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A close relationship has been demonstrated between genomic complexity and clinical outcome in uterine smooth muscle tumors. We studied the genomic profiles by array-CGH of 28 fumarate hydratase deficient leiomyomas and 37 leiomyomas with bizarre nuclei (LMBN) from 64 patients. Follow-up was available for 46 patients (from three to 249 months, mean 87.3 months). All patients were alive without evidence of disease. For 51 array-CGH interpretable tumors the mean Genomic Index (GI) was 16.4 (median: 9.8; from 1 to 57.8), significantly lower than the mean GI in LMS (mean GI 51.8, p < 0.001). We described three groups: (1) a group with FH deletion (24/58) with low GI (mean GI: 11 vs. 22,4, p = 0.02), (2) a group with TP53 deletion (17/58) with higher GI (22.4 vs. 11 p = 0.02), and (3) a group without genomic events on FH or TP53 genes (17/58) (mean GI:18.3; from 1 to 57.8). Because none of these tumors recurred and none showed morphological features of LMS we concluded that GI at the cut-off of 10 was not applicable in these subtypes of LM. By integration of all those findings, a GI <10 in LMBN remains a valuable argument for benignity. Conversely, in LMBN a GI >10 or alteration in tumor suppressor genes, should not alone warrant a diagnosis of malignancy. Nine tumors were tested with Nanocind CINSARC® signature and all were classified in low risk of recurrence. We propose, based on our observations, a diagnostic approach of these challenging lesions., (© 2024 Wiley Periodicals LLC.)

A subset of benign peripheral nerve sheath tumors are "hybrid" combining several lines of differentiation, most often schwannian and perineurial features. The pathogenesis of these tumors was poorly described until the recent discovery of recurrent VGLL3 rearrangements in hybrid schwannoma/perineuriomas, supporting the hypothesis that this entity represents a distinct subgroup of tumors and not only a morphologic variation of other peripheral nerve sheath tumors. Following this finding, we investigated 10 cases of hybrid peripheral nerve sheath tumors with immunohistochemistry, RNA sequencing, and array comparative genomic hybridization. By light microscopy, 7 tumors were hybrid schwannoma/perineurioma tumors, and 3 were hybrid schwannoma/neurofibroma. Most cases of hybrid schwannoma/perineuriomas displayed VGLL3 rearrangements fused in 5' either to CHD7 or CHD9 (n=6/7) and had simple diploid genetic profiles with few copy number alterations. Compared with a control group composed of 28 tumors associated with varied neural phenotypes, all VGLL3-fused tumors clustered together by transcriptomic analysis. In contrast, 1 case of hybrid schwannoma/perineurioma tumor harbored a CDH9-ZFHX3 fusion, a prominent perineurial component identified by immunohistochemistry and clustered with perineuriomas. No recurrent genetic alteration was seen in the 3 hybrid schwannoma/neurofibromas. To summarize, this study confirms and expands the recent findings on hybrid schwannoma/perineurioma, highlighting the predominance of VGLL3 fusions in these tumors., Competing Interests: Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

NFATc2-rearranged sarcomas (NFATc2-Sarcomas) are infrequent round cell tumors characterized by EWSR1-NFATc2 fusions and FUS-NFATc2 fusions. Although our knowledge on these neoplasms has increased recently, novel diagnostic tools and more comprehensive series are still needed. Here, we describe the features of a series of seven molecularly confirmed NFATc2-Sarcomas (EWSR1-NFATc2, n = 4; FUS-NFATc2, n = 3) and demonstrate the utility of AGGRECAN immunohistochemistry for their identification. Patients were four males and three females, ranging in age from 19 to 66 years (median: 33). All were primary bone tumors (femur, n = 4; tibia, n = 2; ilium, n = 1), frequently infiltrating the surrounding soft tissues. Treatment often consisted of neoadjuvant chemotherapy and surgery. Follow-up was available for six patients (median 18 months, range 5-102 months), three patients died of disease and four patients are currently alive. Histologically, tumors consisted of monotonous round cells growing in lobules and sheets in variable amounts of fibrous to myxoid stroma. Other findings included spindle cells, corded and trabecular architecture, nuclear pleomorphism, cartilaginous differentiation, and osteoid-like matrix. Histological response to neoadjuvant chemotherapy was poor in all resection specimens available for review (n = 4). Tumors were diffusely positive for AGGRECAN and CD99 (7/7), and a subset expressed Pan-Keratin (AE1-AE3; 3/6), S100 (2/6), BCOR (2/6), ETV-4 (2/5), WT1 (2/6), and ERG (2/5). Desmin, NKX3-1, and SATB2 were negative (0/6). Diffuse AGGRECAN staining was also seen in 8/129 round cell sarcomas used for comparison, including mesenchymal chondrosarcoma (7/26) and CIC-sarcoma (1/26). Array-CGH showed complex karyotypes with recurrent deletions of tumor suppressor genes (CDKN2A/B, TUSC7, and DMD) in three FUS-NFATC2 cases and a simpler profile without homozygous losses in one EWSR1-NFATc2 case. Segmental chromosomal gains covering the loci of the fusion genes were detected in both variants. Overall, our study confirms and expands previous observations on NFATc2-sarcomas and supports that AGGRECAN is a useful biomarker of these tumors.

