Congenital orbital teratoma

Key points

Definition: Congenital orbital teratomas (COTs) are rare tumors. They are usually benign, complex masses with cystic and solid components containing a mixture of fat, calcium, and bone.
Synonyms: Orbital teratomas, teratomas.
Classic clue: Huge orbital mass containing cystic and solid components, displacing and deforming the globe in young children with a complex, bizarre imaging appearance suggesting multiple tissue types.
COTs are characteristically massive, causing severe proptosis with facial and eyelid deformity, often enlarging the orbit two to three times.
COTs are usually histologically well differentiated and benign.
Teratomas are encapsulated tumors with components resembling normal derivatives of more than one germ layer.
Although the tissues may be normal themselves, they may be quite different from surrounding structures.
Teratomas have been reported to contain hair, teeth, bone, and very rarely more complex structures, such as eyes, limbs, etc. ^,
Preoperative cross-sectional imaging is essential.
Displacement of globe and ocular muscles may impair ocular motility.
Compression of optic nerve (ON) may result in visual impairment.
Rupture may incite a severe inflammatory reaction.

Not preferred, but may be the first imaging study.
Orbit exposure to radiation is undesirable.
Irregular, heterogeneous masses with solid and multiloculated cystic components.
Cystic areas may contain fat-fluid levels.
Calcifications common and may represent bone and teeth.
Bony orbit is typically enlarged.
Lesion may extend intracranially or into sinuses.
Moderate contrast enhancement of solid components.

Preferred imaging procedure is magnetic resonance imaging (MRI) with Gd and fat saturation.
Better at defining disease extent.
Allows sequential follow-up of a patient without increasing the cumulative radiation dose.
Fat saturation imaging is often quite helpful.
Orbital mass with a heterogeneous signal from cystic and solid elements.
Areas with inflammation may be hyperintense on T2 and T1 + Gd images.
T1 shows hyperintense fatty components.
May have fat-fluid levels.
- Upper lipid level brighter T1 and lower T2 signal compared to
- lower water-keratin layer.
T1 + Gd.
- Moderate rim and solid component enhancement.
- No enhancement of cyst cavities.
Calcifications and ossifications less conspicuous than on CT have a low MRI signal similar to cortical bone.
May show a chemical shift artifact.
Not specific to teratoma.
Can be present with lipoma, dermoid, and teratoma, etc.

If the abnormality is not noted on prenatal ultrasound (US), Most COTs present at, or soon after, birth.
COTs present with severe, rapidly progressing unilateral proptosis and prominent craniofacial deformity.
There is considerable eyelid stretching with chemosis and keratopathy.

COTs are rare tumors derived from all three germ cell layers.
Intrauterine diagnosis may be made by US.
Intrauterine rupture of these lesions has been reported as a cause of fetal death.

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

If you are a member. Log in here