Ординатура / Офтальмология / Английские материалы / Rapid Diagnosis in Ophthalmology Series Oculoplastic and Reconstructive Surgery_Nerad, Carter, Alford_2008

Neoplasms• 11 SECTIONOrbit: the of Disorders

Cavernous Hemangioma

Key Facts

•Most common benign primary orbital neoplasm in adults

•About 4% of all orbital tumors

•Unknown cause

•May be a congenital hamartoma of vascular origin

•Typically intraconal, producing axial proptosis

•Usually presents at age 30–50 years

•Often discovered as incidental finding on imaging for other conditions

Clinical Findings

•Painless, slowly progressive proptosis over many years

•Typically unilateral

•Visual loss uncommon

•Found in adults, more common in women

•Encapsulated tumor composed of multiple large, blood-filled channels lined by flattened endothelial cells

Imaging

•CT or MRI shows a discrete round or oval mass without inflammation or infiltration of surrounding tissues

• 88% are intraconal

Differential Diagnosis

•Other round isolated orbital tumors or cysts:

•schwannoma

•neurolemmoma

•dermoid cyst

Treatment

•If asymptomatic and discovered incidentally, many are observed

•Complete surgical excision of tumor indicated for:

•bothersome proptosis

•diplopia (uncommon)

•visual changes due to apical compression or choroidal folds (uncommon)

Prognosis

•Excellent with complete resection

• Recurrences rare

Fig. 11.8 CT scan with a wellcircumscribed lesion in the right orbit.

Fig. 11.9 Another example of a right orbit lesion.

Neoplasms• 11 SECTIONOrbit: the of Disorders

Lymphangioma

Key Facts

•Benign, diffusely infiltrating vascular orbital or periocular malformation

•Typically identified during first decade, may be present at birth

•Unknown cause:

•arise from pluripotent mesodermal stem cells capable of forming vascular or lymphatic structures

•Uncommon

•Associated lesions may be present in face, oropharynx, or throat

•Difficult to treat

Clinical Findings

•Presentation in childhood as:

• slowly progressive proptosis

•sudden onset of proptosis due to hemorrhage (chocolate cyst)

•deep red or bluish, soft, elevated, multilobed lesions of conjunctiva and eyelid

•a combination of above

•May enlarge after upper respiratory tract infection

•No change with Valsalva maneuver

•Consists of multiple thin-walled, endothelial-lined vascular channels containing lymphocytic aggregations, serous fluid, and blood products

Imaging

•Important in diagnosis

•CT shows multiple contiguous, dilated cystic spaces with varying densities

•Cystic spaces rarely enhance because of no direct connection with circulation

•Extension into central nervous system common

Differential Diagnosis

•Capillary hemangioma, varix, arterial–venous malformation

•Mixed venous anomalies may exist in which combinations of tissues occur together

Treatment

•Medical:

•difficult to manage

•observation for small lesions

•corticosteroids and radiotherapy not effective

•Surgical:

•careful surgical debulking to improve deformity

•cyst drainage when vision threatened after rapid growth or hemorrhage

•complete resection rarely possible because of infiltrative nature; multiple procedures often required

Prognosis

•Guarded

•Can be associated with progressive deformity without reasonable options for treatment

•Possibility of vision loss to:

•amblyopia • proptosis • corneal exposure • optic nerve compression

Neoplasms• 11 SECTIONOrbit: the of Disorders

Optic Nerve Glioma

Key Facts

•Benign tumor of optic nerve, causing optic nerve enlargement

•Also called juvenile pilocytic astrocytoma

•Gliomas can occur at other sites along visual pathway

•Uncommon

•About 50% of glioma patients have neurofibromatosis (NF) type 1

Clinical Findings

•Optic nerve tumor seen in childhood

• 75% diagnosed by age 10

•Solitary fusiform enlargement of optic nerve (Fig. 11.15)

•Patients present with gradual, painless axial proptosis (Fig. 11.16)

