Case Report: Ulcerative breast cancer occurring 20 years after breast augmentation with Amazingel injection.

Background: Polyacrylamide hydrogels (PAAG), commercially known as Amazingel, have been widely used for injectable breast augmentation in China since the early 2000s. Because PAAG is non-degradable, long-term retention in the body may lead to complications, including infection, granuloma formation, and induration. Concerns regarding its potential long-term carcinogenicity have also emerged. However, breast cancer developing after PAAG injection has rarely been reported, and cases occurring more than 20 years after injection are exceptionally rare. Previous reports have not described ulcerative presentations or detailed molecular subtypes. Case presentation: We report a case of unilateral ulcerative breast cancer that developed 20 years after PAAG injection for breast augmentation. Following removal of the injected PAAG material and surgical debridement, the infection was controlled, and histopathological examination confirmed invasive ductal carcinoma. Immunohistochemistry demonstrated ER (3+), PR (3+), HER2 (2+), whereas Fluorescence Conclusions: To our knowledge, this is the first reported case of ulcerative breast cancer occurring 20 years after PAAG injection for breast augmentation. The tumor exhibited a molecular profile of particular interest, characterized by robust hormone-receptor positivity and low HER2 expression. Ultra-long-term retention of PAAG may show a temporal association with breast cancer development, highlighting the need for long-term clinical surveillance decades after injection.