Rare Uterine Tumor Research Articles

Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP): A Systematic Review of the Literature in the Last 20 Years.

Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP) is a rare uterine tumor primarily affecting perimenopausal and postmenopausal women, typically aged between 45 and 55 years. Characterized by ambiguous histological features, STUMPs present diagnostic challenges as they cannot be definitively classified as benign or malignant based on morphology alone. This systematic review aims to elucidate the clinical, pathological, immunohistochemical, and treatment-related characteristics of STUMPs through an analysis of the literature from the past 20 years. The study follows PRISMA guidelines, utilizing comprehensive searches of PubMed and Scopus databases, yielding 32 studies that meet the inclusion criteria. From the analysis of these studies, it was revealed that the clinical presentations vary from common symptoms such as abnormal uterine bleeding and pelvic pain to incidental detection of uterine mass. Histologically, STUMPs demonstrate features overlapping with both leiomyomas and leiomyosarcomas, including mild nuclear atypia, low mitotic indices, and focal necrosis. Immunohistochemical markers such as p16 and p53 have been investigated for prognostic significance. Elevated p16 expression, often associated with aggressive behavior, was observed in a subset of STUMPs. Surgical management, typically involving hysterectomy or tumorectomy, is the primary treatment, though the extent of resection is variable. Adjuvant therapies are not routinely recommended, but long-term surveillance is advised, especially for high-risk patients. Recurrence rates for STUMPs are approximately 12%, with factors such as high mitotic counts and coagulative necrosis indicating higher risk. This review highlights the complexity of STUMP diagnosis and management, emphasizing the need for more precise diagnostic criteria and individualized treatment strategies. Understanding the morphological, immunohistochemical, and clinical behavior of STUMPs can improve patient outcomes and guide future research in this diagnostically challenging area.

Uterine Tumours Resembling Ovarian Sex-Cord Tumors: A Case Report and Review of the Literature.

Uterine tumors resembling ovarian sex-cord tumors (UTROSCT) are thought to develop from pluripotent uterine mesenchymal cells or endometrial stromal cells with secondary sex-cord differentiation. The patient was a 73-year-old postmenopausal woman who had abnormal vaginal bleeding, and she underwent a laparoscopic hysterectomy with bilateral salpingo-oophorectomy. The diagnosis was a case of UTROSCT. A scoping review of the UTROSCT case report present in the literature has been conducted, and 63 articles were found, of which 45 were considered for the 66 clinical cases examined. At the time of diagnosis, six metastatic localizations were found in 59 patients undergoing demolitive surgery (10.2%). Recurrences were diagnosed in 13/59 (22%) patients with multiple locations. A molecular study was performed in 18/66 cases (27.3%) and genetic alterations were found in 10/18 (55.6%) patients. UTROSCTs are considered rare uterine tumors, typically with a favorable prognosis, and are generally considered to have a good prognosis. But, from the review done, they may already manifest themselves at advanced stages, with the possibility of recurrences even at a distance. It would, therefore, be important to be able to define the most aggressive forms and, perhaps, molecular investigation with sequencing could help identify patients most at risk.

Highly cellular leiomyoma - A great histopathological masquerader of endometrial stromal sarcoma.

Leiomyoma is the most common benign uterine tumor, whereas endometrial stromal tumors are rare uterine tumors with limited clinical experience. The distinction between highly cellular leiomyoma and endometrial stromal sarcoma can pose a diagnostic challenge to the pathologists as both these tumors have considerable overlapping features on histology.

Smooth muscle tumor of uncertain malignant potential (STUMP)

Uterine smooth muscle tumor of uncertain malignant potential (STUMP) is a rare tumor belonging to a group of smooth muscle tumor that possess both benign and malignant features, complicating the diagnosis. STUMP is a rare uterine tumor with a paucity of literature available regarding management and subsequent malignant potential. A 22-year-old unmarried lady presented as uterine fibroids with 24 weeks size uterus. There was one intramural and another subserosal mass both of which revealed smooth muscle tumor of uncertain malignant potential in histopathology.

