Marked increase of breast density due to a levonorgestrel-releasing intrauterine device

A 44- year old woman presented with bilateral breat pain and a feeling of increasing “tenderness” over the last year. Clinical examination as well as ultrasound performed by her obsterician was unremarkable. Mammography was performed at our department. No suspicious mass or microcalcifications were found. A marked increase in breast density (ACR 4) compared to the previous exam two years previously (ACR 2) was evident (Fig. A, B). The patient reported about the insertion of a levonorgestel-relasing intrauterine device about one an a half year ago (Mirena®, Bayer Healthcare, Leverkusen, Germany). No systemic hormonal intake was reported (oral or transdermal) and clinical history was unremarkable. Especially there were no pathologies with a possible increase in breast density (radiation therapy to the chest, diabetes, congestive heart failure). There was no recent pregnancy.