Should I get this cut out or another steroid injection? (Photos)

I have been shrinking hypertrophic scars, which this seems to be, with gratifying results for well over three decades via the use of intralesional steroid injections. Since, from my understanding, you have had only one treatment in all this time, it would seem prudent to consider this less invasive and less costly route, which also engenders little to no downtime. If necessary, depending upon your response, a small amount of another anti-inflammatory agent, 5-FU, may additionally (or instead) be injected. Finally, depending upon the response to injections, the area can be numbed with a local, the surface projection "sculpted" off flush with the surrounding lip surface or alternatively flattened using light electrocautery and the base then re-injected with Kenalog to suppress recurrence. Make sure that you consult with a board certified aesthetic physician and best of luck. 

Nycguy87.   After six years it is doubtful that Kenalog injections will shrink the scar from your injury. Your best option would be excision of the scar and closure, called scar revision. The lip heals very nicely and improvement should be realized with this procedure. It can be done under local anesthesia in the office and takes less than an hour. Come see me or another or certified plastic surgeon in the region to explore the best options for you. Good luck

I would absolutely have another cortisone injection and hold off on any surgery.  Surgery tends to leave scars, even when you repair a scar which is what is called a scar revision.  Please consult an expert in scars for the best cosmetic results. Best, Dr. Green