Immediate Deep Inferior Epigastric Perforator Flap Reconstruction of a Giant Phyllodes Tumor.

We present a case of a giant phyllodes tumor (PT) requiring simple mastectomy with en bloc pectoralis major resection and immediate deep inferior epigastric perforator (DIEP) flap reconstruction. This patient presented with a four-year history of an enlarging breast mass with ultrasound-guided biopsy results consistent with atypical fibroepithelial proliferation that was highly concerning for a borderline phyllodes tumor. In this large, rare breast tumor that required en bloc pectoralis major resection, we describe the novel use of an immediate single pedicled DIEP flap for the resulting chest wall defect. The patient's postoperative course was uncomplicated, and she reported satisfactory cosmetic and functional outcomes at her initial postoperative follow-up visits. Our findings support the use of simple mastectomy with en bloc resection and immediate single-pedicled DIEP flap for the definitive treatment of giant phyllodes tumors. Our experience shows this is a safe and effective technique for achieving adequate oncologic resection while maintaining postoperative function and cosmesis, which are essential for patient quality of life.