Freitas, PatríciaResende-Neves, TeresaLameira, PedroCosta, MartaDias, PauloFilipe, JulianaFerreira, JoanaFélix, AnaCunha, Teresa Margarida2025-10-242025-10-242024-04Arch Gynecol Obstet . 2024 Apr;309(4):1551-1560. doi: 10.1007/s00404-023-07294-0.http://hdl.handle.net/10400.17/5194Purpose: To evaluate the magnetic resonance imaging (MRI) features that may help distinguish leiomyosarcomas from atypical leiomyomas (those presenting hyperintensity on T2-W images equal or superior to 50% compared to the myometrium). Materials and methods: The authors conducted a retrospective single-centre study that included a total of 57 women diagnosed with smooth muscle tumour of the uterus, who were evaluated with pelvic MRI, between January 2009 and March 2020. All cases had a histologically proven diagnosis (31 Atypical Leiomyomas-ALM; 26 Leiomyosarcomas-LMS). The MRI features evaluated in this study included: age at presentation, dimension, contours, intra-tumoral haemorrhagic areas, T2-WI heterogeneity, T2-WI dark areas, flow voids, cyst areas, necrosis, restriction on diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) values, signal intensity and heterogeneity after contrast administration in T1-WI, presence and location of unenhanced areas. The association between the MRI characteristics and the histological subtype was evaluated using Chi-Square and ANOVA tests. Results: The MRI parameters that showed a statistically significance correlation with malignant histology and thus most strongly associated with LMS were found to be: irregular contours (p < 0.001), intra-tumoral haemorrhagic areas (p = 0.028), T2-WI dark areas (p = 0.016), high signal intensity after contrast administration (p = 0.005), necrosis (p = 0.001), central location for unenhanced areas (p = 0.026), and ADC value lower than 0.88 × 10-3 mm2/s (p = 0.002). Conclusion: With our work, we demonstrate the presence of seven MRI features that are statistically significant in differentiating between LMS and ALM.engHSJ IMAHCC IMAHSM IMAFemaleHumansPortugalNecrosisDiagnosisDifferentialDiffusion Magnetic Resonance ImagingLeiomyoma* / pathologyLeiomyosarcoma* / diagnostic imagingLeiomyosarcoma* / pathologyMagnetic Resonance Imaging / methodsMyometrium / pathologyRetrospective StudiesSmooth Muscle Tumor* / diagnostic imagingSmooth Muscle Tumor* / pathologyUterine Neoplasms* / pathologytext10.1007/s00404-023-07294-0.38055011