I had transphenoidal surgery in april of 2000 to remove a growth hormone secreting pituitary adenoma. All could not be removed so ive been taking 30mg Somavert (pegvisomant) sub Q daily. ( After sandostatin was shown to be ineffective). Since somavert is not tumor suppressing, Ive had Brain and pituitary MRI scans approximately every 6 months since the surgery, w and w/o contrast. Ive had headaches almost everyday of varing degrees occasionally bad enough to go to the ER. Not too often though. The last trip to ER was about 2-3 years ago until about 2 and 1/2 weeks ago. I went to er with a severe migrane, I was given 100mg Demerol and put in a dark room. Usually the headache disappears right away after the shot. This time it didnt. I had a seizure, mild, eyes back into head and I lost my bladder function. I was taken to CT where it was discovered I had a colloid cyst. I had surgery on 2-2 to remove the cyst. My question is how is it possible with Brain MRI scans every 6 months for the past 9 years that this wasnt discovered earlier?, Thanks