Intrahepatic cholesterol stones: a rationale for dissolution therapy

Effect of cholesterol metabolism on hepatolithiasis

Surgical intervention is currently the primary treatment for hepatolithiasis; however, some patients still experience residual stones and high recurrence rates after surgery. Cholesterol metabolism seems to play an important role in hepatolithiasis pathogenesis. A high cholesterol diet is one of the significant reasons for the increasing incidence of hepatolithiasis. Therefore, regular diet and appropriate medical intervention are crucial measures to prevent hepatolithiasis and reduce recurrence rate after surgery. Reducing dietary cholesterol and drugs that increase cholesterol stone solubility are key therapeutic approaches in treating hepatolithiasis. This article discusses the cholesterol metabolic pathways related to the pathogenesis of hepatolithiasis, as well as food intake and targeted therapeutic drugs.

Hepatolithiasis: clinical series, review and current management strategy

OBJECTIVES

Hepatolithiasis (HL) continues to be a problem due to its local and systemic complications, insufficiency in treatment modalities and high risk of recurrence. There are various surgical options available, ranging from endoscopic interventions to a small segment resection and ultimately to transplantation. In this article, patients with the diagnosis of HL and our treatment strategies were evaluated in the light of literature.

MATERIAL AND METHODS

The patients diagnosed with HL in our clinic between 2014-2019 were evaluated retrospectively by examining the patient files. Demographic characteristics of the patients, causes of the disease, complications and treatment options were evaluated.

RESULTS

17 patients were included into the study. Mean age of the patients was 64.3 years (range 32-89 years). Seven patients had previous cholecystectomies. Stenosis was found to be developed in hepaticojejunostomy (HJ) site in three patients (two had HJ due to bile duct injury and one had HJ following the Whipple procedure), and in hepaticoduodenostomy site in one patient who had the history of biliary tract injury during cholecystectomy. Two patients with HL without previous cholecystectomies had no gallbladder stones. Nine patients underwent surgery. Left hepatectomy was performed in two patients and lateral sector resection was performed in 2 patients. Two patients with anastomotic stenosis underwent HJ revision and two patients with anastomotic stenosis and one patient with stent ingrowth underwent bifurcation resection and neo-hepaticojejunostomy. Eight patients were followed-up nonoperatively with medical and endoscopic approaches.

CONCLUSION

Hepatolithiasis is a serious condition that needs to be treated with a multimodal approach. Stenting and anastomotic stenosis facilitate the development of hepatolithiasis and increase the risk of its occurrence. In particular, by performing functional hepaticojejunostomy, the development of this complication will be decreased.

A rare presentation of hepatolithiasis in an adolescent patient: A case report

INTRODUCTION

Hepatolithiasis (intrahepatic stones) is rare in adolescent patients and requires complex management strategies to prevent recurrent infections and progression to hepatic fibrosis. Surgical management is often required. In cases of unclear etiology, further work-up is indicated to provide insight into future management. In this report we describe an extensive stone analysis.

PRESENTATION OF CASE

A 20-year-old Caucasian female presented with known hepatolithiasis and multiple prior recurrent bouts of abdominal pain requiring hospitalization. Magnetic resonance cholangiopancreatography (MRCP) demonstrated an abnormal left-sided hepatic biliary ductal system dilatation. She was treated surgically with a formal left hepatectomy and preservation of the caudate lobe. The right ductal system had no stones or evidence of inflammation, and her bile and stones cultures were negative for organism growth. An extensive analysis demonstrated stone composition primarily of cholesterol.

DISCUSSION

Adolescent presentations of hepatolithiasis are rare and considerations in the differential diagnosis include primary sclerosing cholangitis, bile acid transporter defects, and other known genetic diseases. This case is unique because only the left half of the intrahepatic ductal system had evidence of stone disease and the bile was sterile. A detailed stone analysis demonstrating cholesterol supersaturation provides additional context though the etiology remains unclear in this case and will require lifelong follow-up.

CONCLUSION

Early-onset hepatolithiasis is rare and requires expert management, and in some cases definitive surgical management with life-long follow-up. Extensive stone analysis and genetic testing can be performed to help identify disease etiology in unique cases.

