MR imaging of uterine sarcomas

A Case Report of Uterine Müllerian Adenosarcoma With Sarcomatous Overgrowth

Uterine adenosarcoma remains a highly aggressive tumor and is less described in the literature, with an unfavorable prognosis and an increased risk of local and distant recurrence. However, surgery, chemotherapy, and radiotherapy offer local control of the disease, and overall survival remains reduced. We report the case of a 79-year-old patient with stage IIIB uterine adenosarcoma, confirmed by immunohistochemistry and initially diagnosed with postmenopausal metrorrhagia. The patient was managed through a multimodal treatment by conducting a multidisciplinary consultation.

Smooth Muscle Tumors of the Uterus at MRI: Focus on Leiomyomas and FIGO Classification

Leiomyomas are smooth muscle tumors of the uterus and are the most common uterine neoplasm. Although leiomyomas are usually asymptomatic, they can manifest with symptoms such as pain or uterine bleeding. Leiomyomas are classified on the basis of their anatomic location and morphology. Localization of leiomyomas relative to the endometrium, myometrium, and uterine serosa with use of the International Federation of Gynecology and Obstetrics (FIGO) classification system is helpful for guiding management in symptomatic patients. The FIGO system is a practical and universally accepted approach for classifying leiomyomas to guide radiologists and clinicians in deciding management. The MRI appearance of conventional leiomyomas is related to their tissue contents of smooth muscle and fibrous tissue and is well established. The MRI features of some leiomyoma subtypes and forms of degeneration also have been described. Other smooth muscle tumors of the uterus recognized in the 2020 World Health Organization classification system include intravenous leiomyomatosis, smooth muscle tumors of uncertain malignant potential, and metastasizing leiomyoma. At the far end of the spectrum are leiomyosarcomas, which are frankly malignant and therefore must be managed accordingly. Although MRI features that suggest a diagnosis of leiomyosarcoma have been proposed, these features overlap with those of some leiomyoma subtypes and degeneration. ^© RSNA, 2023 See the invited commentary by Fennessy and Gargiulo in this issue. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

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

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

Advances in the Preoperative Identification of Uterine Sarcoma

Simple Summary

As a lethal malignant tumor, uterine sarcomas lack specific diagnostic criteria due to their similar presentation with uterine fibroids, clinicians are prone to make the wrong diagnosis or adopt incorrect treatment methods, which leads to rapid tumor progression and increased metastatic propensity. In recent years, with the improvement of medical level and awareness of uterine sarcoma, more and more studies have proposed new methods for preoperative differentiation of uterine sarcoma and uterine fibroids. This review outlines the up-to-date knowledge about preoperative differentiation of uterine sarcoma and uterine fibroids, including laboratory tests, imaging examinations, radiomics and machine learning-related methods, preoperative biopsy, integrated model and other relevant emerging technologies, and provides recommendations for future research.

Abstract

Uterine sarcomas are rare malignant tumors of the uterus with a high degree of malignancy. Their clinical manifestations, imaging examination findings, and laboratory test results overlap with those of uterine fibroids. No reliable diagnostic criteria can distinguish uterine sarcomas from other uterine tumors, and the final diagnosis is usually only made after surgery based on histopathological evaluation. Conservative or minimally invasive treatment of patients with uterine sarcomas misdiagnosed preoperatively as uterine fibroids will shorten patient survival. Herein, we will summarize recent advances in the preoperative diagnosis of uterine sarcomas, including epidemiology and clinical manifestations, laboratory tests, imaging examinations, radiomics and machine learning-related methods, preoperative biopsy, integrated model and other relevant emerging technologies.

Ultrasound-Guided Trans-Uterine Cavity Core Needle Biopsy of Uterine Myometrial Tumors to Differentiate Sarcoma from a Benign Lesion—Description of the Method and Review of the Literature

Uterine sarcomas are rare, aggressive tumors with poor prognosis that can be further negatively affected by inadequate surgical approaches such as morcellation. There are no clinical and radiologic criteria for differentiating leiomyoma from malignant uterine tumors. However, some ultrasonography and magnetic resonance imaging findings may be informative. We present a technique of ultrasound-guided trans-uterine cavity (UG-TUC) core needle biopsy for uterine lesions. As the procedure is an in-organ biopsy, there is no risk of needle canal contamination. The technique also enables the biopsy of lesions inaccessible by the transvaginal tru-cut biopsy. The core needle of the automatic biopsy system is inserted via the cervical canal into the uterine cavity and is directed and activated at the myometrial lesion under ultrasound control. The standard local treatment of localized uterine sarcomas is en bloc total hysterectomy; for fibroids, there are multiple options including conservative management or tumorectomy and tumor morcellation using minimally invasive techniques. Fragmentation of the sarcoma significantly worsens oncologic outcomes and should therefore be avoided. The UG-TUC core needle biopsy of uterine lesions can complement imaging to obtain sufficient material for histologic and molecular analyses of suspected or undetermined lesions, thus facilitating treatment planning and decreasing the risk of unsuspected sarcomas.

Clinical value of pre-operative scoring systems to predict leiomyosarcoma: results of a validation study in 177 patients from the NOGGO-REGSA Registry

Objectives

Benign leiomyomas are the most common uterine tumors. In contrast, uterine leiomyosarcomas are malignancies with a poor prognosis due to difficulties in early diagnosis and inappropriate surgical treatment. Most often they are diagnosed incidentally after surgery performed for treatment of leiomyoma. As the appropriate surgical treatment is crucial for survival of the patient, there is a high demand to predict leiomyosarcoma pre-operatively. Available scoring systems to discriminate leiomyoma from leiomyosarcoma are based on retrospective studies with limited numbers of patients and are not implemented in routine clinical practice.

Methods

The aim of our study was to evaluate a recently published score—the pre-operative leiomyosarcoma (pLMS) score—to determine whether it would have been predictive of leiomyosarcoma in 177 patients from the NOGGO-REGSA study, a German register of histologically proven gynecological sarcoma detected during routine clinical investigation.

