Dermoid cyst

Incidence

Dermoid cysts are extremely rare.

Origin

Dermoid cysts are ectodermal inclusion cysts.

Macroscopic appearance and general characteristics

Dermoid cysts are well circumscribed cystic masses with a greasy or cheesy content. They often contain hair. Rupture of the cyst is possible with spread of fat droplets in the ventricles and subarachnoid spaces. The intense neuroglial reaction can lead to vasospasm with brain infarction.

The most frequent location is the parasellar region. Frontal and posterior fossa lesions are less common. The tumor is benign.

Microscopic appearance (image 2)

The cyst is lined by squamous epithelium with underlying dermal appendages, including hair follicles and adnexae. In comparison to epidermoid cysts, they have a more abundant underlying stroma.

Imaging features (see case reports)

- CT

the dermoid cyst appears as a well circumscribed rounded mass. The wall is frequently calcified. The content of the cyst displays negative attenuation values. With appropriate window settings, intracystic hair can be demonstrated. In case of rupture, drops with negative densities can be seen in the subarachnoid spaces and the ventricles.

- MRI

dermoid cysts are characterised by short T1, with signal hyperintensity on T1 weighted sequences. Signal intensity on T2 weighted images is variable. In case of rupture, the fatty droplets have the same T1 hyperintensity (image 3). In atypical cases the intensity of the cyst content can be very similar to that of colloid cysts.

Case reports

Search:
Dermoid cyst
Dermoid cyst, multiple suprasellar
Dermoid cyst, ruptured
Dermoid cyst, atypical
Epidermoid and dermoid cyst, simultaneous occurrence in the posterior fossa

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