A novel nomogram for predicting cancer-specific survival in women with uterine sarcoma: a large population-based study

BackgroundUterine sarcoma (US) is a rare malignant uterine tumor with aggressive behavior and rapid progression. The purpose of this study was to constructa comprehensive nomogram to predict cancer-specific survival (CSS) of patients with US-based on the Surveillance, Epidemiology, and End Results (SEER) database.MethodsA retrospective population-based study was conducted using data from patients with US between 2010 and 2015 from the SEER database. They were randomly divided into a training cohort and a validation cohort ata 7-to-3 ratio. Multivariate Cox analysis was performed to identify independent prognostic factors. Subsequently, a nomogram was established to predict patient CSS. The discrimination and calibration of the nomogram were evaluated by the concordance index (C-index) and the area under the curve (AUC). Finally, net reclassification improvement (NRI), integrated discrimination improvement (IDI), calibration plotting, and decision-curve analysis (DCA) were used to evaluate the benefits of the new prediction model.ResultsA total of 3861 patients with US were included in our study. As revealed in multivariate Cox analysis, age at diagnosis, race, marital status, insurance record, tumor size, pathology grade, histological type, SEER stage, AJCC stage, surgery status, radiotherapy status, and chemotherapy status were found to be independent prognostic factors. In our nomogram, pathology grade had strongest correlation with CSS, followed by age at diagnosis and surgery status. Compared to the AJCC staging system, the new nomogram showed better predictive discrimination with a higher C-index in the training and validation cohorts (0.796 and 0.767 vs. 0.706 and 0.713, respectively). Furthermore, the AUC value, calibration plotting, NRI, IDI, and DCA also demonstrated better performance than the traditional system.ConclusionOur study validated the first comprehensive nomogram for US, which could provide more accurate and individualized survival predictions for US patients in clinical practice.

Endometrial stromal tumors: Diagnostic updates and challenges.

Endometrial stromal tumors are rare uterine mesenchymal tumors of endometrial stromal origin. They are classified into endometrial stromal nodule, low-grade endometrial stromal sarcoma, high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma by the current (2020) WHO classification. Correct diagnosis of endometrial stromal tumors is critical for proper patient management. However, due to infrequent encounters, overlapping morphological features and immunohistochemical profiles, the differential diagnoses among endometrial stromal lesions and their morphologic mimics are often challenging. Partially with our own experience, here we review and summarize the tumor morphology, immunohistochemical phenotype, as well as molecular feature of endometrial stromal tumors and key differential diagnoses, emphasizing the newest developments and their utilization in daily practice.

STUMPed. Is this a case of STUMP or a benign leiomyoma with extensive degenerative changes?

Introduction: Smooth muscle tumors of uncertain malignant potential (STUMP) are rare uterine neoplasms that cannot be histologically identified as explicitly benign or malignant.

Uterine tumor resembling ovarian sex cord tumor: we can diagnose it if we consider it. Case report and literature review

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) represents a rare uterine neoplasm with un­certain malignant potential. Several reports have described re­cur­rences, me­tas­ta­ses and even deaths associated with these generally considered benign tumors, thus making them a controversial disease entity. UTROSCT has an un­clear histogenesis and it possesses a polyphenotypic im­mu­no­phe­no­type. We present a case of UTROSCT in a patient accusing ab­nor­mal genital bleeding and symptoms associated with anemia. After per­for­ming a total abdominal hysterectomy with bilateral sal­pin­gec­tomy, the final pathology report revealed UTROSCT with no sarcomatous features. The pa­tient is still disease-free after 30 months of follow-up. We also present the data avai­la­ble in literature regarding this relative new type of uterine tu­mor. We are of the opinion that a high index of suspicion is of paramount importance when examining a patient with an uterine mass in order to promptly identify the risk factors that may predict agressive tumor behaviour.

Uterine tumor resembling ovarian sex-cord tumor: a case report of recurrence after conservative management and review of the literature

Background: Uterine tumor resembling ovarian sex-cord tumor is an extremely rare uterine mesenchymal neoplasm. Less than 100 cases have been described in literature and only eleven cases were treated with a fertility sparing approach. Three patients treated with preservation of reproductive function presented a local relapse; among these, two patients were treated conservatively and one had a second relapse with peritoneal carcinomatosis.

809P Comprehensive characterization of molecular features distinguishing uterine leiomyoma from leiomyosarcomas

Uterine leiomyosarcomas (LMS) is a highly aggressive but rare uterine tumor. However, it is almost impossible to distinguish LMS from the most common benign uterine leiomyomas (LM) through pre-operative diagnosis, leading to poor prognosis of LMS patients. Thus, it is clinically important to identify molecular differences between LMS from LM, which would not only advance our understanding on tumorigenesis of LMS but also lay a foundation for developing effective early detection strategy.

