break-apart FISH assays missed a significant minority of CIC-DUX4 sarcomas, and full awareness of typical morphology and judicious immunohistochemical work-ups, including analyses of ETV4 and WT1, should complement diagnostic assessment.

Meningeal Ewing Sarcoma (ES)/peripheral primitive neuroectodermal tumor (pPNET) is a rare diagnostically challenging small round cell tumor in the CNS. This study investigates the clinical pathological features of four cases of this tumor from archives of 6 years in our hospital. Patients were within the median age of 21.5 years and male to female ratio was 1:1. The tumors distributed at the supra-tentorial location, posterior fossa and lumbar vertebral canal, usually presenting as the dura-sited nodule or having close connection with the meninges within the cranium or vertebral canal. Histopathologically, small round undifferentiated tumor cells with hypercellularities, scant cytoplasm and inconspicuous nucleoli were observed, although some components such as atypical larger vesicular nuclei, prominent nucleoli of tumor cells, necrotic foci and mesenchymal collagen proliferation forming the lobular structure, were also appreciated. Immunohistochemally, tumor cells displayed membranous positivity of CD99 (4/4), nuclear positivity of FLI-1 (4/4) and NKX2.2 (4/4), negativity of EMA, GFAP and synaptophysin expression. The histochemical PAS staining showed weak positivity in one case. Fluorescence in situ hybridization (FISH) test using EWSR1 (22q12) dual color break apart rearrangement probe showed positive results in two cases. Results suggest that using a panel of immunohistochemical markers, including NKX2.2, CD99, FLI-1, EMA, GFAP and synaptophysin, combined with the supplementary EWSR1 FISH test, helps to define the diagnosis of meningeal ES/pPNET of CNS.

The CIC gene rearrangement exists in a subset of small round cell sarcomas. As the nosologic relationship of these sarcomas to Ewing sarcomas remains undetermined, we examined 20 CIC-rearranged sarcomas to compare their clinicopathologic features with those of Ewing sarcomas. The CIC-rearranged sarcomas were from a group of 14 men and 6 women with a median age of 24.5 years. The primary tumor sites included the limbs, trunk wall, internal trunk, lung, cerebrum, and pharynx. A comparison of the demographic and clinical characteristics of the 20 patients with CIC-rearranged sarcomas with those of the 53 near-consecutive patients with EWSR1-rarranged Ewing sarcomas showed that there were no differences with respect to their ages and sexes. Although none of the CIC-rearranged sarcomas arose in the bone, 40% of the Ewing sarcomas primarily affected the skeleton. The overall survival of patients with Ewing sarcomas was significantly better than that for patients with CIC-rearranged sarcomas. A histologic comparison of the CIC-rearranged sarcomas with 20 EWSR1-rearranged Ewing sarcomas showed significantly higher degrees of lobulation, nuclear pleomorphism, the prominence of the nucleoli, spindle cell elements, and myxoid changes in the CIC-rearranged sarcomas. Distinguishing immunohistochemical features included heterogenous CD99 reactivity, nuclear WT1 expression, and calretinin expression in the CIC-rearranged sarcomas and NKX2.2 expression in the Ewing sarcomas. CIC-rearranged sarcomas are distinct from Ewing sarcomas clinically, morphologically, and immunohistochemically, and they should be considered a separate entity rather than being grouped within the same family of tumors.

OBJECTIVE: To investigate the genome copy number variation (CNV) related with keloid using the whole-gene resequencing technology.
METHODS: A keloid pedigree containing 4 generation of 27 people was studied. Five people (4 cases of keloid patients, and 1 case of normal) were selected to extract the genomic DNA. Then the whole-gene resequencing technique was used to check the variations based on the Illumina Hiseq 2000.
RESULTS: Through database comparison and variation annotation analysis, 15 CNVs associated with scar hyperplasia were obtained. DAVID software was used to do the Gene Ontology and pathway analysis. Five CNVs were closely related to the keloid formation. They were growth factor receptor-bound 7 (Grb7), mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), mitogen-activated protein kinase kinase kinase 15 (MAP3K15), kruppel-like factors 7 (KLF7) and NK2 homeobox 2 (NKX2-2). These CNVs were involved in the process of epidermal cells formation and differentiation, cell exocrine and cell adhesion.
CONCLUSIONS: There are 5 CNVs associated with scar hyperplasia. Especially MAP3K15 and MAP4K4 deserve more research to find their function in keloid formation.