A condition characterized by the formation of granulomas containing “foam cells,” which get their name due to the distinct look created by cholesterol ester deposits within them. These lesions are most commonly found in the skull, especially at its base. When they impact the pituitary gland, they can lead to disorders such as diabetes insipidus and infantilism. While any bone can be affected, deposits can also appear in the liver, kidneys, brain, and other organs. This disease is also known by other names such as Christian-Schuller syndrome, Hand-Schuller-Christian disease, lipoid granulomatosis, and xanthogranulomatosis.