Uterine sarcomas in Norway. A histopathological and prognostic survey of a total population from 1970 to 2000 including 419 patients

Favorable Outcome of High-grade Endometrial Stromal Sarcoma in an Adolescent

High-grade endometrial stromal sarcoma is a rare and aggressive soft tissue tumor characterized by YWHAE::NUTM2A/B translocations, diagnosis at a median of 50-60 years, and a poor prognosis (overall survival 30%-40%). We describe a 16-year-old patient with high-grade endometrial stromal sarcoma and regional nodal and pulmonary metastases who is a long-term survivor after grossly complete tumor resection, intensive chemotherapy, and pelvic radiotherapy. We discovered a previously undescribed YWHAE::NUTM2E translocation in the tumor. Our patient's favorable outcome suggests that intensive multimodality therapy with curative intent is appropriate for young patients with high-grade endometrial stromal sarcoma and highlights the importance of fertility preservation.

Comprehensive Review of Uterine Leiomyosarcoma: Pathogenesis, Diagnosis, Prognosis, and Targeted Therapy

Uterine leiomyosarcoma (uLMS) is the most common subtype of uterine sarcomas. They have a poor prognosis with high rates of recurrence and metastasis. The five-year survival for uLMS patients is between 25 and 76%, with survival rates approaching 10-15% for patients with metastatic disease at the initial diagnosis. Accumulating evidence suggests that several biological pathways are involved in uLMS pathogenesis. Notably, drugs that block abnormal functions of these pathways remarkably improve survival in uLMS patients. However, due to chemotherapy resistance, there remains a need for novel drugs that can target these pathways effectively. In this review article, we provide an overview of the recent progress in ascertaining the biological functions and regulatory mechanisms in uLMS from the perspective of aberrant biological pathways, including DNA repair, immune checkpoint blockade, protein kinase and intracellular signaling pathways, and the hedgehog pathway. We review the emerging role of epigenetics and epitranscriptome in the pathogenesis of uLMS. In addition, we discuss serum markers, artificial intelligence (AI) combined with machine learning, shear wave elastography, current management and medical treatment options, and ongoing clinical trials for patients with uLMS. Comprehensive, integrated, and deeper insights into the pathobiology and underlying molecular mechanisms of uLMS will help develop novel strategies to treat patients with this aggressive tumor.

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.

Uterine Smooth Muscle Tumors: An Overview

Uterine smooth muscle tumors are a heterogeneous group of mesenchymal neoplasms with multiple histologic variants and distinct biological behaviors. Pathologic classification (benign, uncertain malignant potential, malignant) relies on the evaluation of mitotic index, necrosis, and degree of cytologic atypia, with different thresholds based on each subtype. Immunohistochemistry and other ancillary studies may be necessary to establish the diagnosis in a subset of cases, given the morphologic overlap with other mesenchymal neoplasms, including low-grade and high-grade endometrial stromal tumors, inflammatory myofibroblastic tumors, and PEComa. Recent advances in molecular diagnostics have refined the classification of smooth muscle tumors, but most cases are diagnosed purely on histologic grounds.

Prognosis of uterine and extrauterine low-grade endometrial stromal sarcoma: an observational cohort study

OBJECTIVE

Little is known about the survival differences between uterine and extrauterine low-grade endometrial stromal sarcoma (LGESS). Survival outcomes, consisting of disease-free survivals and overall survivals (OS), were compared in these two entities.

METHODS

From February 2012 to June 2019, all primary LGESS cases and LGESS cases with first recurrence in the study center were reviewed. The clinicopathological characteristics and survival outcomes of extrauterine and uterine LGESS patients were compared for both primary and recurrent diseases.

RESULTS

During the study period, 143 patients with primary LGESS and 56 patients with recurrent LGESS were included and followed up to 1 June 2020, among whom 8 (5.6%) and 10 (17.8%) patients were identified as having extrauterine LGESS. Patients with primary and recurrent extrauterine LGESS had similar clinicopathological characteristics to those of patients with uterine LGESS. In primary or in recurrent LGESS cases, in univariate analysis, patients with uterine and extrauterine LGESS had similar disease-free intervals after the last treatment, and they also had similar OSs after the diagnosis. Ovarian preservation led to significantly increased recurrence for primary LGESS [hazard ratio (HR) 4.9, 95% CI: 2.3-10.1, P <0.001) and repeated recurrence for recurrent LGESS (HR 3.1, 95% CI: 1.3-7.3, P =0.009). Surgical treatment for recurrent LGESS decreased repeated recurrence after the first recurrence (HR 0.2, 95% CI: 0.1-0.7, P =0.006). No factors were found to be associated with the OS of primary or recurrent LGESS.

CONCLUSION

The clinical characteristics and survival outcomes of extrauterine LGESS are similar to those of uterine LGESS. Surgery is the treatment of choice for recurrent LGESS. Ovarian preservation is detrimental to disease-free survival but not to OS in both uterine and extrauterine LGESS.

Uterine leiomyosarcoma cell-derived extracellular vesicles induce the formation of cancer-associated fibroblasts

OBJECTIVE

Uterine leiomyosarcoma (ULMS) is a rare malignant tumor, which is aggressive, and has a poor prognosis even during its early stages. Extracellular vesicles (EVs) carry cargo, such as microRNAs (miRNAs), which are involved in intercellular communication in the tumor microenvironment and other processes. Because there are no studies on EV-related miRNAs in ULMS, we identified EV-related miRNAs in ULMS and examined their function.

METHODS

Small EVs (sEVs) and medium/large EVs (m/lEVs) were extracted from ULMS cells by ultracentrifugation and their basic characteristics were evaluated. Then, small RNA sequencing was done to obtain EV-related miRNA profiles. Next, miRNA expression levels in sera and tissues of ULMS patients were compared with those of myoma patients.

RESULTS

miR-654-3p and miR-369-3p were indicated to be highly expressed in both sera and tissues of ULMS patients. These two miRNAs are also highly expressed in ULMS cell lines and ULMS-derived EVs. Some cancer-associated fibroblast (CAF) markers were increased when fibroblasts were treated with ULMS-derived EVs. Furthermore, fibroblasts took up EVs derived from ULMS as determined by confocal laser microscopy. In addition, the transfection of the two candidate miRNAs into fibroblasts significantly increased some CAF markers, particularly ACTA2.

CONCLUSION

miR-654-3p and miR-369-3p are highly expressed in ULMS-derived EVs, indicating that these EV-related miRNAs induce the formation of cancer-associated fibroblasts.

Intravenous metastasis of unexpected uterine sarcoma in the context of uterine fibroids: case report and literature review

Objective

Endometrial stromal tumors are rare and complex mesenchymal tumors that often present with clinical symptoms similar to uterine leiomyomas. Due to their atypical nature, they are prone to be misdiagnosed or overlooked by healthcare professionals. This study presents a case report of an incidentally discovered endometrial stromal sarcoma with venous metastasis, which was initially misdiagnosed as a uterine leiomyoma. In addition, this study reviews previously documented cases of similar tumors.

Case report

During a routine medical examination in 2016, a 50-year-old woman was diagnosed with uterine fibroids. In June 2020, she began experiencing moderate, irregular vaginal bleeding. Nevertheless, a histopathological examination indicated an endometrial stromal sarcoma with a striking amalgamation of both low-grade and high-grade features. Molecular analysis identified a rare MED12 gene mutation. The patient underwent total hysterectomy, bilateral salpingectomy, and resection of the metastatic lesions. Postoperative management included radiotherapy, chemotherapy, and hormone therapy. After completion of chemotherapy, the patient was followed up for 27 months with no evidence of tumor recurrence.

