"The vast majority of nasal dermoids present during the first 3 years of life, although occasionally they go undetected until adulthood 1,2. This is particularly the case when they do not have a superficial component."
"Nasal dermoid cysts have have the same signal characeristics as intracranial dermoid cysts, with components that demonstrate fatty signal and others more reminescent of epidermoid cysts. Presence of hair will make the signal even more heterogeneous."
Expected headings
"Embryology"
"Nasal dermoids are rare and account for only 4-12% of all dermoid cysts of the head and neck, far less common than angular dermoids 1,2. They are, however, the most common congenital midline nasal lesions responsible for 61% of all such cases 2. There is a slight male predilection 1,2."
"During the development of the midface a diverticulum of dura protrudes down from the foramen caecum, anterior to the crista galli, all the way down to the skin of the nose 1,2. This occurs during the eigth and ninth week of gestation 3. Normally this diverticulum is transient and fully involutes, but occasionally when this occurs skin cells are pulled back along its tract. If the tract otherwise obliterates, these cells result in the formation of cysts filled with sebaceous material, hair and desquamated skin cells. Alternatively, a sinus may persist allowing this material to escape 1,2."
"A dermoid cyst is an ectodermal inclusion cyst containing skin and skin appendages; sebaceous glands, hair follicles, and occasionally sweat glands 1,2. If a cyst only contains squamous epithelium, then the term nasal epidermoid, or epidermoid inclusion cyst should be used 2."