Uterine tumors resembling ovarian sex cord tumors are polyphenotypic neoplasms with true sex cord differentiation

Uterine tumors resembling ovarian sex cord tumors: A retrospective analysis of 7 cases from a single institution

To investigate the clinicopathological features, diagnosis, surgical treatment and prognosis of uterine tumors similar to ovarian sex cord tumors (UTROSCT). The clinical data, surgical approach, histopathological, and immunohistochemical features of 7 cases of UTROSCTs were retrospectively reviewed and followed up. All 4 patients were premenopausal women. The most common clinical presentation was menorrhagia (n = 4) followed by postmenopausal lower abdominal mass (n = 2) and postmenopausal bleeding (n = 1). Gynecological ultrasonography suggested uterine fibroids in 4 cases, adenomyosis with uterine fibroids in 2 cases, and an intrauterine mass in 1 case. Pelvic MRI was performed preoperatively in only 2 cases, and both indicated uterine fibroid degeneration, including 1 patient with suspected malignancy. Preoperative serum tumor markers were measured in 6 patients, and only 1 patient had elevated CA125 levels, up to 158 U/mL. Total hysterectomy with bilateral adnexectomy or salpingectomy was the most common treatment pattern (n = 6). The tumors were located within the myometrium (n = 4), submucosa (n = 1), and isthmus to external cervical os (n = 1), with a range of 2 to 12 (mean = 8) cm. Edema and degeneration were observed in 2 cases, and necrosis in 1 case. Postoperative follow-up ranged from 31 to 82 (mean = 43) months. Unfortunately, 1 patient died at 54 months of follow-up without undergoing hysterectomy. The remaining 6 cases showed no tumor recurrence or metastasis after surgery. Histological examination revealed a tumor composed of epithelioid tumor-like cells arranged in cords, trabeculae, and nests. All 7 tumors showed expression of 2 sex cord differentiation markers. Furthermore, all tumors expressed the smooth muscle marker, while epithelial marker CK (4/7). endometrial stromal marker CD10(0/7). The Ki-67 proliferation index was found to be <5% (5/7). The option of total hysterectomy may be considered for women who do not have any fertility requirements. However, for young women who desire to maintain their reproductive capacity, surgery to preserve the uterus may be an alternative, although it necessitates careful postoperative monitoring. In terms of follow-up monitoring, MRI is more suitable than ultrasound. The diagnosis of UTROSCT heavily relies on histopathological examination and immunohistochemical analysis.

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.

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

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

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

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

An Unusual Endometrial Stromal Neoplasm With JAZF1-BCORL1 Rearrangement

Endometrial stromal tumors represent the second most common category of uterine mesenchymal tumors. Several different histologic variants and underlying genetic alterations have been recognized, one such being a group associated with BCORL1 rearrangements. They are usually high-grade endometrial stromal sarcomas, often associated with prominent myxoid background and aggressive behavior. Here, we report an unusual endometrial stromal neoplasm with JAZF1-BCORL1 rearrangement and briefly review the literature. The neoplasm formed a well-circumscribed uterine mass in a 50-yr-old woman and had an unusual morphologic appearance that did not warrant a high-grade categorization. It was characterized by a predominant population of epithelioid cells with clear to focally eosinophilic cytoplasm growing in interanastomosing cords and trabeculae set in a hyalinized stroma as well as nested and fascicular growths imparting focal resemblance to a uterine tumor resembling ovarian sex-cord tumor, PEComa, and a smooth muscle neoplasm. A minor storiform growth of spindle cells reminiscent of the fibroblastic variant of low-grade endometrial stromal sarcoma was also noted but conventional areas of low-grade endometrial stromal neoplasm were not identified. This case expands the spectrum of morphologic features seen in endometrial stromal tumors, especially when associated with a BCORL1 fusion and highlights the utility of immunohistochemical and molecular techniques in the diagnosis of these tumors, not all of which are high grade.

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

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

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

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

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

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

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

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

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

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

Microscopic Sertoliform Sex Cord Proliferations: A Rare Incidental Finding Associated With Endometriosis and Ovarian Epithelial Neoplasia

Microscopic sex cord proliferations are a rare incidental finding seen in association with ovarian and uterine stromal or epithelial neoplasms and more uncommonly non-neoplastic conditions such as endometriosis and adenomyosis. They may also occur in the absence of other pathology, as an incidental finding in the ovaries of pregnant women and in heterotopic locations such as the fallopian tube. Most reports of this phenomenon describe adult granulosa cell tumor-like morphology. Herein, we describe 4 cases of microscopic sex cord proliferations with Sertoliform features, occurring in the stromal component of endometriosis or in the wall of an epithelial ovarian neoplasm; 2 of the patients with endometriosis had concurrent endometrioid adenocarcinoma (1 uterine corpus, 1 ovary). The proliferations were positive with sex cord markers inhibin and calretinin. As far as we are aware, such Sertoliform proliferations have not been reported previously in endometriosis and have only rarely been described in association with ovarian epithelial neoplasia. It is likely that such proliferations represent a benign non-neoplastic phenomenon. Awareness of this phenomenon is important in order to avoid misdiagnosis as a sex cord or other neoplasm. In reporting this unusual phenomenon, we review incidental sex cord and sex cord-like proliferations in the female genital tract.

