A Case of Uterine Tumor Resembling Ovarian Sex Cord Tumor With Prominent Myxoid Features.

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor with low malignant potential that commonly occurs in middle age. Although more than 100 cases have been reported to date, myxoid morphology is not well documented. Here, we present a 75-yr-old woman with abnormal vaginal bleeding, with an 8-cm mass in the uterine corpus detected by irregular, high-intensity signaling on T2-weighted imaging. The uterine mass had a glistening mucinous appearance on gross examination. Microscopically, most of the tumor cells were floating in the myxoid stroma. The tumor cells formed clusters or nests with abundant cytoplasm, while some exhibited trabecular or rhabdoid appearances. Immunohistochemically, tumor cells were positive for pancytokeratin (AE1/AE3), α-smooth muscle actin, CD10, progesterone receptor, and some sex cord markers such as calretinin, inhibin, CD56, steroidogenic factor-1. Electron microscopy demonstrated epithelial and sex cord differentiation. This tumor was negative for JAZF1-JJAZ1 fusion gene that is frequently found in low-grade endometrial stromal sarcoma. Fusion genes related to UTROSCT, including NCOA2/3 , were not detected by reverse transcription polymerase chain reaction. The present case suggests that UTROSCT should be included in the differential diagnosis of myxoid uterine tumors.

JAZF1, YWHAE and BCOR gene translocation in primary extrauterine low-grade and high-grade endometrial stromal sarcomas.

AIMS: JAZF1 translocation is the most common genetic change in low-grade (LG) endometrial stromal sarcoma (ESS), and YWHAE and BCOR translocations are common in high-grade (HG) ESS. Primary extrauterine ESS is rare, and there are limited data on molecular alterations in these tumours. METHODS AND RESULTS: Cases of primary extrauterine ESS, comprising eight LG-ESS cases and five HG-ESS cases were collected. Haematoxylin and eosin and immunohistochemical staining were used to observe the histomorphology and analyse related protein expression. JAZF1, YWHAE and BCOR rearrangements were explored with fluorescence in-situ hybridisation (FISH). In LG-ESS, the tumour cells resembled normal proliferative-phase endometrial stromal cells; CD10, oestrogen receptor and progesterone receptor were expressed in all eight cases. In HG-ESS, the tumour cells had uniform HG round and/or spindle morphology, sometimes with an LG component; CD10 was fully expressed in one case and focally expressed in four cases; BCOR was expressed in all five cases, and cyclin D1 in four of five cases. FISH analysis showed JAZF1 translocation in one of eight LG-ESS cases (12.5%). YWHAE translocation occurred in four of five HG-ESS cases, with a positivity rate of 80%. BCOR translocation was absent in all five cases. CONCLUSIONS: In extrauterine LG-ESS, the rate of JAZF1 rearrangement was significantly lower than in uterine LG-ESS. This result limited the value of JAZF1 translocation for diagnosis. YWHAE rearrangement is a common genetic change in extrauterine HG-ESS. Further studies are required to confirm these findings, especially in LG-ESS.

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.

Unusual morphologic features of low-grade endometrial stromal sarcoma: A case report.

BACKGROUND: Endometrial stromal tumours are uncommon tumours of the uterus. They mainly occur in perimenopausal women. Tumours with typical clinicopathological features do not usually pose diagnostic problems. However, rare clinicopathological features can occur, and clinicians without significant experience may have difficulty diagnosing these tumours and managing these patients. METHODS: Herein, we report a case of endometrial stromal sarcoma that occurred in a 25-year-old woman. The pathological features, immunophenotype, treatment and prognosis were discussed. RESULTS: The tumour revealed morphological heterogeneity, and there were similar proliferative-type endometrial stromal cells, an extensive amount of mature adipose tissue, and prominent rhabdomyoblastic and smooth muscle cells. Histopathological and immunohistochemical studies confirmed low-grade endometrial stromal sarcoma with smooth muscle, adipocytic and rhabdomyoblastic differentiation (approximately 60% were differentiated tissues). The final treatment of the tumour was total abdominal hysterectomy with bilateral salpingo-oophorectomy. There was no evidence of recurrence for 109 months postoperatively. CONCLUSIONS: We found that low-grade endometrial stromal tumours with extensive adipocytic and prominent rhabdomyoblastic differentiation are misdiagnosed because they are infrequent. They must be differentiated from rhabdomyosarcoma with accurate identification of adipocytes, and long-term follow-up is needed.

