Diagnosis:

Usually by MRI imaging

Findings on investigations:

CT: low density, irregularly enhancing rim
MRI:

• Cerebellopontine angle, suprasellar, infrasellar
• variable signal (dependent on lipid content)

Pathology:

Histology:

• Cyst lined by epithelium, keratinisation, no adnexial/dermal tissue (hair & sweat glands) i.e. only top layers of the skin
• Cyst filled with keratinised material

Treatment:

Surgical resection