Pathology of craniopharyngioma

Macroscopic, light and electronmicroscopic findings of craniopharyngioma are selected from the files of Montefiore Medical Center to illustrate common and unusual features of this tumor for the neurosurgeon. The most important diagnostic histopathological hallmark is squamous epithelium. In addition to demonstrating various histological features of the epithelial layer observed in craniopharyngioma, the surrounding connective tissue and its alterations are demonstrated. These include deposits of cholesterol crystals associated with foreign body giant cells, hemorrhage, hemosiderin containing macrophages, lymphocytic infiltration, calcification and bone formation. In addition, invagination of nests of epithelial cells into adjacent tissue, such as pituitary gland and neural parenchyma is observed. The presence of dense astrocytic gliosis with prominent Rosenthal fibers is a well known characteristic features of the brain parenchyma surrounding craniopharyngioma. The significance of these findings are discussed along with the differential diagnosis of this entity and a brief review of the current literature.