Several synonyms exist for epidermoid cysts, including epidermal cyst, infundibular cyst, keratin cyst and the technically incorrect, epidermal inclusion cyst.:778 “Epidermal inclusion cyst” more specifically refers to implantation of epidermal elements into the dermis. The term infundibular cyst refers to the site of origin of the cyst: the infundibular portion of the hair follicle. In fact, the majority of epidermal inclusion cysts originate from the infundibular portion of the hair follicle thus explaining the interchangeable, yet inaccurate, use of these two terms.
The epidermoid cyst may have no symptoms, or it may hurt when touched. It can release pus. It is very common for women on the major or minor labia. In contrast to pilar cysts, epidermoid cysts are usually present on parts of the body with relatively little hair.
Occasionally, an epidermoid cyst will present with Trigeminal neuralgia.
Although they are not malignant, there are rare cases of malignant tumors arising from an epidermoid cyst.