Boney lump in between my breasts on the edge of my right rib cage, what is this?

See physician: Bony lump between breast could be related to the breast bone in the middle of the chest could be a tense cyst that feel hard most likely nothing to worry about but no reason to take any chances have it checked by your physician.

Evaluation: Clearly we cannot evaluate or examine you over the web. If you have concerns get to an MD who can put his/her hands on you and examine he mass

Have it checked: I do not know exactly what you mean by bony lump between the breast a cyst could be tense and feel like a hard lump between the breast there is the sternum the end of it sometime could be outward and feel like a bony lump either way do not take any chances and have it checked by your physician.