Although similar in terms of location, radiographic features depend on the type, although due to a significant minority of tumors having both adamantinomatous and papillary components, they may show overlapping features.
In the vast majority of cases, craniopharyngiomas have a large suprasellar component (95%), with most involving both the suprasellar and intrasellar spaces (75%). A minority are purely suprasellar (20%), whereas purely intrasellar location is quite uncommon (<5%), and may be associated with the expansion of the pituitary fossa 3,7. Larger tumors can extend in all directions, frequently distorting the optic chiasm, or compressing the midbrain with resulting obstructive hydrocephalus.
Occasionally, craniopharyngiomas appear as intraventricular, homogeneous, soft-tissue masses without calcification (papillary subtype). The third ventricle is a particularly common location.
Rare or ectopic locations reported include: nasopharynx, posterior fossa, extension down the cervical spine.
Adamantinomatous craniopharyngiomas typically have a lobulated contour as a result of usually being multiple cystic lesions. Solid components are present, but often form a relatively minor part of the mass and enhance vividly on both CT and MRI. Overall, calcification is very common, but this is only true of the adamantinomatous subtype (~90% are calcified) 4.
These tumors have a predilection to being large, extending superiorly into the third ventricle, and encasing vessels, and even adhering to adjacent structures 4.
cysts near-CSF density typically large and a dominant feature present in 90% of cases solid component soft tissue density enhancement in 90% calcification seen in 90% typically stippled and often peripheral in location
cysts T1: iso- to hyperintense to brain (due to high protein content “motor oil cysts”) T2: variable but ~80% are mostly or partly T2 hyperintense solid component T1 C+ (Gd): vivid enhancement T2: variable or mixed calcification difficult to appreciate on conventional imaging susceptible sequences may better demonstrate calcification MR angiography: may show displacement of the A1 segment of the anterior cerebral artery (ACA) MR spectroscopy: cyst contents may show a broad lipid spectrum, with an otherwise flat baseline
Papillary craniopharyngiomas tend to be more spherical in outline and usually lack the prominent cystic component; most are either solid or contain a few smaller cysts. Calcification is uncommon or even rare in the papillary subtype, a fact often forgotten.
These tumors tend to displace adjacent structures.
cysts small and not a significant feature near-CSF density solid component soft tissue density vivid enhancement calcification uncommon, rare
cysts when present, they are variable in signal T1: 85% are T1 hypointense 4 solid component T1: iso- to slightly hypointense to brain T1 C+ (Gd): vivid enhancement T2: variable/mixed MR spectroscopy: cyst contents does not show a broad lipid spectrum as they are filled with aqueous fluid