"Disappearing" brain lesions

  : : Age 41, female, excellent health until I was recently admitted thru ER with a right visual field problem (about 40% of the right side is a blind spot), confusion, mild headache behind left eye, some memory problems, walking problems due to balance, slow heart rate,thowing PVC's, and very low blood pressure.  Vision blurred totally and the right foot went numb the next day.  Initial diagnosis was a stroke, but MRI showed 4 brain lesions and significant brain swelling.  Decadron and anti-coagulants started immediately after admission.  The anti-coagulants were discontinued within 3 days, decadron continued for about 6 weeks.
  : : One large lesion on top of head, not encapsulated.  Three other lesions deeper, not accessable, small, all encapsulated.  Contrast was used.  Physicians assumed cancer (some thought two different types of cancer), and we spent 1 1/2 weeks looking for source with no results.  Finally did needle biopsy of large lesion with inconclusive results except for gliosis (sp).  At this point, two neurosurgeons recommended craniotomy for another biopsy and to get out as much as possible of the large lesion.   Third opinion recommended steriotactic biopsy of one of the smaller lesions.  Nearly  2 1/2 weeks after admission. I'm glad to report that I went for this approach.  The procedure was stopped before the biopsy as the sterotactic MRI showed no brain lesions anymore.  There was still significant swelling, but far less than on the original MRI.  Reduced swelling clearly coincided with reduction in symptoms.
  : : Other information:
  : : History of many collagen vascular/auto-immune problems 15-20 years ago.  Never diagnosed.
  : : History of pneumonia one month prior to onset of brain swelling.
  : : Family history of auto-immune disorders including MS, endocarditis, chron's disease.
  : : No abnormalities in ANY testing except MRI and brain biopsy (as noted above).  Extensive infectious disease and rhumatology work-ups have not shown anything, and even the sed rate is normal.  Evidence of very old toxoplasmosis infection (probably 20 years ago).  Spinal tap did show increased WBC, but I understand this is non-specific.
  : : Current status (six weeks after episode):  Follow-up MRI shows marked decrease in swelling.  Still some in the visual field area, which is the only symptom that has not gotten better.  Most other problems are resolved, except for mild confusion, minimal memory lapses, some vision blurring and left leg is still somewhat numb.  Right visual field still shot to hell and I still feel like I'm not "thinking" the same way I used to.  Nonetheless, under the circumstances, I'm not complaining!
  : : Physicians are mystified.  Diagnosis being considered include CNS vaculitis, lymphoma, some other auto-immune problem, infection or absess (abscess) (related to pneumonia?).  Have seen or will be seeing neurosurgeon, neurologist, rheumatologist, infectious disease specialist, internist, cardiologist and possibly oncologist.  Most are affiliated with a teaching hospital (though not a major facility as we do not have one here).
  : : My questions:
  : : 1.  I am given to understand that these "disappearing" brain lesions are VERY unusual.  The neurosurgeon was quite shocked when he saw the MRI taken during the stereotactic procedure.  The other physician's seem equally shocked.  Can anyone give me an idea of how commonly this happens?
  : : 2.  Other tests you might recommend?
  : : 3.  Other possible diagnosis you might consider?
  : : 4.  Thoughts on if this visual field problem and other problems will just clear itself up?  The neurosurgeon best guess is that it will resolve itself and an absolute diagnosis will never be finalized.  The neurologist does not agree.  He feels that a diagnosis is still possible, and some the problems may be permanent.  (I know this will be difficult to answer with out examination and MRI's, but your experience counts.  I promise to take it with a grain of salt.)
  : : thank you all for your help and suggestions.  
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  : Dear Jeanette:
  : The actual appearance of the serial MRI's is critically important. Any description of the lesion, however good, cannot substitute for the pictures.
  : Disappearing enhancing lesions (either spontaneous, or on treatment with corticosteroids, as in your case) are not common. They include primary CNS lymphoma, neurosarcoidosis, acute multiple sclerosis plaques, leuckoencephalopathy of hypertensive encephalopathy, lesions of cerebral venous thrombosis, lesions associated with seizures, occasionally some forms of infection (encephalitis, abscesses, cysticercosis), primary CNS vasculitis, and various other obscure transient encephalopathies. This is an incomplete list.
  : The lesions I have most commonly seen biopsied (with non-specific result), that subsequently became smaller (or disappeared) are primary CNS lymphoma, multiple sclerosis plaque, and lesions of venous thrombosis.
  : Cases like yours can be incredibly difficult to diagnose. Additional tests that are helpful in appropriate cases include angiograms, repeated high-volume spinal taps for cytology or flow-cytometry, and repeat biopsies. Some of these tests are invasive and are undertaken in a situation like yours only if there is evidence of disease progression/relapse.
  : I hope this is helpful. Good luck!
  
  Thank you so much for your reply.  It is reassuring to know that the difficulty and confusion of my physicians is warranted!  Two additional questions, please:
  1.  You did NOT include Primary CNS Vasculitis on your list of possible diagnosis, which frankly surprised me.  The physician's I am dealing with feel that this is the most likely diagnosis (in part because of the history of auto-immune disorder).  Is there a reason you do not feel this is reasonable?
  2.  I am in Phoenix.  I am very comfortable and confident of my physician's here (neurologist, internist, rheumatologist, infectious disease and neurosurgeon), I also recognize that I am dealing with something unusual or even rare.  Is there another facility that you might suggest for a consult if this is not resolved in a resonable length of time or if it gets worse?  Traveling is possible, and financial issues should not be considered in your answer (a luxury beyond belief, I assure you).  While I know Cleveland Clinic will be your first recommendation, is there a similar center a little closer to home -- perhaps California or Houston?
  Thank you again.

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Dear Jeanette:
I did include primary CNS vasculitis in my list of diagnoses, and do think it is not an unlikely diagnosis in your situation.
Centers that I can recommend in the areas that you mention are the neurology departments of UCLA, UCSF, and Baylor. They are all world-renowned neurology departments with expertise in almost all subspecialities of neurology.
Good luck!
Good luck!