Ascaris worms may migrate into any organs with luminal continuity to the gastrointestinal tract. They can travel through the Ampulla of Vater, and some can migrate into the extrahepatic bile or pancreatic ducts.
The location of the worm depends on its diameter relative to the ductal lumen. Some worms partially protrude through the Ampulla, while smaller worms may reach the liver.
Possible presentations:
(1) large bile duct obstruction with jaundice
(2) acute cholangitis or biliary colic
(3) acute cholecystitis
(4) pancreatitis
(5) hepatic abscess
Some worms will become dislodged after chemotherapy. Some worms can be removed by endoscopy. If all else fails then the worms can be removed at surgery.
Surgery is indicated if there are persistent complications despite conservative therapy, often due to a dead worm stuck in a duct.
A patient who has had a worm invade the Ampulla is at increased risk for:
(1) recurrence if reinfected
(2) choledocholithiasis (with stones forming around dead worms)
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