Hydatidosis or cyst hydatic disease is a cosmopolitan larval cestodosis caused principally by the <i>Echinococcus granulosus</i> tapeworm, the adult form of which parasitises the intestine of dogs. Hydatidosis generally affects large domestic herbivores; humans are dead-end hosts, infected through contact with herding dogs or through ingestion of food contaminated with canine excrement.

A clonal (malignant) hematopoietic disorder with an acute onset, affecting the bone marrow and the peripheral blood. The malignant cells show minimal differentiation and are called blasts, either myeloid blasts (myeloblasts) or lymphoid blasts (lymphoblasts).