Genomewide copy number analysis of Müllerian adenosarcoma identified chromosomal instability in the aggressive subgroup

Uterine adenosarcoma: Clinical significance of histological classification and SNP array analysis

Mullerian adenosarcoma is a rare malignant biphasic tumor. The mesenchymal component may be low or high grade, with or without sarcomatous overgrowth (SO). Little is known about the molecular heterogeneity of these tumors. In this study, we aim to reclassify a large retrospective monocentric cohort of uterine adenosarcomas according to tumor grade and SO, to evaluate the clinical significance of pathological classification and to correlate with copy-number variations inferred from single nucleotide polymorphism array. Of the 67 uterine adenosarcomas, 18 (26.9%) were low grade without SO, 7 (10.4%) low grade with SO, 8 (11.9%) high grade without SO and 34 (50.7%) high grade with SO. SO, necrosis and RMS were more frequent in high grade than low grade adenosarcomas (p < 0.001). Low-rank test showed that recurrence-free survival was significantly shortened in high grade than low grade adenosarcomas (p = 0.035) and SO was associated with shortened overall and recurrence-free survival (p = 0.038 and p = 0.009, respectively). High-grade tumors displayed complex genomic profiles with multiple segmental losses including TP53, ATM and PTEN genes. The median genomic index was significantly higher in high grade than low grade tumors (27 [3-60] vs 5,3 [0-16], p < 0.0001) and was significantly higher in presence of SO in low grade tumors (12,8 [10-16] vs 2,6 [0-10], p = 0.0006). We propose to report sarcomatous overgrowth with the tumor grade for prognostication in adenosarcoma and representative sampling is crucial for evaluation of these histological criteria.

Next-Generation Sequencing Analysis of 3 Uterine Adenosarcomas with Heterogeneously Differentiated Genomic Mutations

Uterine adenosarcoma (UA) is an uncommon mixed tumor containing a benign to at most mildly atypical epithelial component and a sarcoma-like stroma, usually a low-grade, stromal component, with rare heterogeneous elements. Currently, tumor etiology is largely unknown. To better understand the gene mutations in UA, next-generation sequencing (NGS) technology analysis was performed. This study showed that two low-grade UAs with heterologous components had ATRX gene frameshift mutation, and one patient had a MED12 missense mutation. Copy number amplification genes were mainly observed on chromosome 12q13-15. In this study, PIK3/AKT/PTEN pathway mutations were found to be common in adenosarcoma. In addition, a rare BCORL1-PRR14L fusion mutation was also identified. These findings provide a basis for future research into these molecular changes in tumorigenesis and targeted therapy.

[Endometrial and other rare uterine sarcomas : Diagnostic aspects in the context of the 2020 WHO classification]

Uterine sarcomas are a heterogeneous group of rare malignancies. Mostly (40-50%), they are leiomyosarcomas, followed by endometrial stromal sarcomas (ESS), low-grade (LG) and high-grade (HG), as well as undifferentiated sarcoma of the uterus (UUS) and adenosarcomas (AS). Other, non-organ-specific tumours such as NTRK-rearranged spindle cell neoplasia, perivascular epithelioid cell tumour (PEComa) and inflammatory myofibroblastic tumour (IMT) are extremely difficult to differentiate.In the most recent WHO classification, endometrial stromal tumours are subdivided as follows: benign, expansively growing endometrial stromal nodule (ESN) with sharp demarcation, the histologically similar-looking LG-ESS with infiltrative growth, the highly malignant HG-ESS and, as a diagnosis of exclusion, the highly aggressive UUS lacking specific lines of differentiation. LG-ESS can be differentiated from HG-ESS in most cases histomorphologically and immunohistochemically, but molecular investigations are necessary in individual cases. HG-ESS can be divided into 4 subtypes (YWHAE/NUTM2 fusion low-grade component, YWHAE/NUTM2 fusion high-grade component, ZC3H7B-BCOR fusion or BCOR-ITD) on the basis of molecular findings. Prognostically unfavourable factors in AS are severe sarcomatous overgrowth, deep myometrial invasion, high-grade histology and lymphatic vessel invasion. Tumours with NTRK fusion are immunohistochemically positive for S100 and TRK. PEComas express cathepsin K and HMB45, as well as TFE3 when translocation is present. Almost every IMT shows an alteration in the ALK gene In the case of overlapping morphology and simultaneous therapeutic and prognostic relevance, it is becoming increasingly important to verify or confirm the suspected histomorphological diagnosis by immunohistochemical and possibly molecular investigations.

