Histology and Embryology Related to Craniopharyngiomas
Craniopharyngiomas are complex epithelial neoplasms of the sellar region and are divided by WHO into the adamantinomatous type (aCP) and the papillary type (pCP). It is considered that aCPs derive from neoplastic transformation of ectopic embryonic remnants of the craniopharyngeal duct and Rathke’s pouch, and these tumors share features with odontogenic tumors suggesting a common origin. The pathogenesis of pCPs is less understood, but these tumors may arise from metaplastic transformation of anterior pituitary epithelial cells, especially those located in the pars tuberalis. Thus, craniopharyngiomas do not belong to neuroepithelial tumors, and embryological study is important for elucidating the features of craniopharyngioma.