- Sub frontal
- Through anterior cranial fossa by elevating the frontal lobe of the brain
- Trans sphenoidal
- Through sphenoidal air sinus.
- This is entered either via the ethmodial air cells after raising the periosteum from the medial wall of orbit or by elevating nasal mucosa from nasal septum
- Presents with features of raised intra cranial presseure
- Widens the pitituary fossa and erodes clinoid process and petrous crest.
- Compresses the optic chiasma causing bitemporal hemianopia
- If they involve chromophils, can cause endocrine dysfunction together with compression effects
- Chromophobe adenomas only cause pressure effects and intracranial pressure.