Ophthalmology – Congenital Orbital Tumors

Basics

Description

Congenital orbital tumors and developmental masses are lesions present at birth or arising during early childhood.

The most important entities in this group include:

• Dermoid cyst
• Epidermoid cyst
• Orbital teratoma

Other congenital orbital masses include:

• Lymphatic malformations
• Venous/venolymphatic malformations
• Congenital cystic eye
• Colobomatous cyst
• Encephalocele

Orbital Dermoid and Epidermoid Cysts

These are benign developmental cysts caused by sequestration of ectoderm during embryologic fusion.

They are among the:

Most common orbital masses in children

Typical locations are along bony sutures, especially the:

Frontozymgomatic suture in the superotemporal orbit

Less commonly they occur:

• Superonasally
• Deep within the orbit
• Within bone
• Within orbital soft tissue without obvious suture attachment

Dermoid vs Epidermoid Cyst

Dermoid Cyst

Lined by keratinizing stratified squamous epithelium and contains dermal appendages such as:

• Hair follicles
• Sebaceous glands
• Sweat glands

Contents may include:

• Keratin
• Sebum
• Hair

Epidermoid Cyst

Also lined by stratified squamous epithelium but:

Lacks dermal appendages

It predominantly contains:

• Desquamated keratin

Epidemiology

Dermoid and epidermoid cysts are commonly diagnosed in:

• Infancy
• Early childhood

but may present at any age.

There is no strong sex predilection.

They represent a substantial proportion of excised pediatric orbital lesions.

Orbital Teratoma

Orbital teratoma is a:

Very rare congenital germ-cell tumor

It usually presents:

• At birth
• Shortly after birth

Most are:

• Unilateral
• Mature
• Histologically benign

They can become enormous and produce marked orbital expansion.

Pathophysiology

Dermoid/Epidermoid Cysts

They arise when ectoderm becomes trapped during embryonic fusion along:

• Bony sutures
• Lines of closure

Types may be described anatomically as:

• Juxtasutural
• Sutural
• Soft-tissue/deep orbital

Slow accumulation of keratinous or sebaceous material causes progressive enlargement.

Dermoid Cyst Rupture

Spontaneous or traumatic rupture releases lipid and keratin into surrounding tissues and can cause:

Marked granulomatous inflammation

resulting in:

• Pain
• Redness
• Swelling
• Orbital inflammation

This may mimic infection.

Orbital Teratoma Pathophysiology

Teratomas arise from pluripotent germ cells and contain tissues derived from all three germ layers:

• Ectoderm
• Mesoderm
• Endoderm

They may contain:

• Fat
• Bone
• Cartilage
• Neural tissue
• Epithelium
• Cystic structures

Clinical Presentation

Dermoid / Epidermoid Cyst

Typically presents as:

• Painless
• Slowly enlarging
• Subcutaneous orbital or periocular mass

The classic lesion is:

Superotemporal near the frontozygomatic suture

On palpation it is often:

• Smooth
• Firm or fluctuant
• Nontender
• Partially mobile relative to skin

Associated Findings

Most superficial dermoids do not cause:

• Visual loss
• Elevated IOP
• Significant motility disturbance

Large or deep lesions can cause:

• Globe displacement
• Proptosis
• Diplopia
• Astigmatism
• Amblyopia

Astigmatism and Amblyopia

A lesion compressing the globe may produce:

• Corneal astigmatism
• Anisometropia

which can lead to:

Amblyopia in young children

Therefore refraction should be checked in pediatric patients.

Deep Orbital Dermoid

Deep lesions may present later with:

• Progressive proptosis
• Globe displacement
• Diplopia
• Motility restriction

They are less likely to be visible externally.

Orbital Teratoma – Clinical Presentation

The classic presentation is:

Massive unilateral proptosis present at birth

Features may include:

• Markedly enlarged orbit
• Tense eyelids
• Severe globe displacement
• Exposure keratopathy
• Conjunctival keratinization
• Corneal ulceration
• Vascular congestion

Vision may be severely compromised from:

• Optic nerve stretching/compression
• Exposure damage
• Amblyopia

History

Dermoid / Epidermoid

Usually:

• Long-standing
• Slowly progressive
• Asymptomatic

Sudden pain and swelling suggest:

• Rupture
• Hemorrhage
• Secondary inflammation

Trauma may precipitate rupture but is not the underlying cause.

