I have a breast lump (1cm diameter) under my right nipple and it feels a little sore when i feel it. i'm a 24 year old male. can this be cancerous?

Yes, but not likely: Men do have breast glands and they may fill out during puberty. They can also enlarge if you take certain medicines. If you do not see it shrink in the next week or two. Get checked by surgeon.

Unlikely: Breast cancers are rare in men but still 1 % breast cancers are in men , tend to diagnosed late , at you age is unlikely , but still need to be checked by your doctor

Have it checked: Men can have breast tissue develop, breast lumps, and even breast cancer. Most likely it is gynecomastia - male breast tissue - given your age. Your doctor can evaluate this and direct you in the proper treatment.