The incidence of pituitary adenomas is approximately 10% of all intracranial neoplasms. There are two types of adenomas: 

• microadenomas: those are 10 mm or less in diameter
  • they cause symptoms due to hormonal excess, as their sizes are too small to cause mass effects. Most common microadenoma is prolactinoma, which is associated with prolactin excess. It characterized by amenorrhea and galactorrhea in females. Rests are GH and ACTH producing microadenomas
• macroadenomas: which are more than 10 mm in diameter, such as in this case
  • as they are larger in size they may cause symptoms due to mass effects. Generally it does not cause hormonal excess symptoms. Owing to its large size, macroadenomas may compress optic chiasm, infundibulum, and hypothalamus as well as can cause erosion of sella turcica. Invasive variant may Infiltrate into adjacent cavernous sinuses, which is commonly assessed by encasement of ICA ¹.

MRI features of macroadenomas:

• T1WI- Isointense to gray matter
• T2WI- Iso to hyperintense, often variable
• DWI-May show restricted diffusion (Good transsphenoidal surgical prognosis is observed with pituitary macroadenomas with high diffusivity than with restricted diffusion ²)
• Post-contrast – Enhancement is common.
• Hemorrhage can occur in pituitary macroadenomas which is seen as hyperintense on T1WI and blooming on GRE images

Differentials are meningioma, craniopharyngioma, pituicytoma and GCT.