My research on the web for isotretinoin as a potential cure / treatment for steatocystoma multiplex didn't seem to be that promising. Most medical articles have shown varied results on the use of isotretinoin for the treatment of SM.
http://www.ncbi.nlm.nih.gov/pubmed/3456886
http://www.ncbi.nlm.nih.gov/pubmed/3197445
The first article states a possible adverse reaction with isotretinoin use, while the second shows that could be a possible delayed effect on the shrinkage of cysts.
Can isotretinoin or as it's more commonly referred to as accutane be a possible treatment of SM, aiding in the shrinkage and even full eradication of SM cysts? Personally, I have my doubts on that. Even so, I would guess only a small percentage of SM sufferers would see any beneficial effects while on isotretinoin.