Prognostic factors and survival outcomes of uterine sarcomas in a reference gynecologic oncology cancer center

Background/Aim: Uterine sarcomas are rare and aggressive tumors, and their clinical behavior is unpredictable. A clear-cut clinical course, proven treatment method or definitive prognostic factors affecting the survival of sarcoma patients are not reported in the literature. We aim to evaluate uterine sarcomas, determine clinicopathologic features, adjuvant therapies, and prognostic factors on survival while sharing our experience of these rare uterine tumors in light of the literature. Methods: This retrospective cohort study was conducted in Tepecik Training and Research Hospital, Izmir, Turkey between 2002-2020. Out of the total of 205 uterine sarcoma patients, 173 patients who underwent surgical procedures and were followed up in our hospital’s Gynecologic Oncology Clinic were included in the study. Data of patients were collected from the hospital database. Surgical interventions, clinicopathologic features, adjuvant therapies, and overall and disease-free survivals were evaluated. Patients were grouped as leiomyosarcoma (LMS), carcinosarcoma (CS), endometrial stromal sarcoma (ESS), adenosarcoma (AS), and undifferentiated sarcoma (US). Results: The mean age of the patients was 57.6 (11.2) years. According to the International Federation of Gynecology and Obstetrics (FIGO2009), 115 patients (66.5%) had stage 1, 17 patients (9.8%) had stage 2, 31 (17.9%) patients had stage 3, and 10 patients (5.8%) had stage 4 disease. One hundred and sixty-two patients (93.6%) received adjuvant therapy. Median follow-up period was 39 months (range 3-214). The 120-month OS for the entire group was 87.1%. Conclusion: Stage is a significant prognostic factor for survival in all sarcoma types and recurrence is a significant prognostic factor for survival for LMS and CS patients. Sarcoma type and adjuvant treatments have no impact on survival. ESS patients require extended surgical staging.

Immunohistochemical markers and the clinical course of adenosarcoma: a series of seven cases

BackgroundUterine adenosarcoma, a rare uterine tumor subtype, is a biphasic tumor consisting of epithelial and mesenchymal elements. To date, there is no research comparing the histopathological features and immunohistochemistry of primary and recurrent tumors; furthermore, the relationship between pathology and the clinical course remains unclear. We reviewed the pathology and immunohistochemical features of patients with adenosarcoma and investigated the relevance of the histomorphological features to the clinical course. We also compared the immunohistochemical features of the primary and recurrent tumors.MethodsThe data of seven patients with adenosarcoma who underwent surgery in our hospital were evaluated. We performed immunohistochemical staining for the progesterone receptor, estrogen receptor, p53, and two Switch/Sucrose Non-Fermentable chromatin remodeling proteins (SMARCA4, BCOR), which were recently developed for the undifferentiated sarcoma diagnosis in addition to conventional staining methods.ResultsAll patients had International Federation of Gynecology and Obstetrics stage IB–IC diseases. All tumors were polypoid and every patient presented with abnormal uterine bleeding. Six patients aged over 50 years and were menopausal; one patient aged under 50 years and was non-menopausal (average age: 59.1 years). Histologically, the sarcomatous components were homologous and heterogenous in six and one patient, respectively. Four and three cases were recurrent and non-recurrent, respectively. The recurrent patients showed high-grade morphology with sarcomatous overgrowth and were negative for ER and PR. Three recurrences could be evaluated by imaging, showing recurrence only in a distant area; biopsy specimens from these tissues revealed the identical mesenchymal component found in the primary tumor without a benign epithelial component. Immunohistochemical staining results were also similar to the corresponding of the original tumor, except for the p53 expression in one patient. At the primary site, p53 was overexpressed in two recurrent patients and had a wild-type level in one recurrent patient; however, all three recurrent tissues showed p53 overexpression. None of our patients showed SMARCA4 loss, and BCOR expression was positive in one case.ConclusionsInitial pathological adenosarcoma analysis with appropriate immunohistochemical staining is vital for prognostic assessment. p53 expression might increase at recurrence. SMARCA4 and BCOR might not be an index of malignancy.

Detection of MEAF6-PHF1 translocation in an endometrial stromal nodule.