Conclusion

This case report highlights the importance of pathological, immunohistochemical, and molecular aspects of this rare tumor involving the inferior vena cava and showing the presence of atypical gene mutations. The successful treatment outcome further emphasizes the importance of advances in diagnostic modalities for managing rare tumors like this.

Metastatic Uterine Leiomyosarcoma presenting as small bowel intussusception at two independent visits

•Metastatic disease to the small bowel may present with intussusception.•Clinical decision making for malignant bowel obstruction is difficult and individual specific.•Malignant bowel obstruction due to metastatic year has an average life expectancy of less than 200 days.

Treatment patterns and outcomes for primary uterine leiomyosarcoma with synchronous isolated lung metastases: A National Cancer Database study of primary resection and metastasectomy

Background

One third of patients with uterine leiomyosarcomas (uLMS) present with distant metastases. Current guidelines do not include recommendations around surgery for metastatic uLMS. Patients with distant metastases commonly receive primary tumor resection for symptoms and so oncologic outcomes after surgery warrant exploration. We describe treatment patterns and outcomes for uLMS patients with synchronous isolated lung metastases (SILM).

Methods

This retrospective analysis of the National Cancer Database identified patients with uLMS and SILM. Patients with non-pulmonary metastases were excluded. We collected demographic, disease, and treatment characteristics and assessed clinicopathologic factors associated with the receipt of surgery on multivariate regression. Median, 1-year, and 5-year overall survival (OS) across treatment approaches were compared using Kaplan-Meier curves and log-rank tests. Multivariate Cox proportional hazard regressions identified independent predictors of survival.

Results

We identified 905 patients with uLMS and SILM between 2004 and 2017. 600 patients had primary tumor resection; 63 also had curative intent surgery with metastasectomy. Patients who did not receive chemotherapy were older (p<0.01) with a higher comorbidity index (p<0.05). Women with private health insurance were more likely to receive chemotherapy (p<0.01) and primary tumor resection (p<0.01). Patients who underwent curative intent surgery had 1-year OS of 71.2% and 5-year survival of 18% compared to 1-year survival of 35.6 % and 5-year survival of 5.16 % for patients who had no surgery. Black women had poorer survival on multivariate regression.

Conclusions

Primary tumor resection and curative intent surgery are associated with improved OS in uLMS with SILM and may be a reasonable treatment option in appropriately selected patients.

Dedifferentiated Leiomyosarcoma of the Uterine Corpus with Heterologous Component: Clinicopathological Analysis of Five Consecutive Cases from a Single Institution and Comprehensive Literature Review

Dedifferentiation is a very rare phenomenon in uterine leiomyosarcoma (LMS). The aim of this study was to comprehensively analyze the clinicopathological characteristics of uterine dedifferentiated LMS (DDLMS). We reviewed electronic medical records and pathology slides from five patients with uterine DDLMS and performed immunostaining. The mean age of the patients was 56 years. Two patients presented with abdominal discomfort, while in three cases the uterine tumors were detected on routine medical examination. The mean size of the tumors was 17.0 cm. Four patients underwent hysterectomy. The initial stages were distributed as IB (2/5), IIIC (2/5), and IVC (1/5). Post-operative concurrent chemoradiation therapy, radiation therapy, and chemotherapy were administered in one, one, and two patients, respectively. Despite post-operative treatment, three patients developed metastatic recurrences in the abdominal and pelvic organs. Recurrence-free survival time ranged between 4 and 30 months. Histologically, the differentiated areas demonstrated the classic morphology of malignant smooth muscle differentiation, whereas the dedifferentiated areas resembled undifferentiated pleomorphic sarcoma and were characterized by large pleomorphic tumor cells admixed with haphazardly arranged atypical cells with marked nuclear pleomorphism. All cases also exhibited heterologous components, including chondrosarcoma (CSA; 3/5) and rhabdomyosarcoma (2/5). In two cases, the heterologous components were initially detected in primary tumors. In three cases, the primary tumors did not exhibit any dedifferentiated or heterologous components. Instead, more than half of the recurrent tumors consisted of heterologous components. Three cases showed a sharp demarcation between the LMS and CSA components, while in two cases the dedifferentiated area imperceptibly merged with the differentiated component. Immunostaining revealed that the dedifferentiated components exhibited a lack of desmin immunoreactivity in three of the four examined cases. A subset of uterine LMS represents various amounts and types of dedifferentiation and heterologous components in both primary and recurrent tumors. Routine recognition of DDLMS and distinction from its mimickers are required for accurate diagnosis and further characterization of these rare tumors.

Extrauterine Undifferentiated Uterine Sarcoma Arising from Bladder Endometriosis in a Postmenopausal Woman: A Case Report

Endometriosis (EMS) is a rare condition in postmenopausal women. The incidence of transition from EMS to malignancy is as low as 1%, with endometrial stromal tumors (ESTs) occurring at an even lower incidence of 0.7%. Undifferentiated uterine sarcomas (UUSs) are a subtype of ESTs that account for 25% of all ESTs. Extrauterine UUSs are exceptionally rare, with only a few reported cases in the literature. We present the case of a woman who underwent surgery for deep infiltrating EMS and was later diagnosed with UUS, which originated from the bladder after surgical menopause.

Role of radiotherapy in the management of rare gynaecological cancers

There are a large number of gynaecological cancers with rare histologies, for which the available data are limited and usually retrospective. Because of their rarity and poor prognosis, the management of these cancers must be centralized in expert centres, for both histological diagnosis and treatment. With the exception of sarcomas, most endometrial or cervical cancers with rare histologies respond to the same radiation treatment modalities than cancers with more common histologies, although there are some specificities regarding treatments such as neuroendocrine carcinomas (chemotherapy with platinum and etoposide, major role of surgery). For localized or locally advanced ovarian cancer, external beam radiotherapy has a role in the management of hypercalcaemic small cell carcinoma of the ovary. This article summarizes the current role of external beam radiotherapy and brachytherapy in the management of cancers of the uterine cervix, uterine corpus and ovaries, with rare or very rare histologies, and with localized or locally advanced stages.

Prognostic factors in undifferentiated uterine sarcoma: a subanalysis of the SARCUT study

PURPOSE

The aim of this study was to analyze the prognostic factors related to the recurrence rate and overall survival of patients with undifferentiated uterine sarcoma.

METHODS

An international multicenter study involving 43 international centers, the SARCUT study, collected 966 uterine sarcoma cases; among them 39 cases corresponded to undifferentiated uterine sarcoma and where included in the present subanalysis. The risk factors related to the oncological outcomes where analyzed.

RESULTS

The median age of the patients was 63 (range 14-85) years. Seventeen (43.5%) patients presented FIGO stage I. The 5-year overall survival (OS) was 15.3% and 12-months disease-free survival (DFS) 41%. FIGO stage I was significantly associated with a better prognosis. In addition, patients who received adjuvant radiotherapy showed significant longer disease-free survival compared to those without adjuvant radiotherapy (20.5 vs. 4.0 months, respectively; p = 0.04) and longer overall survival (34.7 vs. 18.2 months, respectively; p = 0.05). Chemotherapy administration was associated with shorter DFS (HR 4.41, 95% CI 1.35-14.43, p = 0.014). Persistent disease after primary treatment (HR = 6.86, 95% CI 1.51-31.09, p = 0.012) and FIGO stage IV (HR 4.12, 95%CI 1.37-12.44, p = 0.011) showed significant worse prognosis for OS.