Orbital Teratoma

History usually reveals:

• Proptosis at birth
• Rapid enlargement during early infancy
• Severe unilateral orbital expansion

Examination

Assess:

• Visual acuity
• Pupils
• Refraction
• Ocular alignment
• Motility
• Degree and direction of globe displacement
• Proptosis
• Exposure keratopathy
• Fundus

In young children, specifically evaluate for:

Amblyopia

Imaging – Dermoid and Epidermoid Cysts

Imaging is particularly useful for:

• Deep lesions
• Fixed lesions
• Atypical location
• Suspected intracranial extension
• Surgical planning

CT

CT is particularly useful for demonstrating:

• Relationship to orbital bone
• Suture location
• Bony remodeling
• Intraosseous extension

A dermoid is often:

• Round or ovoid
• Well circumscribed

Its density varies depending on:

• Fat
• Sebaceous material
• Keratin

A fat-fluid level may occasionally be present.

MRI

MRI provides superior soft-tissue assessment.

Signal characteristics are variable depending on cyst contents.

MRI is especially useful for:

• Deep lesions
• Intracranial extension
• Complex orbital anatomy

Epidermoid on MRI

Epidermoid cysts can show:

Restricted diffusion on diffusion-weighted imaging

which may help distinguish them from other cystic lesions.

Imaging – Orbital Teratoma

Both CT and MRI usually demonstrate a:

Large heterogeneous, multiloculated orbital mass

containing mixtures of:

• Solid tissue
• Cystic components
• Fat
• Calcification
• Bone

CT in Teratoma

CT is particularly good for identifying:

• Calcification
• Ossification
• Orbital expansion
• Bony remodeling

The combination of:

Fat + fluid/cystic tissue + calcification

strongly suggests teratoma.

MRI in Teratoma

MRI better defines:

• Soft-tissue components
• Optic nerve relationship
• Globe compression
• Intracranial extension

Pathology

Dermoid Cyst

Histology shows:

• Keratinizing stratified squamous epithelium
• Hair follicles
• Sebaceous glands
• Sweat glands

Inflammatory giant-cell reaction may occur after rupture.

Epidermoid Cyst

Histology shows:

• Keratinizing squamous epithelial lining
• Keratinaceous contents
• No dermal appendages

Teratoma

A mature teratoma contains differentiated tissue from all three germ layers.

Grossly it may be:

• Solid
• Cystic
• Multiloculated
• Partially calcified or ossified

Most congenital orbital teratomas are mature and benign.

Differential Diagnosis

The differential for an orbital mass in an infant or child includes:

• Infantile hemangioma
• Venous malformation
• Lymphatic malformation
• Rhabdomyosarcoma
• Optic pathway glioma
• Neuroblastoma metastasis
• Retinoblastoma with orbital extension
• Leukemia/chloroma
• Langerhans cell histiocytosis
• Orbital cellulitis
• Abscess
• Lacrimal lesions
• Mucocele
• Encephalocele
• Colobomatous cyst
• Congenital cystic eye

Infantile Hemangioma

Previously often called capillary hemangioma.

Usually develops during the first weeks of life rather than being fully developed at birth.

May cause:

• Eyelid swelling
• Proptosis
• Globe displacement
• Astigmatism
• Amblyopia

It is distinguished from venous/lymphatic malformations by its characteristic proliferative and involutional course.

Lymphatic Malformation

Previously called lymphangioma.

It is a congenital vascular malformation that may involve:

• Eyelid
• Conjunctiva
• Orbit

It often enlarges gradually but may suddenly expand from:

• Intralesional hemorrhage
• Upper respiratory infection

MRI frequently demonstrates:

• Multiloculated cystic spaces
• Fluid-fluid levels after hemorrhage

Rhabdomyosarcoma

The most important malignant pediatric orbital differential.

Typical features:

• Rapidly progressive proptosis
• Eyelid swelling
• Globe displacement
• First decade of life

Unlike a dermoid, it generally enlarges over:

Days to weeks

rather than years.

Optic Pathway Glioma

Usually presents with:

• Slowly progressive visual loss
• Optic atrophy or disc swelling
• Proptosis with intraorbital optic nerve involvement

It is strongly associated with:

NF1

MRI demonstrates:

• Fusiform enlargement of the optic nerve

Modern management is generally observation or systemic therapy when progressive, not routine surgical excision.

Neuroblastoma

Orbital metastatic neuroblastoma may present with:

• Proptosis
• Periorbital ecchymosis
• Eyelid swelling

Bilateral orbital disease is particularly suggestive.

Congenital Cystic Eye

A rare developmental anomaly caused by failure of normal globe formation.

The orbit contains:

• Cystic primitive neuroectodermal/ocular tissue

with no normally developed eye.

Encephalocele

A congenital skull defect may permit herniation of:

• Meninges
• Brain tissue

into or near the orbit.

Imaging before surgery is essential because of intracranial communication.

Colobomatous Cyst

Usually occurs with:

• Microphthalmia
• Inferior ocular coloboma

A cyst extends through the embryonic fissure defect and may occupy part of the orbit.

