We report a case of early breast cancer, which was treated successfully by oncoplastic surgery. A 65-year-old Japanese woman was referred to us for investigation of a grouped calcification on mammography of her left breast, detected during mass screening for breast cancer. No mass lesion was palpated, but we suspected that the grouped calcification seen on the mammography was a malignant lesion in the lower area of the left breast. Ultrasonography and magnetic resonance imaging revealed ductal carcinoma in situ, restricted to the inner quadrant of the left breast. Achieving a good symmetrical outcome after partial mastectomy would have been made difficult by the degree of ptosis. Thus, we performed partial mastectomy followed by an amputation-type reduction operation with free nipple-areola complex grafting, which achieved good cosmetic and oncologic results.