Possible formation of calcareous corpuscles by the brood capsule in secondary hepatic metacestodes of Echinococcus multilocularis.

In secondary hepatic metacestodes of Echinococcus multilocularis at 156 days post-infection, a few small structures exhibiting a central body and a small number of concentric layers were found on the outer surface of the brood capsule, and many such structures were detected on the germinal layer. As these structures are believed to represent immature calcareous corpuscles, we think that not only germinal layer cells but also brood capsule cells of E. multilocularis metacestodes can form calcareous corpuscles.