Uterine Tumor Resembling Ovarian Sex Cord Tumor (UTROSCT): A Morphologic and Molecular Study of 26 Cases Confirms Recurrent NCOA1-3 Rearrangement. Am J Surg Pathol. 2020;44:30-42. [PMID: 31464709 DOI: 10.1097/pas.0000000000001348]

Clinicopathological Comparison Between GREB1- and ESR1-Rearranged Uterine Tumors Resembling Ovarian Sex Cord Tumors (UTROSCTs): A Systematic Review

Introduction: Among uterine tumors resembling ovarian sex cord tumors (UTROSCTs), it has been suggested that GREB1-rearranged cases are biologically distinct from ESR1-rearranged cases and might be considered as a separate entity. Objectives: The aim of this systematic review was to assess the difference between GREB1- and ESR1-rearranged UTROSCTs with regard to several clinico-pathological parameters. Methods: Three electronic databases were searched from their inception to February 2025 for all studies assessing the presence of GREB1 and ESR1 rearrangements in UTROSCTs. Exclusion criteria comprised overlapping patient data, case reports, and reviews. Statistical analysis was performed to compare clinicopathological variables between GREB1- and ESR1-rearranged UTROSCTs. Dichotomous variables were compared by using Fisher's exact test; continuous variables were compared by using Student's t-test. A p-value < 0.05 was considered significant. Results: Six studies with 88 molecularly classified UTROSCTs were included. A total of 36 cases were GREB1-rearranged, and 52 cases were ESR1-rearranged. GREB1-rearranged UTROSCTs showed a significantly older age (p < 0.001), larger tumor size (p = 0.002), less common submucosal/polypoid growth (p = 0.005), higher mitotic index (p = 0.010), more common LVSI (p = 0.049), and higher likelihood to undergo hysterectomy (p = 0.008) compared to ESR1-rearranged cases. No significant differences were detected with regard to margins, cytological atypia, necrosis, retiform pattern, and rhabdoid cells. No significant differences were found in the immunohistochemical expression of any of the assessed markers (wide-spectrum cytokeratins, α-inhibin, calretinin, WT1, CD10, CD56, CD99, smooth muscle actin, desmin, h-caldesmon, Melan-A/MART1, SF1, or Ki67). GREB1-rearranged UTROSCTs showed significantly lower disease-free survival compared to ESR1-rearranged UTROSTCs (p = 0.049). Conclusions: In conclusion, GREB1-rearranged UTROSCTs occur at an older age, are less likely to display a submucosal/polypoid growth, and exhibit larger size, a higher mitotic index, more common lymphovascular space invasion, and lower disease-free survival compared to ESR1-rearranged UTROSCTs. Nonetheless, the similar immunophenotype suggests that they belong to the same tumor family. Further studies are necessary to confirm this point.

VGLL2 and TEAD1 fusion proteins drive YAP/TAZ-independent tumorigenesis by engaging p300

Studies on Hippo pathway regulation of tumorigenesis largely center on YAP and TAZ, the transcriptional co-regulators of TEAD. Here, we present an oncogenic mechanism involving VGLL and TEAD fusions that is Hippo pathway-related but YAP/TAZ-independent. We characterize two recurrent fusions, VGLL2-NCOA2 and TEAD1-NCOA2, recently identified in spindle cell rhabdomyosarcoma. We demonstrate that in contrast to VGLL2 and TEAD1, the fusion proteins are strong activators of TEAD-dependent transcription, and their function does not require YAP/TAZ. Furthermore, we identify that VGLL2 and TEAD1 fusions engage specific epigenetic regulation by recruiting histone acetyltransferase p300 to control TEAD-mediated transcriptional and epigenetic landscapes. We showed that small molecule p300 inhibition can suppress fusion proteins-induced oncogenic transformation both in vitro and in vivo. Overall, our study reveals a molecular basis for VGLL involvement in cancer and provides a framework for targeting tumors carrying VGLL, TEAD, or NCOA translocations.

Immunophenotype of uterine tumor resembling ovarian sex cord tumor (UTROSCT): Case series and meta-analysis of the literature

OBJECTIVES

This study aimed to define the frequency of positivity of several immunohistochemical markers in uterine tumor resembling ovarian sex cord tumor (UTROSCT).

METHODS

All consecutive UTROSCT cases were retrieved from consultation files of one of the authors. Histological and immunohistochemical slides were reviewed. In addition, three electronic databases were searched from their inception to January 2024 for all studies assessing the immunophenotype of UTROSCT. Exclusion criteria were: sample size < 10 patients, overlapping patient data, reviews. Endometrial stromal tumors with sex cord-like areas (formerly called "type I UTROSCT") were excluded. Immunohistochemical markers assessed in ≥ 10 cases in at least 3 different series were included. For each marker, pooled positivity rate was calculated by using a random effect model; mean labeling index was calculated for Ki67.

RESULTS

Thirty UTROSCT cases were retrieved Six studies were included, and 30 new cases were obtained, with a total of 181 UTROSCTs. Fourteen immunohistochemical markers were assessed. Pooled positivity rates were (in descending order): CD56 = 97 %, progesterone receptor = 91 %, estrogen receptor = 85.5 %, WT1 = 84 %, wide-spectrum cytokeratins = 78.7 %, CD99 = 77 %, desmin = 74.5 %, calretinin = 70.6 %, smooth muscle actin = 56.4 %, inhibin = 44.5 %, CD10 = 41 %, caldesmon = 21.9 %, Melan-A/MART-1 = 10.4 %. Mean Ki67 labeling index was 8.7 %.

CONCLUSIONS

Immunophenotypically, UTROSCT is less consistent than ovarian sex cord tumors and overlaps with other mesenchymal and epithelial tumors; an integrated clinico-pathological and immunohistochemical evaluation appears necessary for a correct diagnosis.

Case Report: ESR1::CITED2 Fusion in a Malignant Uterine Tumor Resembling Ovarian Sex Cord Tumor

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare, typically benign uterine tumor occurring over a wide age range (mean 52.4 yr). UTROSCTs often harbor translocations between ESR1 and nuclear receptor coactivators NCOA1-NCOA3. Here, we present a 21-yr-old woman with a 16 cm complex uterine mass on CT. Grossly, the tumor had an infiltrative appearance. Histologically, it consisted of mild to moderately atypical, spindled cells with ovoid nuclei, growing in fascicles and cords within fibrous to myxohyaline stroma, with tongue-like infiltration of the myometrium. Immunohistochemically, tumor cells were positive for AE1/AE3, ER, PR, vimentin, WT-1, and CD56, and negative for inhibin, calretinin, SMA, desmin, and CD10. Whole exome and whole transcriptome sequencing identified a pathogenic ESR1::CITED2 fusion. The tumor recurred twice (15 and 21 mo after initial surgery) in the abdomen and pelvis. Taken together, the findings suggest this tumor may represent a malignant UTROSCT variant with a novel translocation.

The Spectrum of Fusions Occurring in Non-Smooth Muscle Mesenchymal Uterine Tumors: A Review of the Current Knowledge

CONTEXT.—

Non-smooth muscle uterine sarcomas are mostly represented by low-grade endometrial stromal sarcoma. However, several other rare, distinct types of uterine sarcoma are recognized, including high-grade endometrial stromal sarcoma, tumors with kinase fusions, uterine tumors resembling ovarian sex cord tumors, soft tissue-type sarcoma, and emerging entities such as KAT6A/B-rearranged tumors. The landscape of uterine sarcomas has changed, mostly because of the increasing knowledge concerning their molecular aberrations.

OBJECTIVE.—

To offer a comprehensive review of the literature focusing on fusions occurring in tumors other than smooth muscle mesenchymal uterine tumors with respect to their type, frequency, and overlap between diagnostic categories and entities.

DATA SOURCES.—

The data were mined from the PubMed/MEDLINE database covering the time period from January 1988 to June 2023. In total, 156 studies focusing on the problematics of fusions occurring in non-smooth muscle mesenchymal uterine tumors were selected, and thus became the basis for this review.

CONCLUSIONS.—

One hundred ten fusions were identified in 703 tumors. The diagnostic significance of the molecular aberrations occurring in these tumors can be unclear in some cases. This can be related to the rare aberrations with a limited number of reported cases. Additionally, even well-known aberrations considered as specific for a certain distinct entity can occur in other lesions, the biological behavior and clinical significance of which can differ substantially.

