Volume replacement using a latissimus dorsi musculocutaneous flap is the second step in OPBCS(Oncoplastic breast-conserving surgery)Volume replacement. The main features of this technique are stable blood flow and applicability to tissue defects in all regions of the breast. Following incision of the skin island on the back, the flap is dissected toward the axilla, and the muscle insertion is dissected through a lateral thoracic incision(or sentinel lymph node biopsy incision for tumors in the inner quadrants). Usually, this procedure is indicated for tissue defects of up to 30% of the total volume, but the amount of flap tissue that can be filled into the defect is smaller medially than laterally, and caudad than cephalad. By area, indications for this procedure are stricter for defects in the upper-outer, upper-inner, lower-outer, and lower inner quadrants, in that order.