Uterine adenosarcoma with sarcomatous overgrowth and rhabdoid features: A rare case

Uterine adenosarcoma is usually a low-grade neoplasm with a mixed benign epithelial component and malignant stroma, commonly found in postmenopausal women. In the presence of sarcomatous overgrowth, it has been shown to have poor prognosis. Uterine adenosarcoma with sarcomatous overgrowth and rhabdoid features is extremely rare. We report here a case of a 28-year-old female who was found to have adenosarcoma with sarcomatous overgrowth with extensive rhabdoid features. The tumor had metastasized to the pelvis, omentum, iliac, and obturator lymph nodes. She was lost to follow-up for 10 months, after which she presented with recurrent tumor at the hysterectomy site. She was started on palliative chemoradiotherapy, on which she progressed but later experienced drug toxicity, became cachectic, and was unwilling to continue chemotherapy. There are a few cases of adenosarcoma with sarcomatous overgrowth reported in young women and only two cases with rhabdoid features. Based on this report, adenosarcoma with sarcomatous overgrowth and rhabdoid features appears to be an extremely aggressive tumor with poor prognosis.

Atypical uterine polyps show morphologic and molecular overlap with mullerian adenosarcoma but follow a benign clinical course

A subset of clinically benign uterine polyps shows atypical morphologic features worrisome for, but not diagnostic of, Mullerian adenosarcoma. We report clinicopathologic data for 63 polyps from 58 women with atypical morphologic features including abnormal architecture, abnormal periglandular stroma, stromal atypia, and mitoses >2 per 10 hpf. Four (11%) of 36 women with follow-up tissue sampling had residual/recurrent atypical polyp. Twelve (27%) of 44 women underwent hysterectomy subsequent to a diagnosis of atypical polyp. No patient developed adenosarcoma over median follow-up of 150 months. Twenty-one primary atypical polyps underwent molecular profiling. Five (24%) harbored chr 12q13-15 gain or amplification, 9/20 (45%) harbored chr 6q25.1 gain, and 7/21 (33%) had no significant copy number alterations. Gains of chr 1q, chr 8p12, and chr 10q11.21-23, amplifications of chr 12q24.12-13, chr 15p24.1-26.1, and chr 18q21.33, and loss of chr 7 and chr 11q21 were each seen in a single polyp. Mean tumor mutational burden was 3.1 (range, 0.76-8.365) mutations/Mb. Pathogenic point mutations were identified in 12/20 (60%) primary atypical polyps. We propose the term "atypical uterine polyps" for these lesions, which show biologic overlap with early Mullerian adenosarcoma but lack molecular alterations characteristic of clinically aggressive adenosarcoma and appear to follow a benign clinical course. Conservative management with close clinical follow-up and repeat sampling can be considered for these lesions, when clinically appropriate.

Genomic alterations in gynecological malignancies: histotype-associated driver mutations, molecular subtyping schemes, and tumorigenic mechanisms

There are numerous histological subtypes (histotypes) of gynecological malignancies, with each histotype considered to largely reflect a feature of the "cell of origin," and to be tightly linked with the clinical behavior and biological phenotype of the tumor. The recent advances in massive parallel sequencing technologies have provided a more complete picture of the range of the genomic alterations that can persist within individual tumors, and have highlighted the types and frequencies of driver-gene mutations and molecular subtypes often associated with these histotypes. Several large-scale genomic cohorts, including the Cancer Genome Atlas (TCGA), have been used to characterize the genomic features of a range of gynecological malignancies, including high-grade serous ovarian carcinoma, uterine corpus endometrial carcinoma, uterine cervical carcinoma, and uterine carcinosarcoma. These datasets have also been pivotal in identifying clinically relevant molecular targets and biomarkers, and in the construction of molecular subtyping schemes. In addition, the recent widespread use of clinical sequencing for the more ubiquitous types of gynecological cancer has manifested in a series of large genomic datasets that have allowed the characterization of the genomes, driver mutations, and histotypes of even rare cancer types, with sufficient statistical power. Here, we review the field of gynecological cancer, and seek to describe the genomic features by histotype. We also will demonstrate how these are linked with clinicopathological attributes and highlight the potential tumorigenic mechanisms.

