Breast pathology in complications associated with polyacrylamide hydrogel (PAAG) mammoplasty.

[OBJECTIVE] To study the tissue pathology of breast lesions associated with hydrophilic polyacrylamide gel injection augmentation mammoplasty.

[DESIGN] Retrospective study.

[SETTING] Private anatomical pathology practice, Hong Kong.

[PATIENTS] Eight patients who underwent lumpectomy of the breast due to complications of hydrophilic polyacrylamide gel injection for augmentation mammoplasty.

[MAIN OUTCOME MEASURES] Identification of hydrophilic polyacrylamide gel in breast tissue and associated pathological changes.

[RESULTS] We reviewed the pathological changes in breast tissue associated with hydrophilic polyacrylamide gel injection in eight cases retrieved from our archive. Microscopically, the hydrophilic polyacrylamide gel appeared as pools of pale violet gelatinous material of variable size, between the interstices of connective tissue and fat cells. The larger pools were often surrounded by cellular reactions consisting of histiocytic cells and foreign body-type multinucleated giant cells. Inflammatory reaction featuring infiltration by lymphocytes and plasma cells in the adjacent breast tissue was observed in samples from four patients, and a sample from another patient showed acute inflammation with abscess formation. There was no evidence of abnormal cellular proliferation, atypia or malignant change in the stromal connective tissue or ductal-acinic epithelial components of the breast tissue.

[CONCLUSIONS] Hydrophilic polyacrylamide gel injection for augmentation mammoplasty can give rise to a breast lump and inflammation. Pathologically, this complication is associated with fibrosis, foreign body reaction, and inflammation.