Magnetic Resonance Imaging of uterine sarcomas
Number:27ESURABS0068
Type:Educational Electronic Presentation
Authors: Filipa Alves E Sousa, Teresa Margarida Cunha
Keywords:Uterine sarcoma ∙ Leiomyosarcoma ∙ Endometrial Stromal Sarcoma ∙ Adenosarcoma
SECTIONS
Educational objective

To review and summarize the MRI features of each sarcoma subtype and to correlate them with its pathological findings.

 


Topic Review

Introduction

Uterine sarcomas comprise a heterogeneous group of rare uterine malignancies that arise from the myometrium or the connective tissue elements of the endometrium. They are the most aggressive type of uterine malignancies, displaying rapid growth and dissemination, and carrying a very poor prognosis with an overall 5-year survival rate ranging from 17.5 to 54.7%.

According to the 2020 World Health Organization (WHO) classification, the major histological subtypes are leiomyosarcoma (LMS), low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), undifferentiated uterine sarcoma (UUS), and adenosarcoma (AS)[4].

Despite the intensive and ongoing search for more reliable diagnostic parameters, there are still no effective diagnostic criteria to determine the sarcomatous malignant nature of a...

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Fig. 1 Leiomyosarcoma in a 71-year-old woman. Axial T1-weighted image (a) and contrast-enhanced axial T1-weighted image with fat suppression (b) show uterine enlargement due to a heterogeneous myometrial tumor, with irregular border (→), and central hemorrhage and/or necrosis (*) depicted by central heterogenous hyperintensity on T1-weighted image that does not enhance after the administration of gadolinium. Note early intense enhancement in solid tumor components (○). Macroscopy of a leiomyosarcoma from another patient (c) demonstrates a large infiltrative tumor with areas of necrosis (>) and hemorrhage) (◊).
Fig. 2 Leiomyosarcoma in a 58-year-old woman. Sagittal (a) and axial (b) T2WI; sagittal DWI with b value = 1000s/mm2 (c) and ADC map (d); sagittal T1WI with fat suppression before (e) and after contrast administration (f) show: uterine enlargement due to a heterogeneous myometrial tumor displaying a heterogeneous solid component (○) (depicted by intermediate signal-intensity on T2WI, restricted diffusion with high signal-intensity on DWI and low ADC values, and avid contrast-enhancement) and central necrosis (*) (depicted on T2WI as a heterogeneous central area of high signal intensity without restricted diffusion or contrast-enhancement), T2 “dark areas” (open arrow) and hemorrhage (→) (depicted on T1WI as a high signal intensity area).


Conclusions

Conclusions and key points

The distinguishing features between leiomyomas and leiomyosarcomas are summarized in table 1, and the most relevant and distinctive features of each uterine sarcoma subtype are summarized in Table 2.

MRI findings of uterine sarcomas overlap greatly with those of benign (and more common) entities such as uterine leiomyomas, nevertheless, some radiological features should raise suspicion for malignancy. Knowledge of the different histological subtypes of uterine sarcomas and their specific MRI features allows for a more confident diagnosis and may indicate the correct histological subtype. 

Table 1 Distinguishing features between leiomyomas and leiomyosarcomas.
Table 2 Summary of the most typical and discriminating features of each uterine sarcoma subtype