Management of intrahepatic stones: the role of subcutaneous hepaticojejunal access loop. A prospective cohort study

BACKGROUND

Patients with intrahepatic stones usually present with recurrent cholangitis, biliary sepsis and intrahepatic abscesses, may develop liver atrophy and may progress to cholangiocarcinoma. Treatment of intrahepatic stones is difficult and the disease progresses in most patients even after adequate treatment. Surgical removal of stones has been the standard management but residual stones and stone recurrence occur frequently whatever the technique. Because of the need for repeated biliary instrumentation, long-term access routes involving percutaneous transhepatic cholangioscopic lithotripsy (PTCSL), hepaticocutaneousjejunostomy (HCJ) and subparietal hepaticojejunal access loop to permit stone retrieval or stricture dilatation have been developed.

PURPOSE

The aim of this work was to evaluate the outcome of subcutaneous hepaticojejunal access loop in the management of intrahepatic stones.

PATIENTS AND METHODS

Between January 2009 and January 2013, 42 patients with intrahepatic stones underwent surgical treatment at the Gastrointestinal Surgery Unit, Main Alexandria University Hospital. Demographic data, details of operative findings, follow up details, and treatment of recurrent stones were analyzed. After approval of local ethics committee, all patients included in the study were informed well about the procedure and an informed written consent was obtained from every patient before carrying the procedure.

RESULTS

Forty-two patients (17 males and 25 females) with intrahepatic stones underwent surgery with construction of a subcutaneous hepaticojejunal access loop. Stones were confined to the left lobe in 25 patients, the right lobe in 3 patients and bilobar in 14 patients. Associated extrahepatic stones were found in 33 patients. Twenty-two patients had associated intrahepatic duct strictures. Five patients with atrophy of segments II and III underwent hepatic resection at the time of access loop formation. The mean operation time was 4.9 h and mean blood loss was 440 mL. Mean postoperative hospital stay was 10 days. Wound infection was the commonest complication, occurring in 5 (12%) patients. There were no specific complications attributable to the construction of the access loop. The subcutaneous access loop was used to gain access to the biliary tree in 28 patients with residual or recurrent stones. A total of 55 procedures (range 1-5) were attempted with successful access achieved in all cases and successful stone clearance in 21 of the 28 patients, and all of them were symptom free for at least 12 months after the last procedure. Partial stone clearance was achieved in the remaining seven patients. These seven patients had different degrees of biliary strictures.

CONCLUSION

The subcutaneous access loop offers the advantage of permanent access for the successful management of retained or re-formed intrahepatic stones with minimal morbidity since it permitted easy access to intrahepatic ducts using the conventional forward-viewing endoscope or the choledochoscope, without the additional morbidity of a biliary-cutaneous fistula or transhepatic access.

Long-term outcome of liver resection and transplantation for Caroli disease and syndrome

OBJECTIVE

To assess the preoperative disease characteristics as well as the rate of postoperative complications, patient survival, and course of symptoms after liver resection or orthotopic liver transplantation (OLT) for Caroli disease (CD) or syndrome (CS).

SUMMARY BACKGROUND DATA

The clinical course of monolobar or diffuse CD or CS is often characterized by multiple conservative treatment attempts and interventions with recurrent episodes of cholangitis and a serious reduction in quality of life. The role and effectiveness of surgical treatment is still not well defined.

PATIENTS AND METHODS

Between June 1989 and December 2002, we treated 44 consecutive patients with CD or CS who had failure of conservative treatment before and were referred for surgical intervention. Demographic and clinical data, operative procedures and related morbidity, course of symptoms, and long-term follow-up were reviewed. Four patients with palliative resection for cholangiocarcinoma and incidental diagnosis of CD were excluded from the analysis.

