Review common imaging characteristics of epidermoid cysts. Learn to distinguish epidermoid cysts from similar space-occupying lesions. Demonstrate examples of common and unusual appearances of epidermoid cysts.
also known as primary cholesteatomas or ectodermal/epithelial inclusion cysts,
are usually congenital,
arising during neural tube closure in the 3rd to 5th week of foetal life or from focal expansion of a dermal sinus in the spine.
They can also be acquired secondary to trauma,
which is rare in intracranial epidermoids but can account for up to 40% of spinal epidermoids,
which are generally acquired after lumbar puncture or surgery. Epidermoids account for about 0.2-1.8% of...
Findings and procedure details
epidermoid cysts have the same density as CSF and may displace or encase surrounding structures. The investigation of choice is magnetic resonance imaging (MRI) with fluid attenuation inversion recovery (FLAIR) and diffusion weighted imaging (DWI),
although a large number of patients will have had a CT as a first line neurological investigation,
therefore it is important that the radiologist suspects this diagnosis and recommends further confirmatory imaging. Unenhanced CT will...
Although epidermoids represent less than 2% of primary intracranial tumours,
they are the commonest congenital intracranial tumour and the third commonest CPA lesion following vestibular Schwannoma and meningioma. They account for up to 2% of spinal cord lesions,
increasing to 10% in patients below the age of 15.
Recurrence after resection can occur,
as can malignant degeneration,
which tends to occur in recurrent tumours. Therefore,
it is important that the radiologist has a...
Giant intracranial epidermoids: Is total removal feasible? J Neurosurg .
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Intracranial epidermoid cyst with hemorrhage: MR imaging findings. AJNR Am J Neuroradiol .
2006;27(2):427-429. Demir MK,
Rare and challenging extra-axial brain lesions: CT and MRI findings with clinico-radiological differential diagnosis and pathological...