Parkinson's disease and megacolon: concentric hyaline inclusions (Lewy bodies) in enteric ganglion cells.

Concentric hyaline inclusions (Lewy bodies), found in the cytoplasm of pigmented and nonpigmented neurons, are considered characteristic of idiopathic Parkinson's disease. The finding of cytoplasmic inclusions identical to Lewy bodies in ganglion cells of the colonic myenteric plexus in a patient with idiopathic Parkinson's disease and acquired megacolon suggests primary involvement of the enteric nervous system by Parkinson's disease.