New Insights Into the Development of Infantile Intraocular Medulloepithelioma

Early Neuroblastic and Astrocytic Differentiation Demonstrated Immunohistochemically in a Small Intraocular Medulloepithelioma

“…In some medulloepitheliomas, there exists a monolayer referred to as the premedullary epithelium (S100+, CRX-) [2]. The latter can be seen at the periphery of the tumor, both at its base and abutting the lens.…”

“…A similar tumor is found in the brain but has different genetic and epigenetic findings [2,3,4,5]. For every 100-150 retinoblastomas 1 ocular medulloepithelioma may occur.…”

“…For every 100-150 retinoblastomas 1 ocular medulloepithelioma may occur. Medulloepitheliomas may also arise in the eyes of adults [6,7]; some of these tumors appear to be generated from the neuroepithelium of the pars plana [7] as well as more commonly from the ciliary processes [2]. …”

“…The variegated nature of the cellular composition of ocular medulloepithelioma is a subject of ongoing fascination [1,2]. The pseudostratified or multilaminar medullary epithelium has been considered, without solid proof, to be the source of the various differentiations observed within ocular medulloepitheliomas.…”

“…Specifically, we found that certain biomarkers identified immunohistochemically were highly revelatory [2,7]: NeuN for neurorual differentiation, neurofilament protein for neuronal cell bodies and axons, CRX for photoreceptor differentiation, glial fibrillary acidic protein (GFAP) for astrocytes, CD99 for premature precursor neuroepithelium, and S100 for astrocytes and neurons (including their dendrites and axons). It was discovered that astrocytes and neurocytes (neurons) develop separately and not sequentially (that is, not one from the other) out of the medullary epithelium.…”