Adenoid cystic carcinoma (ACC) of the breast with a predominant solid pattern is difficult to diagnose with certainty and differentiate from more common triple-negative breast cancers (TNBCs) of basal-phenotype. To better characterize solid ACC, we performed a clinical, morphological, immunohistochemical, and molecular comparative analysis of 33 ACCs of the breast comprising 17 solid variant ACCs and 16 conventional ACCs. Solid ACCs displayed basaloid morphology with an exclusive or predominant epithelial cell population associated with decreased myoepithelial differentiation, while demonstrating MYB protein overexpression similar to the more common type of ACC. Strong and diffuse MYB expression by immunochemistry was observed in 14/17 (82%) of solid ACCs while MYB rearrangements were detected by break apart fluorescence in situ hybridization (FISH) in only 3/16 (19%) of solid ACCs. Conversely, weak MYB immunohistochemical expression was observed in only 7/204 (3%) of TNBC. Solid ACCs displayed a transcriptomic profile distinct from conventional ACCs with 549 genes showing a highly significant differential expression between conventional and solid ACC [false discovery rate (FDR) < 0.01; log2FC > |1|]. EnrichR and Kegg Pathway analyses identified PI3K-Akt and focal adhesion signaling pathways as significantly overexpressed in conventional ACCs compared with solid ACCs which significantly overexpressed the nitrogen metabolism pathway. CREBBP mutations and NOTCH activating gene mutations were only present in solid ACCs, concerning 5/16 (31%) of cases for each gene. Tumors with NOTCH activating mutations displayed a strong diffuse nuclear NICD1 staining, an established marker of Notch pathway activation. Solid ACCs also differed from basal-type TNBC, with fewer TP53 mutations and a more stable genomic profile on array comparative genomic hybridization (CGH). In summary, solid-type ACC of the breast is a distinct molecular entity within the ACC family and is different from common basal-type TNBC. MYB is a diagnostically useful biomarker of solid ACC and NOTCH could be a novel potential therapeutic target in 30% of cases.

Purpose: Uterine leiomyosarcoma, which accounts for 7% of all soft-tissue sarcomas and 1%-3% of all uterine malignancies, is an aggressive tumor responsible for a significant proportion of uterine cancer-related deaths. While Federation Internationale des Gynaecologistes et Obstetristes (FIGO) stage is the most important prognostic factor, metastatic and relapse rates at stage I exceed 50% so it is currently impossible to predict the clinical outcome of stage I leiomyosarcomas. In 2010, our team published a transcriptomic signature composed of 67 genes related to chromosome biogenesis, mitosis control, and chromosome segregation. It has demonstrated its prognostic value in many cancer types and was recently successfully applied to formalin-fixed, paraffin-embedded sarcomas by NanoCind on NanoString technology, making another step forward toward its use in routine practice., Experimental Design: Sixty uterine leiomyosarcomas at any stage, including 40 localized in the uterus (stage I), were analyzed with the NanoCind (CINSARC with NanoString) signature. Its prognostic value was evaluated for overall survival and relapse-free survival and compared in multivariate analysis with other prognostic markers like FIGO staging and genomic index., Results: The NanoCind signature was able to split the heterogeneous group of uterine leiomyosarcomas of any stage including stage I into two distinct groups with different relapse-free survival and overall survival. These results were validated on an independent cohort of uterine leiomyosarcomas in The Cancer Genome Atlas consortium., Conclusions: The NanoCind signature is a powerful prognosticator that outperforms FIGO staging and the genomic index. The CINSARC signature is platform independent and "ready to use" and should now be used for randomization in future therapeutic trials., (©2019 American Association for Cancer Research.)

