MELANOGENIC NEUROECTODERMAL TUMOR OF THE RETINA (PRIMARY MALIGNANT-MELANOMA OF THE RETINA)

A 35-month-old girl with leukocoria was clinically diagnosed with unil ateral sporadic retinoblastoma. Macroscopic examination of her enuclea ted eye disclosed a white retinal tumor that appeared to be a retinobl astoma. Histopathologic examination, however, revealed that the tumor was composed of poorly differentiated neuroblastic cells, larger spind le-shaped cells, and anaplastic epithelioid cells, which is inconsiste nt with retinoblastoma. Immunohistochemical testing disclosed that the tumor cells were immunoreactive for melanoma-specific antigen HMB-45, while electron microscopy showed premelanosomes in the tumor cells, b oth of which are consistent with melanogenesis. To our knowledge, such an ocular tumor has not been reported previously.