A Rare Cause of Breast Swelling in Lactating Women: Aquafilling Gel Injection.

Aquafilling® gel has been used in recent years as an alternative method to breast augmentation surgery. In this case report, we aimed to discuss radiological imaging findings and complications of Aquafilling® gel injection. Case: A 34-year-old lactating female patient presented with swelling and pain in the left breast. Ultrasonography showed massive septate fluid collections with dense content in both breasts and between the pectoral muscle fibers. On mammography, both breasts appeared dense with large mass opacities. On magnetic resonance imaging, extensive fluid-signal cystic areas were observed. Peripheral enhancement around the fluid in the left breast was present in the contrast-enhanced series. We learned from her anamnesis that Aquafilling® was applied to both breasts 5 years ago. Ultrasonography-guided sampling was performed from the cystic areas in the left breast and cytological examination revealed basophilic Aquafilling® material surrounded by diffuse inflammatory infiltrates. Breast augmentation history should be questioned in suspicious cases because Aquafilling® gel injection and its complications can present with a wide variety of symptoms and may mimic various other conditions on radiological imaging, such as cancer, abscess, granulomatous mastitis, and parasite infections.