A congenital subcutaneous cyst that arises from entrapment of skin along the lines of embryonic fusion. In contrast to epidermal cysts, dermoid cysts tend to contain various adnexal structures such as hair, sebaceous, eccrine or apocrine glands. Dermoid cysts are present at birth, and are indolent, firm, deep, subcutaneous nodules. They are often located on the head and neck, and rarely in the anogenital area. Dermoid cysts are slowly progressive and can grow to a size of 1 to 4 cm. []
