1. CYSTIC ORBITAL LESIONS
1. Dacryops
2. Dermoid cyst
Superficial
Deep
3. Mucocele
4. Encephalocele
Anterior
Posterior

2. Dacryops Ductal cyst of lacrimal gland Frequently bilateral
Round, cystic lesion originating from palpebral
portion of lacrimal gland
Protrudes into superior fornix

3. Superficial dermoid cyst
Presents in infancy
No displacement of globe
Most commonly superotemporal
Occasionally superonasal
Freely mobile under skin
Posterior margins are easily palpable

4. Deep dermoid cyst Presents in adolescence or adult life
Non-axial proptosis
May be extension into temporalis
fossa or intracranially
Associated bony defects
May leak and cause granulomatous
inflammation and fibrosis
CT shows a heterogenous, well-circumscribed
lesion

5. Mucocele Presents - adult life
Caused by obstruction of drainage of normal sinus secretions
(frontal or ethmoidal)
Slowly expanding lesion which gradually erodes sinus walls
Gradual proptosis or globe displacement
Periorbital or upper lid swelling

6. Encephalocele Encephalocele - herniation of
intracranial contents through
congenital skull defect
Meningocele - contains only dura
Meningoencephalocele - contains
dura and brain tissue
Anterior (fronto-ethmoidal)
Posterior (spheno-orbital)
Transmission of CSF pulsation causes
pulsating proptosis without a bruit

7. Anterior encephalocele
Involves supero-medial part of orbit
Displaces globe forwards and laterally

8. Posterior encephalocele
Caused by congenital defect in
sphenoid bone
Globe displacement forward and
downward

9. Associations of encephaloceles
Ocular
Other congenital bony
defects
Neurofibromatosis - 1
Colobomas
Morning glory anomaly
Hypertelorism
Hare lip and cleft palate
Common in posterior
encephalocele