Results

The threshold of the pLMS score for ‘leiomyosarcoma not probable’ (< −3) failed for 7.5% of the patients and the threshold ‘indicator for leiomyosarcoma’ (>+1) was true for 39.1% of the patients. 53.4% of the patients were attributed to the group ‘additional investigations are recommended’ (−3 to +1). The most relevant parameters in our analysis were suspicious sonography and rapid growth, but neither have been quantitatively defined.

Conclusion

In our validation cohort, the pLMS score seems not to be a reliable tool to predict leiomyosarcoma and therefore we do not recommend its clinical implementation to identify leiomyosarcoma.

Superficial myofibroblastoma of the vagina with a stalk: case report of a rare vaginal tumor with notable radiological findings

Superficial myofibroblastoma is a rare benign mesenchymal tumor which predominantly occurs in the female lower genital tract. Here we present a case of a 42-year-old female patient with prolonged vaginal bleeding. Radiological imaging revealed a well circumscribed mass in the vagina with a stalk. The patient underwent surgery and the tumor was histologically diagnosed as superficial myofibroblastoma. Notably, this is the first report of the radiological imaging of a superficial myofibroblastoma harboring a stalk arising from the vaginal wall. We compared the radiological images with histological findings and discuss major differential diagnosis of vaginal tumors. Despite the challenging nature of preoperative diagnosis of mesenchymal vaginal tumors, radiological features may aid in differentiating them from other more aggressive entities or malignant tumors.

Differentiating uterine sarcoma from leiomyoma: BET1T2ER Check!

Although rare, uterine sarcoma is a diagnosis that no one wants to miss. Often benign leiomyomas (fibroids) and uterine sarcomas can be differentiated due to the typical low T2 signal intensity contents and well-defined appearances of benign leiomyomas compared to the suspicious appearances of sarcomas presenting as large uterine masses with irregular outlines and intermediate T2 signal intensity together with possible features of secondary spread. The problem is when these benign lesions are atypical causing suspicious imaging features. This article provides a review of the current literature on imaging features of atypical fibroids and uterine sarcomas with an aide-memoire BET¹T²ER Check! to help identify key features more suggestive of a uterine sarcoma.

Uterine Sarcomas: Are There MRI Signs Predictive of Histopathological Diagnosis? A 50-Patient Case Series with Pathological Correlation

Purpose

To make clear distinction between two radiological types of uterine sarcomas.

Methods

50 preoperative MRI were analyzed retrospectively, blinded to histopathology: 11 endometrial stromal sarcomas (ESS), 19 leiomyosarcomas (LMS), 18 carcinosarcomas/malignant mixed Mullerian tumors (MMMT), and 2 smooth muscle tumors of uncertain malignant potential (STUMP).

Results

According to their locations, two radiological types of sarcomas were identified: type 1: intracavitary (ESS, MMMT) and type 2: intramyometrial (LMS, STUMP). In both types, all tumors displayed intermediate T2-weighted signal (p < 0.001) and high diffusion-weighted imaging (DWI) b1000 signal (p < 0.001). Dynamic contrast-enhanced (DCE) MRI showed intratumoral pathologic vessels (98%) and heterogeneity at venous phase (p < 0.001). In the type 1 subgroup, all tumors displayed local spread: invasion of junctional zone on T2-weighted imaging (T2WI), irregular margins on DWI, and disruption of arcuate arteries subendometrial ring on DCE-MRI. In the type 2 subgroup, all tumors displayed irregular margins on T2WI, DWI, and DCE-MRI. Tumor heterogeneity was due to necrosis (p < 0.001). Most commonly the tumor was single (61%). In both types, apparent diffusion coefficient (ADC) lesser than or equal to 0.86 × 10^-3 mm²/s (sensitivity = 73%, specificity = 92%) was suggestive of malignancy.

Conclusion

It may be feasible to get close to histological type of a uterine sarcoma based on our topographic classification into two radiological subgroups, corresponding to two kinds of diagnostic difficulties. Advances in knowledge. MRI signs suggestive of histopathological malignancy are identifiable, considering the triad T2WI/DWI/DCE-MRI, easily for type 1 but less easily for type 2; the threshold value for ADC is 0.86 × 10^-3 mm²/s.

Diagnostic interpretation of non-contrast qualitative MR imaging features for characterisation of uterine leiomyosarcoma

OBJECTIVE

To assess the value of non-contrast MRI features for characterisation of uterine leiomyosarcoma (LMS) and differentiation from atypical benign leiomyomas.

METHODS

This study included 57 atypical leiomyomas and 16 LMS which were referred pre-operatively for management review to the specialist gynaeoncology multidisciplinary team meeting. Non-contrast MRIs were retrospectively reviewed by five independent readers (three senior, two junior) and a 5-level Likert score (1-low/5-high) was assigned to each mass for likelihood of LMS. Evaluation of qualitative and quantitative MRI features was done using uni- and multivariable regression analysis. Inter-reader reliability for the assessment of MRI features was calculated by using Cohen's κ values.

RESULTS

In the univariate analysis, interruption of the endometrial interface and irregular tumour shape had the highest odds ratios (ORs) (64.00, p < 0.001 and 12.00, p = 0.002, respectively) for prediction of LMS. Likert score of the mass was significant in prediction (OR, 3.14; p < 0.001) with excellent reliability between readers (ICC 0.86; 95% CI, 0.76-0.92). The post-menopausal status, interruption of endometrial interface and thickened endometrial stripe were the most predictive independent variables in multivariable estimation of the risk of leiomyosarcoma with an accuracy of 0.88 (95%CI, 0.78-0.94).

CONCLUSION

At any level of expertise as a radiologist reader, the loss of the normal endometrial stripe (either thickened or not seen) in a post-menopausal patient with a myometrial mass was highly likely to be LMS.

