Craniopharyngioma: a case report and comparative galectin histochemical analysis.

Craniopharyngioma is a rare benign tumour originating from Rathke's pouch. This paper reports a tumour case studied with a set of markers defining protein-carbohydrate recognition. Expression of endogenous lectins and their reactive glycoligands is under differentiation-dependent control in many cell types. These parameters can be related to the degree of cell differentiation in tumours. Therefore, the expression patterns of endogenous lectins, namely galectins-1, -3, and -7, in the craniopharyngioma case were determined. Galectins-1 and -3 were also used to reveal glycoconjugates in cells and extracellular matrices, an approach that has heretofore relied largely on plant lectins. The staining pattern of craniopharyngioma is compared with that of two other types of ectodermally derived tumours, namely basal and squamous cell carcinomas. Clusters of polygonal and flattened cells with morphological characteristics of differentiated cells in the craniopharyngioma and the majority of poorly differentiated cells in squamous cell carcinomas were reactive with galectin-3. No binding of this probe was observed in cells of basal cell carcinomas and the majority of craniopharyngioma cells. In view of the lack of accessible binding in the basal layer of normal squamous epithelia where proliferative cells (including stem cells) are located, galectin-3 binding could be used to distinguish basal from suprabasal cells of squamous epithelial cells.