Multilocular hydatid cysts are caused by:

Ans. b (Echinococcus multilocularis). (Ref. Harrison, Medicine, 18th/ Chapter 220. Cestode Infections)E. multilocularis# produces multilocular alveolar cysts of multilocular characteristics present as a slowly growing hepatic tumor with progressive destruction of liver and extension into vital structures.# Features include: abdominal pain and obstructive jaundice, and sometimes lesions in liver and brain.# Egg-shell or mural calcification on CT, is indicative of E. granulosus infection and helps to distinguish the cyst from carcinomas, bacterial or amebic liver abscesses, or hemangiomas.# Solid mass with central near plaque like calcification is seen with multilocular hydatid.# Treatment includes albendazole, PAIR (percutaneous aspiration, infusion of scolicidal agents, and reaspiration) and PAIR is now recommended instead of surgery. PAIR is contraindicated for superficially located cysts (because of the risk of rupture), for cysts with multiple thick internal septal divisions (honeycombingpattern), and for cysts communicating with the biliary tree. For prophylaxis of secondary peritoneal echinococcosis due to inadvertent spillage of fluid during PAIR, the administration of albendazole (15 mg/kg daily in two divided doses) should be initiated at least 4 days before the procedure and continued for at least 4 weeks afterward.# Surgical resection remains the treatment of choice for E. multilocularis infection.