ADVANCES IN KNOWLEDGE

This study demonstrates the potential utility of non-contrast MRI features in characterisation of LMS over atypical leiomyomas, and therefore influence on optimal management of these cases.

The Risk of Uterine Malignancy in a Population Being Evaluated for Uterine Fibroid Embolization

OBJECTIVE

The aim of the study was to determine the frequency of uterine malignancy in patients evaluated for uterine fibroid embolization (UFE) and the role of magnetic resonance imaging in triage.

METHODS

Records and imaging studies of 864 UFE consult patients were reviewed for MRI findings suggestive of fibroid malignancy. Pathology was obtained for cases with suspicious baseline MRI's, and the most atypical mass was reanalyzed by an experienced radiologist, blinded to the pathological findings.

RESULTS

Twenty one of 864 patients had baseline MRI findings concerning for malignancy at consultation and 17 had complete records. Re-evaluation suggested that 5 were malignant. Three were confirmed malignant (0.35%). One malignancy among the 843 without suspicious baseline MRI findings was missed at consultation.

CONCLUSIONS

In our UFE population, uterine malignancy is rare (4/864, 0.46%), and MRI detected the majority, 3 (75%) of 4 before UFE. The observed prevalence of any malignancy was 0.35%, congruent with current Federal Drug Administration estimates.

Advances in MR Imaging of the Female Pelvis

This article focuses on advanced MR imaging techniques of the female pelvis and clinical applications for benign and malignant disease. General and abbreviated protocols for female pelvic MR imaging are reviewed. Diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and susceptibility-weighted imaging are discussed in the context of adnexal mass characterization using the ADNEx-MR scoring system, evaluation of endometriosis, local staging of cervical and endometrial cancers, assessment of nodal and peritoneal metastasis, and potential detection of leiomyosarcoma. MR defecography is also discussed regarding evaluation of multicompartmental pelvic floor disorders.

A Diagnostic Algorithm using Multi-parametric MRI to Differentiate Benign from Malignant Myometrial Tumors: Machine-Learning Method

This study aimed to develop a diagnostic algorithm for preoperative differentiating uterine sarcoma from leiomyoma through a supervised machine-learning method using multi-parametric MRI. A total of 65 participants with 105 myometrial tumors were included: 84 benign and 21 malignant lesions (belonged to 51 and 14 patients, respectively; based on their postoperative tissue diagnosis). Multi-parametric MRI including T1-, T2-, and diffusion-weighted (DW) sequences with ADC-map, contrast-enhanced images, as well as MR spectroscopy (MRS), was performed for each lesion. Thirteen singular MRI features were extracted from the mentioned sequences. Various combination sets of selective features were fed into a machine classifier (coarse decision-tree) to predict malignant or benign tumors. The accuracy metrics of either singular or combinational models were assessed. Eventually, two diagnostic algorithms, a simple decision-tree and a complex one were proposed using the most accurate models. Our final simple decision-tree obtained accuracy = 96.2%, sensitivity = 100% and specificity = 95%; while the complex tree yielded accuracy, sensitivity and specificity of 100%. To summarise, the complex diagnostic algorithm, compared to the simple one, can differentiate tumors with equal sensitivity, but a higher specificity and accuracy. However, it needs some further time-consuming modalities and difficult imaging calculations. Trading-off costs and benefits in appropriate situations must be determinative.

Differential Diagnosis of Uterine Leiomyoma and Uterine Sarcoma using Magnetic Resonance Images: A Literature Review

MRI plays an essential role in patients before treatment for uterine mesenchymal malignancies. Although MRI includes methods such as diffusion-weighted imaging and dynamic contrast-enhanced MRI, the differentiation between uterine myoma and sarcoma always becomes problematic. The present paper discusses important findings to ensure that sarcomas are not overlooked in magnetic resonance (MR) images, and we describe the update in the differentiation between uterine leiomyoma and sarcoma with recent reports.

T2 hyperintense myometrial tumors: can MRI features differentiate leiomyomas from leiomyosarcomas?

PURPOSE

To establish MRI features that help differentiate atypical leiomyomas and leiomyomas with degeneration that show hyperintensity on T2WI from leiomyosarcomas.

METHODS AND MATERIALS

This retrospective study evaluated 41 women who performed MRI before undergoing hysterectomy and had histologically proven atypical leiomyomas, leiomyomas with degeneration or leiomyosarcomas (21 leiomyomas; 20 leiomyosarcomas); only patients with T2 hyperintense myometrial tumors were included. The association between MRI features (contours; free pelvic fluid; intra-tumoral hemorrhagic areas, T2 heterogeneity; T2 dark areas; flow voids; restriction on diffusion-weighted images; signal intensity and heterogeneity after contrast administration; unenhanced areas, localization of unenhanced areas; necrosis; cystic areas) and the histology (leiomyoma vs. leiomyosarcoma) were calculated using Fisher's exact test. For those features that showed a significant association, a univariate linear regression was performed.

RESULTS

Five MRI features demonstrated a significant correlation with malignant histology: irregular borders (p = 0.03); "T2 dark" areas (p = 0.02); presence of central necrosis (p = 0.01); presence of high signal on b1000 DWI (p < 0.001); ADC value lower than 0.82 × 10^-3 mm²/s; hyperenhancement of the tumor relative to the myometrium on post-contrast images (p = 0.02); and type 3 enhancing curve on DCE. Two of these features demonstrated a significant result predicting a malignant histology: lobulated contours and central necrosis [F(3;34) = 8,95; p < 0.001; R² = 0.506].

CONCLUSION

The presence of lobulated borders, T2 dark areas, necrosis, hyperintensity relative to the myometrium after contrast administration, central necrosis, presence of high signal on b1000 DWI, ADC value lower than 0.82 × 10^-3 mm²/s and type 3 enhancing curve on DCE can help distinguish between leiomyoma and leiomyosarcoma. The association of lobulated borders and central necrosis can help predict a malignant histology.

