Staging resection and reconstruction with temporary wound VAC coverage in a case of giant cystosarcoma phyllodes of the breast

INTRODUCTION: Cystosarcoma phyllodes (CP) is a rare breast tumor occurring most often in females in their fifth decade. While usually benign, some CP tumors exhibit aggressive growth patterns and extensively invade chest wall structures; resecting these tumors to negative surgical margins can be challenging. We present a case of malignant CP involving the chest wall where using a negative pressure vacuum-assisted closure (VAC) system after resection enabled complete histopathologic margin assessment prior to reconstruction. This is the first known report of staged breast tumor resection and reconstruction with interim VAC coverage. CASE PRESENTATION: A 48 year-old woman presented with rapidly increasing left breast size, fevers, and fatigue. On examination, the left breast was massively enlarged with engorged vessels and skin necrosis. Lab analyses revealed unusual metabolic abnormalities requiring preoperative hospitalization. We performed a left modified radical mastectomy with partial resection of pectoralis major and minor muscles, temporarily sealing the wound with a VAC due to concern for deeper tumor extension that could require further resection. Pathology revealed malignant CP with a negative deep margin. The 38 cm defect was then repaired with latissimus myocutaneous flap plus skin graft. At three-year follow up the patient remains free of disease. CONCLUSION: In cases of malignant CP involving the chest wall, minimizing the extent of chest wall resection is critical for reducing morbidity, while completely clearing tumor margins is essential for reducing recurrence risk. Using temporary wound VAC coverage enables cautious debulking followed by histopathologic margin assessment prior to definitively reconstructing the breast.