Photoreceptor Cell Differentiation in Intraocular Medulloepithelioma: An Immunohistopathologic Study

Abstract

We report a case of a teratoid intraocular medulloepithelioma that expressed S-antigen and rhodopsin immunoreactivity. Both proteins are known to be photoreceptor-cell specific and participate in the phototransduction of vision. Our study demonstrates that some medulloepitheliomas may differentiate along a neuronallike cell lineage. Report of a Case. —A 6-year-old white boy was referred to the Ocular Oncology Service, Wills Eye Hospital, Philadelphia, Pa, for evaluation of possible medulloepithelioma. The family medical history was positive for glaucoma and diabetes mellitus in addition to thyroid, breast, lung, and colon cancers. On ocular examination, the patient's best corrected visual acuity was 6/15 OD and 6/7.5 OS. An amelanotic cystic mass of the ciliary body was found inferotemporally in the right eye. Growth of the lesion produced a subluxated lens and minimal early cataractous changes. Because of the progressive growth of the lesion, excision by a partial lamellariridocyclectomy was performed in the right eye.