I had a mastitis after i gave birth to my son and til now i can still feel the mass in my left breast.. can it be develop into cancer ? im worried..

Not likely: It is highly unlikely that this will develop i to breast cancer but it should be evaluated and followed by your physician. This could develop into an abscess or fat necrosis and may benefit from aspiration, drainage or excision if it does it resolve.

Unlikely/check out,,: Breasts swell towards the end of pregnancy to get ready for breastfeeding the infant. So there can be things like mastitis, especially during breastfeeding. You also might have a benign lump/mass like fibroadenoma, or a cyst like in fibrocystic disease. If it doesn't go away or if it increases in size, you should see your doctor. If it hurts/is hot, also see your doctor for rx. Best of luck.

Inflammation?: The inflammation can persist after mastitis for sometime. These area can be follow with ultrasound to rule out any masses or abscess that may have developed.

Abscess?: A more likely mass following mastitis would be an abscess. These pockets of infection are hard for antibiotics to penetrate, and often need to be drained. See your doctor. You may need to look at the area with an ultrasound if you can't just massage away an area of clogged ducts.

Not usually, but....: Mastitis and breast abscess can develop in the young mother after childbirth because the milk is not emptied out in the breast. So it is important to pump the breast if the child does not suckle properly or you are unable to feed the infant in a timely fashion. A tender lump usually means it is an abscess and you need to see a surgeon. No lump in the breast should be neglected. See your doctor.

Not likely.: Given that you still feel a “mass” in the breast after resolution of the inflammation, best to be evaluated again. Only after this evaluation and possible biopsy will you be able to receive meaningful advice and/or reassurance. Best wishes.