What does breast cancer look like on a mammogram?

Dr Sarah Jarvis MBE

If a mammogram is abnormal, further tests will be needed. It is important to bear in mind that most women who are asked to come back after a mammogram do not have breast cancer. It may be that there is a technical problem with the picture and it needs repeating. Or it may mean that there is a non-cancerous lump which has been picked up.

https://patient.info/health/breast-cancer-leaflet/mammogram