[Endometrial and other rare uterine sarcomas : Diagnostic aspects in the context of the 2020 WHO classification]. / Endometriale und weitere seltene uterine Sarkome : Diagnostische Aspekte im Kontext der WHO-Klassifikation 2020.

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

Phase 2 study of anastrozole in patients with estrogen receptor/progesterone receptor positive recurrent low-grade endometrial stromal sarcomas: The PARAGON trial (ANZGOG 0903).

BACKGROUND: Aromatase inhibitors are standard of care for low-grade endometrial stromal sarcomas (LGESS), based on very high response rates reported in retrospective studies. We evaluated the activity of anastrozole in recurrent/metastatic LGESS patients enrolled in PARAGON, a basket trial of anastrozole in estrogen receptor (ER±)/progesterone receptor (PR+) gynecological cancers. METHOD: An investigator-initiated, single-arm, prospective open-label trial of anastrozole 1 mg/day in patients with ER ± PR + ve LGESS with measurable disease, treated until progressive disease or unacceptable toxicity. Primary endpoint was clinical benefit (complete/partial response + stable disease) rate (CBR) at 3 months. Secondary endpoints include progression-free survival (PFS), quality of life and toxicity. RESULTS: 15 eligible patients were enrolled. CBR at 3 months was 73% (95% CI: 48-89.1%); unchanged at 6 months. Best response was 26.7%, including complete response in one (6.7%; 95% CI 1.2-29.8%), partial response in three (20%, 95% CI 7.1-45.2%) and stable disease in seven (46.7%). Four patients ceased treatment by 3 months due to progression. Median PFS was not reached (25th percentile: 2.9 months (95% CI: 1.2-NR)). PFS was 73.3%, 73.3% and 66% at 6, 12, and 18 months, respectively. Six patients remained on treatment for an average of 44.2 months (range 34.5-63.6) up until data cut. Toxicity was as expected, with 3 patients stopping due to adverse effects. CONCLUSION: The 26.7% objective response rate with anastrozole is lower than reported in retrospective series, but the CBR was high and durable. The results underscore the importance of prospective trials in rare cancers.

Does ovarian preservation have an effect on recurrence of early stage low-grade endometrial stromal sarcoma?

Surgical treatment of low-grade endometrial stromal sarcoma consists of hysterectomy. The role of oophorectomy is yet to be established. We aimed to examine the effect of preserving the ovaries on the pattern of recurrences in patients with stage I disease. Thirty-four patients with stage I low-grade endometrial stromal sarcoma were retrospectively analysed. Based on ovarian preservation the whole cohort was divided into two groups. Recurrence (liver, lung, groin and bone) was detected in 4 (11.8%) cases. No significant differences in overall survival or disease-free survival (DFS) were observed between the ovarian preservation and bilateral salpingo-oophorectomy (BSO) groups. Subset analysis revealed no significant difference in DFS between the ovarian preservation and BSO groups in the premenopausal arm. And also, the performance of pelvic (n = 2) or para-aortic lymphadenectomy (n = 6) or adjuvant hormonal therapy did not alter DFS significantly. The 5-year DFS rate for the group which received adjuvant radiotherapy was 62.5 and 94.4% for those which did not (p = .014). Preserving the ovaries had no adverse effect on the recurrence of stage I disease.IMPACT STATEMENTWhat is already known on this subject? Due to the rarity of the disease and the common postoperative diagnosis, only retrospective studies have been reported on low-grade endometrial stromal sarcoma. This disease is commonly diagnosed in premenopausal patients during the early stage. There is no consensus on preserving the ovaries, particularly in young patients, due to the tumour's hormonal characteristics and the risk of late recurrences.What do the results of this study add? Ovarian preservation had no effect on the recurrence of stage I low-grade endometrial stromal sarcoma. Lymphadenectomy and adjuvant hormonal treatment had no effect on DFS, and adjuvant radiotherapy decreased DFS in the current study.What are the implications of these findings for clinical practice and/or further research? Ovarian preservation should be considered, to prevent the negative effects of surgical menopause, particularly in young patients.

Practical roles for molecular diagnostic testing in ovarian adult granulosa cell tumour, Sertoli-Leydig cell tumour, microcystic stromal tumour and their mimics.

