Keep an eye on it if you don't want to nuke it just yet. If you see it split anytime soon, or you see more of them pop up, then start getting rid of them or you will find yourself with quite a few.
We had some a while back in one of our tanks and my wife was feeding it for about 6 months before it actually split. My wife was told that it was a baby BTA, but the guy we got the rock from didn't have a BTA in the tank that the rock came from. Once it split, it was on. It split at least two more times before I got around to getting rid of them.
Of course, I still have a battle waging between me and some aptasia that just don't want to die off in that tank too. LOL.
If you do decide to nuke it though... after you kill it, be sure to remove it completely from the tank otherwise it could come back.
Hope this helps.