Sebaceous adenomas

Question
Hello Dr. Gotthelf:

  My 15-year old Russian blue cat has developed several small cyst-like tumors (I guess they'd be called "tumors") underneath her fur coat.  Her vet has identified them as "sebaceous adenomas". He says nothing needs to be done about them unless they start to bother her.  They don't seem to bother her, but they bother me as I can't comb her for fleas or otherwise groom her for fear of
disturbing them and exacerbating the problem.  Can you tell me what causes them; whether there is anything I can do to shrink or get rid of them; and whether they might magically disappear without any human intervention?  It seems to me the two most prominent ones in the middle of her spine are shrinking a little and sluffing off dried blood or some sort of cellular material.  
I do not want to have them surgically removed if I can help it as I think the treatment might be quite traumatic and possibly worse than the problem itself.  I would appreciate any information and/or advice you can give me as to what to do.  Thanks very much.  Sincerely.

        Dardrie

Answer
Skin tumors in older cats can be cancers.  We do not know why they occur or how to treat them with medicines. I would recommend having them surgically removed and sent to a pathologist to see if they are cancers.  I remove some of these with a laser, which does not affect them post-op as much as incising with a scalpel.