Machine Learning to Differentiate T2-Weighted Hyperintense Uterine Leiomyomas from Uterine Sarcomas by Utilizing Multiparametric Magnetic Resonance Quantitative Imaging Features

RATIONALE AND OBJECTIVE

Uterine leiomyomas with high signal intensity on T2-weighted imaging (T2WI) can be difficult to distinguish from sarcomas. This study assessed the feasibility of using machine learning to differentiate uterine sarcomas from leiomyomas with high signal intensity on T2WI on multiparametric magnetic resonance imaging.

MATERIALS AND METHODS

This retrospective study included 80 patients (50 with benign leiomyoma and 30 with uterine sarcoma) who underwent pelvic 3 T magnetic resonance imaging examination for the evaluation of uterine myometrial smooth muscle masses with high signal intensity on T2WI. We used six machine learning techniques to develop prediction models based on 12 texture parameters on T1WI and T2WI, apparent diffusion coefficient maps, and contrast-enhanced T1WI, as well as tumor size and age. We calculated the areas under the curve (AUCs) using receiver-operating characteristic analysis for each model by 10-fold cross-validation and compared these to those for two board-certified radiologists.

RESULTS

The eXtreme Gradient Boosting model gave the highest AUC (0.93), followed by the random forest, support vector machine, multilayer perceptron, k-nearest neighbors, and logistic regression models. Age was the most important factor for differentiation (leiomyoma 44.9 ± 11.1 years; sarcoma 58.9 ± 14.7 years; p < 0.001). The AUC for the eXtreme Gradient Boosting was significantly higher than those for both radiologists (0.93 vs 0.80 and 0.68, p = 0.03 and p < 0.001, respectively).

CONCLUSION

Machine learning outperformed experienced radiologists in the differentiation of uterine sarcomas from leiomyomas with high signal intensity on T2WI.

Uterine smooth muscle tumors of unknown malignant potential: A challenging question

Uterine smooth muscle tumors of unknown malignant potential [STUMP]s are neoplasms with pathological features that preclude an equivocal diagnosis of leiomyosarcoma, but that do not fulfill the criteria for leiomyoma or its variants, and raise concerns that the tumors may behave in a malign fashion. Total hysterectomy with or without bilateral salpingo-oophorectomy is the standard treatment if fertility is completed, whereas myomectomy alone can be taken into consideration in young patients who desire to preserve childbearing potential. A careful surveillance every 6 months for 5 years and then yearly is strongly warranted. Patients with STUMP can relapse as either STUMP or leiomyosarcoma in approximately 11-13% of the cases, and their 5-year overall survival ranges from 92 to 100%. The present paper reviews the clinicopathological features of uterine STUMPs with a particular focus on most commonly accepted histopathological criteria for the diagnosis and on biological behaviour of these controversial neoplasms.

Preliminary utilization of radiomics in differentiating uterine sarcoma from atypical leiomyoma: Comparison on diagnostic efficacy of MRI features and radiomic features

OBJECTIVES

To explore whether MRI and radiomic features can differentiate uterine sarcoma from atypical leiomyoma. And to compare diagnostic performance of radiomic model with radiologists.

METHODS

78 patients (29 sarcomas, 49 leiomyomas) imaged with pelvic MRI prior to surgery were included in this retrospective study. Certain clinical and MRI features were evaluated for one lesion per patient. Radiological diagnosis was made based on MRI features. A radiomic model using automated texture analysis based on ADC maps was built to predict pathological results. The association between MRI features and pathological results was determined by multivariable logistic regression after controlling for other variables in univariate analyses with P <  0.05. The diagnostic efficacy of radiologists and radiomic model were compared by area under the receiver-operating characteristic curve (AUC), sensitivity, specificity and accuracy.

RESULTS

In univariate analyses, patient's age, menopausal state, intratumor hemorrhage, tumor margin and uterine endometrial cavity were associated with pathological results, P <  0.05. Patient's age, tumor margin and uterine endometrial cavity remained significant in a multivariable model, P <  0.05. Diagnosis efficacy of radiologists based on MRI reached an AUC of 0.752, sensitivity of 58.6%, specificity of 91.8%, and accuracy of 79.5%. The optimal radiomic model reached an AUC of 0.830, sensitivity of 76.0%, average specificity of 73.2%, and accuracy of 73.9%.

CONCLUSIONS

Ill-defined tumor margin and interrupted uterine endometrial cavity of older women were predictors of uterine sarcoma. Radiomic analysis was feasible. Optimal radiomic model showed comparable diagnostic efficacy with experienced radiologists.

Investigating the diagnostic value of quantitative parameters based on T2-weighted and contrast-enhanced MRI with psoas muscle and outer myometrium as internal references for differentiating uterine sarcomas from leiomyomas at 3T MRI

Background

Post-hysterectomy histopathological examination is currently the main diagnostic tool for differentiating uterine sarcomas from leiomyomas. This study aimed to investigate the diagnostic accuracy of preoperative quantitative metrics based on T2-weighted sequences and contrast-enhanced MRI (CE-MRI) for distinguishing uterine sarcomas from leiomyomas.

Materials and methods

The institutional review board approved the study. Sixty-five women confirmed to have a total of 105 lesions participated. Routine pelvic MRI sequences, T2 map and CE-MRI images were performed preoperatively using a 3 T MR scanner. Six quantitative metrics—T2 mapping parameter, T2 scaled ratio, tumor myometrium contrast ratio on T2, tumor psoas contrast ratio on T2, tumor myometrium contrast-enhanced ratio, and tumor psoas contrast-enhanced ratio—were extracted from the acquired image sets. Chi-square test was used to compare the percentage of malignant lesions with the central necrosis to the corresponding percentage for the benign masses. Using the area under receiver operating characteristic (AUC) curve, the performance of different metrics for distinguishing uterine sarcomas from leiomyomas was measured. Moreover, for each metric, we extracted the optimal cut-off value. The values of sensitivity, specificity, negative predictive value, and positive predictive value were calculted for the classifiers based on different metrics.

