What is causing this dark spot? 7.5 months post BBL. Had necrosis revised one month after surgery. (photos)

I’m 7.5 months post bbl. Had fat necrosis in left buttock which will get revised next month. My concern today is this dark spot that’s been on my right buttock for months now, seems to be getting larger. The spot is firm and feels like a lump so to say. Sometimes it itches, sometimes it’s bothersome. What is this? Why is this happening? I was doing research online, could this be a hematoma? If so then what next? Thanks in advance