CONCLUSION

FIGO stage seems to be the most important prognostic factor in patients with undifferentiated uterine sarcoma. Adjuvant radiotherapy seems to be significantly associated also to a better disease-free and overall survival. On the contrary, the role of chemotherapy administration remains unclear since was associated to a shorted DFS.

A Rare Case of Uterine Myxoid Leiomyosarcoma

A 49-year-old female patient was referred to a tertiary care hospital with a history of postmenopausal bleeding and abdominal pain that had persisted for the last two months. An abdominal examination revealed a huge mass that had been present for 12 weeks. A fibroid uterus was suggested by USG. A biopsy was done and sent to histopathology which revealed myxoid leiomyoma. Subsequently, the patient underwent total abdominal hysterectomy without bilateral salpingo-oophorectomy. Histopathological examination confirmed the diagnosis of myxoid leiomyosarcoma (MLMS) of the uterus.

[Uterin adenosarcoma: French Guidelines of the French Sarcoma Group and the Rare Gynecologic Tumor Group]

Uterine adenosarcoma is a very rare malignancy defined as a biphasic tumor composed of both benign epithelial component and a malignant sarcoma component. The stage of the disease is determined by the presence of myometrial invasion and the extent of extra-uterine disease. The most important histopronostic factors are the existence of a sarcomatous overgrowth defined by a sarcomatous contingent occupying more than 25 % of the volume of the tumor (directly correlated to the grade of the disease), the presence of a heterologous and/or a high-grade component. Stage I adenosarcomas without sarcomatous overgrowth have a good prognosis, with an overall 5-year survival of up to 80 %. In localized disease, complete surgical removal is recommended. The role of hormone therapy, chemotherapy and adjuvant radiotherapy is not established. If possible, relapses should be re-treated surgically, with the aim of achieving complete resection. In the advanced inoperable or metastatic setting, hormone therapy is an option for low-grade adenosarcomas with estrogen receptor (ER) and progesterone receptor (PR) overexpression. For high-grade tumors, the standard chemotherapies are doxorubicin-based combinations, although an integrated approach of surgery and medical treatment should also be considered in this setting.

Prognostic factors in patients with uterine sarcoma: the SARCUT study

OBJECTIVE

Uterine sarcomas are a rare and heterogeneous group of malignancies that include different histological sub-types. The aim of this study was to identify and evaluate the impact of the different prognostic factors on overall survival and disease-free survival of patients with uterine sarcoma.

METHODS

This international multicenter retrospective study included 683 patients diagnosed with uterine sarcoma at 46 different institutions between January 2001 and December 2007.

RESULTS

The 5-year overall survival for leiomyosarcoma, endometrial stromal sarcoma, undifferentiated sarcoma, and adenosarcoma was 65.3%, 78.3%, 52.4%, and 89.5%, respectively, and the 5-year disease-free survival was 54.3%, 68.1%, 40.3%, and 85.3%, respectively. The 10-year overall survival for leiomyosarcoma, endometrial stromal sarcoma, undifferentiated sarcoma and adenosarcoma was 52.6%, 64.8%, 52.4%, and 79.5%, respectively, and the 10-year disease-free survival was 44.7%, 53.3%, 40.3%, and 77.5%, respectively. The most significant factor associated with overall survival in all types of sarcoma except for adenosarcoma was the presence of residual disease after primary treatment. In adenosarcoma, disease stage at diagnosis was the most important factor (hazard ratio 17.7; 95% CI 2.86 to 109.93).

CONCLUSION

Incomplete cytoreduction, tumor persistence, advanced stage, extra-uterine and tumor margin involvement, and the presence of necrosis were relevant prognostic factors significantly affecting overall survival in uterine sarcoma. The presence of lymph vascular space involvement and administration of adjuvant chemotherapy were significantly associated with a higher risk of relapse.

Endometrial stromal tumors of the uterus: Epidemiology, pathological and biological features, treatment options and clinical outcomes

Endometrial stromal tumors (EST) are uterine mesenchymal tumors, which histologically resemble endometrial stroma of the functioning endometrium. The majority of EST are malignant tumors classified as low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), and undifferentiated uterine sarcoma (UUS). Overall, ESTs are rare malignancies, with an annual incidence of approximately 0.30 per 100'000 women, mainly affecting peri- or postmenopausal women. The most common genetic alteration identified in LG-ESS is the JAZF1-SUZ12 rearrangement, while t(10;17)(q23,p13) translocation and BCOR gene abnormalities characterize two major subtypes of HG-ESS. The absence of specific genetic abnormalities is the actual hallmark of UUS. Unlike HG-ESSs, LG-ESSs usually express estrogen and progesterone receptors. Total hysterectomy without morcellation and bilateral salpingo-oophorectomy (BSO) is the first-line treatment of early-stage LG-ESS. Ovarian preservation, fertility-sparing treatment, and adjuvant hormonal therapy ± radiotherapy may be an option in selected cases. In advanced or recurrent LG-ESS, surgical cytoreduction followed by hormonal treatment, or vice versa, are acceptable treatments. The standard treatment for apparently early-stage HG-ESS and UUS is total hysterectomy without morcellation with BSO. Ovarian preservation and adjuvant chemotherapy ± radiotherapy may be an option. In advanced or recurrent HG-ESS, surgical cytoreduction and neoadjuvant or adjuvant chemotherapy can be considered. Alternative treatments, including biological agents and immunotherapy, are under investigation. LG-ESSs are indolent tumor with a 5-year overall survival (OS) of 80-100% and present as stage I-II at diagnosis in two third of patients. HG-ESSs carry a poor prognosis, with a median OS ranging from 11 to 24 months, and 70% of patients are in stage III-IV at presentation. UUS median OS ranges from 12 to 23 months and, at diagnosis, 70% of patients are in stage III-IV. The aim of this review is to assess the clinical, pathological, and biological features and the therapeutic options for malignant ESTs.

Sarcomes du stroma endométrial de bas grade : référentiels de prise en charge du GSF-GETO/NETSARC+ et du groupe TMRG

Low-grade endometrial stromal sarcoma (LG-ESS) accounts for approximately 15% of all uterine sarcomas. Median age of patients is around 50 years and half of the patients are premenopausal. In all, 60% of cases present with FIGO stage I disease. Preoperatively radiologic findings of ESS are not specific. Pathological diagnosis remains essential. This review aimed to present the French guidelines for low grade ESS treatment within the Groupe sarcome français - Groupe d'étude des tumeurs osseuse (GSF-GETO)/NETSARC+ and tumeur maligne rare gynécologique (TMRG) networks. Treatments should be validated in multidisciplinary team involved in sarcomas or rare gynecologic tumors. Hysterectomy is the cornerstone of treatment for localized ESS, and morcellation should be avoided. Systematic lymphadenectomy in ESS does not improve the outcome and is not recommended. Leaving the ovaries in situ in stage I tumors could be discussed for young women. Adjuvant hormonal treatment could be considered, for two years for stage I with morcellation or stage II and livelong for stages III or IV. Nevertheless, several questions remain, such as optimal doses, regimens (progestins or aromatase inhibitors) and duration of therapy. Tamoxifen is contraindicated. Secondary cytoreductive surgery if feasible for recurrent disease, appears to be an acceptable approach. Systemic treatment for recurrent or metastatic disease is mainly hormonal, with or without surgery.

