Vascular lesions: hemangiomas
The current classification of vascular lesions establishes clinical, histologic, and prognostic differences between hemangiomas and vascular malformations. The older terms capillary and strawberry hemangioma have been replaced by the single term hemangioma. Cavernous hemangiomas, port-wine stains, and lymphangiomas are classified as “malformations.” This nomenclature has not been used consistently in the ophthalmologic literature.
Hemangiomas are hamartomatous growths composed of proliferating capillary endothelial cells. Periocular hemangiomas can be classified as follows:
preseptal, involving the skin and preseptal orbit
intraorbital, involving the postseptal orbit
compound/mixed, involving the preseptal and postseptal orbit
Hemangiomas occur in 1%–3% of term newborns and are more common in premature infants, in females, and after chorionic villus sampling. Most hemangiomas are clinically insignificant at birth. They can be inapparent or can appear as an erythematous macule or a telangiectasia. The natural history is one of rapid proliferation and growth over the first several months of life, rarely lasting beyond 1 year. Periocular lesions may cause amblyopia by inducing astigmatism or obstructing the visual axis. After the first year of life, the lesions usually begin to regress, although the rate and degree of involution vary.
Figure 18-16 Axial CT image showing unifocal eosinophilic granuloma with partial destruction of the right posterior lateral orbital wall (arrow) in a 15-year-old boy, who presented with retrobulbar pain and mild edema and erythema of the right upper eyelid.
Systemic disease associated with hemangiomas
PHACE is an acronym for posterior fossa malformations, hemangiomas, arterial lesions, and cardiac and eye anomalies. The eye abnormalities include increased retinal vascularity, microphthalmia, optic nerve hypoplasia, proptosis, choroidal hemangiomas, strabismus, colobomas, cataracts, and glaucoma. The PHACE syndrome should be considered in any infant presenting with a large, segmental, plaquelike facial hemangioma involving one or more dermatomes (Fig 18-17).
Kasabach-Merritt syndrome is a thrombocytopenic coagulopathy with a high mortality rate. It is caused by sequestration of platelets within a vascular lesion.
Diffuse neonatal hemangiomatosis is a potentially lethal condition that occurs in infants, with multiple small cutaneous hemangiomas associated with visceral lesions affecting the liver, gastrointestinal tract, and brain. These hemangiomas are initially asymptomatic but can lead to cardiac failure and death within weeks. Infants with more than 3 cutaneous lesions should be evaluated for visceral lesions.
Treatment of hemangiomas
The diagnosis of hemangiomas is usually obvious from the clinical presentation. MRI or ultrasonography is sometimes helpful in establishing the diagnosis and delineating the posterior extent of the lesion.
Observation is indicated when hemangiomas are small and there is no risk of amblyopia.
Propranolol, a nonselective β-adrenergic blocking agent, induces involution of most hemangiomas (Fig 18-18). The risks of systemic treatment with β-blockers in infants include bradycardia, hypotension, hypoglycemia, and bronchospasm, but the medication is usually well tolerated. Particular caution should be taken when propranolol is used in children with PHACE syndrome, because this drug may increase their risk of stroke. Timolol maleate solution applied topically may be effective in treating superficial hemangiomas. Pulsed dye laser can treat superficial hemangiomas with few complications, but it has little effect on deeper components of the tumor.
Figure 18-17 Plaque hemangioma in a child with PHACE (posterior fossa malformations, hemangiomas, arterial lesions, and cardiac and eye anomalies) syndrome.
(Courtesy of Ken K. Nischal, MD.)
A, Two-month-old infant with a large hemangioma above the left eye. B, Resolution of the lesion following treatment with propranolol.
(Courtesy of Gregg T. Lueder, MD.)
Surgical excision of periocular hemangiomas is feasible for some well-localized lesions or for lesions that do not respond to propranolol.
Drolet BA, Frommelt PC, Chamlin SL, et al. Initiation and use of propranolol for infantile hemangioma: report of a consensus conference. Pediatrics. 2013;131(1):128–140.
