Craniopharyngiomas are WHO Grade 1 squamous epithelial tumors typically located in the suprasellar region. Given their location, they often present with dysfunction of the hypothalamus-pituitary axis, visual disturbances, and obstructive hydrocephalus. They have solid and cystic areas (as seen in this image) and are often adherent to the surrounding brain parenchyma with an indistinct interface. The cystic areas are filled with dark thick fluid rich in proteins, blood, and cholesterol and with an appearance of "motor oil." Courtesy of: Dr. Luciano de Souza Queiroz, Dept. of Pathology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, São Paulo State, BRAZIL. Additional images are here.