Recurrent MEIS1-NCOA2/1 fusions in a subset of low-grade spindle cell sarcomas frequently involving the genitourinary and gynecologic tracts

Sarcomas with MEIS1-NCOA2 fusions have been so far reported in 2 cases each of primitive renal sarcomas and intraosseous pelvic rhabdomyosarcomas. Their histologic spectrum, anatomic distribution, and clinical behavior remain poorly defined. In this study, we report 6 additional spindle cell sarcomas with MEIS1-NCOA2 or NCOA1 fusions that fall into the same disease spectrum with the previously reported renal sarcomas. The patients' age range was wide (20-76 years, mean 46) and all except one were female. The tumors arose in the kidney (n = 2), and one each in the uterine corpus, vagina, scrotum, and para-rectal region. The consistent morphology was that of monomorphic spindle to ovoid cells in a storiform, whorling, or solid pattern. Alternating cellularity, myxoid stroma, and microcystic changes were seen in some cases. Mitotic activity varied greatly (<1-33/10 high power fields). The immunophenotype was nonspecific, with most cases expressing variable degrees of TLE1, WT1, cyclin D1, CD56, and CD10. Using various platforms of RNA-based targeted sequencing, MEIS1-NCOA2 fusions were recurrently identified in 5 cases, and a novel MEIS1-NCOA1 fusion was found in one renal tumor. The gene fusions were validated by fluorescence in situ hybridization using custom BAC probes. Of the 5 patients with available follow-up (5 months to 8 years), all experienced local recurrences, but no distant spread or death from disease. Our results expand the clinicopathologic spectrum of sarcomas with MEIS1-NCOA2/1 fusions, providing evidence of an undifferentiated spindle cell phenotype with nonspecific immunoprofile and low-grade clinical behavior.

[Interdisciplinary S2k guidelines on the diagnosis and treatment of uterine sarcomas-recommendations for surgical pathology]

Uterine sarcomas represent a heterogeneous group of rare malignancies, derived from the myometrium, the endometrial stroma, and very rarely from the nonspecialized uterine soft tissue. The actual incidence is about 1.5 for Caucasian and 3.0 for Afro-American women. There is no grading system for leimoysarcoma defined by the WHO classification; however, if clinicians request, the FNCLCC grading can be specified in analogy to soft tissue sarcomas. Adenosarcomas must be distinguished from adenofibromas (the existence of which is questionable)-with the vast majority of these tumors being uterine adenosarcomas. Within adenosarcomas, deep myometrial invasion (>50%), sarcomatous overgrowth, and a high-grade heterologous component are associated with a higher recurrence rate and poor survival. The immunohistochemical panel represents a very helpful tool for distinguishing low-grade from high grade endometrial stromal sarcomas (ESS) and may be supplemented by molecular analyses. Steroid hormone receptor analysis should be performed for all ESS due to the possible therapeutic relevance. Undifferentiated uterine sarcomas represent a diagnosis of exclusion and have a very poor prognosis. Carcinosarcomas represent a special subtype of endometrial carcinomas and are in fact not uterine sarcomas. Uterine sarcomas may present substantial intratumoral heterogeneity and adequate embedding is mandatory. Lesions ≤2 cm in the largest dimension should be processed completely and larger tumors should be processed with one block per centimeter for the largest tumor dimension.

Gynecological Sarcomas: Molecular Characteristics, Behavior, and Histology-Driven Therapy

Gynecological sarcomas represent 3% to 4% of all gynecological malignancies and 13% of all sarcomas. The uterus is the most frequent primary site (83%); less frequently sarcomas are diagnosed originating from the ovary (8%), vulva and vagina (5%), and other gynecologic organs (2%). As the classification of gynecologic sarcomas continues to diversify, so does the management. Accurate histopathologic diagnosis, utilizing appropriate ancillary immunohistochemical and molecular analysis, could lead to a more personalized approach. However, there are subtypes that require further definition, with regard to putative predictive markers and optimal management. The aim of this review is to highlight the importance of accurate diagnosis and classification of gynecologic sarcoma subtypes by the surgical pathologist in order to provide more tailored systemic treatment, and to highlight the increasing importance of close collaboration between the pathologist and the oncologist.

Whole-Genome Sequencing and Target Validation Analysis of Müllerian Adenosarcoma: A Tumor With Complex but Specific Genetic Alterations

