Dermoids

Conveniently located to serve Boise and Ada County


Pre operative photo: note the mass along the left, outer brow
Post - Operative, sutures and dermabond in place
5 days after surgery, sutures in place

Etiology

  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 lead to 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

Differential Diagnosis

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

Work-up / Course / Prognosis

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 raise intraocular pressure

Locations

  • occur in the superotemporal  orbit (the most common site, 70% )
  • the superomedial orbit
  • deep orbit

Trauma might lead to leakage of the cystic contents and likely will lead to in acute inflammation

Pathology

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%)

Treatment

  • 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