In his battle with Saitama, Lord Boros regenerates around a growing purple thing. What is that purple thing?
This detail - i.e. Boros's body essentially exploding into 5cm-long pieces of blood pulp, just to gather back around a glowing point placed roughly in the center of his chest - is only shown in anime continuity.
Murata's illustrations in manga One-Punch Man (chapter 36) are very similar, but the pieces are larger and less spread out. Boros's body gathers back essentially in the same position it was when Saitama started punching him and no glowing point is shown. The way I understood it, the pieces were pulled to position and then the junctions were stitched back together through super-healing.
In the webcomic by ONE (chapter 40) Boros's body is not even actually blown to pieces, but rather heavily chipped. In my opinion, that could arguably be consistent with simple regeneration.
Throughout (i.e. in all three versions), the explanation of Boros's healing process is unchanged: he only states that he can regenerate through "energy" (although apparently he has some sort of untold means to pull his body pieces back together). As far as I know, up to manga chapter 185 it is never stated that he should have a "core bead" like that minion of his who was felled by the S-class heroes.