RESULTS

Twenty-two women and 18 men had a median period of 26.5 months from onset of symptoms to surgical therapy. Their median age at therapy was 49 years and 80% of the patients had monolobar disease with a left-right ratio of 2.6 to 1. Thirty-three (82.5%) patients underwent liver resection, while 4 (10%) patients received OLT for diffuse disease. Biliodigestive anastomosis alone was performed in 3 (7.5%) patients with contraindications to OLT. Patients (37.5%) had minor postoperative complications, which were treated conservatively, while 2 (5%) transplanted patients had a reoperation due to intraperitoneal bleeding. After a median follow-up of 86.5 months, we observed a favorable patient and graft survival. Three deaths during follow-up were not related to treatment or disease complications. Follow-up of disease-related symptoms, biliary complications, and antibiotic treatment revealed a significant improvement.

CONCLUSION

Our data show that liver resection for monolobar CD or CS and OLT for diffuse manifestations can achieve excellent long-term patient survival with marked symptom relief. Because of life-threatening long-term complications such as biliary sepsis and development of cholangiocarcinoma, timely indication for surgical treatment is crucial.

Transpapillary cholangioscopy-directed lithotripsy in patients with difficult bile duct stones

BACKGROUND & AIMS

There are limited prospective data and long-term follow-up on cholangioscopy-directed management of difficult bile duct stones. The study objectives were to evaluate the safety and efficacy of cholangioscopy-directed lithotripsy in patients who had failed standard endoscopic retrograde cholangiopancreatography (ERCP) techniques and to determine the stone recurrence rate.

METHODS

Consecutive patients with biliary stones referred for cholangioscopy after failure of conventional stone therapy were enrolled and followed prospectively.

RESULTS

Between February 2000-October 2004, 32 consecutive patients had cholangioscopy-directed lithotripsy (30 electrohydraulic lithotripsy, 2 mechanical) after a mean of 3.3 (range, 2-14) failed ERCPs. Stones were intrahepatic (N = 8); extrahepatic (N = 18); or both (N = 6). Biliary strictures were present in 20 (63%) patients. Cholangioscopy identified additional stones not seen at ERCP in 9 (28%) patients. A mean of 1.4 lithotripsy sessions achieved complete (N = 26, 81%), partial (N = 5, 16%), or failed (N = 1, 3%) stone clearance. Follow-up was available in 28 (88%) patients for a mean of 29.2 months (95% confidence interval, 20.3-38.1 months). Stone recurrence occurred in 4 of 22 (18%) patients with complete clearance and follow-up data; 3 had primary sclerosing cholangitis. There were 2 minor periprocedural complications and 1 late complication.

CONCLUSIONS

Cholangioscopy-directed lithotripsy is a safe and effective treatment in patients who have failed standard ERCP stone removal techniques. Stone recurrence is low in patients who had complete stone clearance except in patients with primary sclerosing cholangitis. Cholangioscopy detects stones missed by cholangiography.

Gallstone disease: Management of intrahepatic stones

Hepatolithiasis (oriental cholangiohepatitis) has reportedly been endemic only in East Asia. The disease is now occasionally recognized in Western societies, especially in people who have lived in the Orient. Hepatolithiasis is characterized by its intractable nature and frequent recurrence, requiring multiple operative interventions, which is in distinct contrast to gallbladder stones. In addition to frequent cholangitis and chronic sepsis, it is widely known that longstanding intrahepatic stones lead to intrahepatic cholangiocarcinoma. Symptoms of hepatolithiasis include abdominal pain, jaundice and cholangitis. Pyogenic cholangitis due to strictures and hepatolithiasis tends to recur, and sometimes patients may present with liver abscesses. Radiological studies and percutaneous procedures are keys in the diagnosis and treatment of hepatolithiasis. Non-invasive imaging modalities such as ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) accurately depict the normal anatomy and presence of intrahepatic stones. It should be stressed that each modality has its pros and cons, and imaging studies should be performed on the basis of understanding the pathophysiology. As the diagnostic role of magnetic resonance cholangiopancreatography (MRCP) evolves, the roles of both endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC), and their most significant advantage, is primarily therapeutic with their ability to extract stones, biopsy intraductal lesions, and place stents easily. The primary goals of treatment are to eliminate attacks of cholangitis and to stop the progression of the disease (which leads to biliary cirrhosis). Surgery has a primary role in hepatolithiasis because hepatolithiasis tends to recur, so that multiple sessions of the endoscopic approach (i.e. two or three times a year) are often required. PTC is an alternative when surgical resection of the affected lobe is difficult. Techniques for lithotripsy, including shockwave and laser, can be applied in endoscopic sessions, offering a better chance of clearing the stones.

