ADAMANTINOMATOUS CRANIOPHARYNGIOMA

This tumor resembles adamantinoma of jaw
Age – common in first two decades of life but can occur in elderly
Common presentation – as suprasellar mass with endocrine, visual and psychological abnormalities
Unusual site – cerebellopontine angle, sphenoid sinus, posterior fossa and pineal region
Occasional cases may develop chemical meningitis due to spillage of cholesterol rich contents into the CSF
Radiological findings
- Tumor is cystic or solid lobulated presenting as contrast-enhancing, suprasellar or intrasellar mass
- MRI shows bright signal in pre-contrast T1 weighted images due to presence of protein fluid
- CT scan shows the presence of peripheral tumoral calcification
Gross
- Lesions are adherent to structures at the base of the brain and indent the floor of the 3rd ventricle
- These tumors are always cystic, filled with dark brown, turbid, “machinery oil” fluid on which minute glistening cholesterol crystals float
Microscopic findings
- Lesion is composed of prominent epithelial lobules having peripheral palisading of cells and internal loose textured stellate reticulum
- Progression of lesion with degenerative changes around vessels produces cystic spaces filled with amorphous debris or fluid.
- Tumor cells around the cyst have the same palisaded alignment as at periphery
- Characteristic features is wet keratin containing plump, eosinophilic keratinized cells which has ghost nuclei
- Nucleus of these shadow cells undergo dystrophic calcification later
- In macrocystic regions, the epithelium often gets flattened and focally may show stratification
- Other findings are
  - chronic inflammation
  - Extensive fibrosis
  - Cholesterol clefts
  - Cystic change
  - Calcification
  - Presence of melanosomal pigment
- In recurrent and irradiated tumors, entire tumor may undergo degeneration and only wet keratin helps in diagnosis
Craniopharyngiomas invade locally and the adjacent brain tissue shows dense piloid gliosis with Rosenthal fibres
Immunohistochemistry –
- Positive for – Cytokeratins.
- Shadow cells positive with antibodies for human hair keratin
Differential diagnosis
- Epidermoid cyst – lacks palisaded cells, wet keratin, calcifications and fibro degenerative changes
Treatment and prognosis –
- Surgical resection is treatment of choice
- Radiotherapy for incompletely excised or recurrent lesions
- malignant transformation to squamous cell carcinoma has been reported

Reference

Peter C. Burger, Bernd W. Scheithauer. Craniopharyngiomas. In: Tumors of the central nervous system. AFIP Atlas of tumor pathology Series 4. Chapter 15. 461-470

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells. Foci shows wet keratin (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells. Foci shows wet keratin. Adjacent foci (left upper) shows glial tissue (H&E,X100)

Adamantinomatous craniopharyngioma: Lobules of epithelial cells with central loose reticulum having stellate cells. Foci of wet keratin is present. Adjacent glial tissue with hemorrhage is noted (left) (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells with central loose reticulum having stellate cells. Foci shows wet keratin (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells with central loose reticulum having stellate cells. Foci shows wet keratin (H&E,X200)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells with central loose reticulum having stellate cells. Foci shows wet keratin (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells. Foci shows wet keratin with kertinized cells having ghost nuclei (H&E,X200)

Adamantinomatous craniopharyngioma: Epithelial lobules showing peripheral palisading of tumor cells. Few foci shows loose reticulum with stellate cells. Foci shows wet keratin (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobule showing peripheral palisading. Foci of wet keratin is present. Surrounding the epithelila lobule glial tissue is present (H&E,X100)

Adamantinomatous craniopharyngioma: Epithelial lobule with peripheral palisading and adjacent glial tissue (right) (H&E,X400)

Adamantinomatous craniopharyngioma: Epithelial lobules with peripheral palisading in the glial tissue. Foci shows foreign body giant cell reaction adjaent to wet keratin (H&E, X100)

Adamantinomatous craniopharyngioma: Cystic degeneration around the blood vessels and cystic space is lined by epithelial cells showing peripheral palisading pattern below which loose reticulum with stellate cells are present (H&E,X100)

Adamantinomatous craniopharyngioma: Lobules of epithelium with central reticulum showing stellate cells. Adjacent (left) cystic cavity showing eosinophilic material (H&E,X400)

Adamantinomatous craniopharyngioma: Cystic space lined by flattened epithelium (H&E,X400)

Adamantinomatous craniopharyngioma: Lobules of epithelium with central loose reticulum having stellate cells and wet keratin with ghost nuclei (H&E,X200)

Adamantinomatous craniopharyngioma: Cystic change in tumor with cyst lined by tumor cells. Adjacent epithelial lobule with wet keratin shows dystrophic calcification (H&E,X100)

ADAMANTINOMATOUS CRANIOPHARYNGIOMA

This tumor resembles adamantinoma of jaw

Age – common in first two decades of life but can occur in elderly

Common presentation – as suprasellar mass with endocrine, visual and psychological abnormalities

Unusual site – cerebellopontine angle, sphenoid sinus, posterior fossa and pineal region

Occasional cases may develop chemical meningitis due to spillage of cholesterol rich contents into the CSF

Radiological findings

Tumor is cystic or solid lobulated presenting as contrast-enhancing, suprasellar or intrasellar mass

MRI shows bright signal in pre-contrast T1 weighted images due to presence of protein fluid

CT scan shows the presence of peripheral tumoral calcification

Gross

Lesions are adherent to structures at the base of the brain and indent the floor of the 3rd ventricle

These tumors are always cystic, filled with dark brown, turbid, “machinery oil” fluid on which minute glistening cholesterol crystals float

Microscopic findings

Lesion is composed of prominent epithelial lobules having peripheral palisading of cells and internal loose textured stellate reticulum

Progression of lesion with degenerative changes around vessels produces cystic spaces filled with amorphous debris or fluid.

Tumor cells around the cyst have the same palisaded alignment as at periphery

Characteristic features is wet keratin containing plump, eosinophilic keratinized cells which has ghost nuclei

Nucleus of these shadow cells undergo dystrophic calcification later

In macrocystic regions, the epithelium often gets flattened and focally may show stratification

Other findings are

chronic inflammation

Extensive fibrosis

Cholesterol clefts

Cystic change

Calcification

Presence of melanosomal pigment

In recurrent and irradiated tumors, entire tumor may undergo degeneration and only wet keratin helps in diagnosis

Immunohistochemistry –

Positive for – Cytokeratins.

Shadow cells positive with antibodies for human hair keratin

Differential diagnosis

Epidermoid cyst – lacks palisaded cells, wet keratin, calcifications and fibro degenerative changes

Treatment and prognosis –

Surgical resection is treatment of choice

Radiotherapy for incompletely excised or recurrent lesions

malignant transformation to squamous cell carcinoma has been reported

Reference

Peter C. Burger, Bernd W. Scheithauer. Craniopharyngiomas. In: Tumors of the central nervous system. AFIP Atlas of tumor pathology Series 4. Chapter 15. 461-470