The speaker is a woman facing surgery for a breast lump, and the poem follows her from the first frightening words to the moment of the cut. Those words, "lump" and "breast," are called nightmare words, and the way they are stacked on the page makes them feel like a diagnosis arriving piece by piece. Her body is "in rebellion," and nothing comforting anyone says can calm it.
In the operating room, the mood turns cold and exposed. The light "stares down, unblinking," and the speaker lies motionless while the doctor says "Good girl" and "Good soldier." Those pet names seem to shrink her into someone who should simply obey, and the knife "thin as a smile" suggests a polite surface hiding something sharp. The final lines widen the loss beyond tissue: he "cuts more than flesh," and the wound cries "Woman." Judging by that ending, she feels the surgery as a threat to her sense of identity as well as her body. The tone is tense, controlled, and quietly angry.