Uterine tumor resembling ovarian sex cord tumor: A rare case report

RATIONALE

A uterine tumor resembling an ovarian sex cord tumor (UTROSCT) is a clinically rare disease with an unclear origin and biological behavior.

PATIENT CONCERNS

We present a case of UTROSCT in a 42-year-old woman who presented with abnormally increased menstrual volume for 2 years.

DIAGNOSES

Initially, only ultrasound examination was performed to diagnose uterine fibroids, and then the tumor was surgically removed and sent for pathological examination. The patient was ultimately diagnosed with UTROSCT mainly based on pathological immunohistochemical examination and was further diagnosed with low malignant potential for recurrence based on genetic testing.

INTERVENTIONS AND OUTCOMES

The patient underwent hysterectomy and bilateral adnexectomy, and no adjuvant radiotherapy or chemotherapy was performed after the surgery. Follow-up to date has indicated that she is in good condition.

LESSONS

UTROSCT is a rare disease that requires pathological immunohistochemical examination to confirm the diagnosis and genetic testing when necessary so that a clear diagnosis can inform better decision-making regarding treatment measures.

Uterine Tumor Resembling Ovarian Sex Cord Tumor: A Case Report

Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are extremely rare, occurring in less than 1% of uterine stromal tumors, and they are considered to have a low malignant potential. Due to the small number of cases, no standard treatment has been defined. A 77-year-old woman with postmenopausal bleeding was admitted to our department. Imaging studies revealed a substantial mass around 30 mm in size on the anterior uterine wall. A total hysterectomy and bilateral salpingo-oophorectomy were performed for further diagnosis and treatment. The tumor revealed histopathological findings of a sex cord-like growth pattern in the form of fascicles, cords, or small nests. Immunohistochemical findings revealed that the tumor cells were positively reactive to alpha-SMA, calretinin, CD99, estrogen receptor, and progesterone receptor, collectively diagnosed as UTROSCT. No recurrence was observed over 12 months after treatment. We experienced the treatment of UTROSCT, an extremely rare tumor that occurs in elderly women. Although most cases of UTROSCT have a benign clinical course, several cases of recurrence and metastasis have been reported. It should be followed up for a long term after treatment.

Update on Uterine Mesenchymal Neoplasms

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

Uterine Tumor Resembling Ovarian Sex Cord Tumors (UTROSCT): Two Case Reports of the Rare Uterine Neoplasm with Literature Review

INTRODUCTION

Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are rare neoplasms with unknown etiology. This type of tumor has low malignant potential and mostly manifests as a benign clinical course.

MATERIALS AND METHODS

This article analyzes the case data, clinical manifestations, and histopathological characteristics of two cases of UTROSCT, and reviews the relevant literature. The diagnosis of UTROSCT is mainly based on histopathological examination. The histological characteristics of granulosa and Sertoli cell tumours are similar to the ovary under the microscope. These cases' clinical and radiological (MRI) findings have also been discussed.

RESULTS

The sex cord components are mixed in different proportions. The immunohistochemistry is diverse and can express sex cord markers together with both epithelial and smooth muscle markers. Both two cases revealed the signs of intratumoral cystic degeneration, intratumoral hemorrhage, and necrosis under MRI. These MRI features were helpful to prompt UTROSCT, which is histologically similar to granular cell tumors and is conducive to the differential diagnosis.

CONCLUSION

The current recommended treatment is total hysterectomy, but its biological behavior is not yet clear, and long-term follow-up is needed.

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.

When the uterine mass is not a leiomyoma

A 37-year-old nulliparous woman with abnormal uterine bleeding and a uterine mass suggestive of a leiomyoma not responding to medical therapy was submitted to two hysteroscopies with histological analysis. The first one showed a 'leiomyoma' and the second a 'uterine smooth muscle tumour of uncertain malignant potential/epithelioid leiomyosarcoma, with positivity for hormonal receptors'. The patient was submitted to a total hysterectomy with bilateral salpingo-oophorectomy, and the microscopic examination of the tumour revealed a 'uterine tumour resembling ovarian sex-cord tumours'. According to the literature, most cases are diagnosed in postmenopausal women and have a favourable prognosis. These rare tumours have uncertain malignant potential and have no established treatment protocol, but it appears that a fertility-sparing approach is possible once they are well diagnosed.

Uterine tumor resembling an ovarian sex cord tumor: A case report and review of literature

BACKGROUND

Endometrial stromal tumors originate from the endometrial stroma and account for < 2% of all uterine tumors. Uterine tumor resembling an ovarian sex cord tumor (UTROSCT) is a rare histological class of endometrial stromal and related tumors according to the latest World Health Organization classification of female genital tumors. Here, we report a case of UTROSCT in a 51-year-old woman.

CASE SUMMARY

A 51-year-old woman had irregular menses for 6 mo. The patient visited a local hospital for vaginal bleeding. Pelvic computed tomography (CT) showed a mass in the pelvic cavity. Five days later, she came to our hospital for further diagnosis. The results of contrast-enhanced CT and pelvic ultrasound at our hospital suggested a malignant pelvic tumor. She then underwent total removal of the uterus with bilateral salpingectomy. Postoperative histological examination showed that the tumor cells had abundant cytoplasm, ovoid and spindle-shaped nuclei, fine chromatin, a high nucleoplasm ratio, and a lamellar distribution. The findings were consistent with UTROSCT, and the results of immunohistochemical analysis supported that diagnosis. The tumor was International Federation of Gynecology and Obstetrics stage IB. No adjuvant therapy was administered after radical surgery. The patient was followed up for 58 mo, and no recurrence was found.

