My boyfriend gets Sebaceous Cysts...?

I understand that the cysts themselves are harmless and not contagious. My problem is that his doctor says it's just genetics. But I have also read that Pilar Cysts are the ones that are hereditary, NOT the sebaceous cysts. So now, I'm all worried, because I read that Sebaceous Cysts are typically because of a syndrome. The doctor doesn't say any of this yet prescribes all of these medicines for him. So, what if this doctor doesn't know what he is talking about and my boyfriend is taking medicine that isn't good for him. Anybody know anything, FOR CERTAIN, about Sebaceous Cysts?