A Late Complication of Augmentation Mammoplasty by Polyacrylamide Hydrogel Injection: Ultrasound and Magnetic Resonance Imaging Findings of Huge Galactocele Formation in a Puerperal Woman with Pathological Correlation

: Polyacrylamide hydrogel (PAAG) was widely used for injection augmentation mammoplasty in Eastern Europe and China although uncommon in the western countries. However, the safety of this procedure remained controversial. Herein, we report a 30‐year‐old woman with a history of augmentation mammoplasty by PAAG injection developed galactoceles during her pregnancy. Ultrasound and magnetic resonance imaging showed huge cystic lesions in bilateral breasts; as a result, the normal breast tissue was almost completely replaced. On the basis of the imaging findings, the patient underwent mastectomy as well as immediate breast reconstruction with satisfactory outcome. It is important to be familiar with the imaging findings of this rare yet severe complication after augmentation mammoplasty in order to make an accurate diagnosis and a proper management.