Figure 8a. Hypothalamic dermoid cyst in a 30-year-old man with headache. (a) Sagittal T1-weighted MR image shows a well-defined hyperintense lesion (arrow) at the floor of the hypothalamus posterior to the infundibular stalk. (b) On a coronal fat-suppressed T1-weighted MR image, the lesion (arrowheads) exhibits suppressed signal intensity, a finding that indicates adipose contents. The diagnosis (hypothalamic dermoid cyst) was confirmed at surgery.