eyes when used as a primary treatment.2,4,69 In those eyes that need plaque radiotherapy for tumor recurrence after chemoreduction, complete control of the tumor is achieved in 96% of cases.69 Plaque radiotherapy can be used for extensive recurrent subretinal seeds or vitreous seeds but there is a higher failure rate. All eyes treated with plaque radiotherapy should be monitored for radiation maculopathy and papillopathy.

Enucleation is an important and powerful method for managing retinoblastoma.2,4,70 Enucleation is employed for advanced tumor with no hope for useful vision in the affected eye, or if there is a concern for invasion of the tumor into the optic nerve, choroid, or orbit. Eyes with unilateral group D or E are usually managed with primary enucleation. Eyes with bilateral group D or E generally need secondary enucleation in one eye following chemoreduction.

A number of ocular disorders in infants and children can resemble retinoblastoma. The most common pseudoretinoblastomas include Coats’ disease, persistent hyperplastic primary vitreous (PHPV), also known as persistent fetal vasculature (PFV), and ocular inflammation such as toxocariasis.2,4,6 Retinoblastoma should be considered in any child with retinal detachment, vitreous hemorrhage, or intraocular mass. It is important that the diagnosis of retinoblastoma be confidently excluded before treatment of a pseudoretinoblastoma. Vitrectomy or retinal detachment repair should be withheld in a child until the diagnosis of retinoblastoma is reliably excluded.71 Any child with unexplained, atraumatic hyphema or vitreous hemorrhage should be evaluated for retinoblastoma using clinical examination, ultrasonography, and possibly even CT or MRI. Consultation with an ocular oncologist experienced with retinoblastoma could be helpful in confirming the clinical diagnosis and directing therapy.

Retinal capillary hemangioma

Retinal capillary hemangioma is a reddish-pink retinal mass that can occur in the peripheral fundus or adjacent to the optic disc.72 The tumor often has prominent dilated retinal blood vessels that supply and drain the lesion (297). Untreated lesions can cause intraretinal exudation and retinal detachment. Fluorescein angiography shows rapid filling of the tumor with dye and intense late staining of the mass. Patients with retinal capillary hemangioma should be evaluated for the von Hippel–Lindau syndrome (VHL), an AD condition characterized by cerebellar hemangioblastoma, pheochromocytoma, hypernephroma, and other visceral tumors and cysts. If the tumor produces macular exudation or retinal detachment, it can be treated with methods of laser photocoagulation, cryotherapy, photodynamic therapy, plaque radiotherapy, or external beam radiotherapy. The gene responsible for this syndrome has been localized to the short arm of chromosome 3.

297

Retinal cavernous hemangioma

The retinal cavernous hemangioma typically appears as a globular or sessile intraretinal lesion that is composed of multiple vascular channels that have a reddish-blue color.2,4 It may show patches of gray-white fibrous tissue on the surface, but it does not cause the exudation that characterizes the retinal capillary hemangioma. Cavernous hemangioma is a congenital retinal vascular hamartoma that is probably present at birth. This tumor can be associated with similar intracranial and cutaneous vascular hamartomas, but the syndrome does not have the visceral tumors that characterize the VHL syndrome. As a general rule, retinal cavernous hemangioma requires no active treatment. If vitreous hemorrhage should occur, laser or cryotherapy to the tumor can be attempted. If vitreous blood does not resolve, removal by vitrectomy may be necessary.

Retinal racemose hemangioma

The retinal racemose hemangioma is not a true neoplasm but rather a simple or complex arteriovenous communication.2,4 It is characterized by a large dilated tortuous retinal artery that passes from the optic disc for a variable distance into the fundus where it then communicates directly with a similarly dilated retinal vein that passes back to the optic disc (298, 299). It can occur as a solitary unilateral lesion or it can be part of the Wyburn-Mason syndrome, which is characterized by other similar lesions in the midbrain and sometimes the orbit, mandible, and maxilla. It does not appear to have a hereditary tendency.

298

299

298, 299 Retinal racemose hemangioma. 298: Macular image showing the tortuous, dilated vessels;299: wide-angle image showing the entire extent of the hemangioma.

Astrocytic hamartoma of the retina

Astrocytic hamartoma of the retina is a yellowwhite intraretinal lesion that can also occur in the peripheral fundus or in the optic disc region. The lesion can be homogeneous or it may contain glistening foci of calcification (300). Unlike retinal capillary hemangioma, it does not generally produce significant exudation or retinal detachment. Patients with astrocytic hamartoma of the retina should be evaluated for tuberous sclerosis, characterized by intracranial astrocytoma, cardiac rhabdomyoma, renal angiomyolipoma, pleural cysts, and other tumors and cysts. Growing astrocytic hamartoma can be treated with photodynamic therapy.73

Choroidal hemangioma

Choroidal hemangioma is a benign vascular

tumor that can occur as a circumscribed lesion in adults or as a diffuse tumor in children.2,4,76

The diffuse choroidal hemangioma usually occurs in association with ipsilateral facial nevus flammeus or variations of the Sturge–Weber syndrome. Ipsilateral congenital glaucoma is a frequent association. Secondary retinal detachment frequently occurs. Affected children often develop amblyopia in the involved eye. If vision loss from retinal detachment is found, then treatment of circumscribed hemangioma involves photodynamic therapy, whereas diffuse hemangioma is treated with external beam radiotherapy.

Melanocytoma of the optic nerve

Melanocytoma of the optic nerve is a deeply

pigmented congenital tumor that overlies a portion of the optic disc (301).2,74 Unlike uveal

melanoma, which occurs predominantly in Caucasians, melanocytoma occurs with equal frequency in all races. It must be differentiated from malignant melanoma.

Intraocular medulloepithelioma

Medulloepithelioma is an embryonal tumor that arises from the primitive medullary epithelium or the inner layer of the optic cup.2,4,75 It generally becomes clinically apparent in the first decade of life and appears as a fleshy, often cystic mass in the ciliary body (302, 303). Cataract and secondary glaucoma are frequent complications. Although approximately 60–90% are cytologically malignant, intraocular medulloepithelioma tends to be only locally invasive and distant metastasis is exceedingly rare. Larger tumors generally require enucleation of the affected eye. It is possible that some smaller tumors can be resected locally without enucleation.75

Choroidal osteoma

Choroidal osteoma is a benign choroidal tumor that is probably congenital. Although it has

been recognized in infancy, it may not be diagnosed clinically until young adulthood.2,4,77

It is more common in females. It consists of a plaque of mature bone that generally occurs adjacent to the optic disc (304). It generally shows slow enlargement and choroidal neovascularization, with subretinal hemorrhage a frequent complication. The pathogenesis is unknown. Serum calcium and phosphorus levels are normal.

300

300 Retinal astrocytic hamartoma with glistening calcification.

302

302, 303 Medulloepithelioma of the ciliary body.302: Mass is visible peripheral to the lens on scleral depression;303: following enucleation in another case,the mass is seen in the ciliary body with total retinal detachment.

304 Choroidal osteoma surrounding the optic disc.

301

301 Optic disc melanocytoma with choroidal component.

303

304