CONCLUSION

We report a case of UTROSCT with abnormal menstruation as a symptom, which is one of the most common symptoms. In patients with vaginal bleeding, ultrasonography can be used as a screening test because of its convenience, speed, and lack of radiation exposure. For patients with long-term tamoxifen use, routine monitoring of the endometrium is recommended. As UTROSCT may have low malignant potential, surgery remains the primary management strategy. Additionally, fertility preservation in patients of childbearing age is a vital consideration.

Update on Endometrial Stromal Tumours of the Uterus

Endometrial stromal tumours (ESTs) are rare, intriguing uterine mesenchymal neoplasms with variegated histopathological, immunohistochemical and molecular characteristics. Morphologically, ESTs resemble endometrial stromal cells in the proliferative phase of the menstrual cycle. In 1966 Norris and Taylor classified ESTs into benign and malignant categories according to the mitotic count. In the most recent classification by the WHO (2020), ESTs have been divided into four categories: Endometrial Stromal Nodules (ESNs), Low-Grade Endometrial Stromal Sarcomas (LG-ESSs), High-Grade Endometrial Stromal Sarcomas (HG-ESSs) and Undifferentiated Uterine Sarcomas (UUSs). ESNs are clinically benign. LG-ESSs are tumours of low malignant potential, often with indolent clinical behaviour, with some cases presented with a late recurrence after hysterectomy. HG-ESSs are tumours of high malignant potential with more aggressive clinical outcome. UUSs show high-grade morphological features with very aggressive clinical behavior. With the advent of molecular techniques, the morphological classification of ESTs can be integrated with molecular findings in enhanced classification of these tumours. In the future, the morphological and immunohistochemical features correlated with molecular categorisation of ESTs, will become a robust means to plan therapeutic decisions, especially in recurrences and metastatic disease. In this review, we summarise the morphological, immunohistochemical and molecular features of ESTs with particular reference to the most recent molecular findings.

Uterine Tumor Resembling Ovarian Sex Cord Stromal Tumor (UTROSCT): A Series of 3 Cases With Extensive Rhabdoid Differentiation, Malignant Behavior, and ESR1-NCOA2 Fusions

ESR1 and GREB1 fusions have recently been described in uterine tumor resembling ovarian sex cord tumor (UTROSCT). Thus far, recurrences have been documented in a subset of those harboring GREB1 fusions, but not in those with ESR1 rearrangements. Here we describe the clinicopathologic features of 3 recurrent UTROSCTs with striking rhabdoid morphology (an unusual feature of these tumors overall) and ESR1-NCOA2 fusions. The patients were 32, 37, and 54 years at initial diagnosis and first recurrence occurred at 7, 9, and 32 years. The primary tumors (available in two cases) were centered in the myometrium and showed infiltrative borders. They predominantly grew in sheets and cords, but also had a pseudopapillary appearance. Cells were uniformly epithelioid with eccentric nuclei, prominent nucleoli, abundant eosinophilic globular/glassy (rhabdoid) cytoplasm, and infrequent mitoses (≤4/10 high-power fields [HPFs]). Recurrences were morphologically identical to the primary tumors, but demonstrated brisk mitotic activity (≥16/10 HPFs). The third tumor (with only recurrences available) had multiple patterns, including diffuse, corded, trabecular, and a focal retiform growth. Rhabdoid cells were conspicuous, but only comprised ~50% of the tumor, and mitoses numbered up to 2/10 HPFs. All tumors were strongly and diffusely positive for WT1, CAM5.2, ER, and PR, but negative for inhibin. Diffuse calretinin and desmin expression, as well as focal melan-A positivity, was noted in one tumor, but was negative in the others. In all 3 tumors, INI-1 and BRG-1 were retained, and ESR1-NCOA2 fusions were detected by targeted RNA sequencing. This study is the first to highlight an association between UTROSCTs with extensive rhabdoid differentiation, ESR1-NCOA2 fusions, and aggressive behavior. UTROSCTs are considered neoplasms of uncertain malignant potential, but have a benign course in most cases. Thus, it is important to be aware of these specific features and recommend long-term follow-up due to their propensity for late recurrences.

Uterine tumor resembling ovarian sex-cord tumor: Conservative surgery with successful delivery and case series

Uterine tumor resembling ovarian sex-cord tumor (UTROSCT) is a rare distinct cancer included in the current World Health Organization classification of endometrial stromal tumors. A battery of immunohistochemical markers are necessary for accurate diagnosis. Although few case reports and case series have been documented and therefore providing robust prognostic information several authors agree to consider UTROSCT as a low malignant potential tumour. In literature only five cases of conservative management were reported. We reported our experience and a review of conservative cases of literature. In this article we describe a series of 10 cases of UTROSCT and their clinical and pathologic feature. We report two cases of conservative surgical approach obtaining a successfully pregnancies. All of the patients are still alive. In conclusion, fertility sparing surgery should be offered to patients who wish preserve their fertility however radical surgery must be considerate after childbirth. Close follow-up is required for all patients due to the lack of prognostic biomarkers and long follow up is needed to evaluate safety of conservative surgery.

