bad edema in legs and are hard as a rock very painful. white flaky stuffy can be scraped out what.

my mom has a spinal cord tumor and one of her many pain related problems is her legs. Her legs are swollen (edema) but they are hard has a rock.  They hurt really bad.  A white flaky substance comes out of her skin if she scrapes at her legs.  this helps relieve the tight pressure.  What is going on?  She has seen many physicians and they all say it is normal edema.  She is in a lot of pain and she cannot scrape at her skin anymore she has an infection from doing that.  however her legs are so hard and heavy from this white stuff that builds up.  She has severe numbness form it and her toes and feet are the same.  She feels like her circulation is getting cut off.  When it gets bad her toes even appear to be slightly blue.  Any ideas. please help we are in desparate need.  Could it be related to taking  steroids and the steroids is breaking down her skin and building up.