I have fibrocystic breast so I am always massaging them because they hurt. It's true that I notice lumps that are cystic more by doing this because they come and go. I would be aware of one that doesn't go away. I have two on each side that are watched carefully every year that haven't gone away. The good news is they haven't grown. The bad news is they can so feeling them each day keeps me aware of changes.
Koala, sorry about your cousin.