Novel therapeutic strategies targeting UCP2 in uterine leiomyosarcoma

Uterine leiomyosarcoma (ULMS) is a malignant stromal tumor arising from the myometrium with a poor prognosis and very limited response to current chemotherapy. This study aimed to identify novel targets for ULMS through a three-step screening process using a chemical library consisting of 1271 Food and Drug Administration-approved drugs. First, we evaluated their inhibitory effects on ULMS cells and identified four candidates: proscillaridin A, lanatoside C, floxuridine, and digoxin. Then, we subcutaneously or orthotopically transplanted SK-UT-1 cells into mice to establish mouse models. In vivo analyses showed that proscillaridin A and lanatoside C exerted a superior antitumor effect. The results of mRNA sequencing showed that uncoupling protein 2 (UCP2) was suppressed in the sirtuin signaling pathway, increasing reactive oxygen species (ROS) and inducing cell death. Moreover, the downregulation of UCP2 induced ROS and suppressed ULMS cell growth. Furthermore, analyses using clinical samples showed that UCP2 expression was significantly upregulated in ULMS tissues than in myoma tissues both at the RNA and protein levels. These findings suggested that UCP2 is a potential therapeutic target and can contribute to the development of novel therapeutic strategies in patients with ULMS.

Expanding the molecular spectrum of gene fusions in endometrial stromal sarcoma: Novel subunits of the chromatin remodeling complexes PRC2 and NuA4/TIP60 as alternative fusion partners

Endometrial stromal sarcomas (ESS) are morphologically and molecularly heterogeneous. We report novel gene fusions (EPC1::EED, EPC1::EZH2, ING3::PHF1) identified by targeted RNA sequencing in five cases. The ING3::PHF1-fusion positive ESS presented in a 58-year-old female as extrauterine mesocolonic, ovarian masses, and displayed large, monomorphic ovoid-to-epithelioid cells arranged in solid sheets. The patient remained alive with disease 13 months after surgery. The three ESS with EPC1::EED occurred in the uterine corpus in patients with a median age of 58 years (range 27-62 years). One tumor showed a uniform epithelioid nested morphology, while the other two were composed of monomorphic spindle cells in fascicles with elevated mitotic figures, focal tumor cell necrosis, and lymphovascular invasion. At a median follow-up of 20 months, two patients developed local recurrence, including one with concomitant distant metastasis, while one patient remained free of disease. All three patients were alive at the last follow-up. The EPC1::EZH2-fusion positive ESS presented in a 52-year-old female in the uterus, and displayed uniform spindled cells arranged in short fascicles, with focally elevated mitotic activity but without necrosis. The patient remained free of disease 3 months after surgery. All cases were diffusely positive for CD10; four diffusely express estrogen and progesterone receptors. Our study expands the molecular spectrum of EPC1 and PHF1-related gene fusions in ESS to include additional novel subunits of the PRC2 and/or NuA4/TIP60 complexes. These cases displayed a monomorphic epithelioid or spindled phenotype, spanning low-grade and high-grade cytomorphology, all expressing CD10 and commonly ER and PR, and are prone to local and/or distant spread.

Fumarate Hydratase and S-(2-Succinyl)-Cysteine Immunohistochemistry Shows Evidence of Fumarate Hydratase Deficiency in 2% of Uterine Leiomyosarcomas: A Cohort Study of 348 Tumors

Approximately 1% to 1.5% of uterine leiomyomas are fumarate hydratase (FH)-deficient (FHd). A subset of these are associated with germline FH mutations. However, the prevalence and clinicopathologic characteristics of FHd uterine leiomyosarcoma (uLMS) remain unknown. Clinicopathologic data were collected for 348 uLMS. Morphologic features associated with FH deficiency (staghorn-type vessels, alveolar-pattern edema, macronucleoli with perinucleolar clearing, eosinophilic cytoplasmic inclusions, and chain-like nuclear arrangement) were documented. All 348 tumors were studied by FH immunohistochemistry. Eighty-nine were also studied by S-(2-succinyl)-cysteine (2SC) immunohistochemistry. Seven (2%) FHd uLMS were identified. Five showed uniformly negative FH and diffusely positive 2SC immunostaining; 1 showed variably negative to weak to strong FH and diffusely positive 2SC immunostaining; and 1 showed retained FH staining alongside positive 2SC confined to a morphologically distinct subclone. Three of 7 patients had extrauterine disease at presentation, and 3 of 6 had persistent disease or died from disease. Macronucleoli with perinucleolar clearing were significantly more common in FHd uLMS (7/7) than in uLMS with retained FH (182/341; P =0.017). Disease-specific survival, disease-free survival, and other morphologic features of FH deficiency did not differ significantly between FHd and FH-retained tumors. Our data emphasize that immunohistochemical FH deficiency does not preclude malignancy in uterine smooth muscle tumors. However, the biological significance and molecular basis of FH deficiency in uLMS, including any relationship to germline FH mutation, remain unknown, and a larger multi-institutional effort is necessary to gather sufficient FHd uLMS for more robustly powered clinicopathologic and for molecular characterization.

Dedifferentiated leiomyosarcoma of the uterus: a clinicopathologic and immunohistochemical analysis of 23 cases

AIMS

To morphologically and immunophenotypically characterize dedifferentiated uterine leiomyosarcoma (LMS).

METHODS AND RESULTS

We identified 23 dedifferentiated uterine LMS, defined as a malignant uterine smooth muscle tumour containing discrete differentiated and dedifferentiated components (i.e. with and without morphologic and immunophenotypic evidence of smooth muscle differentiation, respectively). The differentiated component was leiomyosarcoma in most cases (17/23), though some arose from a leiomyoma (n = 4) or smooth muscle tumour of uncertain malignant potential (n = 2). The dedifferentiated tumour component showed noncohesive polygonal cells with moderate to abundant cytoplasm, pleomorphic nuclei with coarse vesicular to smudged chromatin, one or more macronucleoli, frequent multinucleation, and atypical mitoses. Three cases showed heterologous osteosarcomatous or chondrosarcomatous differentiation. Immunohistochemistry revealed alterations characteristic of uterine LMS, including Rb loss (18/19); strong diffuse p16 (17/19); strong diffuse (9/19) or complete absence of (5/19) p53; and ATRX loss (6/16). Compared to a control cohort of uterine LMS without dedifferentiation, dedifferentiated uterine LMS showed significantly shorter disease-specific (median, 54 versus 20 months; 5-year DSS, 46% versus 36%; P = 0.04) and disease-free (median, 31 versus 8 months; 5-year DFS, 42% versus 8%; P = 0.002) survival. Of 19 dedifferentiated uterine LMS with follow-up, 12 had died of disease at median 14 (range, 2-73) months; four were alive with disease at 4, 12, 44, and 50 months; and three were alive with no evidence of disease at 56, 109, and 114 months.

CONCLUSION

Routine prospective recognition of dedifferentiated uterine LMS and distinction from mimics is advocated for accurate prognostication and for further characterisation of these tumours.

TEM1 up-regulates MMP-2 and promotes ECM remodeling for facilitating invasion and migration of uterine sarcoma

OBJECTIVES

To explore the correlation between tumor endothelial marker 1 (TEM1) and matrix metalloproteinase 2 (MMP-2) in uterine sarcoma and their roles in the progression of uterine sarcoma.

METHODS

Uterine leiomyosarcoma (uLMS, n = 25) and uterine leiomyoma (n = 25) specimens were collected from a total of 50 patients. Immunohistochemistry assay was conducted to determine the expression of TEM1, MMP-2 and MMP-9. TEM1 over expression (hTEM1) and low expression (shRNA-TEM1) MES-SA cell lines were established as in vitro uterine sarcoma models. MMP-2 mRNA, protein expression and enzymatic activity were verified using qPCR, Western blot and gelatin zymography respectively. MMP-2 expression was downregulated using MMP-2 siRNA in hTEM1 MES-SA cells to better study the role of MMP-2. The invasive and migratory capacities of hTEM1, shRNA-TEM1, and hTEM1 treated with MMP-2 siRNA MES-SA cells were determined using transwell assays. Extracellular matrix (ECM) remodeling mediated by TEM1 was examined using cell-ECM adhesion and fluorescent gelatin-ECM degradation assays. The immunofluorescence of F-actin was examined to analyze the formation of invadopodia. Subcutaneous and intraperitoneal xenografts were established to validate the role of TEM1 in promoting uterine sarcoma metastasis.

