Neurosurgery notes/Tumours/Sellar tumours/Craniopharyngioma/Types of craniopharyngioma

Types of craniopharyngioma

View Details
Status
Done
logo
Parent item
Craniopharyngioma
Sub-item
Adamantinomatous craniopharyngioma
Papillary craniopharyngiomas
General
 
  • A craniopharyngioma characterized by a distinctive epithelium that forms stellate reticulum, wet keratin, and basal palisades, showing CTNNB1 mutations and aberrant nuclear expression of beta-catenin in as many as 95% of cases.
  • A papillary, mostly supratentorial or third ventricular craniopharyngioma characterized by fibrovascular cores lined by non-keratinizing squamous epithelium.
 
Definition
  • Essential criteria
    • Location within the sellar region.
    • Presence of benign, non-keratinizing squamous epithelium.
    • Presence of stellate reticulum and/or wet keratin.
  • Essential criteria
    • The tumour must be located in the sellar or suprasellar region.
    • It must be composed of benign, non-keratinising mature squamous epithelium covering fibrovascular cores or a cyst wall.
 
  • Desirable criteria
    • Nuclear immunoreactivity for p-catenin.
    • Identification of a mutation in the CTNNB1 gene.
    • Absence of a BRAF p.V600E mutation.
  • Desirable criteria
    • Demonstrable immunoreactivity for the BRAF p.V600E protein or a detected BRAF p.V600E mutation.
    • Absence of nuclear beta-catenin immunoreactivity and absence of CTNNB1 mutations.
Numbers
  • M:F 1:1
  • Bimodal age distribution
    • 5-15yrs
    • 45-60yrs
  • M:F 1:1
  • Mainly adults (40-55 yrs)
Genetic
  • Wnt signalling pathway mutation
    • Mutations in exon 3 of the beta-catenin gene (CTNNB1) 95% lead to activation of the WNT signalling pathway,
      • Aberrant cytoplasmic and nuclear accumulation of beta-catenin protein and respective target gene activation
  • BRAF V600E mutation
Origin cells
  • Metaplasia of cells derived from tooth primordia
    Embryogenic theory: arise from epithelial remnant of involuted rathke's pouch or craniopharyngeal duct
  • Metaplasia of cells derived from buccal mucosa primordia
    Metaplastic theory: arise from squamous cell nests normally found at the junction of the pituitary stalk and pars distalis
Imaging
  • Cystic, Cyst is proteinacious
  • Calcific 90% are calcified
  • Lobulated contour because it is made up of multiple
    cystic lesions.
  • Solid components
    • Form minor part of the mass
    • Enhance vividly on both CT and MRI.
  • Large
    • Extends superiorly into the 3rd ventricle,
    • Encasing vessels, and even adhering to adjacent structures.
  • CT
    • 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
        • notion image
  • MRI
    • Cysts
      • T1: iso- to hyperintense to brain (due to high protein content "motor oil cysts")
          • notion image
      • T2: variable but ~80% are mostly or partly T2 hyperintense
          • notion image
    • Solid component
      • T1 C+ (Gd): vivid enhancement
          • notion image
           
          notion image
      • 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
  • Solid, Cyst is aqueous
  • Non calcific
  • More spherical
  • Lack the prominent cystic component;
  • most are solid +/- contain a few small cysts.
  • These tumours tend to displace adjacent structures.
  • CT
    • Cysts
      • Small and not a significant feature
      • Near-CSF density
    • Solid component
      • Soft tissue density
      • Vivid enhancement
    • Calcification
      • Uncommon, rare
        • notion image
  • MRI
    • Cysts
      • When present, they are variable in signal
      • T1: 85% are T1 hypointense
          • notion image
      • T2
          • notion image
    • Solid component
      • T1: iso- to slightly hypointense to brain
      • T1 C+ (Gd): vivid enhancement
          • notion image
          notion image
           
      • T2: variable/mixed
    • MR spectroscopy: cyst contents does not show a broad lipid spectrum as they are filled with aqueous fluid
Macroscopic
Lobulated mass, with multiple cysts
Machines oil greenish brown liquid
Secondary changes (fibrosis, calcification, ossification, presence of cholesterol rich deposits
Adamantinomatous craniopharyngioma extending towards the cerebral peduncles; note the so-called machine-oil appearance of the dorsal portion and calcifications.
Adamantinomatous craniopharyngioma extending towards the cerebral peduncles; note the so-called machine-oil appearance of the dorsal portion and calcifications.
 