Results

The average age, average lesion size, and proportion of premenopausal women in benign and malignant groups were comparable in our dataset. The signal intensity of uterine sarcomas at T2-weighted sequences was significantly higher than that of leiomyomas (p < 0.001), while intensity at T1-weighted sequences exhibited no significant difference between the two masses (p = 0.201). Our data also suggested that a central necrosis was ten times more common among malignant lesions compared to benign ones (p < 0.001). Among different metrics, T2 mapping parameter achieved the highest AUC value and accuracy in differentiating two groups. Three measures—T2 scaled ratio, tumor myometrium contrast ratio on T2, and tumor myometrium contrast-enhanced ratio—achieved a sensitivity of 100%, therefore none of the malignant lesions would have been missed if these metrics had been adopted in patient management.

Conclusions

The findings suggested that the evaluated metrics could be useful in the preoperative assessment of myometrial masses to differentiate uterine sarcomas from leiomyomas. The proposed framework has major implications for improving current practice in the management of myometrial masses.

Analysis of uterine corporeal mesenchymal tumors occurring after menopause

Objective

Because it is difficult to diagnose accurately whether uterine corporeal mesenchymal tumors are benign or malignant before surgery, an understanding of the characteristics of patients with uterine sarcomas occurring in the postmenopausal period is required.

Methods

We retrospectively reviewed the cases of women who underwent surgery for uterine mesenchymal tumors at our hospital.

Results

Among 487 operated cases, 447 tumors occurred in the premenopausal period and 40 occurred in the postmenopausal period. Uterine sarcomas were observed in 5 cases (1.1%) during the premenopausal period and in 11 cases (28%) during the postmenopausal period. Among the postmenopausal patients, age, age at menopause, body mass index (BMI), tumor size, incidence of abnormal vaginal bleeding, serum tumor marker levels (cancer antigen 125, carbohydrate antigen 19–9, and carcinoembryonic antigen), and serum lactate dehydrogenase values were not significantly different between patients with benign tumors and those with malignant tumors. On the other hand, the incidence to have abnormal signal on MRI was significantly higher in patients with malignant tumors than in patients with benign tumors.

Conclusion

In our hospital, the incidence of malignant tumors in women with uterine corporeal mesenchymal tumors was much higher in postmenopausal patients than in premenopausal patients. Because it is generally not easy to diagnose uterine sarcomas before surgery, surgery should be positively considered when uterine sarcomas cannot be ruled out for patients in the postmenopausal period.

Uterine Leiomyosarcoma: Can MRI Differentiate Leiomyosarcoma From Benign Leiomyoma Before Treatment?

OBJECTIVE

The purpose of this article is to provide background on the epidemiologic, clinical, and economic impact of uterine leiomyomas, summarize the concerns associated with treating women with potential occult leiomyosarcomas (LMSs), and review the known and emerging imaging features of typical and atypical leiomyomas and explain how to differentiate them from LMSs.

CONCLUSION

Surgical management of presumed benign uterine leiomyomas received popular media attention when a case of disseminated LMS occurred after laparoscopic power morcellator-assisted hysterectomy. A subsequent U.S. Food and Drug Administration review found a higher prevalence of unsuspected uterine sarcoma and LMS among patients undergoing myomectomy or hysterectomy for presumed benign leiomyomas than was previously reported. This heightened concern has led to increased pressure on radiologists to distinguish LMSs from leiomyomas.

Evaluation of Red Degeneration of Uterine Leiomyoma with Susceptibility-weighted MR Imaging

Purpose:

Red degeneration of uterine leiomyoma (RDL) is a hemorrhagic infarction caused by peripheral venous thrombosis. The peripheral high-intensity rim on T₁-weighted MRI is characteristic for RDL; however, it may not be observed at all the phases of RDL. Susceptibility-weighted MR sequences (SWS) have exquisite sensitivity to blood products, and we hypothesized that the low-intensity rim due to the T2* shortening effects of blood products may be more clearly demonstrated on SWS. The purpose of this study is to evaluate the capability of SWS for the diagnosis of RDL.

Methods:

Surgically proven 15 RDL, which showed suggestive MRI findings (high-intensity rim or entirely high signal intensity on T₁-weighted imaging) were retrospectively evaluated. MRI was qualitatively evaluated for the presence of high-intensity rim around a mass on fat-saturated T₁-weighted images, and low-intensity rim on T₂-weighted images and on SWS (susceptibility-weighted imaging [SWI] or T₂-star-weighted angiography [SWAN]).

Results:

The high-intensity rim on T₁-weighted images, low-intensity rim on T₂-weighted images and on SWS were observed in 47%, 47%, and 100% of RDL, respectively. The other 53% of lesions showed entirely high signal intensity on T₁-weighted images. Pathological examination revealed coagulative necrosis in all 15 lesions.

Conclusion:

SWS may be helpful for the diagnosis of RDL by revealing characteristic peripheral low-intensity rim.

Presurgical Identification of Uterine Smooth Muscle Malignancies through the Characteristic FDG Uptake Pattern on PET Scans

The unidentified presence of uterine smooth muscle malignancies poses a tremendous risk in women planning surgery for presumed benign leiomyomas. We sought to investigate whether preoperative FDG PET may be useful to identify leiomyosarcomas (LMS) and smooth muscle tumors of uncertain malignant potential (STUMP). Methods. We investigated patients with rapidly growing uterine masses which were suspected of being malignant on ultrasound or MRI. Among the 21 patients who underwent FDG PET, we identified 7 LMS, 1 STUMP, and 13 leiomyomas. PET-derived parameters and FDG uptake patterns were analyzed retrospectively. Results. The SUV_max values of LMS/STUMP (range: 3.7–11.8) were significantly higher than those observed in leiomyomas (range: 2.0–9.4; P=0.003) despite a significant overlap. The metabolic tumor/necrosis ratio was significantly higher in LMS/STUMP than in leiomyomas (P < 0.001), with no significant intergroup overlaps. All LMS/STUMP revealed a characteristic pattern of FDG uptake, identifying a specific “hollow ball” sign (corresponding to areas of coagulative tumor necrosis). In contrast, this sign was invariably absent in patients with leiomyomas. Conclusion. The characteristic FDG uptake pattern instead of SUV on PET images allows identifying LMS/STUMP in patients with rapidly growing uterine masses, avoiding the deleterious consequences of regular surgery for presumed benign leiomyomas.