An update of molecular findings in uterine tumor resembling ovarian sex cord tumor and GREB1-rearranged uterine sarcoma with variable sex-cord differentiation

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a uterine mesenchymal tumor defined histologically by showing sex cord-like growth patterns, such as sheets, nests, trabeculae, cords, or tubules, with/without Sertoli-like or Leydig-like components, and immunohistochemically by exhibiting variable sex cord markers in addition to epithelial, myogenic, and sex hormone markers. Recent years have seen the emergence in UTROSCT of novel fusion genes that involve key genes in sex hormone pathways, including ESR1 and GREB1 as the 5' partner, and (co)activator oncogenes, particularly NCOA1-3, as the 3' partner. While the identification of similar fusions in the majority of cases serves as a strong argument for UTROSCT to be a distinct entity, there is no denying significant clinicopathologic heterogeneity within the disease spectrum, which might to some extent correlate with the different fusion types. The current review gives a summary of the recently identified fusions in UTROSCT, along with their possible clinicopathologic relevance. Also discussed are unsolved issues including the relationship between UTROSCT and so-called GREB1-rearranged uterine sarcoma as well as other uterine mesenchymal tumors harboring similar fusions.

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

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

Uterine Tumor Resembling Ovarian Sex Cord Tumor (UTROSCT): A Morphologic and Molecular Study of 26 Cases Confirms Recurrent NCOA1-3 Rearrangement

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare mesenchymal neoplasm, of uncertain biological potential, that was recently reported to exhibit recurrent gene fusions involving NCOA2-3. The purpose of this study was to, using a larger sample size, better characterize the histopathologic and molecular diversity of UTROSCT. Twenty-six cases of UTROSCT from 5 institutions were selected for further study. Fluorescence in situ hybridization for NCOA1, NCOA2, NCOA3, ESR1 and GREB1, and targeted RNA sequencing was performed on 17 and 8 UTROSCTs, respectively. Eight cases underwent massively parallel sequencing to detect single nucleotide variants (SNV), copy number variations, and structural variants using a targeted hybrid-capture based assay. NCOA1-3 rearrangement was identified in 81.8% (18/22) of cases. The most common fusion was ESR1-NCOA3, occurring in 40.9% (9/22). GREB1-NCOA1 (n=4), ESR1-NCOA2 (n=3), and GREB1-NCOA2 (n=1) rearrangements were also identified. No recurrent SNVs were identified and no tumor had SNVs in FOXL2, DICER1, STK11, or AKT1, which can be seen in ovarian sex cord-stromal tumors. Copy number variations were infrequent. Clinical follow-up was available for 11 cases with a mean follow-up interval of 94.4 (range, 1 to 319) months. Only one case had a recurrence 66 months after the initial diagnosis and this was the single case with a GREB1-NCOA2 fusion. This study reports the morphologic spectrum of UTROSCT and confirms the recently reported recurrent NCOA2-3 gene fusions, in addition to identifying novel rearrangements involving NCOA1 in these tumors.

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.

Uterine tumor resembling ovarian sex-cord tumor (UTROSCT) with sarcomatous features without recurrence after extended radical surgery: A case report

RATIONALE

The malignant potential and the appropriate treatment of uterine tumor resembling ovarian sex-cord tumor (UTROSCT) is controversial. Although these tumors generally have benign outcomes, several reports have described recurrences, metastases, and deaths associated with this disease.

PATIENT CONCERNS

A 57-year-old Japanese woman (gravida 2, para 2) was referred to our hospital for the evaluation and treatment of uterine fibroids. Magnetic resonance imaging revealed a right ovarian mass and multiple fibroids in the uterine myometrium.

DIAGNOSES

The patient was diagnosed with UTROSCT with sarcomatous features.

INTERVENTIONS

She initially underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy, followed by second-stage surgery comprising pelvic and para-aortic lymphadenectomy and subtotal omentectomy.

OUTCOMES

No postoperative recurrence was observed in the patient in 36 months.

LESSONS

In this case, extended radical surgery prevented the development of recurrent disease in a patient with UTROSCT with sarcomatous features. These clinicopathological findings suggest that UTROSCT is associated with several risk factors, including older age, presence of necrosis, lymphovascular invasion, significant nuclear atypia, and significant mitotic activity. This lesion type should be considered malignant and treated with curative intent.

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

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

Uterine lesions with sex cord-like architectures: a systematic review

Background

Sex cord-like elements are rarely observed in uterine lesions, but these morphological patterns could appear in a variety of uterine tumors and non-tumorous lesions. In this review, we collected the literatures regarding the uterine tumorous and non-tumorous lesions containing sex cord-like elements and summarized these lesions in terms of clinicopathological, immunohistochemical, and molecular features in order to further understand these lesions and provide some new ideas for differential diagnosis.

