Pectoralis Major Muscle Flap With Fat Grafting in Oncoplastic Breast-Conserving Surgery

Oncoplastic breast-conserving surgery integrates oncological resection with plastic surgery to optimize cosmetic outcomes. We present a novel approach that combines a pectoralis major muscle flap with fat grafting, referred to as the PMFG procedure, for the reconstruction of upper outer quadrant defects. A 52-year-old woman with breast cancer underwent partial mastectomy through a lateral incision, which resulted in a 70 mL defect. Using the same incision, the pectoralis major muscle flap was elevated over the thoracoacromial vessels while preserving the internal mammary perforators along the sternal border. Preoperative computed tomography estimated the flap volume at 80 mL; to account for potential atrophy, 150 mL of fat was injected into the muscle, fascia, and retromammary layers. The patient recovered uneventfully and was discharged on postoperative day 6. Six months after surgery (3 mo after the completion of radiotherapy), the aesthetic outcome was excellent, with no signs of pain or upper limb dysfunction. This case demonstrates that PMFG can safely provide sufficient soft tissue volume with excellent flexibility without the need for additional incisions or patient repositioning. PMFG may offer a valuable reconstruction option for selected patients with small- to moderate-sized breasts and upper quadrant defects.