Melanogenic neuroectodermal tumor of the retina (primary malignant melanoma of the retina)

S. K. Freitag, R. C. Eagle Jr, J. A. Shields, J. S. Duker and R. L. Font
Wills Eye Hospital, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pa 19107, USA.

A 35-month-old girl with leukocoria was clinically diagnosed with unilateral sporadic retinoblastoma. Macroscopic examination of her enucleated eye disclosed a white retinal tumor that appeared to be a retinoblastoma. Histopathologic examination, however, revealed that the tumor was composed of poorly differentiated neuroblastic cells, larger spindle-shaped cells, and anaplastic epithelioid cells, which is inconsistent 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, both of which are consistent with melanogenesis. To our knowledge, such an ocular tumor has not been reported previously.