Can a pituitary tumor disappear on its own without any treatment? I underwent 2 mris with a contrast. The first showed 5 mm pituitary microadenoma. The second, which was done 3 years later showed no tumor at all. Could it be that a radiologist misread th

MRI . Mri machines can vary greatly in quality and in their ability to distinguish a very small lesion in the pituitary gland. Most microadenomas show up as small areas of decreased enhancement compared to the rest of the gland. These small areas can also be artifact, cyst, scar etc. It is possible but unlikely that the radiologist misread the scan. Finally, most microadenomas are biologically active and produce a hormone. Without an endocrine abnormality, the lesion is less likely to be a microadenoma. When there is doubt clinically, a follow up scan in a few months is advised.