SARCP, a Clinical Next-Generation Sequencing Assay for the Detection of Gene Fusions in Sarcomas: A Description of the First 652 Cases

An amplicon-based targeted next-generation sequencing (NGS) assay for the detection of gene fusions in sarcomas was developed, validated, and implemented. This assay can detect fusions in targeted regions of 138 genes and BCOR internal tandem duplications. This study reviews our experience with testing on the first 652 patients analyzed. Gene fusions were detected in 238 (36.5%) of 652 cases, including 83 distinct fusions in the 238 fusion-positive cases, 10 of which had not been previously described. Among the 238 fusion-positive cases, the results assisted in establishing a diagnosis for 137 (58%) cases, confirmed a suspected diagnosis in 66 (28%) cases, changed a suspected diagnosis in 25 (10%) cases, and were novel fusions with unknown clinical significance in 10 (4%) cases. Twenty-six cases had gene fusions (ALK, ROS1, NTRK1, NTRK3, and COL1A1::PDGFB) for which there are targetable therapies. BCOR internal tandem duplications were identified in 6 (1.2%) of 485 patients. Among the 138 genes in the panel, 66 were involved in one or more fusions, and 72 were not involved in any fusions. There was little overlap between the genes involved as 5'-partners (31 different genes) and 3'-partners (37 different genes). This study shows the clinical utility of a next-generation sequencing gene fusion detection assay for the diagnosis and treatment of sarcomas.

[Translocation-associated uterine mesenchymal tumors: The new without forgetting the old. An integrated diagnostic approach]

This review focuses on uterine mesenchymal tumors that are defined on a molecular level by a single and unique genetic alteration, that is somehow necessary and sufficient to allow tumor growth and progression. Although diverse from a clinical, morphological and immunohistochemical point of view, the different entities we are going to talk about share both a simple genomic profile with a low number of chromosomal alterations observed by CGH Array (few deletions, gains or amplifications...) and a low mutational burden observed by sequencing technics. Some of these entities are already well known and described in the literature when found outside of the uterus and gynecological tract. It remains intriguing that uterine mesenchymal pathology has been lagging behind when compared to its extrauterine counterpart. How can we explain that when it comes to inflammatory myofibroblastic tumors, abundant numbers of articles have been published since the 70's, but it was only in the early 2000s that the first relevant descriptions of this tumor in the uterus emerged? Certainly, the increased accuracy, availability, and use of molecular biology technics and in particular RNA sequencing in the area of uterine pathology can partly explain the reduction of the gap between soft tissue and uterine pathology we currently observe. Other reasons explaining this gap may be the high prevalence of smooth muscle tumors in the uterus and the abounding diversity of their morphological aspects, which may have partly eclipsed the array of differential diagnoses. Last but not least, one can hypothesize that the relative "simplicity" of hysterectomy procedures, referring to their safety and accessibility, has cured most of the lesions and partly clouded our knowledge regarding the biological potential and natural history of these newly described entities. As a consequence of this situation, our reader will often encounter the wording "uncertain malignant potential", as for some of these rare entities, evidence to establish reliable prognostic variables is still insufficient. We hope this review to be a useful tool to guide pathologists through the diversity and complexity of uterine mesenchymal tumors. As a scientific and medical community, sharing this knowledge will help us to collectively raise our vigilance and awareness by expanding the array of our differential diagnoses. We hope this will lead to more cases being accurately diagnosed, and ultimately, to a deeper knowledge regarding the biological potential and clinical evolution of these tumors. From a therapeutical point of view, the consequences of an accurate diagnosis for the patient are already appreciable through the use of targeted therapy. Examples include: ALK inhibitors in inflammatory myofibroblastic tumor, tyrosine-kinase inhibitors in COL1A::PDGFB rearranged sarcomas or mTOR inhibitors in PEComa.

Risk Stratification of Miscellaneous Uterine Mesenchymal Neoplasms: The Role of Morphology, Immunohistochemistry, and Molecular Testing

Uterine mesenchymal tumors are a diverse group of tumors that can display a broad range of morphologic, immunohistochemical, and molecular profiles and are associated with varied clinical behaviors. In recent years, they have increasingly been classified by their underlying molecular alterations, leading to a more precise separation of diagnostic entities. As their diagnostic criteria have been refined, so too have the features that can be used to predict clinical outcomes. This review includes a discussion of uterine inflammatory myofibroblastic tumors, perivascular epithelioid cell tumors (PEComa), and uterine tumors resembling ovarian sex cord tumors, with a focus on updates on their clinical behavior and tools for risk stratification to identify malignant tumors. In addition, we discuss the importance of using an integrated approach when classifying uterine mesenchymal tumors to improve diagnostic accuracy and guide clinical management.

Unraveling the Molecular Landscape of Uterine Tumor Resembling Ovarian Sex Cord Tumor: Insights From A Clinicopathological, Morphologic, Immunohistochemical, and Molecular Analysis of 35 Cases

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor of uncertain lineage and low malignant potential. Most tumors behave in a benign manner, but a subset of UTROSCT exhibit an aggressive clinical course with recurrences and metastases. The recurrent molecular alterations in UTROSCT mostly represent gene fusions involving NCOA1-3. We performed a comprehensive clinicopathological, morphologic, immunohistochemical, and molecular analysis on a cohort of 35 UTROSCT. The tumors exhibited various architectural patterns (diffuse, corded/trabecular, tubular, sertoliform, fascicular, whorled, nested, microfollicular, and pseudoglandular), often in combination. The immunohistochemical analysis confirmed the polyphenotypic immunoprofile, often with coexpression of sex cord-stromal, smooth muscle, and epithelial markers, as well as hormone receptors. Next-generation sequencing RNA analysis revealed recurrent NCOA1-3 gene fusions in 22/32 analyzed cases (69%), including ESR1::NCOA3 (11/22), GREB1::NCOA2 (7/22), ESR1::NCOA2 (3/22), and GREB1::NCOA1 (1/22). Tumor mutation burden was low in all cases. The fusion-positive cases exhibited statistically significant association with whorled architecture, conversely necrosis was associated with fusion-negative status. We did not find a significant relationship between any architectural pattern and GREB1 alterations, but the NCOA2-altered tumors were associated with pseudoglandular architecture. The GREB1-altered cases occurred in older patients and tended to be more often intramural masses compared with ESR1-altered cases. On the contrary, the ESR1-altered cases presented more often like submucosal or polypoid tumors. Two tumors exhibited aggressive behavior with recurrent disease. Both of these cases harbored a GREB1::NCOA2 fusion. Unsupervised hierarchical cluster analysis of our cohort revealed 2 main clusters. The tumors with GREB1 or NCOA2 fusion cluster together, suggesting that there are underlying molecular differences between these cases and cases with ESR1::NCOA3 fusion or without fusion. Our findings contribute to the growing knowledge about a rare neoplasm with currently uncertain biological behavior.

STK11 (LKB1) immunohistochemistry is a sensitive and specific marker for STK11 adnexal tumours

AIMS

STK11 adnexal tumour is a rare, recently described malignant neoplasm that is associated with Peutz-Jeghers syndrome. [Correction added on 3 October 2024, after first online publication: 'ST11' in preceding sentence has been corrected to 'STK11' in this version.] It predominantly originates from the para-adnexal soft tissues and often shows secondary involvement of the fallopian tube and ovary. STK11 adnexal tumours have a broad differential diagnosis due to their variable morphology and non-specific immunoprofile, and diagnostic confirmation currently requires sequencing to identify an STK11 mutation. We investigate the diagnostic utility of STK11 (LKB1) immunohistochemistry (IHC) in a cohort of STK11 adnexal tumours and morphological mimics.

METHODS AND RESULTS

IHC for STK11 was performed on 122 tumours, including 17 STK11 adnexal tumours and 105 morphological mimics (10 female adnexal tumours of Wolffian origin, 22 adult granulosa cell tumours, 10 juvenile granulosa cell tumours, four Sertoli-Leydig cell tumours, two Leydig cell tumours, one Sertoli cell tumour, one steroid cell tumour, four extra-ovarian sex cord-stromal tumours, 16 ovarian endometrioid carcinomas, eight tubo-ovarian high-grade serous carcinomas, five ovarian mesonephric-like adenocarcinomas, 14 ovarian carcinosarcomas, five peritoneal malignant mesotheliomas, two pelvic plexiform leiomyomata and one ovarian solid pseudopapillary tumour). All STK11 adnexal tumours showed complete loss of cytoplasmic staining for STK11. All other tumour types showed retained cytoplasmic staining, except for one endometrioid carcinoma with mucinous differentiation which showed complete loss of STK11 expression and a high-grade serous carcinoma with subclonal loss.

CONCLUSIONS

STK11 is a highly sensitive and specific immunohistochemical marker for distinguishing STK11 adnexal tumour from its histological mimics, and can obviate the need for confirmatory molecular studies in the appropriate morphological context.

The "Other" Uterine Mesenchymal Neoplasms: Recent Developments and Emerging Entities

Uterine mesenchymal neoplasms are a challenging group of tumors that often show overlapping morphologic features and immunohistochemical profiles. The increasing use of molecular testing in these tumors has enabled a better appreciation of their pathobiology, resulting in a wave of emerging neoplasms and improved characterization of ones previously considered exceptionally rare. Identification of specific molecular alterations has permitted targeted therapy options in tumors that were typically unresponsive to conventional therapies, as well as recognition that a subset can have a hereditary basis. This review will discuss the more "common" of the uncommon uterine mesenchymal neoplasms, including inflammatory myofibroblastic tumor, perivascular epithelioid cell tumor, uterine tumor resembling ovarian sex cord tumor, and embryonal rhabdomyosarcoma. This will be followed by an overview of emerging entities, including NTRK -rearranged uterine sarcoma, SMARCA4 -deficient uterine sarcoma, KAT6B/A::KANSL1 fusion uterine sarcoma, and MEIS1::NCOA2/1 fusion sarcoma.