Mullerian adenosarcoma (MAS) is a biphasic tumor with malignant stroma. It is most commonly of endometrial origin but occasionally originates in the cervix, ovary, or other pelvic/peritoneal sites. The typical MAS is low grade with an indolent clinical course; however, tumors with sarcomatous overgrowth (SO) or a high-grade sarcoma tend to be aggressive. Tumor etiology is largely unknown. To better understand the global genome alterations and gene mutations in MAS, whole-genome sequencing (WGS) and target validation analysis were performed. MAS showed remarkable chromosome (chr) copy number variation (CNV), specifically, gains in chr 1q, 5p, 12p, 12q, and 17q and losses in chr 3p, 3q, 9p, and 11q. Gain of chr 12q13-15 was present in 50% of cases. The selected gene products in gain regions were upregulated as measured by immunohistochemistry. HMGA2 overexpression was significantly correlated with SO. While the structural variation (SV) rate was relatively low overall, a disproportionally high rate of break-ends at chr 7 was noted involving 6 in-frame rearrangement fusion genes. Among 40 frequently mutated genes detected by WGS and validated in 29 MAS by next generation sequencing (NGS), KMT2C, and BCOR were frequently seen in MAS both with and without SO, while MAGEC1 and KDM6B were strongly associated with SO. Overall, a higher rate of frequently mutated genes was found in MAS with SO (33%) than MAS without (11%). This study uncovers the complex and specific genetic alterations in this malignancy. The findings provide a tool for future investigation of these molecular changes in tumorigenesis and target therapies.

Uterine Mesenchymal Tumors: Update on Classification, Staging, and Molecular Features

The spectrum of mesenchymal neoplasia in the uterus has expanded in recent years. First, the identification of prevalent, recurrent molecular alterations has led to a more biologically and clinically congruent classification of endometrial stromal tumors. Likewise, the diagnostic criteria of several rare and miscellaneous tumor types have been refined in recent case series (Perivascular Epithelioid Cell tumor, inflammatory myofibroblastic tumor). Pure mesenchymal tumors are still broadly classified based on morphology according to the tumor cell phenotype. Smooth muscle tumors predominate in frequency, followed by tumors of endometrial stromal derivation; the latter are covered in depth in this article with an emphasis on defining molecular alterations and their morphologic and clinical correlates. The remaining entities comprise a miscellaneous group in which cell derivation does not have a normal counterpart in the uterus (eg, rhabdomyosarcoma) or is obscure (eg, undifferentiated uterine sarcoma). This article discusses their clinical relevance, recent insights into their molecular biology, and the most important differential diagnoses. Regarding the latter, immunohistochemistry and (increasingly) molecular diagnostics play a role in the diagnostic workup. We conclude with a few considerations on intraoperative consultation and macroscopic examination, as well as pathologic staging and grading of uterine sarcomas as per the most recent American Joint Cancer Commission and the Fédération Internationale de Gynécologie et d'Obstétrique staging systems.

The emerging links between chromosomal instability (CIN), metastasis, inflammation and tumour immunity

Many cancers possess an incorrect number of chromosomes, a state described as aneuploidy. Aneuploidy is often caused by Chromosomal Instability (CIN), a process of continuous chromosome mis-segregation. CIN is believed to endow tumours with enhanced evolutionary capabilities due to increased intratumour heterogeneity, and facilitating adaptive resistance to therapies. Recently, however, additional consequences and associations with CIN have been revealed, prompting the need to understand this universal hallmark of cancer in a multifaceted context. This review is focused on the investigation of possible links between CIN, metastasis and the host immune system in cancer development and treatment. We specifically focus on these links since most cancer deaths are due to the consequences of metastasis, and immunotherapy is a rapidly expanding novel avenue of cancer therapy.

Mutational game changer: Chromothripsis and its emerging relevance to cancer

In recent years, the paradigm that genomic abnormalities in cancer cells arise through progressive accumulation of mutational events has been challenged by the discovery of single catastrophic events. One such phenomenon termed chromothripsis, involving massive chromosomal rearrangements arising all at once, has emerged as a major mutational game changer. The strong interest in this process stems from its widespread association with a range of cancer types and its potential as a mutational driver. In this review, we first describe chromothripsis detection and incidence in cancers. We then explore recently proposed underlying mechanistic origins, which explain the curious observations of the highly localised nature of the rearrangements on chromothriptic chromosomes. Detection of chromothriptic patterns following incorporation of single chromosomes into micronuclei or following telomere attrition have greatly contributed to our understanding of the reasons behind this chromosomal restriction. These underlying cellular events have been found to be participants in the tumourigenic process, strongly suggesting a potential role for chromothripsis in cancer development. Thus, we discuss potential implications of chromothripsis for cancer progression and therapy.

