SCLC that has spread to bone barrow

My 53 year old sister was perfectly normal a month ago.  She went to the er for what we thought was a kidney stone.  They did a catscan and said it looked like her lymph nodes around her lungs were swollen and she had pneumonia.  They did a biopsy and took her off of Methorexate which she was taking for RA and is known to cause lymphoma.  Dr. said it did not appear to be cancer but we had to wait for the biopsy to be sure.  A week later the biobsy was inconsluive.  We were told she more than likely had cancer (either small cell or lymphoma) but that they were leaning towards lymphoma and we had to wait for further testing.

As each day progressed she became weaker and weaker.  We thought this was a rheumotoid arthoritis flare up since she was off her meds.  Biopsy still not back.  I finally convinced her to go to the er where she was told it looked like she had leukemia or lymphoma.  She has a large inoperable mass in her chest wall.  They were still leaning towards lymphoma.  They did a bone marrow biobsy last Thursday. They started her on steriods since that is known to shrink lymphoma tumors and she seemed to be improving until Monday when she was moved into ICU and placed on a ventilator.

She has since improved and is breathing on her own but we were told yesterday that it is small cell that has spread to her bone marrow.  They said she had a couple of days to live without chemo and maybe a couple of weeks with chemo.  Her husband chose chemo with the hope that we see a miracle even though the dr's have said she has zero chance of making it. 

Anyone with extensive small cell that has spread to the bone marrow that has survived?  I keep searching and searching but not finding encouraging news.