ERBB2/ ERBB3-mutated S100/ SOX10-positive unclassified high-grade uterine sarcoma: first detailed description of a novel entity

With the increasing use of innovative next generation sequencing (NGS) platforms in routine diagnostic and research settings, the genetic landscape of uterine sarcomas has been dynamically evolving during the last two decades. Notably, the majority of recently recognized genotypes in uterine sarcomas represent gene fusions, while recurrent oncogene mutations of diagnostic and/ or therapeutic value have been rare. Recently, a distinctive aggressive uterine sarcoma expressing S100 and SOX10, but otherwise lacking diagnostic morphological, immunophenotypic and molecular features of other uterine malignancies has been presented in a scientific abstract form (USCAP, 2023), but detailed description and delineation of the entity is still missing. We herein describe two high-grade unclassified uterine sarcomas characterized by spindle to round cell morphology and diffuse expression of S100 and SOX10, originating in the uterine body and cervix of 53- and 45-year-old women and carrying an ERBB3 (p.Glu928Gly) and an ERBB2 (p.Val777Leu) mutation, respectively. Both tumors harbored in addition genomic HER2 amplification, ATRX mutation and CDKN2A deletion. Methylation studies revealed a methylome most similar to MPNST-like tumors, but distinct from melanoma, MPNST, clear cell sarcoma, and endometrial stromal sarcoma. Case 1 died of progressive peritoneal metastases after multiple trials of chemotherapy 47 months after diagnosis. Case 2 is a recent case who presented with a cervical mass, which was biopsied. This study defines a novel heretofore unrecognized aggressive uterine sarcoma with unique phenotypic and genotypic features. Given the potential value of targeting HER2, recognizing this tumor type is mandatory for appropriate therapeutic strategies and for better future delineation of the entity.

Uterine tumors mimicking ovarian sex cord tumors with rhabdoid differentiation: a clinicopathologic study of 4 cases: A case series analysis

RATIONALE

Uterine tumors resembling ovarian sex cord tumors (UTROSCT) with rhabdoid features are uncommon mesenchymal neoplasms exhibiting diverse histological patterns, including significant rhabdoid morphology. A thorough comprehension of their clinicopathologic features is crucial for precise diagnosis and effective management.

PATIENT CONCERNS

This study presents 4 cases of UTROSCT with rhabdoid features, diagnosed in patients aged 31 to 58. Varied recurrence patterns were observed, including similar recurrent lesions to the primary tumors with subsequent mortality, initial invasion and lymph node metastasis, and presence of only primary tumor.

DIAGNOSES

Histopathological examination revealed diverse morphological patterns, prominently featuring rhabdoid differentiation. Immunohistochemical analysis showed expression of hormone receptors, sex cord, smooth muscle, and epithelial markers, notably WT1, CD56, and CD99. Molecular analysis identified ESR1-NCOA2 fusions and ESR1 and NCOA2/3 rearrangements, indicating a potential association between these genetic alterations and extensive rhabdoid differentiation.

INTERVENTIONS

Various treatments were administered post-recurrence, including chemotherapy and targeted therapies. However, poor clinical outcomes were observed in all cases.

OUTCOMES

Despite aggressive treatments, including chemotherapy and targeted therapies, poor clinical outcomes were observed, highlighting the aggressive nature of UTROSCT with significant rhabdoid differentiation.

LESSONS

This case series emphasizes the importance of detailed pathological reporting, comprehensive molecular testing, and thorough tumor staging in UTROSCT cases with rhabdoid features. Enhanced understanding of the clinicopathologic characteristics of UTROSCT with rhabdoid differentiation is crucial for accurate diagnosis, prognostication, and management strategies.

Uterine Mesenchymal Tumors: Updates on Pathology, Molecular Landscape, and Therapeutics

Background: Mesenchymal uterine tumors are a diverse group of neoplasms with varying biological potential. Many of these neoplasms can have overlapping morphologic similarities, which, in some instances, render their diagnosis and categorization thorough histomorphologic examination inconclusive. In the last decade, an exponential amount of molecular data aiming to more accurately characterize and, consequently, treat these tumors have accumulated. Objective: The goal of this narrative review is to provide a pathologic review, a genetic update, and to know the new therapeutic avenues of primary uterine mesenchymal neoplasms.

Uterine Tumor Resembling Ovarian Sex-Cord Tumor (UTROSCT): A Rare Polyphenotypic Neoplasm

Uterine tumor resembling ovarian sex-cord tumor (UTROSCT) is a rare form of uterine mesenchymal neoplasm. Although UTROSCT generally exhibits benign behavior with a favorable prognosis, this neoplasm is nevertheless classified as being of uncertain malignant potential, given its low rate of recurrence and the fact that it rarely produces metastases (e.g., in the lymph nodes, epiploic appendix, omentum, small bowel, subcutaneous tissue, lungs). Its histogenesis is also uncertain. Typically, UTROSCT occurs in peri-menopausal or menopausal women, but it can sometimes be observed in young women. Usually, this neoplasm can be found in the uterine corpus as a nodular intramural lesion, while it is less frequently submucosal, subserosal, or polypoid/intracavitary. UTROSCT can cause abnormal bleeding, pelvic pain, enlarged uterus, and mass sensation, but sometimes it is found purely by chance. This neoplasm can be considered polyphenotypic on morphological, immunohistochemical, and genetic analyses. Generally, upon microscopic examination, UTROSCT shows a predominant pattern of the cords, nests, and trabeculae typical of sex-cord tumors of the ovary, while immunohistochemically it is characterized by a coexpression of epithelial, smooth muscle, and sex-cord markers. The aim of this review is to report clinical and pathological data and genetic alterations to establish their impact on the prognosis and management of patients affected by this rare entity.

p160 nuclear receptor coactivator family members and their role in rare fusion‑driven neoplasms (Review)

Gene fusions with translocations involving nuclear receptor coactivators (NCoAs) are relatively common among fusion-driven malignancies. NCoAs are essential mediators of environmental cues and can modulate the transcription of downstream target genes upon binding to activated nuclear receptors. Therefore, fusion proteins containing NCoAs can become strong oncogenic drivers, affecting the cell transcriptional profile. These tumors show a strong dependency on the fusion oncogene; therefore, the direct pharmacological targeting of the fusion protein becomes an attractive strategy for therapy. Currently, different combinations of chemotherapy regimens are used to treat a variety of NCoA-fusion-driven tumors, but given the frequent tumor reoccurrence, more efficient treatment strategies are needed. Specific approaches directed towards inhibition or silencing of the fusion gene need to be developed while minimizing the interference with the original genes. This review highlights the relevant literature describing the normal function and structure of NCoAs and their oncogenic activity in NCoA-gene fusion-driven cancers, and explores potential strategies that could be effective in targeting these fusions.

Therapeutic management of uterine tumours resembling ovarian sex cord tumours including a focus on fertility: A systematic review

OBJECTIVE

Uterine tumours resembling ovarian sex cord tumours (UTROSCTs) are extremely rare. To date, most patients with UTROSCTs have undergone hysterectomy and had a benign clinical course. Fertility-preserving surgery should be considered because some patients with UTROSCTs are aged < 40 years. This paper reviews the treatment and prognosis for patients with UTROSCTs, with a focus on fertility.

METHODS

PubMed, MEDLINE and Scopus were searched systematically for case reports and case series of UTROSCTs published in English from inception to December 2022, and initial treatment and recurrence rates were compared. The following data were extracted: age; symptoms; initial therapy; metastasis at diagnosis; disease-free survival (DFS); and recurrence.

RESULTS

In total, 147 patients (72 studies) reporting the clinical course of UTROSCTs were analysed. The median age at diagnosis was 50 years, and 28 (19.0 %) patients were aged < 40 years. Most patients (n = 125, 85.0 %) underwent hysterectomy as the initial surgery, with a recurrence rate of 17.6 % (n = 22). The recurrence rate was 30 % (n = 6) in patients who underwent mass resection (n = 20). Among the 15 patients who underwent mass resection aged < 40 years, seven went on to achieve pregnancy (46.7 %) and six had successful deliveries (40.0 %). No significant differences in 5- and 10-year DFS were found between the hysterectomy and mass resection groups (p = 0.123 and 0.0612, respectively). Bilateral salpingo-oophorectomy in addition to hysterectomy was not significantly associated with 10-year DFS (p = 0.548).

CONCLUSION

While total hysterectomy is the recommended treatment for UTROSCTs based on recurrence rates, mass resection is an acceptable treatment option for patients who wish to retain their childbearing potential. It is recommended that these women should plan for pregnancy and delivery as soon as possible after mass resection, and should undergo hysterectomy within 5 years.

