white epidermoid cyst

White epidermoids are a rare type of epidermoid cyst that do not follow the usual near-CSF density and signal intensity on CT and MR respectively. To make matters worse the literature uses the term inconsistently, although generally the 'white' refers to the T1 weighted imaging appearance.

Radiographic features

MRI

In some cases, the intrinsic high T1 signal is due to a high protein content, which renders them relatively hyperattenuating on CT . In this case, T2 signal can vary from hyper to hypointense.

Alternatively, the high T1 signal can be due to high lipid content (mixed triglycerides and no cholesterol), which are associated with fat density on CT . This need not be uniform and may also result in signal suppression on fat attenuated sequences.

Additionally, intrinsic high T1 signal can be seen in rare instances of hemorrhage into the cyst .

Differential diagnosis

Read more on our article on intracranial fat.

Siehe auch:

• intrakranielle Epidermoidzyste
• intraventricular epidermoid
• epidermale Inklusionszyste
• Tumor vor der Medulla oblongata

und weiter:

• Tumor Kleinhirnbrückenwinkel
• intrakranielle Lipome
• congenital cholesteatoma
• zerebellopontines Lipom (Lipom im Kleinhirnbrueckenwinkel)
• T1 hyperintense posterior fossa cystic lesion