Mesenchymal neoplasms of the uterus (corpus and cervix) encompass a heterogeneous group of tumors with differing morphologies, immunophenotypes and molecular alterations. With the advent of modern molecular techniques, such as next generation sequencing, newly defined genetic abnormalities are being reported in this group of neoplasms. Herein we report the clinicopathological and molecular features of a series of 13 spindle cell sarcomas of the uterus and vagina (10 cervix, 2 uterine corpus, 1 vagina) with morphology resembling fibrosarcoma. After targeted RNA-sequencing, dual FISH fusion and array-CGH analysis, 7 of 13 tumors exhibited NTRK rearrangements (6 TPM3-NTRK1 and 1 EML4-NTRK3) and 3 a COL1A1-PDGFB fusion; in the other 3 neoplasms, all of which were positive with S100 (2 diffuse, 1 focal), we identified no rearrangement. All the NTRK fusion-positive sarcomas were located in the cervix and exhibited diffuse staining with Trk while all the other neoplasms were negative. CD34 was diffusely positive in all 3 of the COL1A1-PDGFB fusion sarcomas. The latter molecular abnormality is identical to that commonly found in dermatofibrosarcoma protuberans and has not been reported previously in uterine mesenchymal neoplasms. We suggest that uterine sarcomas with a morphology resembling fibrosarcoma (and in which leiomyosarcoma and the known molecularly confirmed high-grade endometrial stromal sarcomas have been excluded) can be divided into 3 groups:- an NTRK fusion group, a COL1A1-PDGFB fusion group and a group containing neither of these molecular abnormalities which, on the basis of positive staining with S100, could be tentatively classified as malignant peripheral nerve sheath tumor, although additional molecular studies may identify specific genetic alterations necessitating a nomenclature change. We suggest a diagnostic algorithm when reporting such neoplasms. Identification of these newly described fusion-associated sarcomas is important given the potential for targeted treatments.

Mutations of CTNNB1 have been implicated in tumorigenesis in many organs. However, tumors harboring a CTNNB1 translocation are extremely rare and this translocation has never been reported in a uterine mesenchymal neoplasm. We report a novel translocation t(2;3)(p25;p22) involving the GREB1 (intron 8) and CTNNB1 (exon 3) in a uterine tumor resembling ovarian sex cord tumor (UTROSCT), which exhibited extrauterine metastasis. The translocation detected by RNA-sequencing was validated by RT-PCR, and resulted in nuclear expression of β-catenin. Juxtapositioning with GREB1, which is overexpressed in response to estrogens, resulted in overexpression of a truncated and hypophosphorylated nuclear β-catenin in the primary and recurrent tumors. This accumulation of nuclear β-catenin results in a constitutive activation of the Wnt/β-catenin signaling pathway with a major oncogenic effect. The CTNNB1 gene fusion, promoted by an estrogen-responsive gene (GREB1), could be a potential driver of tumorigenesis in this case and a therapeutic target with adapted inhibitors. RT-PCR and immunohistochemistry performed on 11 additional UTROSCTs showed no CTNNB1 fusion transcript or nuclear β-catenin immunoreactivity., (© 2018 Wiley Periodicals, Inc.)

CIC-fused sarcomas represent an emerging family of tumors, for long connected to the Ewing family group of tumors, but underlined by distinct CIC fusions with different partners. 3' Fusion partners include DUX4, FOXO4, and, as recently emphasized, NUTM1. In this study, we report the clinicopathologic and molecular features of a series of 6 CIC-NUTM1 sarcomas. Mean age at diagnosis was 6 years (2 to 27 y), and 4 patients were male individuals. Primary tumors were located in the central nervous system (n=3), paravertebral soft tissue and epidural spaces (n=1, each), and lung (n=1). Median overall survival was 17.5 months (7 to 37 mo), and all but one patient died of disease. All tumors displayed classic features of CIC-DUX4 sarcomas with round cell to epithelioid microscopic appearance. Most tumors expressed ETV4 and NUTM1 (n=5/6 and 6/6, respectively), whereas WT1cter was positive in only 2 cases. All tested tumors were positive for break-apart fluorescence in situ hybridization for CIC and NUTM1. Apart from CIC or NUTM1 genomic breakpoints, no other recurrent copy number alteration was seen on genomic profiles. Fusion transcripts were identified by RNA-sequencing on either formalin-fixed paraffin-embedded or frozen material. CIC and NUTM1 breakpoints were located between exons 16 and 20 and exons 2 and 5, respectively. Altogether, CIC-NUTM1 sarcomas represent a new molecular variant of CIC-fused sarcomas with a predilection for the central nervous system and younger pediatric population. Its phenotype may be confused with NUT carcinomas.