Can the risks associated with uterine sarcoma morcellation really be prevented? Overview of the role of uterine morcellation in 2018

OBJECTIVES

The objective of this literature review is to reiterate the epidemiology, clinical signs, and radiological signs that should be consistent with a uterine sarcoma as well as the precautionary pre- and postoperative principles that help prevent morcellation of uterine sarcomas when treating patients with uterine fibroids.

METHOD

We conducted this literature review by consulting the Pubmed, Medline, and Cochrane Systematic Review databases up to 28/02/2017 using the following keywords: fibroid, myoma, leiomyoma, sarcoma, leiosarcoma, uterine cancer, myomectomy, hysterectomy, morcellation, and uterine morcellation. We also used the reference lists of the selected articles to find more data on the websites of North-American and European learned societies that specialise in obstetrics and gynaecology.

RESULTS

In the case of morcellation of uterine fibroids, the risk of an undiagnosed uterine sarcoma is estimated to be between 1 in 278 to 1 in 1960 women. Preoperative examination, free informed consent following discussion about the risks and complications associated with morcellation, as well as research on the contraindications to the use of morcellation are the crucial points addressed by learned societies. The main solution recommended at present is morcellation confined to a laparoscopic bag.

CONCLUSION

There is a risk of morcellating an occult sarcoma when performing a myomectomyor hysterectomy for fibroids. Implementing the use of morcellation containment bags should be the norm. The use of minimally invasive surgery (laparoscopic orvaginal) and the associated benefit-risk ratio compared to a laparotomy should also be discussed with the patient before the operation.

Uterine fibroids: correlations between MRI appearance and stiffness via magnetic resonance elastography

RATIONALE AND OBJECTIVES

Magnetic resonance elastography has proven to be a valuable tool in the diagnosis of liver fibrosis, breast and cervical cancer, but its application in uterine fibroids requires further characterization. The aim of the present study was to examine the relationship between uterine fibroid stiffness by MRE and MR imaging characteristics.

MATERIALS AND METHODS

An IRB-approved, HIPAA compliant review was performed of prospectively collected pelvic MRI and 2D-MRE data in patients with symptomatic uterine fibroids (N = 102). T1 and T2 weighted pelvic MRI with gadolinium enhancement were performed. In a small patient subset, fibroid stiffness was assessed by both 2D and 3D MRE. Fibroid stiffness by modality or imaging characteristics was analyzed using one-way analysis of variance followed by Student t test.

RESULTS

Four fibroid groups were identified based on T2 appearance: Isointense (N = 7), bright (N = 6), dark with minimal heterogeneity (N = 69), and dark with substantial heterogeneity (N = 20). Mean fibroid stiffness was 4.81 ± 2.12 kPa. Comparison of fibroid stiffness by T2 signal intensity showed that T2 bright fibroids were significantly less stiff than fibroids appearing T2 dark with minimal heterogeneity (mean stiffness difference = 2.38 kPa; p < 0.05) and T2 dark fibroids with substantial heterogeneity were significantly less stiff than T2 dark fibroids with minimal heterogeneity (mean difference = 1.25 kPa; p < 0.05). There was no significant association between fibroid stiffness and T1 signal characteristics or gadolinium enhancement. There was no significant difference in stiffness values obtained by either 2D vs. 3D MRE.

CONCLUSIONS

These data suggest differences in fibroid stiffness are associated with different T2 imaging characteristics with less stiff fibroids being T2 bright and more stiff fibroids being T2 dark. Further studies are needed to determine if fibroid stiffness by MRE may serve as an imaging biomarker to help predict MR-guided treatment response.

PREOPERATIVE MAGNETIC RESONANCE IMAGING DIAGNOSTIC FEATURES OF UTERINE LEIOMYOSARCOMAS: A SYSTEMATIC REVIEW

Objectives: There are no current established pathognomonic diagnostic features for uterine leiomyosarcomas in the pre- or perioperative setting. Recent inadvertent upstaging of this rare malignancy during laparoscopic morcellation of a presumed fibroid has prompted widespread debate among clinicians regarding the safety of current surgical techniques for management of fibroids. This study aims to conduct a systematic review investigating significant diagnostic features in magnetic resonance imaging (MRI) of uterine leiomyosarcomas.

Methods: A comprehensive database search was conducted guided by PRISMA recommendations for peer-reviewed publications to November 2017. Parameters available in MRI were compared for reliability and accuracy of diagnosis of leiomyosarcomas. A decision tree algorithm classifier model was constructed to investigate whether T1 and T2 MRI signal intensities are useful indicators.

Results: Nine eligible studies were identified for analysis. There appears to be a significant relationship between histopathological type and T1 and T2 intensity signals (p < .05). A decision tree model analyzing T1 and T2 signal intensity readings supports this trend, with a diagnostic specificity of 77.78 percent for uterine leiomyosarcomas. The apparent diffusion coefficient (ADC) values were not observed to have a significant relationship with tumor pathology (p = .18).

Conclusions: Various studies have investigated pre- and perioperative techniques in differentiating uterine leiomyosarcoma from benign fibroids. Given the rarity of the malignancy and lack of pathognomonic diagnostic parameters, there is difficulty in establishing definitive criteria. A decision tree model is proposed to aid diagnosis based on MRI signal intensities.

