Dermoid cyst with rupture into the subarachnoid space

Case contributed by Dr Bruno Di Muzio


Previous history of a dermoid tumour resection.

Patient Data

Age: 38
Gender: Female

In the suprasellar cisternal/planum sphenoidale an extra-axial high T1 signal mass measuring 3.5 x 2.5 x 2.1 cm which is consistent with the known history of prior resection of a dermoid cyst. There is extensive spread of T1 hyperintense material throughout the subarachnoid space consistent with rupture. Following administration of contrast, no solid enhancing component can be identified and minimal if any leptomeningeal enhancement. The pituitary fossa and pituitary gland appear normal. Ventricles are unremarkable in size, and posterior fossa is normal. Note is made of a prior right-sided craniotomy.


Characteristic appearances of a suprasellar dermoid cyst with rupture into the subarachnoid space.

Non-contrast CT performed previously to surgical resection confirms the well defined low attenuating (fat density) lobulated mass.

Case Discussion

Intracranial dermoid cysts are uncommon lesions with characteristic imaging appearances. They can be thought of as along the spectrum from epidermoid cysts at one end and teratomas at the other.

They are typically midline tumors, with no enhancement and, unlike intracranial lipomas which follow fat density on all sequences, dermoids have more variable signal characteristics.  

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Case information

rID: 37761
Published: 24th Jun 2015
Last edited: 14th Aug 2019
Tag: rmh
Inclusion in quiz mode: Included

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