Abdomen trauma swelling. Advice me?

My husband had a blunt injury to his left upper abdomen about 10 months ago, after which a localized swelling developed in the same area. The swelling was present even before a later knife stab injury occurred near that site. At the time of the stabbing, a CT scan of the abdomen and chest was performed, which showed a soft tissue injury with an intramuscular hematoma involving the left rectus abdominis muscle, with no injury to internal organs. Currently, there is a visible swelling in the left upper anterior abdominal wall that appears more like swelling than a discrete lump; it is non-mobile, with no pain and no change in size. The CT scan report is attached for reference and further evaluation. When that swelling ll go... What to do please advice me?? Is this serious issue..