Endometrial stromal nodule (ESN) and low-grade endometrial stromal sarcoma (LG-ESS) are rare uterine tumors known as endometrial stromal tumors (ESTs). In addition to their similarity in morphological features, recent studies have shown that these two tumors share common genetic alterations. In particular, JAZF1-SUZ12 fusion is found with high frequency in both ESN and LG-ESS. In LG-ESS, some minor fusions have also been described, which include rearrangements involving PHF1 and its partner genes, such as JAZF1, EPC1, MEAF6, BRD8, EPC2, and MBTD1. Because of the rarity of ESN, genetic alterations other than JAZF1 fusion have not been investigated in detail. In this study, we performed a next-generation sequencing-based analysis in a case of ESN with peripheral metaplastic bone formation and detected MEAF6-PHF1 fusion, which has been reported in a small subset of uterine LG-ESSs and soft tissue ossifying fibromyxoid tumors. The finding that MEAF6-PHF1 fusion is a background genetic abnormality detected both in ESN and LG-ESS, along with JAZF1-SUZ12, provides further support for the similarity and continuum between these two types of ESTs. Furthermore, the association between metaplastic bone formation and MEAF6-PHF1 fusion may not be limited to soft tissue tumors.

Renal Hemangioblastoma with Mixed Mullerian tumour of endometrium: A tale of two rare primary tumours

IntroductionRenal hemangioblastoma (RH) is a very rare benign tumour. Hemangioblastoma most commonly occurs in the central nervous system (CNS), and only few cases of RH have been reported as they occur most commonly as asymptomatic masses found incidentally. Mixed Mullerian tumour (MMT) of the uterus is a rarer and aggressive form of uterine malignancy. The detection of two primary rare tumours incidentally is a rare entity.Case presentationA 50-year-old female presented with abnormal uterine bleeding which on endometrial sampling was diagnosed as a rare variety of endometrial cancer, i.e. MMT or uterine carcinosarcoma. On preoperative imaging, a renal mass was also detected which was highly vascular and was mimicking renal cell carcinoma (RCC). Fine needle aspiration cytology (FNAC) was done from the renal mass to differentiate between RCC and metastasis, but it showed only blood cells. Patient underwent staging laparotomy for endometrial cancer and frozen section examination of the renal mass which was inconclusive with few atypical cells, and thus, patient underwent radical nephrectomy too. Histopathological examination revealed it to be a RH which is a very rare benign tumour.DiscussionRH is a rare benign tumour which does not require any treatment in majority of the patients. Only 26 cases of RH outside the CNS have been reported till date. MMT is a rare aggressive uterine tumour with an incidence of 1–2 % of all uterine neoplasms, which metastasizes early, and thus, early identification and treatment is the key. RH needs to be differentiated from RCC to avoid over treatment. Morphological findings are similar in RCC and RH; preoperative FNAC, PET scan, and intraoperative frozen section can be utilized to differentiate the two, in well-circumcised tumours and high index of suspicion. Occurrence of renal mass as an incidental finding in the preoperative work up of uterine malignancy directed us to the differentials of metastasis or another histologically distinct primary tumour. The presence of two rare primary tumours, i.e. RH and MMT in the same patient which are unrelated, is a rare entity.

Atypical polypoid adenomyoma follow-up and management: Systematic review of case reports and series and meta-analysis.

Atypical polypoid adenomyoma (APA) is a rare uterine tumor typically found in fertile age and associated with infertility. Among young nullipara women, conservative treatment is proposed despite the high recurrence rate and the association with endometrial cancer.Our aim was to assess the risk of recurrence with different conservative treatments in fertile ages and the prevalence of malignant or pre-malignant associated lesions to better address an adequate patient counselling when treatment modalities are discussed. This study is a systematic review and meta-analysis of case reports and case series about APA management and follow-up. A literature search was carried from Medline and Scopus for studies published from January 1, 1980 to December 31, 2018. We included 46 observational studies and 296 cases in fertile women. The prevalence of APA relapse was 44% (CI.95 33-57%) and was lower in cases treated with operative hysteroscopy (22%; CI.95 11-39%) than in cases treated with blind curettage and polypectomy (38%; CI.95 15-67%). The prevalence of the concomitant or during the follow-up diagnosis of endometrial carcinoma was 16% (CI.95 9-29%). The risk of cancer development during follow-up was significantly less in cases treated with histeroscopy (10.56% new cumulative diagnosis at 5 years follow up; CI.95 0-23.7%) than blind curettage and polypectomy (35.5% new cumulative diagnosis at 5 years; CI.95 11.65-52.92%; P < .05). Medical treatment with medroxyprogesterone acetate after surgery does not reduce APA recurrence. Pregnancy was observed in 79% cases in which the desire was expressed. This review suggests that conservative treatment performed by operative hysteroscopy is the optimal choice because it lowers the risk of recurrence, improves the accuracy of concomitant carcinoma or hyperplasia diagnosis, and leaves the possibility of future pregnancies.

