What does breast cancer feel like? is it painful?

Firm mass: Most malignant lesions of the breast can be felt at 1/2 cm. in size. Palpation of breast with hand behind head on side of palpation using opposite hand with fingers moving in a clockwise direction will detect a firm solitary mass different than any other lesions or lumps. The mass is very firm and non tender. Should be biopsied even if not detected on follow up mammo.