Clinical Data
40-year-old female presents with acute severe headache at the emergency department.
The neurologist wants to rule out an intracranial haemorrhage and orders a CT brain.
Showing images CT without contrast
More images: MRI
What do you see?
What do you see?
CT shows
* low attenuating suprasellar lesion (fat density) with rim calcification.
* multiple scattered smaller similar subarachnoid lesions supra and infratentorial.
* enlarged supratentorial ventricles.
MRI shows
* the suprasellar lesion shows T1 heterogenous and T2-hyperintense signal,
* multiple scattered T1-hyperintense foci subarachnoid and intraventricular in the left frontal horn (arrows).
* no enhancement.
* no diffusion restriction (not shown).
What is the most likely diagnosis?
What is the most likely diagnosis?
Ruptured suprasellar dermoid cyst.
Ruptured intracranial dermoid cyst
Intracranial dermoid cysts are often incidental findings and most do not cause symptoms. Both dermoid and epidermoid cysts are ectodermal in origin and lined by stratified squamous epithelium. In addition, dermoid cysts contain epidermal appendages such as sebaceous glands which secrete sebum, an oily substance.
Symptoms occur due to mass effect or rupture. In case of rupture, dermoid material (sebum droplets) can leak into the subarachnoid space which can lead to chemical meningitis and cause symptoms such as headaches, seizures, and vasospasms.
CT shows
-hypoattenuating primary lesion (fat density due to sebum).
-typically, not exclusively, in midline location.
-sometimes rim calcification of the primary lesion.
-smaller similar hypoattenuating lesions in the subarachnoid space in case of rupture.
MRI shows
-generally T1-hyperintense signal (sebum).
-scattered T1-hyperintense droplets in the subarachnoid space and intraventricular. Fat-fluid level within the ventricles.
-variable T2 signal.
-generally no enhancement of the lesion. Leptomeningeal enhancement in case of chemical meningitis.
References
https://radiopaedia.org/articles/intracranial-dermoid-cyst-1