Main body

This section provides a comprehensive overview of the clinicopathological, immunohistochemical, and molecular features of uterine lesions with sex cord-like architectures including uterine tumors resembling ovarian sex cord tumors, endometrial stromal tumors, adenomyosis, endometrial polyps, leiomyoma, epithelioid leiomyosarcoma, adenosarcoma, sertoliform endometrioid carcinoma, corded and hyalinized endometrioid carcinoma, mesonephric adenocarcinoma, and mesonephric-like adenocarcinoma. The differential diagnosis based on morphology, immunohistochemistry, and molecular alterations has also been discussed.

Conclusion

The sex cord-like areas in these lesions show heterogeneous but similar morphological features. Additionally, immunohistochemical staining plays a limited role in differential diagnosis. Furthermore, it is of significance for pathologists to better understand these lesions in order to avoid confusion and mistakes during pathological diagnosis, especially in a biopsy/curettage specimen.

Uterine Tumor Resembling Ovarian Sex Cord Tumor: A Distinct Entity Characterized by Recurrent NCOA2/3 Gene Fusions

Uterine tumor resembling ovarian sex-cord tumor (UTROSCT) is a rare and distinctive neoplasm of unclear histogenesis, and uncertain malignant potential. These neoplasms morphologically resemble sex-cord stromal tumors of the ovary, and possess a polyphenotypic immunophenotype. Their molecular pathogenesis has yet to be elucidated; notably, however, tumors lack alterations found in other uterine tumors bearing sex-cord-like differentiation, such as endometrial stromal sarcoma. Following identification of an index patient with an ESR1-NCOA3 fusion gene by RNA-sequencing, we undertook a retrospective review for additional cases of UTROSCT. We identified a total of 4 patients, with an average age of 53 years (range, 38 to 68 y). RNA-sequencing was performed in all cases, revealing an ESR1-NCOA3 fusion in 2 cases and one case each with related ESR1-NCOA2 and GREB1-NCOA2 fusions. Each of the tumors showed histologic and an immunophenotype features within the previously reported spectrum of UTROSCT; interestingly, one case contained prominent spindle cell fascicles and another was largely comprised of sheets of small round cells. Our results demonstrate UTROSCT are defined by recurrent fusions involving NCOA2 or NCOA3, a finding that is directly amenable to diagnostic evaluation. This study confirms UTROSCT is molecularly distinct from endometrial stromal sarcoma, and raises intriguing new questions into the pathogenesis of these neoplasms and possible relationship with other NCOA fusion-positive uterine tumors.

Uterine tumor resembling ovarian sex cord tumor: a clinicopathological and immunohistochemical analysis of two cases and a literature review

A uterine tumor resembling an ovarian sex cord tumor (UTROSCT) is a rare type of neoplasm that is almost thoroughly differentiated towards ovarian sex cord elements. Because of abnormal uterine bleeding, a 64-year-old postmenopausal woman received total abdominal hysterectomy with bilateral salpingo-oophorectomy. Under a microscope, the tumor cells showed an anastomosing fascicular and trabecular pattern with a reticular architecture. Immunohistochemistry showed that the tumor cells were positive for calretinin, Wilm’s tumor-1, and vimentin. A 33-year-old woman who suffered from menorrhagia, and was treated for bilateral salpingectomy, total abdominal hysterectomy, and bilateral ovarian biopsy, was also studied. Using histology, the patient was diagnosed with UTROSCT as shown by CD99, smooth muscle actin, calretinin, vimentin, and desmin expression. As a type of rare uterine tumor, UTROSCT can be diagnosed based on morphological and immunohistochemical conditions. Generally, these tumors are benign, but can easily relapse through incomplete resection. Hysterectomy should be performed after completion of family planning.

Beyond Smooth Muscle-Other Mesenchymal Neoplasms of the Uterus

Mesenchymal tumors of the uterus comprise a heterogeneous group of neoplasms of varied biologic potential. In addition to being host to several anatomically unique entities, the uterus may contain mesenchymal neoplasms typically found elsewhere in the body. Although smooth muscle neoplasms are common, other mesenchymal neoplasms in this location are relatively rare. Many of these neoplasms exhibit morphologic overlap. In addition to a careful histomorphologic review, definitive classification frequently depends on the judicious application of ancillary immunohistochemical and molecular testing. The intent of this review is to offer a basic approach to the classification of primary uterine mesenchymal neoplasms.

Tamoxifen related Uterine Tumor Resembling Ovarian Sex Cord Tumor (UTROSCT): A case report and literature review of this possible association

It is well known that a large number of patients treated with Tamoxifen develops endometrial pathologies ranging from benign endometrial polyps and hyperplasia to adenocarcinomas, carcinosarcomas and adenosarcomas. UTROSCT (Uterine Tumor Resembling Ovarian Sex Cord Tumor) is defined as a mesenchymal tumors of the uterine corpus that morphologically resembles ovarian sex cord tumors, without recognizable endometrial stroma. To date only 4 cases have been reported in patients treated with tamoxifen. In this article, we describe an additional case occurring in a 62-years-old patient undergoing 3 years of Tamoxifen therapy for bilateral breast carcinoma. The present work represents a further evidence of the possible association between Tamoxifen therapy and UTROSCT. A comprehensive literature review on this topic is also provided.

