The patient went on to have surgery which confirmed the diagnosis of a non-tumor cyst, presumably a Rathke's cleft cyst. 

Histology

MACROSCOPIC DESCRIPTION: "Cyst wall": A small fragment.

MICROSCOPIC DESCRIPTION: The sections show extremely small fragments of anterior pituitary tissue in each of the two specimens submitted. These show infiltration by small lymphocytes and monocyte-macrophages. No evidence of tumor is seen in either specimen. 

FINAL DIAGNOSIS: Cyst wall & contents: Small fragments of unremarkable anterior pituitary tissue; no evidence of tumor seen.

Discussion

The patient has been followed up for a number of years without recurrence. 

This case also highlights the difficulty in correctly identifying presence of enhancement, particularly on fat sat T1 C+ Images; they are great for delineating the extent of enhancement, but can suggest enhancement is present when in fact none is. Read a more complete discussion here.