Teratoma-associated and so-called pure Wilms tumour of the ovary represent two separate tumour types with distinct molecular features

AIMS

Ovarian Wilms tumour (WT)/nephroblastoma is an extremely rare neoplasm that has been reported to occur in pure form or as a component of a teratomatous neoplasm. We hypothesized that teratoma-associated and pure ovarian WT may represent different tumour types with diverging molecular backgrounds. To test this hypothesis, we comprehensively characterized a series of five tumours originally diagnosed as ovarian WT.

METHODS AND RESULTS

The five cases comprised three teratoma-associated (two mature and one immature) and two pure WTs. Two of the teratoma-associated WTs consisted of small nodular arrangements of "glandular"/epithelial structures, while the third consisted of both an epithelial and a diffuse spindle cell/blastemal component. The pure WTs consisted of "glandular" structures, which were positive for sex cord markers (including inhibin and SF1) together with a rhabdomyosarcomatous component. The two pure WTs harboured DICER1 pathogenic variants (PVs), while the three associated with teratomas were DICER1 wildtype. Panel-based DNA sequencing of four of the cases did not identify PVs in the other genes investigated. Analysis of the HA19/IGF2 imprinting region showed retention of imprinting in the pure WTs but loss of heterozygosity with hypomethylation of the ICR1 region in two of three teratoma-associated WTs. Furthermore, copy number variation and clustering-based whole-genome DNA methylation analyses identified divergent molecular profiles for pure and teratoma-associated WTs.

CONCLUSION

Based on the morphological features, immunophenotype, and molecular findings (DICER1 PVs, copy number, and DNA methylation profiles), we suggest that the two cases diagnosed as pure primary ovarian WT represent moderately to poorly differentiated Sertoli Leydig cell tumours (SLCTs), while the tumours arising in teratomas represent true WTs. It is possible that at least some prior cases reported as pure primary ovarian WT represent SLCTs.

The management of uterine tumor resembling an ovarian sex cord tumor (UTROSCT): case series and literature review

AIMS

To present a case series of 11 rare uterine tumors resembling ovarian sex cord tumors (UTROSCTs), and review the literature on this topic to offer up-to-date treatment management for UTROSCTs.

METHOD

Eight cases from Fujian Cancer Hospital between January 2017 and May 2023 and three patients from Fujian Union Hospital between October 2012 and October 2020 were retrospectively reviewed. All cases were pathologically confirmed as UTROSCTs by two senior and experienced pathologists. Clinical behaviors, medical data, histopathological features, therapy approaches, and survival outcomes were discussed.

RESULTS

The median age at initial diagnosis was 53 years (29-70 years). 3 (27.3%) patients were under 40. Seven cases presented with abnormal vaginal bleeding, one with menstrual disorder, one with abnormal vaginal secretion, and two patients were accidentally found by physical examination without any symptoms. Three patients were initially misdiagnosed with endometrial cancer by MRI. Curettage was performed in all cases. Nine of them were well diagnosed by routine curettage, except for two samples, which were identified after surgery. Immunohistochemical biomarkers, such as CD99, Desmin, WT-1, CK, Vimentin, SMA, α-Inhibin, Ki67, CD56, ER, PR, and CR, tend to be positive in UTRO SCs patients. Six patients underwent hysterectomy with bilateral salpingo-oophorectomy. Two cases received a radical hysterectomy with bilateral salpingo-oophorectomy, retroperitoneal lymph node dissection, and omentum dissection. Three UTROSCTs were under observation after mass resection. The median PFS was 24 months (range 1-125 months).

CONCLUSION

UTROSCT is a rare mesenchymal tumor with low malignant potential. Treatment modalities should be carefully considered to balance the therapy outcomes and patient needs. Surgery conservative management might be suitable for young women with fertility desires.

Uterine Tumors Resembling Ovarian Sex Cord Tumors (UTROSCTs): A Scoping Review of 511 Cases, Including 2 New Cases

Uterine Tumors Resembling Ovarian Sex Cord Tumors (UTROSCTs) are rare uterine mesenchymal neoplasms with uncertain biological potential. These tumors, which affect both premenopausal and postmenopausal women, usually have a benign clinical course. Nevertheless, local recurrences and distant metastases have been described. By analyzing 511 cases retrieved from individual reports and cases series, we provide here the most comprehensive overview of UTROSCT cases available in the literature, supplemented by two new cases of UTROSCTs. Case 1 was an asymptomatic 31-year-old woman who underwent a laparoscopic resection of a presumed leiomyoma. Case 2 was a 58-year-old postmenopausal woman with abnormal vaginal bleeding who underwent an outpatient hysteroscopic biopsy of a suspicious endometrial area. In both cases, immunohistochemical positivity for Calretinin and Inhibin was noted, typical for a sex cord differentiation. In both cases, total laparoscopic hysterectomy with bilateral salpingo-oophorectomy was performed. In light of the available literature, no pathognomonic clinical or imaging finding can be attributed to UTROSCT. Patients usually present with abnormal uterine bleeding or pelvic discomfort, but 20% of them are asymptomatic. In most cases, a simple hysterectomy appears to be the appropriate treatment, but for women who wish to become pregnant, uterus-preserving approaches should be discussed after excluding risk factors. Age, tumor size, lymphovascular space invasion, nuclear atypia, and cervical involvement are not reliable prognostic factors in UTROSCT. The current research suggests that aggressive cases (with extrauterine spread or recurrence) can be identified based on a distinct genetic and immunohistochemical phenotype. For instance, UTROSCTs characterized by GREB1::NCOA1-3 fusions and PD-L1 molecule expression appear to be predisposed to more aggressive behaviors and recurrence, with GREB1::NCOA2 being the most common gene fusion in recurrent tumors. Hence, redefining the criteria for UTROSCTs may allow a better selection of women suitable for fertility-sparing treatments or requiring more aggressive treatments in the future.

Targeted RNA Sequencing Highlights a Diverse Genomic and Morphologic Landscape in Low-grade Endometrial Stromal Sarcoma, Including Novel Fusion Genes

Low-grade endometrial stromal sarcoma (LGESS) represents a morphologically and genetically heterogenous mesenchymal neoplasm. Previous work has shown that approximately half of LGESS are characterized by JAZF1::SUZ12 gene fusions, while a smaller proportion involves rearrangement of other genes. However, a subset of cases has no known genetic abnormalities. To better characterize the genomic landscape of LGESS, we interrogated a cohort with targeted RNA sequencing (RNA-Seq). Cases previously diagnosed as low-grade endometrial stromal neoplasia (n=51) were identified and re-reviewed for morphology and subjected to RNA-Seq, of which 47 were successfully sequenced. The median patient age was 49 years (range: 19 to 85). The most commonly detected fusions were JAZF1::SUZ12 (n=26, 55%) and BRD8::PHF1 (n=3, 6%). In addition to the usual/typical LGESS morphology, some JAZF1::SUZ12 fusion tumors showed other morphologies, including fibrous, smooth muscle, sex-cord differentiation, and myxoid change. Novel translocations were identified in 2 cases: MEAF6::PTGR2 and HCFC1::PHF1 . Ten tumors (21%) had no identifiable fusion, despite a similar morphology and immunophenotype to fusion-positive cases. This suggests that a subset of cases may be attributable to fusion products among genes that are not covered by the assay, or perhaps altogether different molecular mechanisms. In all, these findings confirm that RNA-Seq is a potentially useful ancillary test in the diagnosis of endometrial stromal neoplasms and highlight their diverse morphology.

Myxoid epithelioid smooth muscle tumor of the vulva: A distinct entity with MEF2D::NCOA2 gene fusion

Smooth muscle tumors are the most common mesenchymal tumors of the female genital tract, including the vulva. Since vulvar smooth muscle tumors are rare, our understanding of them compared to their uterine counterparts continues to evolve. Herein, we present two cases of morphologically distinct myxoid epithelioid smooth muscle tumors of the vulva with novel MEF2D::NCOA2 gene fusion. The tumors involved 24 and 37-year-old women. Both tumors presented as palpable vulvar masses that were circumscribed, measuring 2.8 and 5.1 cm in greatest dimension. Histologically, they were composed of epithelioid to spindle-shaped cells with minimal cytologic atypia and prominent myxoid matrix. Rare mitotic figures were present (1-3 mitotic figures per 10 high-power field (HPF)), and no areas of tumor necrosis were identified. By immunohistochemistry, the neoplastic cells strongly expressed smooth muscle actin, calponin, and desmin, confirming smooth muscle origin. Next-generation sequencing identified identical MEF2D::NCOA2 gene fusions. These two cases demonstrate that at least a subset of myxoid epithelioid smooth muscle tumors of the vulva represent a distinct entity characterized by a novel MEF2D::NCOA2 gene fusion. Importantly, recognition of the distinct morphologic and genetic features of these tumors is key to understanding the biological potential of these rare tumors.

