Medulloepithelioma, non-teratoid

Source horse, 8 year castrated male thoroughbred
Fixative formalin
Stain hematoxylin and eosin
Notes arose from ciliary body; notice the retinal rosette-like pattern to the cells (hence its frequent confusion with retinoblastoma)
See also lower magnification
lower magnification
Legend integral to image
Illustration click on image to see larger picture