Intraocular medulloepithelioma – A review of clinical features, DICER 1 mutation, and management

Intraocular medulloepithelioma is a nonhereditary neoplasm of childhood arising from primitive medullary epithelium. It most often involves the ciliary body. Most patients present between 2 and 10 years of age with loss of vision, pain, leucocoria, or conjunctival congestion. The mass appears as a grey-white ciliary body lesion with intratumoral cysts. Presence of a neoplastic cyclitic membrane with extension to retrolental region is characteristic. Secondary manifestations like cataract and neovascular glaucoma may be present in up to 50% and 60% patients, respectively. These could be the first signs for which, unfortunately, about 50% patients undergo surgery before recognition of the hidden tumor. Systemic correlation with pleuropulmonary blastoma (DICER1 gene) has been documented in 5% cases. Histopathology shows primitive neuroepithelial cells arranged as cords closely resembling the primitive retina. Histopathologically, the tumor is classified as teratoid (containing heteroplastic elements) and nonteratoid (containing medullary epithelial elements), each of which are further subclassified as benign or malignant. Retinoblastoma-like and sarcoma-like areas may be seen within the tissue. The treatment modality depends on tumor size and extent of invasion. For small localized tumors (?3-4 clock hours), conservative treatments with cryotherapy, plaque radiotherapy, or partial lamellar sclerouvectomy (PLSU) have been used. Plaque brachytherapy is generally preferred for best tumor control. Advanced and extensive tumors require enucleation. Rare use of intra-arterial and intravitreal chemotherapy has been employed. Systemic prognosis is favorable, but those with extraocular extension and orbital involvement show risk for local recurrence and metastatic disease, which can lead to death.

A Case of Adenoma of Nonpigmented Ciliary Epithelium

Acquired tumors of the nonpigmented ciliary epithelium are rare diseases. They are difficult to diagnose and present as pseudoadenomatous hyperplasia, adenoma or adenocarcinoma. They exhibit slowly progressive enlargement leading to a subluxated lens, cataract, and secondary glaucoma. And some of the more malignant tumors may extend extrasclerally. We report a case of adenoma of nonpigmented ciliary epithelium which produced a cataract.

Papillary Adenocarcinoma of Nonpigmented Ciliary Epithelium of the Eye

Adenocarcinoma of the ciliary epithelium is a rare tumor, usually occuring in elderly patients who have a history of severe ocular trauma or chronic inflammation. We report an adenocarcinoma of the nonpigmented ciliary epithelium found within the phthisical globe of a 36-year-old female whose eye had been loss of vision since infancy. The mass, measured 4.0 x 4.0 cm, was relatively limited by sclera but had invasion to posterior portion. Histologically, the tumor was a compact mass which consisted of tubular and papillary structures with foci of the pleomorphic area. Strands of cells and individual cells were invested with thick basement membrane that have positivity for periodic acid-Schiff stain. Immunohistochemical staining showed strong reactivity for cytokeratin and epithelial membrane antigen, and focal for neuron-specific enolase and S-100 protein.

Toxic Effect of Mitomycin C in the Rabbit Ciliary Epithelium

Mitomycin C(MMC) is one of the alkylating agents, which is commonly used adjunctively to inhibit the over-growth of the fibroblasts in high-risk filtering surgery. However, it increases the incidence of the complications including persistent postoperative hypotony. The hypotony may be caused by the toxic effect of MMC on the ciliary epithelium. The morphological changes of the ciliary epithelium were evaluated using transmission electron microscope four and twelve weeks after the application of balanced salt solution(BSS) and MMC on the exposed sclera against the ciliary body in the rabbit eyes. There was no specific change in the ciliary epithelium four and twelve weeks after the application of BSS. Four weeks after the application of 0.2mg/ml of MMC, the mitochondria in the nonpigmented epithelium of the applied region were swollen mildly. The mitochondria of both pigmented and nonpigmented epithelia were swollen moderately in the region applied with 0.5mg/ml of MMC. Twelve weeks after the application of either 0.2 or 0.5mg/ml of MMC, the mitochondria were swollen markedly, the nuclear membranes in the pigmented and nonpigmented epithelia were wrinkled, and the heterochromatins of the nuclei faded in both applied and contralateral ciliary epithelia. These findings indicate that mitomycin C causes degenerative changes in the ciliary epithelium decrease aqueous production.

Morphological Studies on the Rabbits Ciliary Epithelium by Bunazosin

Bunazosin is a alpha-1 blocker that is more selective and effective than other alpha-1 receptor blockers. Bunazosin has been shown to lower intraocular pressure but it's mechanism is uncertain. The purpose of this study is to know the morphological changes in the ciliary epithelium by bunazosin. 0.1% Bunazosin was instilled on the eye of the rabbits and the eyes were enucleated on 1, 2, 6 and 24 hours after instillation to find out the tissue response under the electronmicroscopy. As a result, widening of the cell membranes and swelling of the mitochondria were observed in the pigmented and non-pigmented epithelium and these changes were recovered with time and seem to be the morphological changes of bunazosin against aqueous formation in the ciliary body.

Morphological Studies on the Rabbits Ciliary Epithelium by Apraclonidine

Apraclonidine is a potent alpha-adrenergic agonist that, like clonidine, is relatively selective for alpha-2 receptors. Apraclonidine has been shown to lower intraocular pressure by diminishing aqueous humor formation. The purpose of this study is to know the morphological changes in the ciliary epithelium by apraclonidine against aqueous formation. In group I, two drops of 1% apraclonidine hydrochloride were instilled on the right eye of the pigmented rabbits and the eyes were enucleated on 1,2.6 and 24 hours after instillation to find out the duration of action of the drug and the tissue response. In group II, one drop was instilled twice daily for seven days on the right eye and the eyes were enucleated on 1, 2 and 5 days after cessation of the instillation observing the cumulative effect of the drug and the tissue response. These eyes were studied with electron mIcroscopIc examiation. As a result, widening of cell membranes(basal infoldings) of the non-pigmented epithelium(NPE) were observed. This change was recovered with time, and seems to be the principal morphological changes of apraclonidine against aqueous formation in the ciliary body. In group II, the cellular changes were minimal except for well developed rough endoplasmic reticulum representing resumed secretary function of the cell.