 [ Symptoms ] my boyfriend has an extra bone in his leg [ Disease ] hi these are osteochondromas a kind of bone outgrowths that are hereditary and usually cause no complications over the lifetime unless its hit by something u can get a xray done to see the extent of the growth just for curiosity these wont reduce in size wont cause any pain these can be removed with a bony surgery but its only for cosmetic purpose and wont cause any variation in ones life span if at all these growths start to get abnoramaaly big or start hurting then they need medical attention thanks