Presentation
Four weeks of burred vision.
Patient Data
No enhancing intracranial lesion identified ~ 10 mm fat density lesion within the suprasellar cistern posterior to the pituitary infundibulum. Bilateral cerebellar tonsillar descent of approximately 9mm below the foramen magnum.
Courtesy of Dr Kapilan Varatharajah.
In the suprasellar cistern is a small (~10 mm) mass that is T1 and T2 hyperintense with loss of signal on fat suppression sequences. There is no enhancement but there is chemical shift artifact. This mass sits posteroinferior to the optic chiasm, with distortion of the post-chiasmatic left optic nerve.
Peg-like cerebellar tonsils crowd the foramen magnum with 8 mm of descent below the foramen magnum. Imaged upper cervical cord is normal with no syrinx. No hydrocephalus.
8mm pineal cyst.
Case Discussion
The patient's blurred vision is almost certainly due to the lipoma distorting the optic chiasm. The Chiari 1 malformation and pineal cyst are most likely incidental to presentation, and I don't know of an association between them.