Vascular lesions: malformations
Vascular malformations are developmental anomalies derived from capillary venous, arterial, or lymphatic vessels. In contrast to hemangiomas, vascular malformations remain relatively static. The age at onset and mode of clinical presentation vary. Cutaneous vascular malformations such as port-wine stains are evident from birth, but many vascular malformations do not manifest until later in life.
Orbital lymphatic malformation
Orbital lymphatic malformation, previously known as lymphangioma, may produce proptosis in infancy, but usually does not until the second decade of life or later. Unilateral smaller cornea, anomalous anterior segment vessels, and abnormal retinal vessel branching in association with orbital lymphatic malformation represent a unique malformation syndrome. Lymphatic malformation of the orbit is best managed conservatively. Exacerbations tend to occur during upper respiratory tract infections and may be managed with a short course of systemic corticosteroids. Rapid expansion may be seen in cases of intralesional hemorrhage (Fig 18-19). Partial resection and drainage may be required if vision is threatened. Because of the infiltrative character of this malformation, complete removal is usually impossible. Newer treatments include oral sildenafil and intralesional injection of sclerosing agents.
Figure 18-19 Lymphatic malformation with hemorrhage involving the right orbit, upper eyelid, and conjunctiva in a 15-year-old girl.
Orbital venous malformations
Orbital venous malformations, or varices, can be divided into 2 types: primary and secondary. The primary type is confined to the orbit and is not associated with arteriovenous malformations (AVMs). Secondary orbital varices occur as a result of intracranial AVM shunts that cause dilation of the orbital veins. Orbital venous malformations usually become symptomatic after years of progressive congestion and rarely manifest before the second decade of life. Treatment is reserved for highly symptomatic lesions.
Orbital arteriovenous malformations
AVMs isolated within the orbit are extremely rare. Patients with congenital AVMs of the retina and midbrain (Wyburn-Mason syndrome; see Chapter 28) may have orbital involvement. AVMs of the bony orbit rarely manifest in childhood but when present are characterized by pulsatile proptosis, chemosis, congested conjunctival vessels, and elevated intraocular pressure. AVMs may be treated by embolization, surgical resection, or both.
Tumors of bony origin
During the early years of life, a variety of uncommon benign orbital tumors of bony origin can present with gradually increasing proptosis. Fibrous dysplasia and juvenile ossifying fibroma are similar disorders in which normal bone is replaced by fibro-osseous tissue. In both conditions, orbital CT shows varying degrees of lucency and sclerosis.
Fibrous dysplasia has a slow progression that ceases when skeletal maturation is complete. The most serious complication is vision loss caused by optic nerve compression, which may occur acutely. Periodic assessment of vision, pupil function, and optic disc appearance is indicated. Surgical treatment is indicated for functional deterioration or disfigurement.
Juvenile ossifying fibroma is distinguished histologically by the presence of osteoblasts. It tends to be more locally invasive than fibrous dysplasia; some authorities recommend early excision.
Brown tumor of bone is an osteoclastic giant cell reaction resulting from hyperparathyroidism. Aneurysmal bone cyst is a degenerative process in which normal bone is replaced by cystic cavities containing fibrous tissue, inflammatory cells, and blood, producing a characteristic radiographic appearance.
Tumors of connective tissue origin
Benign orbital tumors originating from connective tissue are rare in childhood. Juvenile fibromatosis may present as a mass in the inferoanterior part of the orbit. These tumors, sometimes called myofibromas or desmoid tumors, are composed of relatively mature fibroblasts. They tend to recur locally after excision and can be difficult to control, but they do not metastasize.
Tumors of neural origin
Optic pathway glioma is the most important orbital tumor of neural origin in childhood. Optic pathway gliomas are usually low-grade pilocytic astrocytomas, but the rate of growth with or without therapeutic intervention is unpredictable. Management of these tumors is controversial and depends largely on their location. Approximately 30% of optic pathway gliomas are associated with neurofibromatosis type 1. Plexiform neurofibroma nearly always occurs in the context of neurofibromatosis and frequently involves the eyelid and orbit. See Chapter 28 for further discussion of plexiform neurofibroma and optic pathway glioma. Orbital meningioma and schwannoma (neurilemoma, neurinoma) are rare in childhood.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.