Ultrasound and clinical characteristics of uterine smooth muscle tumors of uncertain malignant potential (STUMPs)

Objective(s)Smooth muscle tumors of uncertain malignant potential are rare uterine neoplasms. Their identification through imaging is still limited due to the few available descriptions in the scientific literature. The objective of this paper is to provide clinical and ultrasound features that could support an early identification of these neoplasms. Study designWe retrospectively evaluated preoperative sonographic data of patients receiving a histopathological diagnosis of smooth muscle tumors of uncertain malignant potential between 2014 and 2019 at the S. Anna Hospital (Turin, Italy), a tertiary gynecological center. Tumors were characterized on the basis of ultrasound images using terms and definitions according to the morphological uterus sonographic assessment group. ResultsA total of fourteen patients with smooth muscle tumors of uncertain malignant potential (20 lesions, including 18 pure and 2 with associated leiomyosarcoma) were identified. The median age was 47 years (range 28–77) and nine (64%) patients were of reproductive age. Six patients (43%) were asymptomatic, two (14%) presented with abdominal pain, two (14 %) with menorrhagia and four (29%) with both symptoms. Two (14%) patients developed local recurrences as uterine smooth muscle tumor of uncertain malignant potential and leiomyosarcoma, respectively.At ultrasound imaging, nine (69%) smooth muscle tumors of uncertain malignant potential were poorly or moderately vascularized and nine (82%) showed both circumferential and intra-lesional flows. Only three (15%) showed shadowing. The outlines were well-defined in seventeen cases (85%) and most (90%) showed isoechoic or mixed echogenicity with microcystic anechoic areas in fourteen (70%) of cases. Conclusion(s)Sonographic features of smooth muscle tumors of uncertain malignant potential may vary and a pathognomonic description has not been recognized. However, the identification of single or multiple lesions with specific ultrasound features should raise the suspicion of tumors of uncertain malignant potential. These features include isoechogenicity or mixed echogenicity, regular borders, presence of internal microcystic and anechoic areas, circumferential and intralesional vascularization ranging from minimal to high and absence of shadowing.

A retrospective study of endometrial stromal sarcoma: an institutional review.

This is a retrospective study conducted at Shaukat Khanum Memorial Cancer Hospital, Lahore, from January 1995 to April 2016, to determine the clinical presentations, pathological features, cancer free survival and rate of recurrence in patients with Endometrial Stromal Sarcoma (ESS). Data was collected from May to August 2017. A total of 31 patients with a mean age of 40.0±11.72 years were treated. Among them, 12 (38.7%) had stage I, 2 (6.4%) had stage II, 6 (19.3%) had stage III and 11 (35.5%) had stage IV ESS. All patients underwent surgical management as an initial treatment modality for ESS. Out of these 31 patients, 17 were under active surveillance, 4 had expired and 10 patients were lost to follow up. Eleven (65%) patients were disease free, recurrence was noted in 4 (23.5%) patients and 2 (12%) patients had persistent disease. Recurrence of disease was managed with surgical excision and multimodality treatment. Median duration of follow-up was 38.29 months. Endometrial stromal sarcoma (ESS) is a rare uterine tumour. Our patients were young and had lower rate of recurrence. Surgical management was the mainstay of treatment in patients with resectable disease while other options used included hormonal therapy, radio therapy or chemotherapy.

Clinicopathologic Characterization of GREB1-rearranged Uterine Sarcomas With Variable Sex-Cord Differentiation.

