solid and enhancing pituitary region mass

Solid lesions with enhancement are by far the most commonly encountered appearance of pituitary region masses.

macroadenoma
- by far the most common entity
- typically enhances less vividly than other entities
- elevates the dura of the diaphragma sella (as the origin is within the pituitary)
- the sella is expanded and remodeled
- non-normal pituitary tissue is usually visible
pilocytic astrocytoma
- children
- enlarged optic chiasm or nerve
- variable enhancement
craniopharyngioma
- papillary subtype is more frequently solid, although cystic components are still more common than entirely solid lesions
- epicenter is in ~85-95% of cases in the suprasellar region
- in ~20% of cases, there is extension into the pituitary fossa
meningioma
- epicenter is usually outside the pituitary fossa
- dural tail common
- enhancement is homogeneous and vivid
- if the carotid is encased, then it is usually narrowed
metastasis
- uncommon
- irregular margins
- may have erosion/destruction of bony margins without expansion (rapid rather the slow growth)
inflammation / infiltration
- e.g.
  - lymphocytic hypophysitis
  - lymphoma/leukemia
  - neurosarcoidosis
  - IgG4-related hypophysitis
- vivid enhancement
- irregular margins
- dural tail may be seen
- infundibulum may be thickened
germinoma
- usually pediatric population
- often involves inferior recesses of the third ventricle
- often also involves pineal region
pituicytoma
granular cell tumor of the pituitary (pituitary choristoma)