PMC

Microdissection-based analysis (case 8). A and B: Sections after microdissection for epithelial (A) and mesenchymal (B) components. Microdissection was performed using peripherally palisading cells as a hallmark of borders between the epithelial and mesenchymal cells. Microdissected areas were marked by arrowheads. C: Direct sequencing of the β-catenin gene. Both components harbor missense mutations affecting a threonine residue at GSK-3β phosphorylation sites. H&E (A, B). Original magnifications, ×200 (A, B).

Adamantinomatous craniopharyngioma with a mesenchymal component (A, C: case 8; B, D: case 1). A and B: Whorling and streaming spindle-cell fascicles are observed around the epithelial cell nests. A highly cellular area is seen in case 8 (A). C and D: Immunohistochemistry for β-catenin. Spindle cells around the epithelial cell nests show moderate to strong cytoplasmic and nuclear expression and lack membranous staining observed in epithelial cells. H&E (A, B) and immunohistochemistry for β-catenin (C, D). Original magnifications, ×200.

Representative histology of cases (A, B) and immunohistochemistry for β-catenin (C, D). A: Adamantinomatous craniopharyngioma. Loosely cohesive squamous cells surrounded by peripherally palisading cells. A squamous nodule (wet keratin) (arrowheads) is observed (case 7-1). B: Papillary craniopharyngioma. Well-differentiated squamous epithelium lining loose connective tissue (case 16). C: Adamantinomatous craniopharyngioma. Membranous and cytoplasmic staining for β-catenin. Peripherally palisading cells show stronger expression. Clusters of cells along the epithelial cell whorls show strong nuclear accumulation (case 7-1). D: Papillary craniopharyngioma. Membranous staining pattern (case 11). H&E (A, B) and immunohistochemistry for β-catenin (C, D). Original magnifications: ×100 (A, B); ×200 (C, D).