Distant migration of gluteal augmentation fat presenting as a soft tissue knee mass

Gluteal augmentation with autologous fat grafting is an increasingly popular procedure. While complication rates are low, the clinical and imaging evaluation of the various complications can be challenging. We report a case of distal migration of a failed gluteal fat graft in a young female patient presenting as a soft tissue mass in the knee, mimicking a soft tissue sarcoma. Surgical resection of the migrated fat graft confirmed the diagnosis. The diagnosis was challenging as the patient was initially reluctant to disclose her surgical history due to perceived negative social stigmas related to cosmetic contouring procedures. This case highlights the imaging findings of a rare complication following autologous fat grafting for gluteal augmentation and the importance of obtaining a thorough medical history.