Abstract
Summary The liver was found to be the primary site of infection for Echinococcus alveolaris; however, lung, kidney, spleen, pancreas and alimentary canal were also found to be affected. The acute cellular reaction caused by the infection and the pathological changes produced in the different organs are also described in detail. Perivascular infiltration with mononuclear cells was found to be characteristic of this infection and was observed in liver, lung and kidney. The chief characteristic of the larval stage of E. alveolaris is the type of lesion, which behaves very much like an infiltrating neoplasm.