Utility of diffusion-weighted and contrast-enhanced magnetic resonance imaging in diagnosing and differentiating between high- and low-grade uterine endometrial stromal sarcoma

Abstract

Background Endometrial stromal sarcoma (ESS) is a rare uterine malignancy that features different prognoses for its high- and low-grade subtypes. We investigated the diagnostic accuracy of magnetic resonance (MR) imaging in diagnosing and differentiating between high- and low-grade ESS. Methods We retrospectively reviewed the preoperative pelvic MR images of consecutive patients who received histologically confirmed diagnoses of high-grade ESS (n = 11) and low-grade ESS (n = 9) and T2-hyperintense leiomyoma (n = 16). Two radiologists independently evaluated imaging features in T1-, T2-, and diffusion-weighted and contrast-enhanced MR images. Statistical analysis included Mann-Whitney tests and Fisher’s exact test, with sensitivity, specificity and diagnostic accuracy of imaging features. Results High-grade ESS was associated with significantly more extensive necrosis and hemorrhage and distinct feather-like enhancement compared with low-grade ESS (P < .05 for all). The feather-like enhancement pattern yielded a diagnostic accuracy of 95%, sensitivity of 91%, and specificity of 100% in differentiating high-grade from low-grade ESS. This imaging characteristic was significantly superior to the necrosis (80%, P = .033) or hemorrhage (75%, P = .007). Both high- and low-grade ESS demonstrated T2 hypointense bands, marginal nodules, intratumoral nodules, and worm-like intra-myometrial nodules, and their tumor apparent diffusion coefficient (ADC) values were significantly lower than those of T2-hyperintense leiomyomas (P < .001). Conclusions Diffusion-weighted MR imaging is useful in diagnosing ESS against T2-hyperintense leiomyomas, and contrast enhancement aids in further differentiating between high- and low-grade ESS.

Utility of magnetic resonance imaging for differentiating malignant mesenchymal tumors of the uterus from T2-weighted hyperintense leiomyomas

“…The decreased ADC values could be attributed to the restricted motion of water molecules [ 18 , 30 ]. These results were similar to those of previous studies that reported lower ADC values in malignant sarcomas and endometrial stromal sarcomas than in benign leiomyomas [ 8 , 18 , 22 , 23 ]. Furthermore, in this study, the ADC value showed the highest AUC (0.81) as a single quantitative parameter, which was slightly higher than the AUC of 0.74 reported for the combination of ADC value and DWI findings by Lin et al [ 8 ], who compared the ADC values of leiomyosarcoma with those of ordinary leiomyoma.…”

“…Multiple MRI findings were used to distinguish between MMTU and T2HILM. However, a single MRI finding, such as T1 bright area, necrosis, or feather-like enhancement, has limited distinguishing ability 3.655x 1 + 2.198x 2 + 2.268x 3 − 11.610 and demonstrates relatively low accuracy compared to the combination of multiple findings [14,23,28,29]. As a quantitative assessment method, the usefulness of the mean ADC value and the maximum tumor size has been reported; however, there was an overlap between MMTU and leiomyoma [8,18,23].…”

“…2 ). Feather-like enhancements were defined as fine and wispy enhancements interspersed within the tumors [ 23 ] as shown in Fig. 4 .…”

A nationwide survey of the use of the laparoscopic power morcellator

“…Representative preoperative examinations include those listed in this survey. Among them, MRI is especially a useful diagnostic modality for uterine diseases 11,12 . Its tissue contrast is better than that of ultrasonography or CT, and a high signal on a diffusion‐weighted image and a low value of the apparent diffusion coefficient (ADC) suggest a high cellular density.…”

Differentiation of uterine low-grade endometrial stromal sarcoma from rare leiomyoma variants by magnetic resonance imaging

“…Recently, diffusion-weighted imaging (DWI) has been highlighted as a potentially useful tool for the differentiation of uterine sarcoma, reflecting the cellular density of tumor 11 – 13 . Compared to leiomyosarcoma, evidence of MRI about LGESS remains very limited because of its extreme rarity 5 , 14 . Characteristic MRI features of LGESS have been reported in small case series: worm-like nodular extension 15 , intra-tumoral low signal intensity (SI) bands on T2 weighted-images (T2WI) 16 , and low SI rim on T2WI 17 .…”