Solid pituitary lesions with enhancement are by far the most commonly encountered appearance of pituitary region masses.
Differential diagnosis
-
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 1
- in ~20% of cases, there is extension into the pituitary fossa 1
-
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 than 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
- e.g.
-
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)