· To describe the radiological features and common locations of epidermoid and dermoid cysts in children.

Concept and location Epidermoid and dermoid cysts (EC/DC) represent together the epithelial inclusion cysts. These cysts account for a majority of cutaneous nodules found in children. They may be present at birth or appear anytime in childhood. EC/DC can appear on almost all skin surface, but are more commonly located in the head and neck. EC often occur on the forehead, lateral corner of the eyebrow (which is the most frequent location), anterior fontanelle or postauricular and periorbitary spaces. DC are typically found in the...

EC/DC are suspected upon physical examination. Imaging is usually requested before surgical removal to confirm the diagnosis and evaluate the extension in depth. Ultrasonography (US) usually shows a well-defined, round to ovoid, hypoechogenic mass in the subcutaneous tissue. Larger lesions can be a little heterogeneous or present a laminated appearance, like the layers of an onion skin, that corresponds to the alternating layers of compacted keratin and desquamated squamous cells seen histologically. The capsule may be echogenic and calcified sometimes. In Colour Doppler study there...

Head and neck EC/DC have typical clinical and imaging features, even though none of these are pathognomonic. Diagnosis is usually made by clinical examination and imaging findings, however, it has to be confirmed with the histological exam. Surgical treatment is recommended, being curative in most cases.

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