We just had this happen to our 12 1/2 year olf SWCAH son.  I took him to the pediatrician and he said it is not uncommon for this to happen in boys as they are in the throws of puberty, independent of CAH.  In fact, he said if our son didn’t have CAH, his recommendation would be to do nothing at all, unless the breast bud continued to grow.  Seeing as he does have CAH, he deferred to the pediatric endocrinologist.  I spoke with him too and he is not at all concerned as long as it doesn’t progress any further.  It’s only minor on just one side.  Our son’s well-supressed with a 17OHP of about 50.  When we do the next set of bloodwork in January, we will have some additional bloodwork done at the docs request, just as a precaution.  But the endo said this is not uncommon at all in boys at this age.  Hope that helps.

Michele