E tiology | Differential Diagnosis | Work-up / Course / Prognosis | Pathology | Treatment | Compare with Epidermoid

Pre operative photo: note the mass along the left, outer brow

5 days after surgery, sutures in place

1. benign cystic lesions that are choristomas (tumors composed of tissues not usually found at the involved site)
2. originate at bony suture sites during embryogenesis as a result of surface skin elements becoming entrapped
3. 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
4. Not to be confused with Epidermoid cysts which are   similar but lack certain elements in the wall of the cyst (see Filling below)

• encephalocele
• lacrimal mass/tumor
• lacrimal mass or tumor

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

1. Lining
   • the cysts are lined by keratinizing, stratified squamous epithelium (85% of lesions), or
   • nonkeratinized stratified squamous epithelium
2. 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%)

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

Compare with EPIDERMOID