Most breast lumps in men are a condition called gynaecomastia; this is button-like growth under the nipple and areola area that can be felt and is sometimes visible to the naked eye; occasionally it can be sore or tender.
This increase in the amount of breast tissue is not a tumour; it often occurs due to changes in hormone balances at times like adolescence, but it can happen at any age.
It's normal, it's not cancer, and it's temporary.
Men do get breast cancer, but fewer than 1% of those diagnosed with breast cancer are male. You don't say how old you are; most men diagnosed with breast cancer are over 60. Through breast cancer support networks, I've met a few men with breast cancer in their 50s and late 40s, but that's rare.
80% of all people diagnosed with breast cancer are over 50. It's rare in women under 40, fewer than 0.1% of women diagnosed are under 30, and it's almost unheard of in women under 25.
The youngest man ever to be diagnosed with breast cancer anywhere in the world was 24; his case made news because he was the youngest by several years.