To tell you the truth, I never understood what this meant either. I just remember a diagram from medical school days which showed sample incisions "along skin lines" on the breast. The lines went in the direction: chest wall towards nipple. Thus a circumferential incision (even a very short one) is not along skin lines. If this is wrong due to my ever increasingly failing memory, the idea was *not* to make circumferential incisions, even partial circumferential incisions. Jack Newman, MD, FRCPC