INTRAHEPATIC BILIARY STONES - IMAGING FEATURES AND A POSSIBLE RELATIONSHIP WITH ASCARIS-LUMBRICOIDES

Intrahepatic (IH) biliary stones are common in East Asia as part of a disease known as Oriental cholangiohepatitis (OCH). At a hospital serv ing non-Oriental communities, 40 patients were diagnosed on ultrasound (US) during an 8-year period as having IH stones. Follow-up showed th at the diagnosis was false in three cases. In the 37 patients with IH stones, 33 conventional retrograde cholangiograms were done; 26 undere stimated the IH abnormalities or missed them entirely. Computed tomogr aphy (CT) was done in 15 of these 37 patients the attenuation of the s tones was found to be only slightly above that of liver. The evidence that Ascaris lumbricoides was the cause of IH stones in our patients w as that: they came mainly from communities in which A. lumbricoides in festation is virtually universal at some stage of childhood, and none from communities in which it is infrequent; their average age was youn ger than that of patients with conventional gall-stones, fitting with the fact that infestation is predominantly in childhood; A. lumbricoid es is the only parasite in our region that invades the biliary system; the histories of the first 12 of the 37 patients had been investigate d for intestinal infestation, and were all positive; and 12 of the 37 showed evidence at some time of roundworms or remnants in the biliary system, either within the US appearance of the stones ('bundles' and ' pipes') or separately on US, surgery or duodenoscopy. Biliary strictur es, which occur in OCH, were not seen in our patients.