A method for surgically removing a tumor from a woman's breast is provided. The method can include inserting an optical trocar having a working channel and a transparent tip through a skin incision, guiding the transparent tip of the trocar through breast tissue with visualization such that the transparent tip of the trocar is placed adjacent to the tumor, insufflating gas via the working channel of the trocar to create a cavity in an operative field next to the tumor, dissecting the tumor free with a surgical instrument inserted through the working channel and removing the tumor through the trocar.