GREB1-CTNNB1 fusion transcript detected by RNA-sequencing in a uterine tumor resembling ovarian sex cord tumor (UTROSCT): A novel CTNNB1 rearrangement

Mutations of CTNNB1 have been implicated in tumorigenesis in many organs. However, tumors harboring a CTNNB1 translocation are extremely rare and this translocation has never been reported in a uterine mesenchymal neoplasm. We report a novel translocation t(2;3)(p25;p22) involving the GREB1 (intron 8) and CTNNB1 (exon 3) in a uterine tumor resembling ovarian sex cord tumor (UTROSCT), which exhibited extrauterine metastasis. The translocation detected by RNA-sequencing was validated by RT-PCR, and resulted in nuclear expression of β-catenin. Juxtapositioning with GREB1, which is overexpressed in response to estrogens, resulted in overexpression of a truncated and hypophosphorylated nuclear β-catenin in the primary and recurrent tumors. This accumulation of nuclear β-catenin results in a constitutive activation of the Wnt/β-catenin signaling pathway with a major oncogenic effect. The CTNNB1 gene fusion, promoted by an estrogen-responsive gene (GREB1), could be a potential driver of tumorigenesis in this case and a therapeutic target with adapted inhibitors. RT-PCR and immunohistochemistry performed on 11 additional UTROSCTs showed no CTNNB1 fusion transcript or nuclear β-catenin immunoreactivity.

Uterine Tumors Resembling Ovarian Sex Cord Tumors in Four Baboons ( Papio spp.)

Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are rare uterine neoplasms that exhibit prominent sex cord-like differentiation. The authors describe 4 cases of UTROSCTs that were identified as incidental lesions in female baboons. All baboons were in good body condition. One animal had a 2-mm-diameter yellow-tan mass in the uterine body along the attachment of the left broad ligament; the other 3 did not have any gross lesions in the uterus. Histologically, the myometrium contained multifocal well-demarcated neoplasms composed of cuboidal to columnar cells arranged in variable arrangements of sheets, nests, cords, trabecular, and retiform patterns that occasionally formed Call-Exner-like bodies. In all cases, the neoplastic cells were diffusely positive for WT-1 and negative for calretinin, CD99, and desmin. One case was positive for inhibin and CD10. To the best of the authors' knowledge, this is the first report of UTROSCTs in nonhuman primates and in the veterinary literature.

Metastatic uterine tumor resembling ovarian sex cord tumor: A case report and review of the literature

Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are rare and commonly characterized as benign tumors, with infrequent reports of metastasis and recurrence. Treatment recommendations have not been well established, particularly for more advanced cases. We present the first reported death from a metastatic UTROSCT, summarize the available literature, and describe characteristics common to UTROSCTs with aggressive features. In this case, a 49-year-old woman presented with abdominal distension and pain; initial imaging and diagnostic workup suggested metastatic epithelial ovarian cancer to be the cause. The patient subsequently underwent neoadjuvant chemotherapy followed by optimal cytoreductive surgery and adjuvant chemotherapy. Final pathology revealed UTROSCT with omental and peritoneal metastases. She then underwent adjuvant chemotherapy with subsequent recurrence and died 15 months after her initial diagnosis. Our analysis of this case and the available literature led us to identify pathologic risk factors that may help predict aggressive UTROSCT behavior.

Uterine Tumor Resembling Ovarian Sex Cord Tumor (UTROSCT) Commonly Exhibits Positivity With Sex Cord Markers FOXL2 and SF-1 but Lacks FOXL2 and DICER1 Mutations

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare neoplasm which morphologically and immunohistochemically exhibits overlap with an ovarian sex cord tumor. Although many of these neoplasms are positive with markers of ovarian sex cord-stromal tumors, staining is often limited and the pathogenesis of UTROSCT is unknown. To further explore the sex cord lineage of UTROSCT, we studied 19 of these neoplasms and examined the expression of 2 recently described markers of ovarian sex cord-stromal tumors, FOXL2, and steroidogenic factor-1. We also undertook FOXL2 and DICER1 mutation analysis in these cases; a somatic missense mutation in codon C134W (402C→G) of FOXL2 gene has been demonstrated in the vast majority (>95%) of ovarian adult granulosa cell tumors and somatic DICER1 mutations are found in approximately 60% of ovarian Sertoli-Leydig cell tumors. Ten of 19 cases (53%) exhibited nuclear immunoreactivity with FOXL2 and 11 of 19 (58%) exhibited nuclear staining with steroidogenic factor-1. Neither FOXL2 nor DICER1 mutations were identified in any case where there was sufficient tumor tissue for analysis (18 and 9 cases, respectively). Despite exhibiting an immunophenotype characteristic of a sex cord-stromal tumor, mutations in FOXL2 and DICER1, the 2 most common mutations hitherto reported in ovarian sex cord-stromal tumors, are not a feature of UTROSCT.

Uterine Tumors Resembling Ovarian Sex Cord Tumors: Case Report of Rare Pathological and Clinical Entity

Uterine tumors resembling ovarian sex cord tumors (UTROSCT) are rare uterine neoplasms. These tumors are usually benign, displaying a nodular or polypoid growth pattern; common occurrence is observed at the 4th to 6th decade of life. This entity is divided according to clinical behavior and pathological typical findings including different immunohistochemical staining. Traditionally type I tumors show a predominant endometrial stromal pattern with less than 50% ovarian sex cord component. This type has been shown to behave more aggressively with a decreased disease free survival period. Type II tumors, the classical UTROSCT, are less invasive but have the tendency to recur. We report a case of a 57-year-old patient presenting with postmenopausal bleeding. Hysteroscopic polypectomy showed the diagnosis of UTROSCT. This case presents a less morbid minimally invasive treatment plan and exemplifies that in patients where low malignant potential exists and their will is taken into consideration such management is both crucial and correct.