RESULTS

TEM1 and MMP-2 were expressed in 92% (n = 23) and 88% (n = 22) of uterine leiomyosarcoma specimens, respectively. Both TEM1 and MMP-2 were highly expressed in 100% (n = 17) of high stage (III-IV) uterine leiomyosarcoma specimens. In addition, TEM1 expression was positively correlated with MMP-2 expression in uterine leiomyosarcoma. The successful establishment of in vitro uterine sarcoma models was confirmed with qPCR and Western blotting tests. TEM1 promoted the invasion and metastasis of uterine sarcoma in vivo and in vitro. MMP-2 expression and activity were up-regulated in hTEM1 cells but down-regulated in shRNA-TEM1 cells. Importantly, MMP-2 knockdown impaired the invasive and migratory capacity of hTEM1 cells. TEM1 promoted ECM remodeling by increasing cell-ECM adhesion and ECM degradation. TEM1 overexpression also induced the formation of invadopodia.

CONCLUSION

TEM1 was co-expressed and positively correlated with MMP-2 in uterine leiomyosarcoma specimens. In addition, both TEM1 and MMP-2 were associated with tumor development. TEM1 promoted uterine sarcoma progression by regulating MMP-2 activity and ECM remodeling.

Clinical Analysis and Prognostic Prediction Model for Patients with Uterine Leiomyosarcoma at FIGO Stage I

Purpose

To reveal the clinical status and construct a predictive prognostic model for patients with uterine leiomyosarcoma (uLMS) at International Federation of Gynecology and Obstetrics (FIGO) stage I.

Patients and Methods

The medical records of patients with stage I uLMS during the study period were retrospectively reviewed. Multiple imputation, Martingale residuals and restricted cubic spline were used for data processing. Univariate and multivariate analyses were used to determine independent prognostic factors. The Schoenfeld individual test was used to verify the proportional hazards (PH) assumption. The predictive ability of the nomogram was validated internally.

Results

Ultimately, 102 patients were included. The median age at diagnosis was 51 years old. During the medium follow-up time of 68 months, 55 (53.9%) patients developed recurrence. The median recurrence interval was 32 months. The most common metastatic site was the lung (27 cases). Eventually, 38 (37.3%) patients died of uLMS. The 3-year and 5-year overall survival rates were 66.0% and 52.0%, respectively. Age at diagnosis >49 years, larger tumor size, MI>10/10HPF, presence of LVSI and Ki-67 labeling index (LI) >25% (P=0.0467, 0.0077, 0.0475, 0.0294, and 0.0427, respectively) were independent prognostic factors. The PH assumption remained inviolate. The concordance index was 0.847, the area under the time-dependent receiver operating characteristic curve surpassed 0.7, and the calibration curve showed gratifying consistency.

Conclusion

Age at diagnosis, tumor size, MI, LVSI, and Ki-67 LI were identified as independent prognostic factors for stage I uLMS. This prognostic nomogram would provide personalized assessment with superior predictive performance.

Loss of dystrophin is common in uterine leiomyosarcoma: a potential biomarker for clinical application

Uterine leiomyosarcoma (LMS) is a deadly disease with high rates of recurrence and a poor prognosis. Its tumorigenesis remains largely unknown, and no specific biomarkers can be used for the differential diagnosis of LMS from other mimics. Recent whole-genome studies revealed a loss of dystrophin is common in LMS, especially in uterine LMS. To investigate the expression pattern of dystrophin expression across different types of uterine smooth muscle tumors, immunohistochemistry was performed, including usual-type leiomyoma, fumarate hydratase-deficient leiomyoma, leiomyoma with bizarre nuclei, conventional LMS, and normal myometrium for this study. To further evaluate the genomic change in dystrophin gene region, whole-genome sequencing in 10 LMS cases were analyzed. Dystrophin expression was detected in 94% (45/48) of myometrium, 97% (34/35) of usual-type leiomyoma, 84% (26/31) of fumarate hydratase-deficient leiomyoma, 60% (12/20) of leiomyoma with bizarre nuclei, and 18% (6/34) of LMS. Loss of dystrophin expression was significantly different between benign and malignant tumors (LMS cases counted as malignant only) (p < 0.01). Of note, copy number loss in the dystrophin genomic region was found in all 10 cases of LMS. Additionally, patients with dystrophin-positive LMS tend to have a better overall survival than patients with dystrophin-negative LMS.

An Extremely Rare Case of Disseminated Peritoneal Leiomyomatosis with a Pelvic Leiomyosarcoma and Omental Metastasis after Laparoscopic Morcellation: Systematic Review of the Literature

Minimally invasive treatment of uterine fibroids usually requires a power morcellation, which could be associated with several complications. A rare sequela is disseminated peritoneal leiomyomatosis. Indeed, recurrence or metastasis in these cases could be attributed to iatrogenic or under-evaluation of primary tumors, although a subset of cases is a sporadic sample of biological progression. We present an extremely rare case of a patient who underwent laparoscopic morcellation and after 12 years developed a pelvic leiomyosarcoma with two omental metastases, disseminated peritoneal leiomyomatosis with a parasite leiomyoma with bizarre nuclei and a parasite cellular leiomyoma simultaneously. The diagnosis was predicted preoperatively by an expert sonographer who recognized the ultrasound characteristics of uterine sarcoma and the localization of some of the masses, so the patient was referred to the gynaecological oncologists who could appropriately treat her. We present here a case report and a systematic review that could be a useful tool for further discussion and future clinical practice guidelines.

Leiomyoma with Bizarre Nuclei: A Current Update

Leiomyoma with bizarre nuclei (LBN), also known as symplastic leiomyoma, is a histological subtype of benign leiomyoma with bizarre cells and nuclear atypia. Differentiating LBN from other benign leiomyoma subtypes, uterine smooth muscle tumors of uncertain malignant potential (STUMP), or leiomyosarcoma (LMS) can be diagnostically challenging owing to overlapping features in clinical presentation and pathologic morphological analysis. The difficulty of distinguishing LBN from other lesions, especially from LMS, and the potential of LBN for subsequent malignant transformation make LBN an important topic of research. Herein, we review the definition, diagnosis, treatment, and prognosis of LBN. Histopathological examination is essential for distinguishing LBN from other diseases. Pathology sampling and morphological examination remain the key to diagnosis. The newly established ancillary immunohistochemical (IHC) and molecular genetic analysis can be useful tools for differential diagnosis. Furthermore, serum biomarkers and imaging examination may also be useful diagnostic tools. Attention should be paid to the differentiation between LBN and LMS because morphological diagnosis may still be challenging in some cases. Some IHC markers of LBN have been identified, which may be helpful for differential diagnosis. Furthermore, the use of IHC panels as diagnostic markers may be advocated. Molecular genetic studies suggest that some genes can aid with the differential diagnosis between LBN and LMS. However, increasing evidence support the idea that LBN and LMS are molecularly related, indicating that LBN may represent a potentially malignant stage of precancerous progression. At present, conservative treatment is recommended for primary LBN, especially for patients desiring to retain fertility, but close follow-up with imaging examinations is required.

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.

