Ovoid bodies in choroidal neurofibromatosis.

We studied the ultrastructure of the ovoid bodies in choroidal neurofibromatosis. Ovoid bodies consisted of groups of the same kind of elongated cells arranged in lamellar patterns. The elongated cell was characterized by a fragmented circumferential basal lamina, groups of pinocytotic vesicles, a desmosomelike intercellular contact, and intimate contact with axons. These findings suggest that elongated cells are proliferated Schwann's cells and ovoid bodies do not correspond with real sensory nerve end organs; rather, they are enlarged peripheral nerves due to neoplastic hyperplasia of Schwann's cells around axons.