Uterine smooth muscle tumours with hyperintense area on T1 weighted images: differentiation between leiomyosarcomas and leiomyomas

OBJECTIVE

Hyperintense area on T₁ weighted images (T₁ HIA) have been reported as suggestive features of uterine leiomyosarcoma (LMS), but differentiating LMS from leiomyoma (LM) is often difficult. This study aimed to evaluate the differences between uterine LMS and LM demonstrating intratumoral T₁ HIA.

METHODS

MRI was performed in 509 patients with 1137 uterine smooth muscle tumours [14 LMSs, 5 smooth muscle tumours of uncertain malignant potential , and 1118 LMs] which exceeded 3 cm in diameter. LM with red degeneration and lipoleiomyoma were excluded from the study. We retrospectively reviewed the images and assessed T₁ HIA within tumours. Results T₁ HIAs were observed in 11/14 (78.6%) LMSs, 0/5 (0%) smooth muscle tumours of uncertain malignant potential, and 15/1118 (1.3%) LMs. T₁ HIAs were more homogenous (53 vs 0%, p < 0.01) and more well-demarcated (60 vs 9%, p < 0.05) in LMs than in LMSs. T₂ hypointense rim within T₁ HIA (53 vs 9%, p < 0.05) was more frequently observed in LMs than in LMSs. The occupying rate of T₁ HIA (0.20 ± 0.24 vs 0.42 ± 0.27, p < 0.05) was smaller in LMs than in LMSs. The signal intensity ratio of T₁ HIA (1.83 ± 0.36 vs 1.38 ± 0.23, p < 0.01) was greater in LMs than in LMSs.

CONCLUSION

T₁ HIA within LM showed more homogeneity, better demarcation, smaller occupying rate, and higher signal intensity than T₁ HIA within LMS. Advances in knowledge: The differences in T₁ HIA within tumours may be useful for differentiating between LMS and LM.

Magnetic Resonance Imaging in Mixed Mullerian Tumour: Report of Two Cases

Malignant Mixed Mullerian Tumours (MMMTs) or carcinosarcomas of uterus are rare aggressive tumours of mesenchymal origin. It is associated with high incidence of lymphatic, pulmonary and peritoneal metastasis. We hereby present two cases of mixed mullerian tumour. Case-1 was a 60-year-old post menopausal woman who had come with complaint of metrorrhagia and a protruding mass in the vagina. Case-2 was of a 54-year-old post-menopausal woman who came with complaints of heavy vaginal bleeding, pelvic pain since two months. For the assessment of these tumours Magnetic Resonance Imaging (MRI) is preferred imaging modality due to excellent tissue contrast to detect the myometrial invasion, local extent and staging. Preoperative differentiation of mullerian tumour with endometrial carcinoma is important as both have different treatment.

Hypovolemic Shock and Hemoperitoneum from Spontaneous Avulsion of a Large Pedunculated Uterine Leiomyoma

Hemoperitoneum with hypovolemic shock from avulsion of a pedunculated leiomyoma is a rare but highly fatal condition that can occur spontaneously or as a result of trauma. We report a case of hemoperitoneum and hypovolemic shock secondary to a bleeding leiomyoma detected via computed tomography (CT) scan in a 39 year old premenopausal, gravida 0 female that presented with abdominal pain and became hemodynamically unstable in the emergency department. A preoperative bimanual exam revealed a mass consistent with a 20 week gestational uterus. Following fluid resuscitation, the patient underwent emergent myomectomy and ligation of the right uterine artery and was discharged home in good condition.

Differentiation of Uterine Leiomyosarcoma from Atypical Leiomyoma: Diagnostic Accuracy of Qualitative MR Imaging Features and Feasibility of Texture Analysis

PURPOSE

To investigate whether qualitative magnetic resonance (MR) features can distinguish leiomyosarcoma (LMS) from atypical leiomyoma (ALM) and assess the feasibility of texture analysis (TA).

METHODS

This retrospective study included 41 women (ALM = 22, LMS = 19) imaged with MRI prior to surgery. Two readers (R1, R2) evaluated each lesion for qualitative MR features. Associations between MR features and LMS were evaluated with Fisher's exact test. Accuracy measures were calculated for the four most significant features. TA was performed for 24 patients (ALM = 14, LMS = 10) with uniform imaging following lesion segmentation on axial T2-weighted images. Texture features were pre-selected using Wilcoxon signed-rank test with Bonferroni correction and analyzed with unsupervised clustering to separate LMS from ALM.

RESULTS

Four qualitative MR features most strongly associated with LMS were nodular borders, haemorrhage, "T2 dark" area(s), and central unenhanced area(s) (p ≤ 0.0001 each feature/reader). The highest sensitivity [1.00 (95%CI:0.82-1.00)/0.95 (95%CI: 0.74-1.00)] and specificity [0.95 (95%CI:0.77-1.00)/1.00 (95%CI:0.85-1.00)] were achieved for R1/R2, respectively, when a lesion had ≥3 of these four features. Sixteen texture features differed significantly between LMS and ALM (p-values: <0.001-0.036). Unsupervised clustering achieved accuracy of 0.75 (sensitivity: 0.70; specificity: 0.79).

CONCLUSIONS

Combination of ≥3 qualitative MR features accurately distinguished LMS from ALM. TA was feasible.

KEY POINTS

• Four qualitative MR features demonstrated the strongest statistical association with LMS. • Combination of ≥3 these features could accurately differentiate LMS from ALM. • Texture analysis was a feasible semi-automated approach for lesion categorization.

Functional MR imaging in gynecologic malignancies: current status and future perspectives

Using functional MR imaging techniques, we can approach the functional assessment of gynecologic malignancies. Among them, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MR imaging (DCE-MRI) are two important techniques. This article provides an overview of functional MR imaging techniques, focusing DWI and DCE-MRI on clinical application in gynecologic malignancies. Functional MR imaging techniques play an important role in detection, characterization, staging, treatment response, and outcome prediction, as well as providing conventional morphologic imaging. Familiarity with the characteristics and imaging features of functional MR imaging in gynecologic malignancies will facilitate prompt and accurate diagnosis and treatment.