Clinical characteristics and prognosis analysis of uterine sarcoma: a single-institution retrospective study

Background

Uterine sarcomas are rare and aggressive gynaecologic malignancies, characterized by a relatively high recurrence rate and poor prognosis. The aim of this study was to investigate the clinicopathological features and explore the prognostic factors of these malignancies.

Methods

This was a single-institution, retrospective study. We reviewed the medical records of 155 patients with pathologically confirmed uterine sarcomas including uterine leiomyosarcoma (ULMS), low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), undifferentiated uterine sarcoma (UUS) and adenosarcoma (AS) between 2006 and 2022. A total of 112 patients who underwent surgery between January 2006 and April 2019 were included in the survival analysis. The current study recorded the clinicopathological, treatment and outcome data to determine clinical characteristics and survival.

Results

The most common histopathological type was ULMS (63/155, 40.64%), followed by LG-ESS (56/155, 36.13%) and HG-ESS (16/155, 10.32%). The mean age at diagnosis of all patients was 49.27±48.50 years and 32.90% (51/155) of patients were postmenopausal. Fifteen patients underwent fast-frozen sectioning, 63(54.78%) were diagnosed with malignancy, 29(25.22%) were highly suspected of malignancy that needed further clarification and 23(14.84%) were diagnosed with benign disease. A total of 124(80%) patients underwent total hysterectomy (TH) and salpingo-oophorectomy. Multivariate analyses showed that histological type and tumour size were independent prognostic factors both for overall survival (OS) (p<0.001 and P=0.017, respectively) and progression-free survival (PFS) (p<0.001 and P=0.018, respectively). Tumour stage was only significantly associated with PFS (P=0.002). Elevated preoperative NLR, PLR and postmenopausal status were significantly correlated with shorter PFS and OS in univariate analysis, but no statistically significant difference was found in multivariate analysis.

Conclusions

In patients with uterine sarcoma, in comparison to LMS and LG-ESS, UUS and HG-ESS tend to present as more aggressive tumour with poorer outcomes. Furthermore, larger tumour (>7.5 cm) were an important predictor of shorter PFS and OS.

Epithelioid Leiomyosarcoma of the Uterus and the Diagnostic Challenge in Diagnosing it on Small Biopsy

Epithelioid leiomyosarcoma of the uterus is a rare soft-tissue tumor of the pelvis with <1% cases. It can be asymptomatic or can reach an enormous size, resulting in chronic pelvic pain, postmenopausal bleeding, or may cause bowel and bladder dysfunction. The diagnostic dilemma arises especially when they have epithelioid morphology. This case is being presented because of its rare incidence along with the diagnostic dilemma it presented due to epithelioid morphology which is a very rare presentation, especially challenging on small biopsies. This case also highlights the usefulness of immunohistochemical markers, such as WT1, p53, and p16, which has important diagnostic as well as prognostic values in rare variants of usual tumors. Leiomyosarcoma per se is a highly aggressive tumor, therefore, timely diagnosis and management are advised.

Low-Grade Uterine Endometrial Stromal Sarcoma: Prognostic Analysis of Clinico-Pathological Characteristics, Surgical Management, and Adjuvant Treatments. Experience From Two Referral Centers

Objective

Low-grade uterine endometrial stromal sarcoma (LG-ESS) is a rare tumor characterized by an overall good survival but showing a indolent behavior and a variable risk of recurrence. There is no clear consensus on the optimal management of these tumors and no prognostic or predictive factors have been established. With this study, we evaluated the prognostic relevance of several clinical, surgical, and pathological features in patients affected by LG-ESS to identify risk factors associated with recurrence.

Methods

We retrospectively analyzed 52 LG-ESS cases, treated from January 1st, 1994, to May 31st, 2020, in two referral centers. The relationship between recurrence and clinicopathological characteristics as well as surgical treatment was investigated. Risk of recurrence and disease-free survival (DFS) were estimated by Cox regression and the Kaplan-Meier analysis, respectively.

Results

Of 52 patients with LG-ESS, 8 experienced recurrence (15%). The median follow-up was 100 months (SD ± 96, range: 15–336). By univariate analysis, fragmentation/morcellation, tumor size, FIGO stage, higher mitotic count, presence of necrosis, and lymphovascular space invasion (LSVI) resulted associated with a poorer outcome. Conversely, the surgical modality (laparotomic vs laparoscopic and hysterectomy with bilateral salpingo-oophorectomy vs local excision) and pelvic lymphadenectomy were not. Even the different modalities of adjuvant therapy (hormonal therapy, radiotherapy, and chemotherapy) showed no prognostic significance. Tumor fragmentation/morcellation and higher mitotic count resulted independent prognostic variables at multivariate analysis.

Conclusions

This data supports the avoidance of any type of morcellation if LG-ESS is suspected preoperatively. Higher mitotic count and, possibly, tumor size, advanced FIGO stage, necrosis, and LVSI could be exploited to tailor the adjuvant therapy, but these results need to be confirmed in larger prospective studies.

A novel morphology-based risk stratification model for stage I uterine leiomyosarcoma: an analysis of 203 cases

Uterine leiomyosarcoma is the most common uterine mesenchymal malignancy. The majority present at stage I, and clinical outcomes vary widely. However, no widely accepted risk stratification system for stage I uterine leiomyosarcoma is currently available. We studied 17 routinely evaluated clinicopathologic parameters in 203 stage I uterine leiomyosarcoma from three institutions to generate a novel risk stratification model for these tumors. Mitoses >25 per 2.4 mm2 (10 high-power fields), atypical mitoses, coagulative necrosis, lymphovascular invasion, and serosal abutment were significantly associated with disease-free and disease-specific survival in univariate and multivariate analyses. These prognostic parameters were each scored as binary ("yes" or "no") variables and fitted to a single optimized algebraic risk model:Risk score = (coagulative necrosis)(1) + (mitoses > 25 per 2.4 mm2)(2) + (atypical mitoses)(2) + (lymphovascular invasion)(3) + (serosal abutment)(5)By logistic regression, the risk model was significantly associated with 5-year disease-free (AUC = 0.9270) and 5-year disease-specific survival (AUC = 0.8517). Internal and external validation substantiated the model. The continuous score (range, 0-13) was optimally divided into 3 risk groups with distinct 5-year disease-free and disease-specific survival: low risk (0-2 points), intermediate risk (3-5 points), and high risk (6-13 points) groups. Our novel risk model performed significantly better than alternative uterine leiomyosarcoma risk stratification systems in predicting 5-year disease-free and disease-specific survival in stage I tumors. A simplified risk model, omitting terms for serosal abutment and lymphovascular invasion, can be accurately applied to myomectomy or morcellated specimens. We advocate routine application of this novel risk model in stage I uterine leiomyosarcoma to facilitate patient counseling and proper risk stratification for clinical trials.

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.

Aberrant Activation of Cell-Cycle-Related Kinases and the Potential Therapeutic Impact of PLK1 or CHEK1 Inhibition in Uterine Leiomyosarcoma

PURPOSE

Uterine leiomyosarcoma is among the most aggressive gynecological malignancies. No effective treatment strategies have been established. This study aimed to identify novel therapeutic targets for uterine leiomyosarcoma based on transcriptome analysis and assess the preclinical efficacy of novel drug candidates.

EXPERIMENTAL DESIGN

Transcriptome analysis was performed using fresh-frozen samples of six uterine leiomyosarcomas and three myomas. The Ingenuity Pathway Analysis (IPA) was used to identify potential therapeutic target genes for uterine leiomyosarcoma. Afterward, our results were validated using three independent datasets, including 40 uterine leiomyosarcomas. Then, the inhibitory effects of several selective inhibitors for the candidate genes were examined using SK-UT-1, SK-LMS-1, and SKN cell lines.

