Encephalofacial cavernous hemangiomatosis (Sturge–Weber syndrome)

DEFINITION/OVERVIEW AND ETIOLOGY

In 1879, Sturge described a syndrome composed of a facial hemangioma with ipsilateral buphthalmos and contralateral seizures.26 Later, Weber studied the clinical manifestations in greater detail and the fully expressed entity became known as the Sturge–Weber (SW) syndrome.27 The SW syndrome is now recognized to consist of a facial hemangioma, buphthalmos, seizures, and

radiographic evidence of intracranial calcification (Table 24).28–30 Most patients,

however, have a forme fruste rather than the entire syndrome. In contrast to most other systemic hamartomatoses, there is no recognizable hereditary pattern associated with SW syndrome.

CLINICAL PRESENTATION

The ocular findings associated with SW syndrome include eyelid involvement with the nevus flammeus, prominent epibulbar blood vessels, glaucoma, retinal vascular tortuosity, and diffuse choroidal hemangioma (Table 24).

The facial hemangioma can frequently involve the eyelids (265). Although it is usually nilateral, bilateral involvement occasionally occurs. Involvement of the upper eyelid has a high association with ipsilateral glaucoma. Prominent tortuous epibulbar blood vessels, in both the conjunctiva and episclera, are common findings (266). Glaucoma is more common in patients with SW syndrome than in the other ONCS. In one study, if the facial hemangioma involved both the first and second division of the trigeminal nerve, the incidence was 15%.28 The glaucoma occurs unilaterally on the side of the facial hemangioma.

The only important abnormality of the uveal tract in patients with SW syndrome is the diffuse choroidal hemangioma. Patients with this tumor usually have a bright red pupillary reflex in the involved eye (‘tomato catsup fundus’) as compared to the normal contralateral eye.

The diffuse choroidal hemangioma is usually diagnosed when the affected patient is young (median age 8 years), either because the associated facial hemangioma prompts a fundus examination or because visual impairment occurs from hyperopic amblyopia or from a secondary retinal detachment. The diffuse choroidal hemangioma appears as a red-orange thickening of the choroid, often with overlying subretinal fluid. The tumor is usually a few millimeters thicker than normal choroid.

The details of fluorescein angiography, indocyanine green angiography, and ultrasonography, which can be helpful in the diagnosis, are discussed elsewhere.1,3

Histopathologically the choroidal hemangioma is a diffuse thickening of the choroid consisting of variable sized venous

channels separated by thin intervascular septa.1,3,30 Overlying retinal edema with cystoid

changes, and fibrous and osseous metaplasia of the RPE are sometimes found.

OTHER FEATURES

The typical CNS change associated with SW syndrome is a diffuse leptomeningeal

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265 Sturge–Weber syndrome,with facial nevus flammeus.

hemangiomatosis that is ipsilateral to the facial hemangioma.1,3 The adjacent cerebral cortex can show secondary linear calcification on computed tomography (CT), referred to as the ‘railroad track’ sign. Convulsions, which frequently occur, are characteristically localized to the side contralateral to the CNS involvement.

The classic skin lesion of SW syndrome is the facial hemangioma, often referred to as nevus flammeus or port wine stain. Although it usually occurs in the cutaneous distribution of the fifth cranial nerve, it can have many variations, ranging from minor involvement of the first division of the nerve to massive involvement of all three divisions. It sometimes crosses the midline in an irregular pattern and it is occasionally bilateral.

MANAGEMENT/TREATMENT

Management of the diffuse choroidal hemangioma can be difficult and it varies with the extent of the tumor. It may range from observation only to laser photocoagulation or retinal detachment surgery or irradiation, depending on the clinical circumstances.3

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266 Conjunctival and episcleral dilated blood vessels in Sturge–Weber syndrome.

Oculoneurocutaneous cavernous hemangiomatosis

DEFINITION/OVERVIEW AND ETIOLOGY

There are several systemic syndromes that are characterized by multiple cavernous hemangiomas or other vascular malformations. This chapter includes only those with a combination of cavernous hemangiomas that involve the eye, skin, and CNS. Oculoneurocutaneous cavernous hemangiomatosis (ONCCH) is a syndrome characterized by

cavernous hemangiomas that affect the retina, CNS, and skin (Table 25).1,33–37 The retinal

and skin tumors are frequently asymptomatic, but the CNS hamartomas can sometimes produce clinical symptoms. This syndrome

appears to have an AD mode of inheritance.33–37 A 7q locus has also been

implicated in a large family with retinal cavernous hemangioma, choroidal cavernous hemangioma, and widespread CNS and cutaneous lesions.35 Although the genetics is poorly understood, a mutation in the KRIT1 gene has been recognized in a family with retinal and CNS cavernous hemangiomas.37

CLINICAL PRESENTATION

The only ocular manifestation of this syndrome is the retinal cavernous hemangioma and the iris cavernous hemangioma, with the latter being extremely rare. The retinal lesions appear as a cluster of dark venous intraretinal aneurysms on ophthalmoscopic examination (267). There is no feeder artery and usually no yellow exudation, but white fibroglial tissue is characteristically present on the surface of the tumor. The main complication of retinal cavernous hemangioma is vitreous hemorrhage. Severe fibrogliosis and dragging of the retina can occur. During fluorescein angiography, the vascular channels comprising the lesion remain hypofluorescent until the late venous phase, when fluorescein begins slowly to enter the vascular spaces and produces the characteristic fluorescein–blood interface.

Table 25 Clinical features of retinal cavernous hemangiomatosis

Cavernous hemangioma

Skin

Various vascular malformations

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267 Cavernous hemangioma of the retina and CNS.

OTHER FEATURES

Vascular malformations in the CNS can lead to seizures, oculomotor palsies, and other neurologic symptoms. The hemangiomas of the skin in this syndrome are often subtle and are quite variable in their appearance and distribution on the body.

TREATMENT

Most patients require no treatment. Patients who experience recurrent vitreous hemorrhages may benefit from laser photocoagulation of the lesion.

Organoid nevus syndrome

DEFINITION/OVERVIEW AND ETIOLOGY

The organoid nevus syndrome (ONS) has recently been included with the ONCS.

CLINICAL PRESENTATION AND PROGNOSIS

ONS is characterized by the nevus sebaceous of Jadassohn, cerebral atrophy, epibulbar complex choristoma, posterior scleral cartilage, and occasionally other features (Table 26, overleaf).38 The full syndrome is uncommon and the exact incidence is unknown. The two most important ophthalmologic features are the epibulbar complex choristoma and posterior scleral cartilage.

The epibulbar complex choristoma is a fleshy lesion of the conjunctiva that can extend onto

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268 Organoid nevus syndrome:epibulbar complex choristoma.

the cornea (268). The posterior scleral cartilage produces a peculiar yellow-white discoloration of the fundus in the area of involvement. Since the cartilage produces a pattern similar to bone with ultrasonography and CT, it has sometimes been misinterpreted as a choroidal osteoma. The main dermatologic feature of the ONS is the nevus sebaceous of Jadassohn. It appears as a geographic yellow-brown lesion that often involves the preauricular region and extends onto the scalp, where it is associated with alopecia (269).

Patients with this syndrome can develop seizures, due mainly to enlarging subarachnoid cysts in the CNS. Rarely, the affected patient can have various cardiac and renal abnormalities.

TREATMENT

Most patients can be observed and do not require treatment. Larger or progressive lesions may require surgical excision.

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