I doubt you have a cholesteotoma, the other growth (http://www.bad.org.uk/public/leaflets/chondroderm.asp) I have mostly seen in people that have a history of swimming in cold water, or growing up in really cold climates.
http://www.drhull.com/EncyMaster/C/cholesteotoma.html
http://www.bad.org.uk/public/leaflets/chondroderm.asp