[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Uterine MEIS1::NCOA2 Fusion Sarcoma With Lung Metastasis: A Case Report and Review of the Literature

MEIS1::NCOA1/2 fusion sarcomas are a recently described novel entity arising in a variety of locations with a predilection for the genitourinary tract and gynecologic organs. Despite multiple locoregional recurrences, these tumors are thought to behave in a low-grade malignant manner. Here we report a uterine MEIS1::NCOA2 fusion sarcoma with lung metastasis. The patient was a 47-yr-old woman with a history of abnormal uterine bleeding who was found to have a myometrial mass confirmed by pathology to be uterine sarcoma. The tumor was predominantly composed of monotonous spindle cells with scant cytoplasm, crowded nuclei, and brisk mitotic activity, growing in a fascicular and streaming pattern. The morphologic and immunophenotypic features were nonspecific and a diagnosis of high-grade uterine sarcoma with a differential of leiomyosarcoma versus high-grade endometrial stromal sarcoma was rendered. At the 27-mo follow-up, the patient was found to have a lung metastasis consisting of a monotonous round cell sarcoma. A retrospective RNA-based and DNA-based next-generation sequencing of the primary uterine sarcoma revealed a MEIS1::NCOA2 gene fusion, a c.94G>C/p.D32H mutation in exon 3 of CTNNB1 gene, HMGA2 , and CDK4 gene amplification, and an intermediate/marginal level of MDM2 gene amplification. Polymerase chain reaction-based molecular analysis further demonstrated that the MEIS1::NCOA2 gene fusion and CTNNB1 somatic mutation were also present in the lung metastasis. This case represents the first case of such gynecologic sarcoma with distant (lung) metastasis, and the second metastatic case among all reported MEIS1::NCOA1/2 fusion sarcomas, highlighting the malignant metastatic potential of this emerging entity. Our case also indicates that HMGA2/CDK4/MDM2 region amplification and CTNNB1 somatic mutation might be recurrent genetic events in this rare sarcoma subtype.

Clinicopathological features and molecular genetic changes in 17 cases of uterine tumor resembling ovarian sex cord tumor

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare mesenchymal neoplasm that was recently reported to exhibit recurrent NCOA1-3rearrangement with the most frequent partners ESR1 and GREB1. In this study, the clinicopathological characteristics of 17 UTROSCT cases were summarized; among them, the fusion genes of 12 cases were retrospectively analyzed by targeted RNA sequencing. The mean age of our cohort was 47 years (19-67 y). Although the majority of UTROSCTs had clear boundaries on gross examination, microscopic infiltration into the myometrium was observed in 82.4 % of cases. The tumor cells showed diffuse, trabecular, nested, reticular, pseudopapillary, hollow and solid tubular patterns, expressing sex cord, epithelial, and myogenic markers. Six fusion genes, including ESR1::NCOA3 (n = 4), ESR1::NCOA2 (n = 2), ESR1::CITED2 (n = 2), GREB1::NCOA2 (n = 2), GREB1::NCOA1 (n = 1), and GREB1::NCOA3 (n = 1), were identified. The fusion genes of the three cases with recurrence and metastasis were GREB1::NCOA2, ESR1::NCOA3, and ESR1::CITED2. All 3 cases of recurrent tumors showed infiltrative growth, with moderate to severe dysplasia of tumor cells and different degrees of rhabdomyoid differentiation. This is the first report of the ESR1::CITED2 fusion genes in UTROSCT, and one of the two patients had recurrence and metastasis. Compared with UTROSCT withESR1 rearrangement, UTROSCT with GREB1 rearrangement was more common in elderly patientsand was more likely to present with intramural masses, less sex cord differentiation, poor prognosis, and relapse and metastasis.

A MYCN-independent mechanism mediating secretome reprogramming and metastasis in MYCN-amplified neuroblastoma

MYCN amplification (MNA) is a defining feature of high-risk neuroblastoma (NB) and predicts poor prognosis. However, whether genes within or in close proximity to the MYCN amplicon also contribute to MNA+ NB remains poorly understood. Here, we identify that GREB1, a transcription factor encoding gene neighboring the MYCN locus, is frequently coexpressed with MYCN and promotes cell survival in MNA+ NB. GREB1 controls gene expression independently of MYCN, among which we uncover myosin 1B (MYO1B) as being highly expressed in MNA+ NB and, using a chick chorioallantoic membrane (CAM) model, as a crucial regulator of invasion and metastasis. Global secretome and proteome profiling further delineates MYO1B in regulating secretome reprogramming in MNA+ NB cells, and the cytokine MIF as an important pro-invasive and pro-metastatic mediator of MYO1B activity. Together, we have identified a putative GREB1-MYO1B-MIF axis as an unconventional mechanism promoting aggressive behavior in MNA+ NB and independently of MYCN.

Active Estrogen-Succinate Metabolism Promotes Heme Accumulation and Increases the Proliferative and Invasive Potential of Endometrial Cancer Cells

Uterine endometrial cancer (UEC) is an estrogen-related tumor. Succinate and heme metabolism play important roles in the progression of multiple tumors. However, the relationship between estrogen, succinate, and heme metabolism and related regulatory mechanisms remain largely unknown. In this study, we observed that the expression of aminolevulinate delta synthase 1 (ALAS1) and solute carrier family member 38 (SLC25A38) in UEC tissues is significantly higher than that in normal tissues. Further analysis showed that estrogen and succinate increased the expression of ALAS1 and SLC25A38 in uterine endometrial cancer cells (UECC), and the administration of succinate upregulated the level of the estrogen receptor (ER). Silencing nuclear receptor coactivator 1 (NCOA1) reversed the effects of estrogen and succinate via downregulation of ALAS1 expression. Additionally, exposure of UECC to heme increased cell viability and invasiveness, while silencing the NCOA1 gene weakened this effect. These findings revealed that estrogen and succinate can synergistically increase the expression of ALAS1 and SLC25A38 via the ERβ/NCOA1 axis, promoting heme accumulation and increasing the proliferative and invasive potential of UECC.

Unusual presentation of uterine tumors resembling ovarian sex cord tumor: A rare case report of cervical involvement

INTRODUCTION AND IMPORTANCE

Cervical localization of uterine tumor resembling an ovarian sex cord tumor is very rare (UTROSCT) and this is the third case reported in the English literature. Given its rarity, the diagnosis is frequently challenging. Our aim was to discuss pathological characteristics and treatment choices of this rare disease happening in a rare location.

CASE PRESENTATION

Our case interested a 19-year-old female patient who presented with a lower abdominal pain and irregular menstrual cycles for a duration of two months. Gynecological examination revealed a cervical firm mass. The patient underwent a cervical lumpectomy. Microscopically, the tumor had nested and trabecular/cord patterns. Tumor cells had abundant cytoplasm, ovoid and spindle-shaped nuclei with fine chromatin. Mitoses were < 1/10 HPFs. A delicate vascular network of small capillaries was noted. Immunohistochemical staining showed that tumor cells were positive for Calretinin, AE1/AE3, Desmin, progesteron receptors, SMA and h-caldesmon. Pathological examination concluded to an UTROSCT.

CLINICAL DISCUSSION

UTROSC is a rare tumor with only two cases with cervical involvement reported so far. They have an indolent clinical history and thus require a more cautious and less invasive therapeutic decision. The diagnosis remains on the pathological examination.

CONCLUSION

This case is original by its location and the age of presentation. Careful follow-up is necessary searching for local recurrence or metastasis.

DICER1 -Altered Extraovarian Moderately Differentiated Sertoli-Leydig Cell Tumor: Report of a Rare Case

We report an unusual case of a pelvic extraovarian moderately differentiated Sertoli-Leydig cell tumor arising in a 4-yr-old female. The tumor contained a DICER1 pathogenic variant which was absent in the germline ruling out DICER1 syndrome. In reporting this case, we discuss the differential diagnosis and possible histogenesis and review reported cases of extraovarian Sertoli-Leydig cell tumor.