RESULTS

We identified 512 considerably dysregulated genes in uterine leiomyosarcoma compared with myoma. The IPA revealed that the function of several genes, including CHEK1 and PLK1, were predicted to be activated in uterine leiomyosarcoma. Through an in vitro drug screening, PLK1 or CHEK1 inhibitors (BI-2536 or prexasertib) were found to exert a superior anticancer effect against cell lines at low nanomolar concentrations and induce cell-cycle arrest. In SK-UT-1 tumor-bearing mice, BI-2536 monotherapy remarkably suppressed tumorigenicity. Moreover, the prexasertib and cisplatin combination therapy inhibited tumor proliferation and prolonged the time to tumor progression.

CONCLUSIONS

We identified upregulated expressions of PLK1 and CHEK1; their kinase activity was activated in uterine leiomyosarcoma. BI-2536 and prexasertib demonstrated a significant anticancer effect. Therefore, cell-cycle-related kinases may present a promising therapeutic strategy for the treatment of uterine leiomyosarcoma.

Presentation, management and outcome of primary leiomyosarcoma of the spine: A systematic review

OBJECTIVE

Primary spinal leiomyosarcoma (PSL) is extremely rare. A case is presented, followed by a systematic review establishing the consensus on presentation, diagnosis, management and outcomes. Comparison being made with metastatic spinal leiomyosarcoma (MSL).

METHODS

A systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligibility criteria was decided upon before the literature search was conducted. Data were extracted and analysed.

RESULTS

397 articles were identified, 25 articles conformed to the eligibility criteria. 34 cases were included in the analysis. PSL had a female preponderance (69.2%) with back pain being the most common presenting symptom (60.9%). Neurological signs were present in the majority (69.6%) with tumours typically being in the thoracic spine (46.9%). Diagnosis was primarily made using MRI (64.7%) and CT (55.9%), with a histological sample being obtained in all cases. Most patients underwent operative management (91.2%) with variable use of neoadjuvant and adjuvant therapies. Operative approach differed greatly and outcome following surgical management was stated in 48.4% of cases, all noting an improvement from presentation. Patient follow up was limited (median 7 months), with the majority of patients being free of disease (43.8%).

CONCLUSIONS

PSL diagnosis is challenging with PET-CT and histopathological sampling playing an important role. There is a limited evidence base for the treatment strategies employed but surgical management is key with generally good outcomes. Prognosis for PSL would appear to be better than MSL. There is scope for more dedicated research in PSL and MSL.

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.

Novel Therapeutics in the Treatment of Uterine Sarcoma

Uterine sarcomas reflect the diversity of sarcoma as a whole. The most common histologies include leiomyosarcoma, high- and low-grade endometrial stromal sarcoma, and adenosarcoma. These are clinically and biologically heterogeneous diseases that are challenging to treat in the advanced setting. Recent advances in our understanding of the cancer biology of uterine sarcomas has improved diagnostic evaluation and therapeutic management. Promising approaches for patients with advanced uterine leiomyosarcoma include targeting DNA damage repair pathways and depleting immunosuppressive macrophage populations. A subset of endometrial stromal sarcomas harbor potentially actionable alterations in the Wnt, cyclin D-CDK4/6-Rb, and MDM2-p53 pathways. There remains an urgent need to translate molecular findings into prospective clinical trials of novel agents for patients with these diseases; progress will depend on academic collaborations and enrollment of patients with uterine sarcoma in biomarker-driven basket studies.

Evaluating the role of aromatase inhibitors in the treatment of low-grade endometrial stromal sarcomas

•

AIs may offer prolonged disease stability even in metastatic ESS, but response rates are modest.

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After disease progression on one AI, some patients may benefit from trial of a different AI.

•

Optimal duration of therapy is unclear; results of a phase 2 study on interruption vs maintenance of AI in LGESS are awaited.

Objectives

Endometrial stromal sarcomas (ESS) are rare, accounting for < 1% of all uterine malignancies. Treatment has been guided by small case series and retrospective studies. Endocrine therapy is used in both adjuvant and metastatic settings. Aromatase inhibitors (AIs) are widely used in clinical practice. We sought to evaluate clinical outcomes of AI use in the largest cohort of patients with LGESS to date.

Methods

We performed a retrospective study of patients with LGESS treated with an AI at our institution from 1/1998–12/2020. Response was evaluated using RECIST 1.1. The Kaplan-Meier method was used to estimate median progression-free (PFS) and overall (OS) survival.

Results

Forty patients were identified. Treatment was well tolerated, with 57.5% experiencing adverse effects. The most common were arthralgias (12 patients, 30%) and hot flashes (9, 22.5%). Two of 11 patients with RECIST-evaluable imaging experienced a partial response to treatment. Median PFS for the entire cohort was 79.2 months (95% CI 39.7 months to NE); the 5-year PFS rate was 59.6% (95% CI 41.8% to 73.6, p = 0.065). Median follow-up for the 29 survivors was 97.9 months (range: 12.6–226.7). The 5-year OS rate was 81.5% (95% CI 64.9–90.7%). One patient who discontinued AI after 10 years of treatment recurred 1 year later.

Conclusion

AIs were well tolerated and offered periods of prolonged disease stability, even in the metastatic setting. Our study suggests, however, that response rates may be lower than previously reported. Data on optimal duration of treatment is needed, but the rarity of LGESS is an obstacle to conducting large clinical trials.

Retrospective analysis of adjuvant treatment for localized, operable uterine leiomyosarcoma

OBJECTIVE

Currently, there is no standard adjuvant treatment protocol for localized uterine leiomyosarcoma (uLMS) as clinical trials to address this question have been retrospective, underpowered, or undermined by slow accrual rates. The aim of this study is to determine the benefit of adjuvant chemotherapy for uLMS.

METHODS

We reviewed the medical records of localized uLMS patients who had underwent adjuvant therapy after upfront surgery between 2000 and 2020. The cases were blinded for review. We evaluated the influence of various clinical characteristics and different types of adjuvant therapies on specific outcomes.

RESULTS

Sixty-eight patients (median age: 50 years) were included for analysis. Forty of 68 (58.8%) patients received adjuvant chemotherapy +/- radiation therapy and 25 patients (38.6%) did not receive any adjuvant therapy. At a median follow-up time of 43.3 months, 45 patients (66.1%) had relapsed disease. The median disease-free survival (mDFS) for all patients was 23.1 months. Patients who received any adjuvant treatment (chemotherapy and/or radiation) trended toward a longer mDFS compared with those who did not receive any adjuvant therapy (29.7 vs. 14.1 months, p = 0.26). Patients who received adjuvant chemotherapy alone had a longer, but nonstatistically significant mDFS compared with those who did not receive any adjuvant treatment (22.2 vs. 14.1 months, p = 0.18). Additionally, univariate analysis found that tumor size large than 10 cm, and a mitotic rate >10/10hpf were independent prognostic factors for worse DFS.

CONCLUSIONS

Though DFS was more favorable among those who received adjuvant therapy, it was not statistically significant, and thus based on this data adjuvant therapy for resected uLMS is still in question.

Adjuvant radiotherapy shows benefit in selected stage I uterine sarcoma: A risk scoring system based on a population analysis

Background

The potential therapeutic benefit of adjuvant radiotherapy for patients with stage I uterine sarcoma has not been clear. In this study, we aimed to develop a risk scoring model to select the subgroup of patients with stage I uterine sarcoma who might benefit from adjuvant radiotherapy.

