Intestinal pathology in human metagonimiasis with ultrastructural observations of parasites

A human case of intestinal metagonimiasis that was incidentally found during the histological examination of a resected segment of jejunum was described. The small adults trematode of Metagonimus yokogawai were found free in jejunal lumen as well as impacted in intervillous spaces. Histologically intestinal lesions were massive lymphoplasmacytic and eosinophilic infiltration in stroma, erosion of neanby enterocytes, goblet cell depletion and occasional villous edema. Scanning electron microscopy revealed the worm of spatulate appearance with rake-shaped tegumental spines. By transmission electron microscopy, the syncytial integument with dense discoidal bodies, basement membrane muscle cells and subtegumental cells were observed. Characteristic junctional complex was demonstrated between subtegumental and parenchymal cells as well as between parenchymal cells.