Dermoid cysts are benign masses with mature squamous epithelium as well as adnexal structures such as hair follicles and sebaceous glands. The oils from hair follicles is in part thought to relate to the lipid content.
These are much less common than epidermoid cysts and typically present in relatively much younger patients (age between 20-30s). These cysts are often asymptomatic unless they rupture, which may be further complicated by chemical meningitis that may result in seizure or infarction.
Because these are fatty lesions, both CT and MRI should demonstrate lesions that follow fatty density or intensity, respectively.