Uterine Tumor Resembling Ovarian Sex Cord Tumors: 23 Cases Indicating Molecular Heterogeneity With Variable Biological Behavior

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare mesenchymal neoplasm that mainly harbors NCOA1-3 rearrangements with partner genes ESR1 or GREB1 . Here, we explored 23 UTROSCTs by targeted RNA sequencing. The association between molecular diversity and clinicopathologic features was investigated. The mean age of our cohort was 43 years (23-65 y). Only 15 patients (65%) were originally diagnosed with UTROSCTs. Mitotic figures ranged from 1 to 7/10 high power fields, of primary tumors and increased from 1 to 9/10 high power fields in recurrent tumors. Five types of gene fusions were identified in these patients, including GREB1::NCOA2 (n=7), GREB1::NCOA1 (n=5), ESR1::NCOA2 (n=3), ESR1::NCOA3 (n=7), and GTF2A1::NCOA2 (n=1). To our knowledge, our group included the largest cohort of tumors with GREB1::NCOA2 fusions. Recurrences were most common in patients with GREB1::NCOA2 fusion (57%), followed by 40% ( GREB1::NCOA1 ), 33% ( ESR1::NCOA2 ), and 14% ( ESR1::NCOA3 ). The recurrent patient who harbored an ESR1::NCOA2 fusion was characterized by extensive rhabdoid features. Both of the recurrent patients who harbored GREB1::NCOA1 and ESR1::NCOA3 had the largest tumor sizes in their own gene alteration groups, and another recurrent GREB1::NCOA1 patient had extrauterine involvement. The GREB1 -rearranged patients were of older age, larger tumor size, and higher stage than non- GREB1 -rearranged patients ( P =0.004, 0.028, and 0.016, respectively). In addition, the GREB1 -rearranged tumors presented more commonly as intramural masses rather than non- GREB1 -rearranged tumors presenting as polypoid/submucosal masses ( P =0.021). Microscopically, nested and whorled patterns were frequently seen in GREB1- rearranged patients ( P =0.006). Of note, estrogen receptor expression was weaker than progesterone receptor in all 12 GREB1- rearranged tumors, whereas the similar staining intensity of estrogen receptor and progesterone receptor was observed in all 11 non- GREB1- rearranged tumors ( P <0.0001). This study demonstrated that UTROSCTs were present at a younger age in the Chinese population. The genetic heterogeneity of UTROSCTs was correlated with variable recurrence rate. Tumors with GREB1::NCOA2 fusions are more likely to recur compared with those with other genetic alterations.

PD-L1 expression, morphology, and molecular characteristic of a subset of aggressive uterine tumor resembling ovarian sex cord tumor and a literature review

BACKGROUND

Uterine tumors resembling ovarian sex cord tumor (UTROSCT) is a rare neoplasm of unknown etiology and has undetermined malignant potential. The emergence of recurrent UTROSCT case reports has led to its initial identification as a tumor of low malignancy potential. Owing to its low incidence, we currently lack any in-depth studies regarding the subset of UTROSCTs that may be aggressive in nature. Here, we sought to identify unique characteristics in aggressive UTROSCT.

METHODS

19 cases of UTROSCT were collected. Their histologic and tumor immune microenvironment were evaluated by three gynecologic pathologists. The gene alteration was also detected by RNA sequencing. For later analyses regarding differences between benign and malignant tumors, we supplemented our 19 included cases with additional reports from the literature.

RESULTS

Interestingly, we found PD-L1 expression in stromal tumor-infiltrating immune cells (stromal PD-L1) was markedly higher in aggressive UTROSCT. Patients with high stromal PD-L1 (≥ 22.5 cells/mm2) had worse prognosis. When our cases were added with previous cases identified in the literature, we discovered that aggressive UTROSCT was more likely to have significant mitotic activity and NCOA2 gene alterations than benign UTROSCT. Consistence with those results, patients with significant mitotic activity and gene alteration of NCOA2 had worse prognoses.

CONCLUSIONS

Collectively, high expression of stromal PD-L1, significant mitotic activity, and gene alteration of NCOA2 may be useful markers to predict aggressive UTROSCT.

Metastatic signet-ring carcinoma to the uterus presenting as an endometrial polyp

Primary signet-ring cell carcinoma of the uterus is rare and requires exclusion of possible metastatic tumour to the uterus. We report a case of a woman in her 70s who underwent hysteroscopy and a polypectomy for a polyp arising from the uterine wall. On histological examination, malignant cells with signet-ring cell morphology were found within the fragments of endometrial tissue. Immunohistochemical studies indicated a metastatic adenocarcinoma possibly from the gastrointestinal tract. Additional radiological investigations revealed a possible primary gastric tumour, which was further confirmed on subsequent biopsies. This case illustrates that gastric carcinomas can rarely metastasise to the endometrium and highlights the importance of clinical correlation in arriving at the final diagnosis.

Spindle Cell Sarcoma of the Uterus Harboring MEIS1::NCOA1 Fusion Gene and Mimicking Endometrial Stromal Sarcoma

MEIS1::NCOA1/2 sarcomas are a newly recognized group of exceedingly rare low-grade spindle cell sarcomas that often involve the genitourinary and gynecologic tracts. Due to its deceptively low-grade morphology and the non-specific immunoprofile, these neoplasms may pose a diagnostic challenge by histologically mimicking other entities such as endometrial stromal sarcoma, smooth muscle tumor, or uterine perivascular epithelioid cell tumor (PEComa). Histologically, MEIS1::NCOA1/2 sarcomas typically show spindle cell proliferation with hyperchromatic nuclei and a generalized cytologic uniformity, arranged in short fascicles and exhibiting alternating zones of hypo- and hypercellularity. Among the previously reported cases, molecular analysis revealed the MEIS1::NCOA2 fusion as the most commonly detected fusion gene, whereas the MEIS1::NCOA1 fusion gene has been reported in only a single case that involved kidney. Herein we report the first case of uterine sarcoma harboring the MEIS1::NCOA1 fusion gene that was initially misclassified as low-grade endometrial stromal sarcoma, demonstrating its clinicopathologic features, and highlighting the essential role of molecular pathology to arrive at the accurate diagnosis that may alter disease classification and inform therapy.

Uterine Tumors Resembling Ovarian Sex Cord Tumors: A Clinicopathologic Study of 75 Cases Emphasizing Features Predicting Adverse Outcome and Differential Diagnosis

Uterine tumors resembling ovarian sex cord tumors (UTROSCTs), first characterized by Drs Clement and Scully in 1976, are rare neoplasms showing clinical, morphologic, and immunohistochemical overlap with a number of other uterine tumors, most being mesenchymal. Criteria for aggressive behavior are not clearly established. We report 75 tumors from patients ranging from 21 to 84 (mean=52.4) years. Seventy-one patients were treated by hysterectomy and 4 by conservative total excision. Thirty-eight tumors were intramyometrial, 34 submucosal, and 3 cervical; they ranged from 0.6 to 20 (mean=4.9) cm and were typically tan-yellow. Sixty-eight neoplasms were well-circumscribed and 7 had infiltrative borders (4 only minimally). In 56 tumors, a smooth muscle component was intimately admixed with the neoplastic cells ("pseudoinfiltration"; extensive in 29). Architectural patterns included cords (n=53), diffuse (n=51), hollow tubules (n=48), nests (n=38), trabeculae (n=37), retiform (n=23), solid tubules (n=21), pseudoangiomatoid (n=11), pseudopapillary (n=4), and whorled (n=2); typically, more than 1 pattern was seen. Tumor cells were epithelioid (n=62), epithelioid and spindled (n=12), or spindled (n=1) and/or rhabdoid (n=20; extensive in 2). Cytologic atypia was absent to mild in 57, moderate in 16, and moderate to severe in 2 tumors. Fifty-seven UTROSCTs had ≤2mitoses/10 high power fields (HPF), 12 had 3 to 5/10 HPF, and 6 >5/10 HPF. Necrosis was present in 3 and lymphovascular invasion in 1. Tumor cells showed a polyphenotypic immunohistochemical profile (with positivity for sex cord, smooth muscle, and epithelial markers), most commonly inhibin (17/33+) and calretinin (22/31+) positive. Five of 58 patients with follow-up (22 to 192; mean=73.2 mo) had recurrences/metastases from 30 to 144 months, and 2 died of disease. Malignant tumors showed >3 of the following 5 features compared with benign tumors: size >5 cm, at least moderate cytologic atypia, ≥3 mitoses/10 HPF, infiltrative borders, and necrosis. One of the 5 malignant tumors showed an extensive rhabdoid morphology. UTROSCTs are uncommon, show a wide morphologic spectrum, often pose problems in differential diagnosis, and typically have a benign outcome. Rare tumors are associated with late recurrences and a combination of more than 3 of the 5 features listed above predicted aggressive behavior in this series.

NCOA1/2/3 rearrangements in uterine tumor resembling ovarian sex cord tumor: A clinicopathological and molecular study of 18 cases

Recurrent NCOA1/2/3 gene fusions emerged in uterine tumor resembling ovarian sex cord tumor (UTROSCT). More cases are required to consolidate these molecular alterations. In this study, the clinicopathological features and immunostaining profiles were reviewed in 18 UTROSCT. Fluorescence in situ hybridization for dual color break-apart probes of NCOA1, NCOA2, NCOA3, BCOR, YWHAE, PHF1 and JAZF1 were performed on 16 tumors. Eight cases were subjected to targeted next-generation sequencing to detect genomic alterations. We found that the tumors predominantly showed various sex-cord patterns without a recognizable endometrial stromal component. They exhibited a diverse immunohistochemical profile, frequently co-expressing sex cord (calretinin, inhibin, WT1, SF-1, and FOXL2), smooth muscle (SMA, desmin and caldesmon), epithelial (CK) and other markers (CD10 and IFITM1). Fourteen of 16 tumors (87.5%) showed NCOA1-3 gene rearranges, but none had BCOR, YWHAE, PHF1 and JAZF1 fusions. Five tumors contained 6 non-recurrent pathogenic (likely) mutations and one had gains in c-MYC. Our study supports frequent NCOA1-3 rearrangements in UTROSCT. Rare, non-recurrent mutations suggest that these gene rearrangements be potential drivers in tumorigenesis. Detection of gene rearrangements can contribute to the correct interpretation of UTROSCT. However, large comparative studies with molecular tests are required to confirm these findings.

