Stop a pimple in its tracks?

It's the sore kind that are under the skin, kind of like a cyst i guess. How can i stop it from growing and coming to the surface...i know i could pop it safely but that still always leaves a scar (due to the nature of the pimple) that takes a while to heal.





I have benzoyl peroxide gel and tretinoin gel 0.025%, as well as salicylic acid gel. Which do you recommend would stop a pimple from growing further?Stop a pimple in its tracks?
I used to get cystic acne all the time, before I started birth control, and the best thing for it was tea tree oil, either straight up or in an acne product. It's very powerful and if you use it straight from the bottle you should be careful not to use too much.