Effect of albendazole on human hydatid cysts: an ultrastructural study.

Five patients with hepatic (3), pelvic (1) or spinal (1) hydatid cysts received 10 mg/kg/d albendazole for 1-3 months prior to surgery. Daughter cysts were present in the spinal hydatid and in one patient with hepatic disease. Electron microscope examination of the cyst tissue of the pelvic and the 2 hepatic cysts lacking daughter cysts showed no evidence of germinal layer, and the protoscoleces were dead. The primary cyst of the hepatic hydatid with daughter cysts (1 month therapy) was also judged dead but some pieces of the daughter cyst germinal layer appeared normal and had unaffected protoscoleces. The daughter cyst tissue of the spinal hydatid (3 month therapy) appeared normal and the protoscoleces viable. In view of the undetermined viability of human hydatids before chemotherapy, treatment of longer than 1 month is advocated for hepatic cysts, particularly if daughter cysts are present, and longer therapy is indicated for spinal disease.