My sister has been in the hospital since Sept and has been slowly deteriorating. She is bed ridden, unable to walk and can barely move her arms. She has had extreme back pain ever since Sept that has not responded to pain meds. She had 3 spinal taps that all came back negative for cancer and everything else they could think to test for. She also had several MRI s and CT scans that have all been negative. Jan 12th the doctor said that she had a very rare virus that they couldn t identify??? The following week they did a biobsy and now they say she has cancer in the spinal fluid, but that she does not have any tumours anywhere else. All the reading I have done points to CSF cancer as secondary, is it possible for it to be primary in very rare cases?