Correlation between ADC value and Ki-67 index in the pathological grading of endometrial stromal sarcoma

Objective: To investigate the characteristics of endometrial stromal sarcoma (ESS) on conventional MRI, and to preliminarily analyze the correlation between apparent diffusion coefficient (ADC) value and Ki-67 index. Methods: A retrospective analysis was carried out on the clinical and MRI data of 26 patients with ESS confirmed by surgical resection and pathology, with an average age of 52 ± 13 years. The pathological classifications were low-grade ESS (LGESS, 9 cases) and high-grade ESS (HGESS, 17 cases). The morphological features of the ESS on MRI were analyzed, and the ESS signal intensity on DWI and ADC value were measured. Immunohistochemical analysis was performed to calculate the Ki-67 index. The t-test was used to compare the ADC values and Ki-67 indexes between the HGESS and LGESS groups, and the Pearson correlation coefficient was used to analyze the correlation between ADC values and Ki-67 indexes. Results: All the 26 patients showed either homogeneous or heterogeneous isointensity and hypointensity on T₁WI, heterogeneous hyperintensity on T₂WI, and hyperinetensity on DWI. The mean ADC of the solid components was lower in the HGESS group [(0.74 ± 0.11) × 10^-3 mm²/s] than in the LGESS group [(1.07 ± 0.24) × 10^-3mm²/s] (P < 0.05). The mean Ki-67 index was higher in the HGESS group (45.53% ± 14.23%) than in the LGESS group (8.33% ± 2.50%) (P < 0.05). The ADC values were negatively correlated with Ki-67 indexes (r = -0.726, P < 0.001). Conclusion: The ESS presents certain characteristics on MRI, and the ADC value of tumor can indirectly reflect the pathological grading of ESS. (authors)