Within the last decade, molecular advances have provided insights into the genetics of several ovarian sex cord-stromal tumours that have otherwise been enigmatic. Chief among these advances are the identification of FOXL2, DICER1 and CTNNB1 mutations in adult granulosa cell tumours, Sertoli-Leydig cell tumours (SLCTs), and microcystic stromal tumours (MCSTs), respectively. As access to molecular diagnostic laboratories continues to become more widely available, the potential roles for tumour mutation testing in the pathological diagnosis of these tumours merit discussion. Furthermore, links to inherited cancer susceptibility syndromes may exist for some women with SLCT (DICER1 syndrome) and MCST [familial adenomatous polyposis (FAP)]. This review will address practical issues in deciding when and how to apply mutation testing in the diagnosis of these three sex cord-stromal tumours. The pathologist's role in recommending referral for formal risk assessment for DICER1 syndrome and FAP will also be discussed.

Uterine Endometrial Stromal Tumors With Limited Infiltration: First Report of a Case Series Indicating Potential for Malignant Behavior.

The distinction between a uterine endometrial stromal nodule (ESN) and low-grade endometrial stromal sarcoma (LGESS) is based on the nature of the interface between the lesion and the surrounding myometrium and the presence or absence of vascular invasion. Most LGESS exhibit widespread irregular myometrial invasion with or without vascular invasion, whereas ESNs are well-circumscribed without vascular invasion. Tavassoli and Norris proposed that minor marginal irregularity (up to 3 protrusions, each <3 mm beyond the main mass) is allowable in an ESN and these criteria have been incorporated into the World Health Organization Classification. There is a small group of neoplasms with marginal irregularity greater than that allowable in ESN but without the widespread myometrial infiltration typical of most LGESS. Such neoplasms have been categorized as endometrial stromal tumor with limited infiltration but there have been no studies which have provided follow-up in this group of neoplasms. We aimed to determine the clinical behavior of this uncommon group of neoplasms. From a series of 19 endometrial stromal tumors with limited infiltration, mainly from consultation practice, we obtained follow-up information in 16 cases by contacting referring pathologists and clinicians. The patient age ranged from 32 to 84 yr (median: 54 yr) and follow-up ranged from 16 to 187 mo (median: 52 mo). Two of 16 patients (12.5%) developed metastatic disease to the small intestine and peritoneum (1 case-metastasis at 23 mo) and bone and lung (1 case-humeral metastasis at 135 mo; lung and sacral metastases subsequently). No patient died from disease during the follow-up period. A small percentage of endometrial stromal tumors with limited infiltration exhibit malignant behavior with distant metastasis. Such neoplasms should be regarded as potentially malignant and the term LGESS with limited infiltration is an appropriate designation.

Vaginal Low-Grade Endometrial Stromal Sarcoma: An Extremely Rare Case Report and Review of the Literature.

Endometrial stromal sarcoma (ESS) is a malignant tumor of the uterus that has been described as the second most common malignant uterine mesenchymal tumor. Primary extrauterine ESS (EESS) is an extremely uncommon occurrence. We hereby report a new bona fide case of low-grade EESS in a 74-yr-old woman arising in the vagina, presenting as a polypoid mass associated with irregular vaginal bleeding. On examination, a 6×2×2 cm polypoid mass was found in the left vaginal wall. Consequently, the patient underwent partial vaginectomy and repair. No ESS or endometriotic lesion was found in the endometrium and bilateral adnexa. The diagnosis of ESS performed by typical pathologic and immunohistochemical evaluation was as follows: beta-catenin (+++), estrogen receptor (+++), progesterone receptor (++), vimentin (++), and uniformly negative for CD10, EMA, CD31, CD34, CD117,CD99, SMA, desmin, h-caldesmon, S-100, MelanA, and HMB45. She has remained disease free with no signs or symptoms of recurrent or advanced disease for 46 mo. Although CD10 is the most useful immunohistochemical marker for the diagnosis of this tumor, negative CD10 staining can be encountered with underfixation. Therefore, it is important to use a panel of immunostains that includes CD10, beta-catenin, and smooth muscle markers. The present study describes the clinical and pathologic features of low-grade EESS through a case report and literature review. To the best of our knowledge, this is the eighth report of EESS arising from the vagina.

Imaging in gynecological disease (19): clinical and ultrasound features of extragastrointestinal stromal tumors (eGIST).

