Hello,
Dermaroller is used for Stretch marks,
wrinkles, scars and uneven, pitted
skin. It is not used for bumps on the chest which could be due to sebaceous cysts. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.