Methods

Patients with stage I uterine sarcoma from the Surveillance, Epidemiology, and End Results program from 2010 to 2014 were retrospectively included in this analysis. Cox proportional hazards models were performed to identify risk factors.

Results

A total of 947 stage I uterine sarcoma patients were included. The 5‐year disease‐specific survival (DSS) of the overall cohort was 75.81%. Multivariate analysis identified stage (p = 0.013), tumor grade (p <0.001) and histology (p = 0.043) as independent prognostic factors for DSS, and these factors were used to generate the risk scoring model. The low‐risk group presented a better DSS than the high‐risk group (95.51% vs. 49.88%, p < 0.001). The addition of radiotherapy to surgery significantly increased the DSS in the high‐risk group compared with surgery alone (78.06% vs. 46.88%, p = 0.022), but no significant survival benefit was observed in the low‐risk group (98.36% vs. 100%, p = 0.766).

Conclusions

Our risk scoring model based on stage, tumor grade, and histology predicted the outcome of patients with stage I uterine sarcoma cancer. This system may help to select stage I uterine sarcoma cancer patients who might benefit from adjuvant radiotherapy.

Retrospective Analysis of Patients with Gynaecological Uterine Sarcomas in a Tertiary Hospital

Uterine sarcomas are rare and heterogeneous malignancies accounting for 1% to 3% of all gynaecological tumours. There are many histological subtypes recognised, including leiomyosarcomas, endometrial stromal sarcoma, and uterine carcinosarcoma, although the latest has been recently discarded in this group. Despite its low incidence, these types of cancer currently entail multiple challenges, either in diagnostics or clinical management, with a poor prognosis associated. The present work aimed to complete a comparative analysis of the different histological subtypes based on the clinicopathological characteristics of our population, the therapeutic characteristics, and associated prognosis in 161 patients treated in our centre during the period between 1985 and 2020. Moreover, a systematic review grouped a total of 2211 patients with a diagnosis of uterine sarcoma from 19 articles published in 16 countries from 2002 to 2021 was performed, all with retrospective analyses. Our results showed that apart from uterine carcinosarcoma, leiomyosarcoma is the most frequent subtype of uterine sarcoma, with unique clinical, demographic, and survival parameters. To our knowledge, this is the first systematic review conducted in this field and, thus, it shows the difficulties of collecting a significant number of patients per year, a valid reason why multicentre or national registries are recommended to allow a more exhaustive analysis of this pathology.

Leiomyoma with nuclear atypia: Rare diseases that present a common diagnostic problem

Leiomyoma with nuclear atypia describes a group of uterine smooth muscle tumors with a wide range of histologic and clinical presentations and remarkable nuclear atypia. These include fumarate hydratase-deficient leiomyoma (FH-LM), intravenous leiomyomatosis (IV-LM), and leiomyoma with bizarre nuclei (LM-BN). Other uterine mesenchymal tumors, such as perivascular epithelioid tumor (PEComa) and inflammatory myofibroblastic tumors (IMFT) are the mimickers of leiomyoma with nuclear atypia. LM-BN is the primary tumor model with a long history in gynecologic pathology, but the histogenesis of LM-BN remains largely unknown. Differentiating LM-BN from other benign variants, tumors with uncertain malignant potential (STUMP), or fully malignant leiomyosarcoma (LMS) can be diagnostically challenging. Recent progress has improved the diagnosis of many types of leiomyoma with nuclear atypia based on their specific histology and molecular alterations. LM-BN is now a diagnosis of exclusion. In this article, I review the history of leiomyoma with nuclear atypia and compare the clinical, histologic, and molecular features of LM-BN with those of its mimics. In particular, I highlight the current progress made in molecular genetics and pitfalls in the diagnosis of different myogenic tumors with nuclear atypia.

FOXP3+ T cells in uterine sarcomas are associated with favorable prognosis, low extracellular matrix expression and reduced YAP activation

Uterine sarcomas are rare but deadly malignancies without effective treatment. Immunotherapy is a promising new approach to treat these tumors but has shown heterogeneous effects in sarcoma patients. With the goal of identifying key factors for improved patient treatment, we characterized the tumor immune landscape in 58 uterine sarcoma cases with full clinicopathological annotation. Immune cell characterization revealed the overall prevalence of FOXP3+ cells and pro-tumor M2-like macrophages. Hierarchical clustering of patients showed four tumor type-independent immune signatures, where infiltration of FOXP3+ cells and M1-like macrophages associated with favorable prognosis. High CD8+/FOXP3+ ratio in UUS and ESS correlated with poor survival, upregulation of immunosuppressive markers, extracellular matrix (ECM)-related genes and proteins, and YAP activation. This study shows that uterine sarcomas present distinct immune signatures with prognostic value, independent of tumor type, and suggests that targeting the ECM could be beneficial for future treatments.

Cervical leiomyosarcoma in a teenage girl: A rare form of uterine leiomyosarcoma

Sarcomas arising from the cervix are rare, and the reported prevalence is 0.20–0.55%. A 15-year-old Para 0⁺⁰ secondary school student presented to the emergency department in shock with a 1-year history of painless vaginal protrusion, vaginal bleeding, foul-smelling vaginal discharge, occasional passage of blood clots, fatigue, fainting episodes, and weight loss. She was resuscitated with intravenous fluids and blood transfusions. General examination revealed a young girl with a 16-week sized abdominal mass. Vaginal examination revealed a large mobile fleshy mass 14 cm by 10 cm with an offensive discharge and odour. It was externally friable, bled actively on contact, had areas of tissue necrosis, and was oedematous. It was difficult to determine the adnexa structures because of tenderness. Examination under anaesthesia showed that the mass was continuous with the cervix and was not attached to the vagina or vulva. The histology report of the biopsied specimens showed features consistent with cervical leiomyosarcoma (LMS). Cervical LMS was confirmed by immunohistochemistry and a total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed as definitive treatment. Postoperative hormone replacement therapy was initiated. The patient's postoperative condition was stable and there was no tumour recurrence for >2 years on follow-up. Making a diagnosis and instituting surgical and adjuvant treatments for LMS in a low-resource setting are challenging. This is due to lack of access to universal healthcare coverage. A multidisciplinary approach with early diagnosis and complete surgical resection of the tumour provides the most favourable possibility of an improved survival and quality of life.

New imaging modalities to distinguish rare uterine mesenchymal cancers from benign uterine lesions

PURPOSE OF REVIEW

Uterine sarcomas are rare and are often challenging to differentiate on imaging from benign mimics, such as leiomyoma. As functional MRI techniques have improved and new adjuncts, such as machine learning and texture analysis, are now being investigated, it is helpful to be aware of the current literature on imaging features that may sometimes allow for preoperative distinction.

RECENT FINDINGS

MRI, with both conventional and functional imaging, is the modality of choice for evaluating uterine mesenchymal tumors, especially in differentiating uterine leiomyosarcoma from leiomyoma through validated diagnostic algorithms. MRI is sometimes helpful in differentiating high-grade stromal sarcoma from low-grade stromal sarcoma or differentiating endometrial stromal sarcoma from endometrial carcinoma. However, imaging remains nonspecific for evaluating rarer neoplasms, such as uterine tumor resembling ovarian sex cord tumor or perivascular epithelioid cell tumor, primarily because of the small number and power of relevant studies.

SUMMARY

Through advances in MRI techniques and novel investigational imaging adjuncts, such as machine learning and texture analysis, imaging differentiation of malignant from benign uterine mesenchymal tumors has improved and could help reduce morbidity relating to misdiagnosis or diagnostic delays.