Intradiploic epidermoid cyst
Disclosures
- updated 10 May 2022:
Nothing to disclose
Updates to Article Attributes
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was changed:
Intradiploic epidermoid cysts refer to epidermoid cysts that occur in the diploë of the skull.
Clinical presentation
Painless slowly progressive scalp swelling.
Pathology
- epidermoid cysts may be congenital (most common, arising from ectodermal inclusion during neural tube closure and subsequently remain within the cranial bones) or acquired (e.g. post-surgical or post-traumatic implantation) 4
- intradiploic epidermoids are less frequent than the intradural variety 1
Radiographic features
Intradiploic epidermoids occurs within the frontal, parietal, occipital and sphenoid bones, as well as the spine 1.
Plain radiograph
- rounded or lobulated area of bone destruction, well-delineated sclerotic scalloped margins
CT
- non-enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications
- it may alter the outer and/or inner tables of the skull (the inner table more than the outer)
MRI
- T1: slightly hyperintense to the CSF
- T2: isointense/hyperintense to the CSF
- FLAIR: hyperintense to the CSF space
- DWI: restricted diffusion with characteristic hyperintensity
- T1C+: none
History and etymology
The first intradiploic epidermoid cyst was reported by J Müller in 1838 5.
The radiological pattern of intradiploic epidermoids was first described by Cushing in 1922.
Differential diagnosis
Consider:
-<li><a title="Dermoid cyst of the anterior fontanelle" href="/articles/anterior-fontanelle-inclusion-cyst">dermoid cyst</a></li>- +<li><a href="/articles/anterior-fontanelle-inclusion-cyst">dermoid cyst</a></li>
Images Changes:
Image 9 MRI (FLAIR) ( create )
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