Uterine mesenchymal tumors are genetically heterogenous; those with uniform cytomorphology, best exemplified by endometrial stromal tumors, often contain various fusion genes. Novel fusions involving ESR1 and GREB1, key factors in sex hormone pathways, have been implicated in rare uterine mesenchymal tumors. Particularly, the fusions between 5'-ESR1/GREB1 and 3'-NCOA2/NCOA3 were recently identified in 4 uterine tumors resembling ovarian sex-cord tumor (UTROSCT). By RNA sequencing, pathology review, and FISH screening, we identified 4 uterine sarcomas harboring rearranged GREB1, including GREB1-NCOA2 and the novel GREB1-NR4A3, GREB1-SS18, and GREB1-NCOA1, validated by RT-PCR and/or FISH. They occurred in the myometrium of postmenopausal women and were pathologically similar despite minor differences. Tumor cells were generally uniform and epithelioid, with vesicular nuclei and distinct to prominent nucleoli. Growth patterns included solid sheets, trabeculae/cords, nests, and fascicles. Only 1 tumor showed small foci of definitive sex-cord components featuring well-formed tubules, retiform structures, Leydig-like cells, and lipid-laden cells and exhibiting convincing immunoreactivity to sex-cord markers (calretinin, α-inhibin, and Melan-A). In contrast, all the 4 classic UTROSCT we collected occurred in premenopausal patients, consisted predominantly of unequivocal sex-cord elements, prominently expressed multiple sex-cord markers, and harbored ESR1-NCOA3 fusion. Combined with previously reported cases, GREB1-rearranged tumors involved significantly older women (P=0.001), tended to be larger and more mitotically active, showed more variable and often inconspicuous sex-cord differentiation, and appeared to behave more aggressively than ESR1-rearranged UTROSCT. Therefore, these 2 groups of tumors might deserve separate consideration, despite some overlapping features and the possibility of belonging to the same disease spectrum.

MiRNAs 144-3p, 34a-5p, and 206 are a useful signature for distinguishing uterine leiomyosarcoma from other smooth muscle tumors

BackgroundLeiomyosarcoma (LMS) is a rare uterine neoplasm that has a high mortality rate and no specific treatment. The origin of LMS remains unknown; although, it is hypothesized that LMS arises from the malignant transformation of a degenerated uterine leiomyoma (LM). LMs are the most common benign tumors diagnosed and rare variants of LM (unconventional LM) morphologically resemble LMS, thereby making an early and precise diagnosis of LMS difficult. Various molecular features may influence the malignancy risk of LMS tumors, including microRNAs (miRNAs). However, the role of miRNAs in uterine mesenchymal tumors remains poorly understood. Here, our aim was to assess the miRNA expression profiles of LMS, LM, and LM variants (ULM) to identify a specific signature that may facilitate differentiation among these tumor types. Possible associations between these profiles and patients’ clinical and pathological features were also analyzed.MethodsTotal RNA was extracted from formalin-fixed paraffin-embedded tissue samples of uterine LMS (n = 37), LM (n = 3), ULM (n = 8), and myometrium (MM) (n = 2) to perform real-time PCR analyses and detect expression levels of a panel of 84 miRNA sequences related to cancer.ResultsBetween the LMS and LM samples, 16 miRNAs were found to be differentially expressed, with miR-372 and miR-34a-5p exhibiting the highest and lowest levels of expression, respectively. When LMS and ULM were compared, 5 differentially expressed miRNAs were identified, with miR-34a-5p downregulated and miR-144-3p upregulated. Between ULM and LM, all of the differentially expressed miRNAs were upregulated, and miR122-5p exhibited 10-fold higher expression. In addition, significant correlations were found between various miRNAs and tumor relapse (miR-148a-3p), metastasis (miR-27b-3p), and patient death (miR-124-3p and miR-183-5p). Downregulation of miR135b-5p was associated with disease-free survival.ConclusionExpression profiling of miRNAs 144-3p, 34a-5p, and 206 may be useful in characterizing uterine LMS and distinguishing it from benign tumors. Furthermore, deregulation of miRNAs 148a-3p, 27b-3p, 124-3p, 183-5p, and 135b-5p appear to indicate a poor prognosis for LMS patients.

Durable Response to Letrozole in a Patient with Relapsed Low Grade Endometrial Stromal Sarcoma Metastatic to the Lung - A Case Report

Low Grade Endometrial Stromal Sarcomas (LGESS) are rare uterine neoplasms, with high propensity for local recurrence and an indolent course. Distant metastasis is rare. Hormonal therapy with progestin or aromatase inhibitors has been used successfully to treat relapsed and unresectable disease. We report a 55-year-old female patient with relapsed LGESS in the lungs, who achieved almost complete response to letrozole for more than 6 years. To our knowledge, this is the longest reported durable response with letrozole in patients with LGESS and lung metastasis.