OBJECTIVE: To describe the clinical and sonographic characteristics of extragastrointestinal stromal tumors (eGISTs). METHODS: This was a retrospective multicenter study. The data of patients with a histological diagnosis of eGIST who had undergone preoperative ultrasound examination were retrieved from the databases of nine large European gynecologic oncology centers. One investigator from each center reviewed stored images and ultrasound reports, and described the lesions using the terminology of the International Ovarian Tumor Analysis and Morphological Uterus Sonographic Assessment groups, following a predefined ultrasound evaluation form. Clinical, surgical and pathological information was also recorded. RESULTS: Thirty-five women with an eGIST were identified; in 17 cases, the findings were incidental, and 18 cases were symptomatic. Median age was 57 years (range, 21-85 years). Tumor marker CA 125 was available in 23 (65.7%) patients, with a median level of 23 U/mL (range, 7-403 U/mL). The vast majority of eGISTs were intraperitoneal lesions (n = 32 (91.4%)); the remaining lesions were retroperitoneal (n = 2 (5.7%)) or preperitoneal (n = 1 (2.9%)). The most common site of the tumor was the abdomen (n = 23 (65.7%)), and less frequently the pelvis (n = 12 (34.3%)). eGISTs were typically large (median largest diameter, 79 mm) solid (n = 31 (88.6%)) tumors, and were less frequently multilocular-solid tumors (n = 4 (11.4%)). The echogenicity of solid tumors was uniform in 8/31 (25.8%) cases, which were all hypoechogenic. Twenty-three solid eGISTs were non-uniform, either with mixed echogenicity (9/23 (39.1%)) or with cystic areas (14/23 (60.9%)). The tumor shape was mainly lobular (n = 19 (54.3%)) or irregular (n = 10 (28.6%)). Tumors were typically richly vascularized (color score of 3 or 4, n = 31 (88.6%)) with no shadowing (n = 31 (88.6%)). Based on pattern recognition, eGISTs were usually correctly classified as a malignant lesion in the ultrasound reports (n = 32 (91.4%)), and the specific diagnosis of eGIST was the most frequent differential diagnosis (n = 16 (45.7%)), followed by primary ovarian cancer (n = 5 (14.3%)), lymphoma (n = 2 (5.7%)) and pedunculated uterine fibroid (n = 2 (5.7%)). CONCLUSIONS: On ultrasound, eGISTs were usually solid, non-uniform pelvic or abdominal lobular tumors of mixed echogenicity, with or without cystic areas, with rich vascularization and no shadowing. The presence of a tumor with these features, without connection to the bowel wall, and not originating from the uterus or adnexa, is highly suspicious for eGIST. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Long-term impact of lymphadenectomies in patients with low-grade, early-stage uterine endometrial stroma sarcoma.

AIM: The aim of our study was to investigate the lymph node metastasis (LNM) rate and effect of lymph node dissection (LND) in patients with stage I, low-grade endometrial stromal sarcoma (LGESS). METHODS: Patients with stage I LGESS (n = 119) that underwent surgery from July 1969 to July 2017, following up over 48 years at the China National Cancer Center were retrospectively analyzed in this study. RESULTS: Surgical records and consulting data for patients with LGESS were analyzed to find that 47 patients received systematic pelvic LND. The number of patients with menopause in the LND(+) group were significantly lower than those in LND(-) group (2.1% vs 22.2%, P = 0.005), meanwhile, patients received bilateral salpingo-oophorectomy procedure in LND(+) group were significantly higher than LND(-) (97.9% vs 58.3%, P < 0.001). Neither progression-free survival nor overall survival was significantly improved in the LND(+) group even after propensity score matching although the progression-free survival has a stronger trend in LND(+) population. CONCLUSION: A systematic LND was not significantly associated with prognosis for patients with early-stage LGESS. There is no sufficient indication for a systematic LND for patients with early-stage LGESS. A systematic LND might be necessary if enlarged lymph nodes were detected by image graphology or observation during surgery.

A Pan-Cancer Landscape Analysis Reveals a Subset of Endometrial Stromal and Pediatric Tumors Defined by Internal Tandem Duplications of BCOR.