Uterine tumour resembling ovarian sex cord tumour: first report of a large series with follow-up

AIMS

Uterine tumour resembling ovarian sex cord tumour (UTROSCT) is an uncommon mesenchymal neoplasm of uncertain histogenesis. While it is considered a neoplasm of uncertain but low malignant potential, there is limited evidence for this as there are no large studies with follow-up. We aimed to determine the clinical behaviour of this uncommon neoplasm and investigate clinicopathological parameters which predict behaviour.

METHODS AND RESULTS

From a series of 34 cases of UTROSCT, mainly from consultation practice, we obtained follow-up information which was obtained by contacting referring pathologists and clinicians. The follow-up periods ranged from 6 to 135 months (mean 39 months). Eight of 34 patients (23.5%) developed extrauterine metastasis to a variety of sites, including pelvic and abdominal peritoneum, ovary, lymph nodes, bone, liver and lung, and three patients (8.8%) died of tumour. Those neoplasms which exhibited malignant behaviour occurred on average in older patients, and were larger and more likely to exhibit necrosis, lymphovascular invasion, cervical involvement, significant nuclear atypia and significant mitotic activity. However, only the presence of necrosis and significant mitotic activity was statistically significant.

CONCLUSIONS

While our figure of 23.5% of cases exhibiting malignant behaviour may reflect some bias related to consultation practice our results show that, not uncommonly, these neoplasms have an aggressive clinical course with extrauterine metastasis. Given the overlap in pathological parameters between clinically benign and malignant neoplasms, UTROSCTs are all best regarded as potentially malignant.

[New features in the 2014 WHO classification of uterine neoplasms]

The 2014 World Health Organization (WHO) classification of uterine tumors revealed simplification of the classification by fusion of several entities and the introduction of novel entities. Among the multitude of alterations, the following are named: a simplified classification for precursor lesions of endometrial carcinoma now distinguishes between hyperplasia without atypia and atypical hyperplasia, the latter also known as endometrioid intraepithelial neoplasia (EIN). For endometrial carcinoma a differentiation is made between type 1 (endometrioid carcinoma with variants and mucinous carcinoma) and type 2 (serous and clear cell carcinoma). Besides a papillary architecture serous carcinomas may show solid and glandular features and TP53 immunohistochemistry with an "all or null pattern" assists in the diagnosis of serous carcinoma with ambiguous features. Neuroendocrine neoplasms are categorized in a similar way to the gastrointestinal tract into well differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas (small cell and large cell types). Leiomyosarcomas of the uterus are typically high grade and characterized by marked nuclear atypia and lively mitotic activity. Low grade stromal neoplasms frequently show gene fusions, such as JAZF1/SUZ12. High grade endometrial stromal sarcoma is newly defined by cyclin D1 overexpression and the presence of the fusion gene YWHAE/FAM22 and must be distinguished from undifferentiated uterine sarcoma. Carcinosarcomas (malignant mixed Mullerian tumors MMMT) show biological and molecular similarities to high-grade carcinomas.

Extensive Overgrowth of Sex Cord-Like Differentiation in Uterine Mullerian Adenosarcoma: A Rare and Challenging Entity

Sex cord-like differentiation has been well documented in endometrial stromal tumors. On the basis of the extent of sex cord differentiation, uterine stromal tumors with this kind of differentiation have been classified into 2 subgroups of endometrial stromal tumor with sex cord-like elements and uterine tumors resembling ovarian sex cord tumor. When extensive, this differentiation has been accompanied with indolent clinical behavior and rather good prognosis in most cases. Sex cord differentiation has been rarely observed in uterine mullerian adenosarcoma. Only 3 cases of such occurrence have been reported in the English literature. Herein, we report a case of uterine mullerian adenosarcoma extensively overgrown by uterine tumor resembling ovarian sex cord tumor in a young woman. The presence of an ovarian sex cord tumor component has been confirmed by immunohistochemistry. To the best of our knowledge, this is the second report of such a case in the English literature.

SF1 immunohistochemistry is useful in differentiating uterine tumours resembling sex cord-stromal tumours from potential histological mimics

The aim of this study was to perform an immunohistochemical comparison of uterine tumour resembling ovarian sex cord-stromal tumour (UTROSCT) and other uterine lesions with sex cord-like (SCL) differentiation. Six UTROSCTs and 10 potential histological mimics with focal SCL elements were examined, the latter comprising three endometrial stromal nodules, three low-grade endometrial stromal sarcomas, three Müllerian adenosarcomas, and one case of adenomyosis. All cases were stained immunohistochemically for SF1, FOXL2, calretinin and inhibin, and for the less specific markers smooth muscle actin, desmin, CD10, CD56, CD99, cytokeratin, oestrogen receptor and progesterone receptor. Three, four, six and three UTROSCT expressed SF1, FOXL2, calretinin and inhibin, respectively. However, calretinin staining was focal (≤50% cells positive) in five of the cases. Three potential histological mimics demonstrated calretinin, FOXL2 and/or inhibin staining but none was SF1 positive. Most cases in both groups expressed the less specific immunomarkers. SF1 and FOXL2 immunoreactivity in UTROSCT further supports the concept that these tumours demonstrate genuine sex cord-stromal differentiation. While calretinin was the most sensitive UTROSCT marker, staining was usually focal and expression was also seen in two of 10 potential histological mimics. SF1 staining was 100% specific for UTROSCT in this series but this finding should be confirmed in larger studies.

