lipoma

  Hi and thanks for taking my question.
   I have had two MRIs done recently, one in mid Sept and one a week ago.
  Neither the radiologist nor the neurosurgeon had the Sept film to
  compare with. The radiologist's report stated in part:
  The examination done 9-98 reportedly demostrated a 6MM diameter fat signal
  intensity lesion in the interpenduncular cistern. Today's examination
  demonstrates a mildly lobulated fat signal intensity lesion in the
  interpenduncular cistern which measures 11MM X 9MM X 7MM in dimension on
  today's post contrast scans. Based on the report of 9-98, this would
  appear to have demonstrated an interval increase in size since the prior
  exam. Again, differential considerations would include lipoma versus
  fat containing dermoid or epidermoid.
  There was also a mass with the diff. diag. of low grade glioma on both
  scans. My question is about the Lipoma... is a 1MM increase in size over
  a ten week period something to be concerned about? I have no idea where
  the interpenduncular cistern is... is it a place that can contain an
  expanding growth without a problem?  
  Thanks again,
  Carolyn
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I am at an even greater disadvantage having had the opportunity tio view
neither scan, howwever I am very skeptical about the report of a 1mm
difference in size reported by some one who did not have the origional
scan for comparison.
Even if the older scan was available this difference is so small as to fall within the
margin of error of both measurements.Effectively therefore it can only be
said that the mass is approximately the same size and that a definitive
statement vcannot really be made about any change.
The interpeduncular cistern is a space in below the brain where the two
main branches of nervous tissue diverge from the brainstenm and enter the
cerebral hemispheres on each side, it is not part of the brain proper,but
nerves and blood vessels travel through the area.
Like anywhere in the skull there is not much room for expansion,and
anything which is expanding here needs to be carefully monitored, it sound
like you are recieving good surveilance although in my opinion it is too
early to say definitely that this has grown.