[Histological analysis of craniopharyngiomas--with special reference to their histological origin and differentiation].

The histogenesis of craniopharyngiomas was immunohistochemically studied on the basis of cytokeratins (CK) expression, with special reference to histological subtype, i.e., the squamous type (Sq) and adamantinomatous type (Ad). Alcian-Blue staining and immunohistochemical expression of secretory component were also studied to assess secretory activity. Although combined expression of simple-, stratified-, and skin-type CK was detected in both Sq and Ad, the pattern of expression in Sq and Ad was different. Sq displayed epidermal differentiation of CK, and secretory activity was limited to the apical cells of Sq. Based on these findings, the histogenesis of Sq appeared to be from Rathke's pouch, but that of Ad remained obscure.