Hello, and thanks for writing in.
With leg swelling and bruising present, cancer certainly is a possibility, but a few other things can also cause this, such as a bleeding disorder (low platelet count, or platelets that are not functioning properly - bone marrow disorder, trauma, auto-immune disease), ingestion of rodent poison (which also causes a different type of bleeding disorder), swollen lymph nodes (many reasons), vasculitis ("leaky" blood vessels that occur from inflamation in that part of the body), possibly a liver problem. So, hopefully the lab work will provide an answer for you. If blood clot time tests have not been run (PT, PTT, mucosal bleeding time), I would highly recommend that also. Sometimes tissue biopsies are also needed to get a diagnosis.
I hope this helps.