How Can Finger Hematoma With A Residual Hard Sore Lump Be Treated?

I have a probable haematoma on the my middle finger. It was jammed in an automatic car window a week ago. The main swelling went down after a day or so, and bruising around the knuckle is fading, but there is a very hard, sore lump on the dorsal side. Is it worth getting it checked out or assume it's a haematoma and leave it to resolve on its own? Any treatment needed?