Treatment – Dermoid/Epidermoid Cyst

Small, asymptomatic lesions may sometimes be observed.

Surgical excision is generally favored when there is:

• Progressive enlargement
• Cosmetic deformity
• Pain
• Recurrent inflammation
• Globe displacement
• Astigmatism
• Amblyopia risk
• Exposure to repeated trauma
• Diagnostic uncertainty

Surgical Excision

The goal is:

Complete removal of the cyst with the capsule intact

because rupture can cause:

• Intense inflammation
• Foreign-body granuloma
• Incomplete removal
• Recurrence

If rupture occurs intraoperatively, copious irrigation and removal of cyst contents are important.

Deep Dermoid

Deep orbital dermoids require careful preoperative imaging because they may:

• Extend through sutures
• Cause bony remodeling
• Have intracranial extension

Surgical approach depends on location and extent.

Treatment – Orbital Teratoma

The main treatment is:

Early surgical excision

Goals are to:

• Preserve the globe when possible
• Protect visual potential
• Reduce exposure complications
• Preserve orbital and facial growth
• Achieve good cosmesis

Globe Preservation

Modern surgery emphasizes globe-sparing removal whenever technically possible.

Because most congenital orbital teratomas are benign:

Radical surgery should be avoided when adequate complete excision can preserve the eye and orbit.

Exenteration

Orbital exenteration is now:

Rarely required

and reserved for extraordinary cases in which the mass cannot otherwise be safely controlled or the orbital structures are irreversibly compromised.

Postoperative Care

Monitor for:

• Residual or recurrent lesion
• Visual impairment
• Amblyopia
• Strabismus
• Orbital asymmetry
• Exposure disease
• Need for reconstructive surgery

Follow-Up – Dermoid/Epidermoid

If observation is selected, monitor for:

• Growth
• New pain
• Inflammation
• Globe displacement
• Visual effects

After complete excision, recurrence is uncommon.

Follow-Up – Teratoma

Follow-up should assess:

• Recurrence
• Orbital development
• Globe position
• Vision
• Amblyopia
• Cosmetic development

Repeat imaging is appropriate when:

• Excision was incomplete
• Pathology is atypical
• Recurrence is suspected

Prognosis

Dermoid/Epidermoid Cysts

Prognosis is:

Excellent

Most children maintain normal vision if:

• Astigmatism is detected
• Amblyopia is treated
• Complicated rupture is avoided

Complete excision is usually curative.

Orbital Teratoma

Systemic prognosis is generally excellent because most congenital orbital teratomas are:

Mature and benign

Visual prognosis is more variable.

It depends on:

• Duration and severity of proptosis
• Optic nerve compression
• Exposure keratopathy
• Degree of globe distortion
• Amblyopia

Even when the globe can be preserved, useful vision may be limited.

Complications

Dermoid/Epidermoid

Potential complications include:

• Cyst rupture
• Granulomatous inflammation
• Pain
• Globe displacement
• Astigmatism
• Amblyopia
• Recurrence after incomplete excision

Orbital Teratoma

Potential complications include:

• Massive proptosis
• Exposure keratopathy
• Corneal ulceration
• Optic nerve injury
• Permanent visual loss
• Amblyopia
• Orbital/facial asymmetry
• Rare recurrence

Malignant transformation of a mature congenital orbital teratoma is exceedingly uncommon.

Ophthalmology Pearls

• Dermoid cyst is one of the most common orbital masses of childhood.
• The classic dermoid is a painless superotemporal mass at the frontozygomatic suture.
• Dermoid cysts contain skin appendages; epidermoid cysts do not.
• Sudden painful enlargement of a previously quiet dermoid suggests rupture with granulomatous inflammation.
• Large orbital dermoids can induce astigmatism and amblyopia, so refraction matters in children.
• CT is particularly useful for bone and calcification; MRI is better for soft tissue and intracranial extension.
• Epidermoid cysts characteristically may show restricted diffusion on MRI.
• Orbital teratoma classically causes massive unilateral proptosis at birth.
• A teratoma containing fat, cystic tissue, and calcification on imaging is highly characteristic.
• Mature orbital teratomas contain tissue from all three germ layers: ectoderm, mesoderm, and endoderm.
• Complete dermoid excision should ideally preserve the capsule because rupture increases inflammation and recurrence risk.
• Modern teratoma surgery aims for globe preservation, with exenteration reserved for exceptional cases.
• In a child with rapidly progressive proptosis, always exclude rhabdomyosarcoma.
• Use modern terminology: infantile hemangioma rather than capillary hemangioma, and lymphatic malformation rather than lymphangioma.