BACKGROUND: The Polycomb Repressive Complex 1 (PRC1) regulates epigenetic silencing and is manifestly linked to rare cancer types. The X-linked BCOR gene (BCL-6 Corepressor) is a member of the PRC1 complex and potentiates transcriptional repression through BCL6 binding of PRC1. Accumulating evidence suggests that internal tandem duplications (ITD) of BCOR are oncogenic drivers in a subset of pediatric sarcomas and rare adult tumors. OBJECTIVE: We reviewed the genomic profiles of a large series of advanced cancer patients to determine the frequency and genomic spectrum of ITD of BCOR across cancer. METHODS: Tissues from 140,411 unique advanced cancers were sequenced by hybrid-capture-NGS-based comprehensive genomic profiling of 186-315 genes plus introns from 14 to 28 genes commonly rearranged in cancer, as well as RNA for 265 genes for a portion of these cases. RESULTS: BCOR-ITDs were present in 0.024% of all cases (33/140,411). Of this dataset, sarcoma cancer types were most frequent, 63.6% (21/33), either of uterine origin 52.4% (11/21), or pediatric (nonuterine) 42.8% (9/21). The identified BCOR-ITDs occurred most frequently in exon 15, near C-terminus, 69.7% (23/33), with a mean insertion length of 31.7 codons (range 30-38). Of uterine cases, an expert gynecologic pathology central review identified all these cases as having a similar high-grade morphology consistent with endometrial stromal sarcomas (ESS), and 90% of cases having a round cell component. Of the uterine sarcoma cases harboring exon 15 BCOR-ITDs, none simultaneously carried gene fusions typically associated with ESS. CONCLUSION: BCOR-ITDs define a rare subset of pediatric sarcomas and clinically aggressive endometrial stromal sarcoma cases, as defined by NGS for the first time. Our findings help delineate the pan-cancer landscape of this alteration and suggest the need for focused investigation to delineate the pro-oncogenic function of BCOR, along with any sensitivity to targeted therapies.

Ovarian preservation for low-grade endometrial stromal sarcoma: a systematic review of the literature and meta-analysis.

OBJECTIVE: To evaluate the effect of ovarian preservation on oncologic outcomes for women with low-grade endometrial stromal sarcoma of the uterus. METHODS: A systematic search of the Medline, Embase, Cohrane, and Web of Science databases was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Studies including patients with low-grade endometrial stromal sarcoma who had hysterectomy were identified. Data on tumor recurrence and death rate were pooled using a random effects model. RESULTS: A total of 17 studies met the inclusion criteria and reported on 786 patients. Based on available information, ovarian preservation was noted in 190 patients while 501 had bilateral salpingo-oophorectomy. A significantly increased tumor recurrence rate was observed in the ovarian preservation group (89/190, 46.8%) compared with the bilateral salpingo-oophorectomy group (121/501, 24.2%) (OR 2.70, 95% CI 1.39 to 5.28). Based on data from 162 patients, no difference in death rate was noted between the ovarian preservation (2/34, 5.9%) and bilateral salpingo-oophorectomy (9/128, 7%) groups (OR 0.80, 95% CI 0.18 to 3.47). CONCLUSIONS: Approximately one-quarter of patients with low-grade endometrial stromal sarcoma were managed with ovarian preservation. These women experienced a higher recurrence rate. Hormone exposure may be responsible for this elevated risk. Given the apparent high salvage rate, however, ovarian preservation may be an option only in a well-informed patient population.

Retroperitoneal low grade endometrial stromal sarcoma with florid endometrioid glandular differentiation: Cytologic-histologic correlation and differential diagnosis.

Low grade endometrial stromal sarcoma (LGESS) is a rare neoplasm that typically arises in the uterine corpus and accounts for less than 1% of uterine sarcomas. Infrequently, extra-uterine LGESS can occur. Histologically, LGESS is characterized by a monotonous population of cells that resemble the proliferative phase of endometrial stroma and in their classic form they exhibit tongue-like growth pattern of infiltration and/or lymphovascular invasion. Infrequently LGESS can demonstrate various morphologic differentiation patterns, including endometrioid-type glands. We report the first fine needle aspiration (FNA) case of a periduodenal mass that was incidentally discovered on Computed Tomography (CT) scan of a 60-year-old female. The cytomorphologic and histologic findings and the immunohistochemical staining were consistent with a LGESS with endometrioid glandular differentiation. We are presenting the correlation between the cytologic, radiologic and pathologic features.

Treatment of low-grade endometrial stromal sarcoma in a nulligravid woman.

A 32 year-old nulligravid woman with a uterine mass underwent exploratory laparotomy with myomectomy. Final pathology revealed a low-grade endometrial stromal sarcoma (ESS) with positive margins. She subsequently underwent definitive robotic hysterectomy and bilateral salpingectomy with ovarian preservation. She was diagnosed with a stage IB low-grade ESS. She is currently undergoing observation. Discussion of classification, surgical options, and adjuvant therapy is presented.

