An mri (with contrast) of the pituitary shows the pituitary itself as a bright/white area, but there are a couple dark/black spots, a few mm in diameter, on it. what does dark indicate here, and what types of anomalies can they be?

It is not feasible to comment on MRI images in absence of seeing the films themselves. You could discuss this with the local radiologist, or if you wish, you could go to the paid portion of our site for a virtual consult where the films and report could be reviewed directly (www.connect@healthtap.com)

If the spots are dark on all sequences, the likelihood is high that it is calcification.