Paraffin sections show normal anterior pituitary tissue composed of acini with a mixed cell population. At one edge there is a rim of loose fibrous tissue containing irregular trabeculae of calcium and collections of ghosts of effete squamous epithelial cells cells consistent with craniopharyngioma. No intact squamous epithelium is identified.
The sections show fragments of tissue in which there are irregular shaped islands of epithelium. These have a peripheral basaloid layer, central squamous differentiation and an intermediate zone of loose stellate reticulum. Multifocal calcification is noted and there are collections of ghosts of effete squamous epithelial cells within hyalinised fibrous tissue. The features are of craniopharyngioma.
Tumor is seen to extend between trabeculae of viable bone. No adjacent brain parenchyma is included.