Endometrial Stromal Neoplasm in the Placenta: Report of a Case and Review of the Literature.

Placental neoplasms involving the fetal membranes are exceptionally rare. In leiomyomas and endometrial stromal neoplasms, a uterine origin for nodules in the membranes is also a possibility. We present a case of an incidental endometrial stromal nodule found in the decidua of the free membranes and review the literature.

IFITM1 Outperforms CD10 in Differentiating Low-grade Endometrial Stromal Sarcomas From Smooth Muscle Neoplasms of the Uterus.

Distinguishing between uterine neoplasms of smooth muscle and endometrial stromal origin is a frequent diagnostic challenge. We investigated the staining pattern of interferon-induced transmembrane protein-1 (IFITM1), a novel endometrial stromal marker, in endometrial and smooth muscle uterine neoplasms and compared it with CD10 in its ability to differentiate between these two groups. Immunohistochemistry for IFITM1 and CD10 was performed in 20 cases of smooth muscle neoplasms (10 cases leiomyoma, 10 cases leiomyosarcoma), 14 cases of endometrial stromal sarcoma (ESS) (12 cases of low grade and 2 cases of high grade) and 12 cases of carcinosarcoma. Staining was scored in terms of intensity and distribution (0=absent, 1=weak/<50%, 2=moderate/50%-75%, 3=strong/>75%). A total score was obtained by adding intensity and distribution scores and classified as positive (score 3-6) or negative (score 0-2). IFITM1 was positive in 10 of 12 (83%) low-grade ESSs, 6 of 20 (30%) smooth muscle tumors (leiomyomas and leiomyosarcomas) and 11 of 12 carcinosarcomas (91.6%). The 2 cases of high-grade ESS were IFITM1 negative. While both IFITM1 (83%) and CD10 (91%) had high sensitivity in differentiating low-grade ESSs from smooth muscle neoplasms, IFITM1 (70%) had higher specificity compared with CD10 (45%). In this study IFITM1 appears to be a more specific marker of endometrial stromal differentiation compared with CD10 in differentiating low-grade ESSs from smooth muscle neoplasms. Thus, IFITM1 may be a valuable tool as part of an immunohistochemical evaluation panel in this diagnostic scenario.

Recurrence after fertility-preserving surgery for low-grade endometrial stromal sarcoma.

Considering the characteristics of low-grade endometrial stromal sarcoma (ESS), such as relative indolent course, younger age at diagnosis and favorable prognosis, the fertility-preserving management of low-grade ESS has been described by several authors. We report a 34-year-old female with stage IB low-grade ESS who developed recurrence 7 years after neoadjuvant high-dose progestin therapy followed by fertility-preserving surgery and postoperative progestin therapy. The patient stopped progestin therapy and was disease free for 4 years after diagnosis but experienced recurrence with peritoneal dissemination at 7 years. Considering the tendency of late recurrence, long-term surveillance is necessary to ensure timely action. Long-term progestin treatment might be considered after complete remission even beyond 5 years. We performed a literature review and found that many of the cases did not meet solid pathological criteria of low-grade ESS. The diagnostic criteria of low-grade ESS (vs endometrial stromal nodule) should be deliberately documented for future studies of this rare disease.

Low-grade endometrial stromal sarcoma presenting as multiple pulmonary nodules: A potential pitfall in fine needle aspiration and core biopsy specimens - A Cytological - Pathological Correlation.

Low-grade endometrial stromal sarcoma (LGESS) is the second most common malignant mesenchymal tumor of the uterus. The most common location is the uterine corpus, but it can also primarily arise in a variety of extrauterine locations such as pelvis, ovary, abdominal cavity, vagina, and vulva. We are reporting a case of a 47-year-old female with no significant medical history who presented with multiple pulmonary nodules. Fine needle aspiration (FNA) specimen revealed spindle cell neoplasm consistent with the diagnosis of LGESS. The differential diagnosis included neuroendocrine tumor, synovial sarcoma, solitary fibrous tumor, smooth muscle tumors, and peripheral nerve sheath tumors. The clinical, cytological, and histopathologic details of this case, as well as a discussion of the potential pitfalls and differential diagnosis of spindle cell lesions of the lung are described.