Iris neovascularization in children as a manifestation of underlying medulloepithelioma

TUMORS OF THE NONPIGMENTED EPITHELIUM OF THE CILIARY BODY: The Lorenz E. Zimmerman Tribute Lecture

BACKGROUND

In 1970, Dr. Lorenz Zimmerman delivered the Norman McAlister Gregg Lecture entitled "The remarkable polymorphism of tumors of the ciliary epithelium." Therein, he proposed a classification of these tumors that included congenital lesions (mainly medulloepithelioma) and acquired lesions (mainly adenoma and adenocarcinoma). The classification was based on histopathologic observations without detailed clinical information.

METHODS

Review of the published literature and personal experience with tumors of the nonpigmented ciliary body epithelium.

RESULTS

Since 1970, further observations through clinical examination and advanced testing with ultrasound biomicroscopy, anterior segment optical coherence tomography, and magnetic resonance imaging have expanded our knowledge regarding tumors of the nonpigmented ciliary body epithelium. Regarding medulloepithelioma, we have learned of the common associated features of neovascular glaucoma, retrolenticular neoplastic or vascular cyclitic membrane, intralesional cysts, response to radiotherapy, and association with Dicer-1 mutation. Regarding adenoma/adenocarcinoma, improved management with surgical resection (sparing globe) can be achieved. Fuchs adenoma, also termed coronal adenoma, is commonly found histopathologically, despite its rare clinical visualization, and should be added to the Zimmerman classification.

CONCLUSION

Since Zimmerman's report on histopathologic features of tumors of the nonpigmented ciliary body epithelium, there have been numerous publications and further observations on the clinical features and management of these intriguing neoplasms.

Ciliary body medulloepithelioma in an adult

A 67-year-old woman presented with complaints of poor vision and persistent redness in the right eye of 4 months duration. She had undergone an uncomplicated cataract surgery in the same eye 2 years ago and had regained visual acuity of 20/20 with a then otherwise unremarkable eye examination. She had only light perception in the affected right eye with an intraocular pressure of 42 mm Hg. There were dilated episcleral vessels inferotemporally. Powdery white material was dispersed over the corneal endothelium and in the anterior chamber. There was diffuse iris neovascularization and a large yellowish white, fluffy, ciliary body mass. A metastasis was suspected, but systemic evaluation failed to reveal a primary. In view of the neovascular glaucoma, poor visual potential, and suspicion of a malignancy, the eye was enucleated. Histopathological examination revealed malignant nonteratoid ciliary body medulloepithelioma. Although ciliary body medulloepithelioma is predominantly a pediatric tumor, this case emphasizes the need to include it in the differential diagnosis of ciliary body tumors in adults.

Neovascular glaucoma

Neovascular glaucoma (NVG) is a severely blinding, intractable disease. The objective of this review is to provide detailed information on its basic and clinical aspects, to enable us to manage it logically. Therefore, its causes, pathogenesis and pathology, methods of early diagnosis and management are discussed. To prevent or reduce the extent of visual loss caused by NVG, the first essential is to have a high index of suspicion of its development. The most common diseases responsible for development of NVG are ischemic central retinal vein occlusion (CRVO), diabetic retinopathy and ocular ischemic syndrome. In the management strategy, the first priority should be to try to prevent its development by appropriate management of the causative diseases. If NVG develops, early diagnosis is crucial to reduce the extent of visual loss. Management of NVG primarily consists of controlling the high IOP by medical and/or surgical means to minimize the visual loss. Currently, we still do not have a satisfactory means of treating NVG and preventing visual loss in the majority, in spite of multiple modes of medical and surgical options advocated over the years and claims made. This review discusses the pros and cons for the various advocated treatments.

Anterior segment tumors: current concepts and innovations

The most common anterior segment tumors are primary neuroepithelial cysts, uveal melanomas, metastatic tumors, and benign tumors. In the majority of cases, the diagnosis can be made utilizing a careful clinical history and ocular examination. Ultrasound examination (low and high frequency) has become an indispensable tool used to determine tumor extension and involvement of the surrounding structures. In particular, high-frequency ultrasound has been used to uncover iris pigment epithelial cysts, to allow for the diagnosis of small ciliary body melanomas, and to measure tumors for plaque radiation planning. Whereas fluorescein angiography and computerized tomography have come to play a limited role, fine-needle aspiration biopsy has been found to be quite helpful in selected cases. Once the diagnosis is established, treatment decisions depend on the tumors' location, size, local extension, patterns of growth, and secondary complications. Most anterior segment tumors can be observed for growth prior to treatment. Other options include local resection (iridectomy, lamellar sclerouvectomy, or eye-wall resection) and radiation (ophthalmic plaque or external beam). Enucleation is typically employed if these eye- and vision-sparing treatments are not possible and for uncontrollable secondary glaucoma. This review examines the unique role of high-frequency ultrasonography for the diagnosis and treatment of anterior segment tumors as well as an overview of clinical practice.