Uterine Tumor Resembling Ovarian Sex Cord Tumor With Aggressive Histologic Features Harboring a GREB1-NCOA2 Fusion: Case Report With a Brief Review

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare mesenchymal neoplasm, of uncertain lineage, that shows predominantly sex cord-like differentiation with a broad range of histologic appearances and polyphenotypic immunohistochemical features. Although generally having a favorable prognosis, a subset can recur/metastasize. Most recently, several studies of UTROSCT have described novel fusion genes involving ESR1 and GREB1 as the 5 partner, and NCOA1-3 as the 3 partner. Genotype and phenotype correlation has suggested that GREB1 -rearranged tumors may have a higher tendency to behave aggressively. Herein, we report a UTROSCT with aggressive histologic features harboring a GREB1-NCOA2 fusion. A 51-yr-old woman presented with menometrorrhagia and progressive dysmenorrhea and was found to have a submucous uterine lesion by ultrasonography. Gross examination of the hysterectomy specimen showed an 8.5-cm, polypoid, soft, intracavitary mass. Histologic examination revealed a deeply invasive neoplasm composed of uniform round to plump spindle cells, arranged predominantly in diffuse sheets and fascicles and focally in anastomosing cords patterns. Groups of rhabdoid tumor cells were occasionally noted. Worrisome features, including increased mitotic figures (up to 3/10 high power fields), geographic necrosis, and lymphovascular invasion, were evident. Immunohistochemical analysis showed variable positivity for epithelial, smooth muscle, neuroendocrine, and sex cord markers, as well as hormone receptors. RNA sequencing revealed an in-frame fusion between exon 3 of GREB1 and exon 14 of NCOA2 . Fluorescence in situ hybridization analyses confirmed rearrangements of both the GREB1 and NCOA2 loci. Our case lends further supports that GREB1 -rearranged UTROSCTs frequently exhibit aggressive histological features with inconspicuous sex cord-like differentiation.

ZFP64::NCOA3 gene fusion defines a novel subset of spindle cell rhabdomyosarcoma

Spindle cell rhabdomyosarcoma represents a rare neoplasm characterized by monomorphic spindle cells with a fascicular architecture and variable skeletal muscle differentiation. Following incidental identification of a ZFP64::NCOA3 gene fusion in an unclassified spindle cell sarcoma resembling adult-type fibrosarcoma, we performed a retrospective archival review and identified four additional cases with a similar histology and identical gene fusion. All tumors arose in adult males (28-71 years). The neoplasms were found in the deep soft tissues, two were gluteal, and one each arose in the thigh, abdominal wall, and chest wall. Morphologically, the tumors were characterized by spindle cells with a distinctive herringbone pattern and variable collagenous to myxoid stroma. The nuclei were relatively monomorphic with variable mitotic activity. Three tumors had immunoreactivity for MyoD1, and four contained variable expression of desmin and smooth muscle actin. All cases tested for myogenin, CD34, S100, pankeratin, and epithelial membrane antigen were negative. Targeted RNA sequencing revealed a ZFP64::NCOA3 fusion product in all five tumors. Three patients developed distant metastases, and two ultimately succumbed to their disease within 2 years of initial diagnosis. This study suggests ZFP64::NCOA3 fusions define a novel subtype of rhabdomyosarcoma with a spindle cell morphology and aggressive clinical behavior. The potential for morphologic and immunohistochemical overlap with several other sarcoma types underscores the value of molecular testing as a diagnostic adjunct to ensure accurate classification and management of these neoplasms.

Clinicopathological characteristics and genetic variations of uterine tumours resembling ovarian sex cord tumours

AIMS

To investigate the clinicopathological and molecular characteristics of uterine tumours resembling ovarian sex cord tumours (UTROSCTs) and the value of molecular diversity in the clinical diagnosis and treatment.

METHODS

Five patients with UTROSCT were enrolled, and their clinical data, pathological morphologies, immunophenotypes and molecular features were analysed. Fluorescence in situ hybridisation for NCOA1, NCOA2, NCOA3, JAZF1 and PHF1 and next-generation sequencing for 27 homologous recombination/repair (HRR) pathway genes were performed on five and three UTROSCT specimens, respectively.

RESULTS

All five patients were treated for abnormal uterine bleeding and grossly presented with intrauterine polyps. Under a microscope, tumour cells grew diffusely and presented a cordlike arrangement and glandular duct-like structures, with nuclei ranging from round to oval, vesicular chromatin and visible nucleoli in some cases. The mitotic count was less than 3/10 high-power fields. Immunohistochemistry showed sex cord, epithelial cell and smooth muscle cell biomarkers and diffuse, strong staining for B cell lymphoma-2 (BCL-2). NCOA1 and NCOA3 rearrangements were identified in 80% (4/5) of the cases. JAZF1 and PHF1 rearrangements were not detected in any of five patients. HRR pathway gene mutations were detected in all three patients, including FANCE, ATR and ARID1A mutations in one case each.

CONCLUSION

UTROSCT is a rare mesenchymal tumour, and biopsy specimens are easily misdiagnosed. UTROSCT diagnosis requires the combined use of biomarkers and molecular detection. BCL-2 has potential diagnostic value as a marker. UTROSCT can have mutations related to the HRR pathway, suggesting that this tumour type may be sensitive to platinum/poly (ADP-ribose) polymerase inhibitors.

Uterine sarcomas and rare uterine mesenchymal tumors with malignant potential. Diagnostic guidelines of the French Sarcoma Group and the Rare Gynecological Tumors Group

The landscape of uterine sarcomas is becoming increasingly complex with the description of new entities associated with recurrent molecular alterations. Uterine sarcomas, as well as soft tissue sarcomas, can be distinguished into complex genomic sarcomas and simple genomic sarcomas. Leiomyosarcoma and pleomorphic type undifferentiated uterine sarcoma belong to the first group. Low-grade and high-grade endometrial stromal sarcomas, NTRK, COL1A1::PDGFB, ALK, RET, ROS1 associated sarcomas, and SMARCA4 deficient uterine sarcoma belong to the second group. Leiomyosarcoma is the most common uterine sarcoma followed by endometrial stromal sarcomas. Three different histologic subtypes of leiomyosarcomas are recognized with distinct diagnostic criteria and different clinical outcomes, the myxoid and epithelioid leiomyosarcomas being even more aggressive than the fusiform type. The distinction between low-grade and high-grade endometrial stromal sarcoma is based first on morphology and immunohistochemistry. The detection of fusion transcripts helps in the diagnosis. Definitely recognized as a separate entity, uterine PEComa is a rare tumor whose diagnostic criteria are being recently defined. Uterine PEComa has a specific algorithm stratifying the tumors into uncertain malignant potential and malignant tumors. Embryonal rhabdomyosarcomas of the uterine cervix are not restricted to children but can also be observed in adult women and are almost always DICER1 mutated, unlike embryonal rhabdomyosarcoma of the vagina which are DICER1wild-type, and adenosarcoma which can be DICER1 mutated but with less frequency. As sarcomas associated with fusion transcripts involving the NTRK, ALK, COL1A1::PDGFB genes can benefit from targeted therapy, systematic detection are now relevant especially for patients with high risk of relapse or in recurrent setting. The integration of molecular data with dedicated expert pathology review for histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Data Set for Reporting of Uterine Malignant and Potentially Malignant Mesenchymal Tumors: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

The International Collaboration on Cancer Reporting (ICCR) seeks to produce standardized, evidence-based protocols for the reporting of tumors with the aim of ensuring that all cancer reports generated worldwide will be of similar high quality and record the same elements. Herein, we describe the development of the data set for the reporting of uterine malignant and potentially malignant mesenchymal tumors by a panel of expert pathologists and a single clinician and provide the commentary and rationale for the inclusion of core and noncore elements. This data set, which incorporates the recent updates from the 5th edition of the World Health Organization Classification of Female Genital Tumors, addresses several subjects of debate including which mesenchymal tumors should be graded, how to document extent of invasion, mitotic counts, and the role of ancillary testing in tumor diagnosis and patient management. The inclusion of elements is evidence-based or based on consensus of the expert panel with clinical relevance being the guiding standard.

