Orbital Tumors - Dermoids

Pre operative photo: note the mass along the left, outer bro w

Post - Operative, sutures and dermabond in place

5 days after surgery, sutures in place

Etiology

benign cystic lesions that are choristomas (tumors composed of tissues not usually found at the involved site)
originate at bony suture sites during embryogenesis as a result of surface skin elements becoming entrapped
usually found in early childhood (25% are noted at birth), but can also be diagnosed in adults
- in adults, they often involve the deep orbital tissues and grow to a very large size
Not to be confused with Epidermoid cysts which are similar but lack certain elements in the wall of the cyst

CT/MRI imaging reveals characteristic round to oval shaped cystic lesion with a defined lining
Symptoms
- painless
- slow-growing
signs
- typically do not displace the globe
- typically do not pull up intraocular pressure
locations
- occur in the superotemporal orbit (the most common site, 70% )
- the superomedial orbit
- deep orbit
Trauma could lead to leakage of the cystic contents and likely will result in acute inflammation

Lining
- the cysts are lined by keratinizing, stratified squamous epithelium (85% of lesions), or
- nonkeratinized stratified squamous epithelium
Filling
- filled with keratin
- hair shafts are usually present in lumen or wall of cyst (99%)
- sebaceous glands are usually present in lumen or wall of cyst (75%)
- sweat glands are often present in lumen or wall of cyst (20%)

surgical excision is the treatment of choice. With complete excision, the prognosis is excellent.
usually once they child has reached age 12 months

Compare with EPIDERMOID

Orbital Tumors - Dermoids Compare with EPIDERMOID