•Visual acuity can be normal but gradually decreases with time

•Early, papilledema may be seen

•Later, optic atrophy may occur

•Classic radiologic finding is a kink in the anterior portion of the nerve (Fig. 11.17)

•MRI of the tumor is isointense on T1- and hyperintense on T2-weighted studies (Fig. 11.18)

•Early diagnosis important to identify chiasmal involvement

•Elongated pilocytic astrocytes form bulk of tumor

•Cystic spaces can occur

•Rosenthal fibers (eosinophilic substance in astrocyte) are seen

•Extension into meninges can cause confusion with meningioma diagnosis

Ancillary Testing

•CT or MRI provides excellent view of orbital portion of tumor

•Optic nerve calcification does not occur

•MRI preferred to evaluate posterior extent of tumor

Differential Diagnosis

•Optic nerve meningioma

•Diagnosis of NF type 1 should be considered

• Bilateral optic nerve tumors are diagnostic of NF

Neoplasms• 11 SECTIONOrbit: the of Disorders

Optic Nerve Glioma (Continued)

Treatment

•Based on location of tumor and current vision of patient

•Most cases are observed, with repeated ophthalmic examinations to monitor vision, proptosis, and corneal status every 6–12 months

•Serial MRI studies to monitor for posterior growth of tumor (rarely, if ever, seen)

•Surgical resection for tumors that extend into optic canal, threatening extension into chiasm

•Blind eyes that present with cosmetically significant proptosis or corneal damage may benefit from tumor removal

•Transcranial approach to orbit preferred

•Optic nerve should be resected from chiasm to globe

•Radiation for unresectable optic nerve tumors or when tumor involves chiasm or optic radiations

•Chemotherapy avoids potential radiation effects on bony growth orbit

Prognosis

•Good for tumors confined to orbit

•Intracranial extension can be complicated by involvement of hypothalamus or pituitary gland, which may be associated with endocrine abnormalities or obstructive hydrocephalus

A

B

Fig. 11.18 (A) The optic nerve glioma is isointense on this T1-weighted study. (B) T2-weighted MRI with a hyperintense signal from the optic nerve glioma.

(continued) Glioma Nerve Optic

Neoplasms• 11 SECTIONOrbit: the of Disorders

Neurofibroma

Key Facts

•Benign peripheral nerve sheath tumor, a hamartoma

•Can arise from cranial nerves to extraocular muscles, sympathetic and parasympathetic fibers, or sensory branches

•Seen as solitary or multiple skin masses

• Multiple lesions common in neurofibromatosis (NF)

•S-shaped ptosis due to plexiform neurofibroma

Clinical Findings

•Solitary neurofibromas occur in middle age and later

• These lesions may be superficial or subcutaneous

•Superficial lesions may be elevated, sometimes pedunculated

•Deep lesions may be tender or painful

•Plexiform neuromas:

•S-shaped ptosis of upper eyelid caused by plexiform (bag of worms) neurofibroma (Fig. 11.19)

•Proptosis or diplopia for orbital neurofibroma (Fig. 11.20)

•Two types of NF, both autosomal dominant

•NF type 1: 85% of cases; skin manifestations common (including café-au-lait spots and multiple neurofibromas); also plexiform neuromas, optic nerve glioma, Lisch nodules, sphenoid wing dysplasia (pulsatile exophthalmos)

•NF type 2: bilateral acoustic neuromas, multiple meningiomas, and other lesions in brain and spinal cord

Ancillary Testing

•CT or MRI for evaluation of orbital plexiform or solitary neurofibroma

•MRI to evaluate optic nerve and central nervous system

Differential Diagnosis

• Rule out systemic disease (NF)

Treatment

•Excision if solitary cutaneous or orbital lesion

•Plexiform neurofibromas are infiltrative, often cannot be completely excised

Prognosis

•Good prognosis for solitary lesions

•Recurrence rate high with plexiform neurofibroma

•Facial nerve palsy with corneal exposure may occur after acoustic neuroma removal. Also check corneal sensation