Found a lump on my breast but i am breastfeeding, what's the possibilities of a benign cancer?

"Possible"-Need Exam: As you know first-hand, the breast changes quite a bit during breastfeeding, becoming quite "lumpy-bumpy". It is very difficult to differentiate a lump that counts from one that doesn't on self-exam. It is best to go see your gynecologist for their opinion. If they are at all concerned, they will refer you to a breast doctor for formal evaluation+/-ultrasound+/-biopsy.

Usually benign lump: Women who are breastfeeding may find lumps in their breast and this can be scary. When in doubt always have it checked by your doctor. The vast majority of cases are due to plugged ducts that could lead to an infection like mastitis or even an abscess. Proper nutrition, hygiene, hydration and rest helps prevent plugging of milk ducts. http://www.pregnancy-info.net/breast-lumps-while-breastfeeding.