Pathological characteristics of breast nodules after large-volume fat grafting for breast augmentation.

[BACKGROUND] The complications of large-volume fat grafting (LVFG) for breast augmentation remain unpredictable and include palpable breast nodules, oil cysts, and calcifications.

[AIMS] This study was aimed to provide an optimal treatment option for breast nodules after LVFG and evaluate their pathological characteristics.

[PATIENTS/METHODS] We effectively performed complete resection of breast nodules in 29 patients after LVFG using a minimal skin incision with the vacuum-assisted breast biopsy (VABB) system under ultrasound guidance. And we further carried on histologic examination of excised nodules and evaluated their pathological characteristics.

[RESULTS] The breast nodules were excised thoroughly with cosmetic effect satisfactorily. Interestingly, subsequent histologic examination showed that type I and VI collagens were strongly expressed in the fibrotic area and type IV collagen were positively expressed around the blood vessel. Furthermore, we found that the type VI collagen+ area appeared around mac2+ macrophages and α-SMA+ myofibroblasts.

[CONCLUSIONS] The VABB system may be the optimal treatment option for breast nodules after LVFG. And type VI collagens may serve as a biomarker of grafted adipose tissue fibrosis. The relationship between macrophages, fibroblasts, and collagen formation may be therapeutic targets for regulating fibrosis.