A Single-Centre Experience on the Management of Adenosarcoma: A Successful Report of an Integrated Medical and Surgical Approach

Adenosarcomas are the rarest form of uterine sarcomas, and clinical experience with their management is still limited. Here, we reported 7 patients with uterine adenosarcoma referred to our institution, focusing on main pathologic features, their medical history, and long-term follow-up. Among these patients, we provided a detailed description of the medical history of a 49-year-old woman with advanced uterine adenosarcoma with sarcomatous overgrowth who presented a brilliant radiologic and pathologic response after 3 cycles of epirubicin and ifosfamide, ultimately achieving an extraordinary long-term outcome through an integrated surgical and medical approach. Our single-centre experience would suggest that aggressive uterine adenosarcomas with sarcomatous overgrowth are sensitive to standard epirubicin and ifosfamide and that an integrated approach, both medical and surgical, could be considered in clinical practice, again emphasizing the relevant role of multidisciplinary management for this extremely rare disease.

Müllerian Adenosarcoma of the Urinary Bladder: Clinicopathologic and Immunohistochemical Features With Novel Genetic Aberrations

BACKGROUND

Müllerian adenosarcoma is a biphasic neoplasm most commonly occurring in the uterus and less frequently of the ovary. It has been rarely described to occur in other sites such as peritoneum and liver.

PATIENTS AND METHODS

In this study, we report the clinicopathologic, immunohistochemical and molecular features of a primary Müllerian adenosarcoma of the urinary bladder in a 62-year-old woman. To our knowledge, this is the first report of detailed pathologic characterization of Müllerian adenosarcoma primary to the urinary bladder in the literature.

RESULTS

Light microscopy showed a biphasic epithelial and stromal tumor with benign-appearing glands surrounded by densely cellular endometrial-type stroma that is densely cellular with increased mitotic figures. The stroma surrounding the glands was more cellular than the intervening areas, which were more loose and edematous. Immunohistochemistry staining revealed positive staining for Pax-2/8 within the glands, for positive CD10 and WT-1 within the spindle cell stroma, and for estrogen and progesterone receptors in both. Staining for desmin, GATA3, p63, and human papillomavirus was negative. Molecular analyses identified mutations in protein kinase B E17K, fms related tyrosine kinase 3 D835N, KRAS proto-oncogene, GTPase G12D, and HRAS proto-oncogene, GTPase G12S. These novel molecular aberrations have yet to be reported in the medical literature. X chromosome inactivation analysis revealed a clonal pattern in the stromal component and a nonclonal pattern in the epithelial component. Currently, the patient is disease/recurrence-free after regular follow-up of approximately 84 months.

CONCLUSION

This case represents, to our knowledge, the first reported diagnosis of Müllerian adenosarcoma arising in the urinary bladder with extensive clinicopathologic, immunohistochemical, and molecular analyses.

Characterization of FN1-FGFR1 and novel FN1-FGF1 fusion genes in a large series of phosphaturic mesenchymal tumors

Phosphaturic mesenchymal tumors typically cause paraneoplastic osteomalacia, chiefly as a result of FGF23 secretion. In a prior study, we identified FN1-FGFR1 fusion in 9 of 15 phosphaturic mesenchymal tumors. In this study, a total of 66 phosphaturic mesenchymal tumors and 7 tumors resembling phosphaturic mesenchymal tumor but without known phosphaturia were studied. A novel FN1-FGF1 fusion gene was identified in two cases without FN1-FGFR1 fusion by RNA sequencing and cross-validated with direct sequencing and western blot. Fluorescence in situ hybridization analyses revealed FN1-FGFR1 fusion in 16 of 39 (41%) phosphaturic mesenchymal tumors and identified an additional case with FN1-FGF1 fusion. The two fusion genes were mutually exclusive. Combined with previous data, the overall prevalence of FN1-FGFR1 and FN1-FGF1 fusions was 42% (21/50) and 6% (3/50), respectively. FGFR1 immunohistochemistry was positive in 82% (45/55) of phosphaturic mesenchymal tumors regardless of fusion status. By contrast, 121 cases of potential morphologic mimics (belonging to 13 tumor types) rarely expressed FGFR1, the main exceptions being solitary fibrous tumors (positive in 40%), chondroblastomas (40%), and giant cell tumors of bone (38%), suggesting a possible role for FGFR1 immunohistochemistry in the diagnosis of phosphaturic mesenchymal tumor. With the exception of one case reported in our prior study, none of the remaining tumors resembling phosphaturic mesenchymal tumor had either fusion type or expressed significant FGFR1. Our findings provide insight into possible mechanisms underlying the pathogenesis of phosphaturic mesenchymal tumor and imply a central role of the FGF1-FGFR1 signaling pathway. The novel FN1-FGF1 protein is expected to be secreted and serves as a ligand that binds and activates FGFR1 to achieve an autocrine loop. Further study is required to determine the functions of these fusion proteins.