Conservative Resectoscopic Surgery, Successful Delivery, and 60 Months of Follow-Up in a Patient with Endometrial Stromal Tumor with Sex-Cord-Like Differentiation

Uterine tumors with sex-cord-like differentiation are extremely rare types of uterine stromal neoplasm. These tumors were classified into two groups with considerable practical relevance because clinical behaviour of uterine tumor resembling ovarian sex cord tumor (UTROSCT) differs widely from its closely related endometrial stromal tumors with sex-cord-like elements (ESTSCLE). Treatment and prognosis of these tumors are unresolved issues because of the exiguous number of reported cases. We describe a rare case of endometrial stromal tumor with sex-cord-like differentiation successfully treated by resectoscopic surgery and conservation of the uterus, in an infertile patient affected by metrorrhagia. This procedure resulted in a pregnancy immediately after treatment and in a successful delivery. During 60 months of follow-up no evidence of recurrence was observed.

Practical issues related to uterine pathology: endometrial stromal tumors

Uterine mesenchymal tumors continue to be a challenge to diagnose due to their non-specific clinical presentation, often non-distinctive gross appearance, varied (and many times overlapping) morphologic appearance, and unsuspected pitfalls in immunohistochemical expression. This review will focus on endometrial stromal tumors and those features that help in their distinction. In particular, a practical approach to the diagnosis of endometrial stromal neoplasia will be covered including recognition as a stromal process in a biopsy/curettage and distinction from a highly cellular leiomyoma. In addition, distinction of a stromal nodule from a low-grade endometrial stromal sarcoma (LGESS) and stromal sarcoma with limited infiltration in a hysterectomy specimen will be covered. The salient features that help distinguish a LGESS from a uterine tumor resembling ovarian sex-cord tumor as well as high-grade endometrial stromal sarcoma, the latter a tumor recently reintroduced in the WHO classification will also be discussed. Finally, a practical approach to the diagnosis of undifferentiated uterine sarcoma (UUS) will be presented.

Practical issues in uterine pathology from banal to bewildering: the remarkable spectrum of smooth muscle neoplasia

Among mesenchymal tumors of the uterus, smooth muscle neoplasms are most common. The wide morphologic spectrum, especially within the category of leiomyomas, is responsible for diagnostic problems more frequently with leiomyosarcoma (including mitotically active, apoplectic, and leiomyoma with bizarre nuclei) but also with endometrial stromal tumors. In the former scenario, clinical information, gross appearance as well as strict utilization of morphologic criteria including cytologic atypia, mitotic activity, and tumor cell necrosis are clues in establishing the correct diagnosis. It is important to keep in mind that mitotic rate thresholds vary for the different subtypes of leiomyosarcoma. Of note, p16 should be used with caution in supporting a diagnosis of leiomyosarcoma as it is often positive in leiomyomas with bizarre nuclei and leiomyomas with apoplectic change (in the latter most frequently and more intense near areas of necrosis). MED12 mutations have also a very limited role in this differential diagnosis. Endometrial stromal tumors are by far, less common than smooth muscle tumors, but can be confused with leiomyosarcomas if they are associated with an undifferentiated uterine sarcoma and the low-grade component is overlooked or they have a myxoid/fibroblastic morphology. The differential diagnosis may be confounded if the latter is associated with a high-grade endometrial stromal sarcoma. It is important to highlight that CD10 is not a reliable marker in these differentials and should be used as a part of a panel of antibodies that also includes desmin and h-caldesmon. Two other recently categorized tumors in the uterus that merit special mention are PEComa and inflammatory myofibroblastic tumor as they enter in the differential diagnosis of smooth muscle tumors. PEComa may be part of the tuberous sclerosis syndrome and may show either a predominantly epithelioid or spindle morphology or combination thereof. Rarely, it may contain melanin pigment. There is variable positivity for HMB-45, MelanA, MiTF, and CathepsinK, and some tumors have been shown to express TFE-3 especially when associated with "clear cell" morphology. Patients with adverse outcome have tumors with ≥2 of the following features: ≥5 cm, infiltration, high-grade cytologic features, mitotic rate ≥1/50 high-power fields, necrosis, or lymphovascular invasion. Inflammatory myofibroblastic tumor is important to recognize as it often mimics myxoid smooth muscle tumors, either benign or malignant. The presence of an associated lymphoplasmacytic infiltrate should alert to that possibility and ALK studies (immunostain or FISH) are helpful in establishing this diagnosis. These tumors can behave in a malignant manner if large, associated with abundant myxoid change, brisk mitotic rate or show tumor cell necrosis.