We describe two cases of echinococcus alveolaris (multilocularis) cyst
s of the kidney, which, in contrast to renal hydatid disease, are very
rarely seen, even in endemic regions of this parasitic disease. The v
ery difficult differentiation of the clinical picture from a cystic re
nal tumor, especially in the abscence of cysts of other organs, may ne
cessitate a nephrectomy to establish the final diagnosis, as in our ca
ses.