Carcinosarcoma of the uterus: MRI findings including diffusion-weighted imaging and MR spectroscopy

BACKGROUND

Recently carcinosarcoma has become regarded as a subset of endometrial carcinoma. Because the clinical course of carcinosarcoma is aggressive with poor prognosis, it should be differentiated from endometrial carcinomas for the appropriate surgical management and adjuvant therapy.

PURPOSE

To clarify the magnetic resonance imaging (MRI) characteristics of uterine carcinosarcoma including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement and MR spectroscopy (MRS) with quantitative metabolite evaluation.

MATERIAL AND METHODS

MRI findings of 12 pathologically diagnosed uterine carcinosarcomas obtained on 3T MRI were retrospectively evaluated. The mean and minimum ADCs, and the lipid and choline concentration levels were compared with those of pathologically diagnosed 38 endometrial carcinomas.

RESULTS

The mean and minimum ADCs in carcinosarcomas and endometrial carcinomas were not significantly different. The mean ADC of carcinosarcomas was significantly higher than that of higher grade (G2 and G3) endometrial carcinomas. The choline concentration in carcinosarcomas was significantly lower than that in endometrial carcinomas. High lipid peak was observed in 91% of carcinosarcomas and in 24% of endometrial carcinomas.

CONCLUSION

Large, exophytic heterogeneous endometrial mass containing strongly enhanced areas, which may exhibit "tumor delivery", is a suggestive of carcinosarcoma. Relatively high mean ADC and low choline concentration considering its highly malignant nature due to intra-tumoral heterogeneity with necrosis and epithelial cystic components, and the presence of necrosis-associated high lipid peak may be compatible with carcinosarcoma.

Superficial myofibroblastoma of the lower female genital tract with description of the MRI features

Superficial myofibroblastomas of the lower female genital tract are an unusual type of benign mesenchymal tumour. To the authors’ knowledge, there has been no previous imaging description of a superficial myofibroblastoma in the literature. Here, we describe a case that presented with symptoms consistent with vaginal prolapse. However, a mass was palpable on clinical examination with unusual features on MRI. Following surgery, the histopathological features were considered consistent with superficial myofibroblastoma. By presenting the MRI and histological findings, we aim to raise awareness about this lesion so that it may be considered in the differential diagnosis of a vaginal mass.

Imaging Features of Uncommon Gynecologic Cancers

OBJECTIVE

The role of imaging in patients with suspected gynecologic malignancies is to provide an accurate diagnosis to achieve the best and most tailored treatment plan. Uncommon cancers pose a distinct challenge, because current knowledge of these diseases is still limited. Our purpose is to highlight the role of cross-sectional imaging techniques, including ultrasound, CT, MRI, and PET/CT, in the diagnosis and pretreatment stratification of patients with rare gynecologic cancers.

CONCLUSION

This review shows the relevance of imaging findings for diagnosis, staging, and treatment planning in patients with uncommon uterine, cervical, vaginal, vulvar, and ovarian cancers.

Functional MR Imaging in Gynecologic Cancer

Dynamic-contrast enhanced (DCE) and diffusion-weighted (DW) MR imaging are invaluable in the detection, staging, and characterization of uterine and ovarian malignancies, for monitoring treatment response, and for identifying disease recurrence. When used as adjuncts to morphologic T2-weighted (T2-W) MR imaging, these techniques improve accuracy of disease detection and staging. DW-MR imaging is preferred because of its ease of implementation and lack of need for an extrinsic contrast agent. MR spectroscopy is difficult to implement in the clinical workflow and lacks both sensitivity and specificity. If used quantitatively in multicenter clinical trials, standardization of DCE- and DW-MR imaging techniques and rigorous quality assurance is mandatory.

Uterine sarcoma vs adenocarcinoma: can MRI distinguish between them?

OBJECTIVE

To analyze the MRI characteristics of uterine sarcomas (mainly carcinosarcomas) and to compare them with those of adenocarcinomas to define the findings that would be useful for the differential diagnosis.

MATERIALS AND METHODS

We retrospectively reviewed the MRI studies of 13 patients with histologically diagnosed uterine sarcoma. We analyzed tumor size, signal in T2-weighted, unenhanced and gadolinium-enhanced T1-weighted, and diffusion-weighted sequences. We compared the data obtained with those of another series of 30 consecutive cases of adenocarcinomas studied with MRI.

RESULTS

The sarcomas (> 9cm in 77% of cases) were considerably larger than the adenocarcinomas (p<0.001). There were no differences in FIGO staging by MRI or surgery: both tumor types were diagnosed in early stages. The signal intensity in T2-weighted images differed significantly between the two tumor types: all the sarcomas were heterogeneous and predominantly hyperintense with respect to the myometrium in T2-weighted sequences (p<0.001). In postcontrast studies, all the sarcomas showed enhancement greater than or equal to the myometrium; this finding was significantly different from the adenocarcinomas (p<0.001). In diffusion-weighted sequences, we found no significant differences in ADC values in the areas with greatest restriction, but the ADC map was more heterogeneous in the sarcomas.

CONCLUSION

Uterine sarcomas do not have specific characteristics on MRI, but some findings can indicate the diagnosis. In our study, we found significant differences between sarcomas and adenocarcinomas. Sarcomas were larger, had more hyperintense and heterogeneous signal intensity in T2-weighted sequences, and enhanced more than or at least as much as the myometrium.

Magnetic resonance imaging of an endometrial stromal nodule

Endometrial stromal nodules are rare benign tumors that appear as well-circumscribed globular masses in the myometrium. In this report, a myometrial mass exhibited heterogeneous hyperintensity without hypointense bands on T2-weighted images and homogeneous isointensity on T1-weighted images. A dynamic contrast study revealed the same degree of uterine myometrial enhancement only in the marginal area. The structures were pathologically confirmed to correspond with proliferating endometrial stromal cells. Herein, we report this rare tumor and the correlation between magnetic resonance imaging and pathological findings.