Purpose: The purpose of this study was to identify the magnetic resonance imaging (MRI) features of uterine endometrial carcinoma (EC) with DNA mismatch repair (MMR) deficiency.
Materials and methods: This was a retrospective study approved by our institutional review board. The study included 118 patients pathologically diagnosed as having EC in our institution from April 2014 to December 2016. Of 118 patients, 8 were excluded because of insufficient data. Immunohistochemical analysis of MMR was performed retrospectively to observe the expressions of MLH1, MSH2, MSH6, and PMS2. A tumor with MMR deficiency was detected in 17 of 110 cases (15%). Clinical background characteristics and MRI findings were reviewed. These findings were compared between MMR deficiency group and the other group as a control group. Statistical significance was determined using the Fisher's exact test and the Mann-Whitney U test, as appropriate.
Results: The clinical background characteristics of patients with EC with MMR deficiency were not significantly different from those of other patients. On MRI, the tumor was significantly more often located in the lower uterine site (MMR(-) vs. MMR(+): 29.4 vs. 8.9% [p = 0.0366]).
Conclusion: EC with MMR deficiency tends to be located lower in the uterus, though most other findings were not significantly different from those of EC without MMR deficiency.
Keywords: Endometrial carcinoma; Lynch syndrome; MMR deficiency; MRI; Uterus.