Background: The case histories of two patients who developed endometrial adenocarcinoma with a Mirena intrauterine system (IUS) in place are reported.
Case: Two patients had a Mirena IUS inserted to treat abnormal vaginal bleeding. After 12 and 36 months with the device in place they presented with a recurrence of their heavy, irregular menstrual bleeding. Endometrial biopsies confirmed the presence of endometrial adenocarcinoma, and hysterectomies were performed. In one patient the cancer was localized and below the stem of the device, in the other metastatic disease had developed.
Conclusion: These cases raises important issues regarding the use of the Mirena IUS to treat menorrhagia.