Sometimes a cancerous lump is on the surface of the breast. However, not all lumps and bumps are cancer. Many are cysts (fluid collections) or harmless, benign lumps (fibroadenomas). Many women have lumpy, bumpy breasts. However, if it’s something that concerns you, show a doctor. If other tests are inconclusive, looking at the cells from the lump under a microscope with a biopsy can help to determine if it’s cancer.