Figure 3. (A–D) Photomicrographs from a colonoscopic rectal biopsy shows several Schistosoma eggs (arrows) embedded in the lamina propria of the rectal mucosa. The Schistosoma eggs are yellowish brown, elongated to ovoid with a refractile shell. The large eccentric lateral spine projecting near one end (arrowhead) is a characteristic feature of a Schistosoma mansoni eggs. In addition, the rectal mucosa shows mild hyalinization of the lamina propria with mild chronic inflammation, edema, and extravasated red blood cells. There is no dysplasia or invasive carcinoma seen. This biopsy was diagnosed as schistosomiasis of the large intestine in which the location and histomorphology of the eggs are consistent with Schistosoma mansoni infection (hematoxylin and eosin stain, original magnification ×100, ×200, ×400, and ×600, respectively).