Adamantinomatous craniopharyngioma. Fresh tumour material showing an uneven surface with small calcifications and flakes of wet keratin (white deposits).
Adamantinomatous craniopharyngioma. Fresh tumour material showing an uneven surface with small calcifications and flakes of wet keratin (white deposits).
 
Solid, rarely cystic
Without cholesterol rich machine oil like fluid
No calcification
Surface look like corrugated or cauliflower like
Papillary craniopharyngioma. Fixed coronal section of papillary cranio­ pharyngioma showing a solid and cystic mass involving the Infundibulotuberal region and third ventricle in an adult patient without prior surgical intervention. The tumour mass has a cauliflower-like configuration. Calcifications are absent.
Papillary craniopharyngioma. Fixed coronal section of papillary cranio­ pharyngioma showing a solid and cystic mass involving the Infundibulotuberal region and third ventricle in an adult patient without prior surgical intervention. The tumour mass has a cauliflower-like configuration. Calcifications are absent.
Microscopic
 
Well-differentiated
epithelium arranged in cords, lobules, nodular whorls, and irregular trabeculae
bordered by palisading columnar epithelium.
Presence of
  • Calcifications
  • Picket fence-like palisades,
  • Whorl-like cell nodules
  • Wet keratin: anucleate ghost-like remnants of squamous cells
Cystic
cavities containing cell debris and fibrosis are lined by flattened epithelium
Finger-like tumour protrusions in the surrounding brain tissue.
Finger-like tumour protrusions in the surrounding brain tissue.
Cell groups of an adamantinomatous craniopharyngioma in the surrounding brain tissue, in which a distinct piloid gliosis with abundant Rosenthal fibres is evident.
Cell groups of an adamantinomatous craniopharyngioma in the surrounding brain tissue, in which a distinct piloid gliosis with abundant Rosenthal fibres is evident.
The distinctive epithelium features loose microcystic areas known as stellate reticulum (green dot), whorls, basal palisading (blue dot), and anucleate nests of pale, squamous ghost cells known as wet keratin (red dot).
The distinctive epithelium features loose microcystic areas known as stellate reticulum (green dot), whorls, basal palisading (blue dot), and anucleate nests of pale, squamous ghost cells known as wet keratin (red dot).
Compact
monomorphic sheets of well differentiated squamous epithelium without surface
keratinization
Lack
  • Calcifications,
  • Picket fence-like palisades,
  • Whorl-like cell nodules,
  • Wet keratin
Rudimentary
papillae may surround the fibrovascular cores.
Rare but
can see ciliated epithelium and periodic acid-Schiffpositive goblet cells
At low magnification, the tumour has a cauliflower-like appearance, with surface epithelium covering central fibrovascular cores.
At low magnification, the tumour has a cauliflower-like appearance, with surface epithelium covering central fibrovascular cores.
At higher magnification, the lining is consistent with non-keratinizing squamous epithelium.
At higher magnification, the lining is consistent with non-keratinizing squamous epithelium.
Immunophenotype
Positive
  • Beta-catenin (nuclear)
    • Especially in the whorl-like cell clusters along the tumour margin and in finger-like tumour protrusions
  • Less claudin-1 (membranous)
Positive
  • BRAF V600E mutations
  • More claudin-1 (membranous)
Prognosis
Worse, more brain invasion
Better, less brain invasion hence less complication from surgery