A Constellation of Rare Gynecological Malignancies and Familial Adenomatous Polyposis Gastrointestinal Adenocarcinoma: A Case Report

Ovarian microcystic stromal tumors (MST) are a rare subtype of sex-cord stromal tumors. We are presenting a case of a MST arising in a patient with familial adenomatous polyposis (FAP) and concurrent colonic adenocarcinoma. During the patient's workup of an ampullary adenoma associated with her FAP, she was found to have an enlarged uterus with a thickened endometrium and an incidental pelvic mass on the fundus of the uterus. Subsequent imaging identified heterogenous bulky ovaries. This patient underwent surgical resection including a total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, bilateral pelvic sentinel lymph node biopsy during her planned total proctocolectomy and transduodenal ampullectomy. Extensive histologic and immunohistochemical investigations were completed and the final pathology report revealed a unique compilation of International Federation of Gynecology and Obstetrics Stage II, grade 1 endometrioid endometrial adenocarcinoma, bilateral ovarian MST, a sperate pedunculated mass favoring a diagnosis of uterine tumor resembling ovarian sex cord tumor (UTROSCT), 2 distinct adenocarcinomas of the colon (T2N0 and T1N0) and a tubular adenoma of the ampulla. The pathology showed the endometroid adenocarcinoma was β-catenin negative while the MST and UTROSCT both showed nuclear positivity with β-catenin. To our knowledge this is the first reported case of a UTROSCT with concurrent endometrial adenocarcinoma presenting with bilateral ovarian MST's and adenomatous polyposis coli gene positive FAP colon adenocarcinoma.

Recurrent KAT6B/A::KANSL1 Fusions Characterize a Potentially Aggressive Uterine Sarcoma Morphologically Overlapping With Low-grade Endometrial Stromal Sarcoma

With the widespread application of next-generation sequencing, the genetic landscape of uterine mesenchymal neoplasms has been evolving rapidly to include several recently identified fusion genes. Although chromosomal rearrangements involving the 10q22 and 17q21.31 loci have been reported in occasional uterine leiomyomas decades ago, the corresponding KAT6B::KANSL1 fusion has been only recently identified in 2 uterine tumors diagnosed as leiomyoma and leiomyosarcoma. We herein describe 13 uterine stromal neoplasms carrying a KAT6B::KANSL1 (n=11) and KAT6A::KANSL1 (n=2) fusion. Patient ages ranged from 33 to 81 years (median, 49 y). Tumor size was 2.6 to 23.5 cm (median, 8.2 cm). Nine tumors were myometrium-centered, and 3 had an intracavitary component. Original diagnoses were mostly low-grade endometrial stromal sarcoma (LG-ESS; 10 cases) with atypical features (limited CD10 expression, sex cord-like features, pericytic vasculature, and frequent myxoid changes). Treatment was hysterectomy±bilateral salpingo-oophorectomy (10), myomectomy (1), and curettage (2). Five patients were disease-free at 6 to 34 months, 3 (27%) died of disease at 2 to 47 months, and 3 were alive with disease at 2, 17, and 17 years. Histologically, most tumors showed variable overlap with LG-ESS, but they were generally well-circumscribed lacking the extensive permeative and angioinvasive growth typical of LG-ESS. They were composed of monotonous medium-sized oval and spindle cells arranged into diffuse sheets with prominent spiral-type arterioles and frequent pericytoma-like vascular pattern. Variable myxoid stromal changes were frequent. Mitotic activity ranged from 1 to >20 in 10 HPFs. Immunohistochemistry showed variable expression of CD10 (12/13), estrogen receptor (8/11), progesterone receptor (8/11), smooth muscle actin (9/11), desmin (4/12), h-caldesmon (2/10), calretinin (3/8), inhibin (1/7), WT1 (4/7), cyclin D1 (5/11; diffuse in only 1 case), and pankeratin (5/10). This series characterizes a KAT6B/A::KANSL1 fusion-positive uterine stromal neoplasm within the morphologic spectrum of LG-ESS but with atypical features. The relationship of these neoplasms to genuine LG-ESS remains unclear. This molecular subtype of uterine endometrial stromal sarcoma has the potential for an unfavorable clinical course despite the absence of widely invasive growth; nevertheless, analysis of more cases is necessary to delineate the phenotypic spectrum and biological potential of this tumor.

Uterine tumor resembling ovarian sex-cord tumor: case report and review of the literature

Background

We report the clinicopathological characteristics, immunohistochemical features, ultrastructure, tissue source, differential diagnosis, treatment, and prognosis of a patient with a uterine tumor resembling ovarian sex-cord tumor (UTROSCT).

Case report

A 40-year-old woman had a uterine myoma with enlargement for 2.5 years. An ultrasound examination showed a mixed echogenic mass at the posterior wall of the uterus and a dark cyst in the right adnexal area, which suggested a suspected uterine myoma with liquefaction and a suspected chocolate cyst. The patient underwent transabdominal tumor resection with removal of the right adnexal mass. Through postoperative pathological examination, the patient was diagnosed with UTROSCT. No recurrence was observed after a follow-up of 1 year.

Conclusion

Although UTROSCT is usually benign, it can relapse or metastasize, and patients with UTROSCT need comprehensive diagnosis and treatment.

Update on Uterine Mesenchymal Neoplasms

This review focuses on recent advances in epithelioid and myxoid uterine mesenchymal neoplasms, a category of tumors whereby diagnostic criteria have been rapidly evolving due to advances in molecular testing. Pertinent clinicopathological and molecular features are highlighted for perivascular epithelioid cell tumors, uterine tumors resembling ovarian sex cord tumors, BCOR/BCORL1-altered high-grade endometrial stromal sarcomas, and inflammatory myofibroblastic tumors. Novel developments in epithelioid and myxoid leiomyosarcomas are briefly discussed, and differential diagnoses with key diagnostic criteria are provided for morphologic mimickers.

Epithelioid Leiomyosarcoma of the Uterus: Modern Outcome-based Appraisal of Diagnostic Criteria in a Large Institutional Series

Epithelioid leiomyosarcoma of the uterus is rare and poorly understood. Herein, we characterize a large institutional series of epithelioid leiomyosarcomas aiming to define outcome-determinant diagnostic pathologic features. We also retrieved epithelioid smooth muscle tumors of unknown malignant potential and evaluated a consecutive cohort of leiomyomas for epithelioid subtypes. Of a total of 1177 uterine leiomyosarcomas, 81 (7%) were categorized as epithelioid after review. Epithelioid leiomyosarcoma was strictly defined as having round to polygonal cells with visible pink cytoplasm and round to ovoid nuclei in ≥50% of the tumor volume. Average age was 55 years (range: 26 to 81 y). Median tumor size was 11 cm; tumor was >5 cm in 93% of subjects; 47% were stage 1 at presentation. An infiltrative tumor border was observed, grossly and/or microscopically, in 89% of cases; necrosis was noted in 80%, and vascular invasion in 47%. Mitotic count in 2.4 mm2 (totalling 10 high-power fields, each field 0.55 mm in diameter) ranged from 3 to 100 (median: 26). All cases had moderate, severe or highly pleomorphic atypia. All cases had 2 or 3 of the following: necrosis, at least moderate atypia and ≥4 mitoses in 2.4 mm2. Immunohistochemistry revealed frequent expression of smooth muscle markers including SMA (96%), desmin (95%), and caldesmon (81%). HMB45 and Melan-A were negative in 92% and 100% of cases, respectively. Estrogen and progesterone receptors were expressed by 65% and 54% of tumors, respectively. Follow-up information was available in 68 subjects (median: 23 mo, range: 1 to 254); cancer-related death occurred in 63%, and an additional 15% had recurrent or metastatic disease at last follow-up. Disease-specific survival was shorter in epithelioid leiomyosarcoma patients (median: 44  mo; 35% at 5-y) than in a matched cohort of nonepithelioid leiomyosarcoma (median: 55 mo; 46% at 5-y) (P=0.03). Three epithelioid smooth muscle tumors of unknown malignant potential were evaluated, all <5 cm in size and with atypia and/or irregular borders but mitotic count below the threshold for malignancy. Two of these had follow-up available, which was uneventful. Of 142 consecutive leiomyomas assessed, none had epithelioid morphology as defined. Epithelioid leiomyosarcoma is an aggressive neoplasm, sometimes with a remarkably low mitotic count. In the setting of an epithelioid smooth muscle tumor of the uterus, we postulate that the diagnosis of malignancy is made in the presence of ≥2 of the following: moderate or severe atypia, ≥4 mitoses/2.4 mm2 and tumor cell necrosis. In their absence, the finding of tumor size ≥5 cm, vascular invasion, infiltrative edges or atypical mitoses should be treated with caution, and designation as of at least uncertain malignant potential is warranted.

Primary Fallopian Tube Mullerian Adenosarcoma With Sarcomatous Overgrowth and a Previously Unreported MEIS1-NCOA2 Gene Fusion

Extrauterine Mullerian adenosarcomas (MA) are rare and often associated with endometriosis. We report a 55-yr-old patient seen in consultation for abdominal pain and bloating. Imaging was suggestive of a left adnexal mass and "peritoneal carcinomatosis". Pathological examination of the specimen revealed a MA arising in the left fallopian tube, with sarcomatous overgrowth, diffuse peritoneal involvement and omental "caking". Next-generation sequencing identified a MEIS1-NCOA2 gene fusion, previously unreported in MA.