Anybody ever heard of "streaking" in the brain?

My aunt has been having problems since before Easter with constantly falling and memory problems.  Has seen numerous doctors, been to multiple hospitals, etc.  The one neurologist actually told her to go to PT for a month and he would see her back after that.  The one hospital wanted to do a brain biopsy.  They say its not MS - have done multiple spinal taps.  She has now been in Cleveland Clinic for over a week now, has PT/OT three times a day.  Is having to relearn a lot of normal skills - having to dress herself, etc.  They told my uncle they believed there were multiple brain tumors and scheduled her for a PET scan that they were going to use to do the brain biopsy, which we thought was going to happen today.  My sister went up to sit with my uncle during the wait, and called a little bit ago and said the biopsy is now rescheduled until July 1 because the neurosurgeon is going out of town.  They did tell her that from the MRI, this isn't so much a "mass" but more like "somebody took a paintbrush and painted a "streak" on her brain that is approximately 4" long x 1/2-3/4" wide.  I'm trying to research this to try to give my mom some ease, but I'm not really coming up with anything.  Anybody else hear of something like this?  If you knew her, it would break your heart right now.  She has always been a vibrant 62 year old active woman, always watched what she ate, exercised daily, etc.  Now, she can't even remember how to dress herself being told how, can't carry on a conversation, etc.  She is "aware" of things around her and she can talk to you, knows us, etc., but she can't "retain a thought".  She actually said on Monday when I saw her "I know I should be worried, but I can't remember it long enough to know what I should worry about".  Any ideas?  Thanks for any input.