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| ==Causes== | | ==Causes== |
| *Craniopharyngioma is a nonglial intracranial tumor derived from a malformation of embryonic tissue.
| | *The cause of craniopharyngioma has not been identified. |
| *There are differing hypotheses on its embryonic origin.
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| *The caause of craniopharygioma is although not completely understood. | |
| *Some authorities advocate that it originates from ectodermal remnants of Rathke's pouch.
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| *Few pathologists believe that it originates from residual embryonal epithelium of the anterior pituitary gland and of the anterior infundibulum.
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| ===Embryonic theory===
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| *According to this theory Craniopharyniomas arise from neoplastic transformation of embryonic squamous cell nests of Rathke's pouch with the stomodeum.
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| *During the process of proliferation and rotation of the cells of Rathke's pouch leading to the formation of the adenohypophysis, cell remnants of the craniopharyngeal *duct are spread through the intrasellar and suprasellar region.
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| *The rotation of the adenohypophysis is caused by different rates of cellular multiplication, resulting in a spread of cells of the craniopharyngeal duct to the suprasellar region.
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| *The rare location at the cerebellopontine angle could fit with this hypothesis.
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| ===Metaplastic theory===
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| *Papillary craniopharyngiomas are the result of metaplasia of the adenohypophyseal cells in the anterior pituitary, resulting in the formation of squamous cell nests.
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| *This theory is supported by the presence of metaplastic nests in the gland
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| ===Genetics===
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| *Multiple chromosomal abnormalities have been reported by classic cytogenetic analysis.
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| *Most tumors had abnormalities involving chromosomes 2 and 12.
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| *More than 70% of adamantinomatous craniopharyngiomas harbor a mutation of the β-catenin gene.
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| *Most of the mutations affect exon 3, which encodes the degradation targeting box of β-catenin compatible with an accumulation of nuclear β-catenin protein.
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| *In a few cases of adamantinomatous craniopharyngioma, the same β-catenin mutations occurring in the epithelial cells have been identified in mesenchymal cells.
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| *No mutations have been demonstrated in papillary craniopharyngioma.
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