Mesectodermal leiomyoma of the ciliary body associated with a nevus
F. A. Jakobiec and T. Iwamoto
A ciliary body tumor that was believed clinically to be a malignant
melanoma developed in a 28-year-old woman and led to enucleation of her
eye. The light microscopic appearance of the tumor was interpreted by light
microscopy as a neurogenic neoplasm, possibly a choristomatous astrocytoma.
Electron microscopic studies disclosed the smooth muscle origin of the
tumor. Results of experimental embryologic studies performed on lower
animals have proved that the neural crest contributes most of the
connective tissues, "mesectoderm," of the globe and orbit in these species.
The occurrence of hybrid neurogenic-myogenic tumors in the human eye
supports the applicability of these embryologic discoveries to man. The
association of a pigmented nevus with the present tumor is additional
evidence of the neural crest origin of mesectodermal leiomyomas, since
melanocytes are well-recognized descendants from the neural crest.