Cholesterol hepatolithiasis with peribiliary cysts

A 78-year-old man was admitted to our clinic because of fatigue. Imaging modalities showed beaded stricture and dilation of the intrahepatic left segmental bile duct. Anomalous pancreatico-biliary ductal union and polycystic kidney disease were absent. Resection of the hepatic left lobe was performed. Grossly, cholesterol stones were impacted in the dilated intrahepatic large bile ducts, and multiple tiny cysts measuring 2-8 mm were noted in the peribiliary areas (peribiliary cysts). Histologically, the cholesterol hepatoliths consisted of cholesterol empty spaces and fibrinous materials, and, in places, foreign body giant cells were seen around the cholesterol crystals. The peribiliary cysts were lined by a layer of cuboidal epithelia. They were intimately intermingled with intrahepatic peribiliary glands, and a close association between the two components was recognized in some places. A mild degree of ascending cholangitis was noted. Bile duct anomalies including von-Meyenburg complexes and simple cysts were not recognized. Peribiliary cysts have been reported in various liver diseases, including portal hypertension, portal thrombosis, cirrhosis, hepatocellular carcinoma, and adult polycystic kidney disease. However, to the best of our knowledge, there have been no reports on peribiliary cysts developing in hepatolithiasis. The present case indicates that peribiliary cysts occur in cholesterol hepatolithiasis, and suggests that they are derived from cystic dilations of intrahepatic peribiliary glands.

Characterization of primary pure cholesterol hepatolithiasis: cholangioscopic and selective cholangiographic findings

BACKGROUND

Primary pure cholesterol hepatolithiasis has been described recently. The aim of this study was to analyze its clinical and radiologic features, focusing on the cholangioscopic and selective cholangiographic findings.

METHODS

Primary pure cholesterol hepatolithiasis was identified in 3% (6 of 172) of patients who were treated with cholangioscopic stone removal for primary hepatolithiasis during the study period from 1995 to 1999. These 6 consecutive patients (M/F 5:1, mean age 40 years) were enrolled in the study. They underwent abdominal US, CT, endoscopic retrograde cholangiography (ERC), and percutaneous transhepatic cholangioscopy (PTCS). After confirming that the stones were of the cholesterol type, cholangioscopic stone removal via the percutaneous transhepatic route was performed. For the prevention of recurrence, ursodeoxycholic acid (10 mg/kg/day) was prescribed during follow-up.

RESULTS

US demonstrated high echogenicity with strong shadowing in dilated peripheral ducts, whereas CT failed to demonstrate any intraductal abnormal density or calcification except localized duct dilatation. PTCS demonstrated multiple, white to yellowish stones that were morphologically readily distinguishable from brown pigment intrahepatic stones. In all patients, selective cholangiography disclosed the ductal abnormalities, which could not be delineated by ERC in 4 patients. Complete stone removal by PTCS was achieved in 5 of 6 patients. During follow-up (12 to 49 months, mean 22 months), they were asymptomatic and stone recurrence was not detected by US.

CONCLUSIONS

Primary pure cholesterol hepatolithiasis is distinguishable from the more common brown pigment hepatolithiasis by its cholangioscopic and selective cholangiographic characteristics.

Hepatolithiasis and biliary parasites

Hepatolithiasis, or the presence of intrahepatic stones, is prevalent in East Asia and is characterized by the finding of stones within the intrahepatic bile ducts proximal to the confluence of the right and left hepatic ducts. Bile stasis and bacterial infection have been incriminated as the major aetiopathogenic factors. Clinical features include recurrent pyogenic cholangitis, multiple liver abscesses, secondary biliary cirrhosis and cholangiocarcinoma. The goals of management include accurate localization of pathologies, control of biliary sepsis and the elimination of stones and stasis. Ultrasonography, computed tomography and direct cholangiography complement each other in defining the stones, strictures and degree of liver damage. Non-operative biliary decompression by endoscopy and interventional radiology is effective in controlling the infection, but surgery remains the mainstay for the treatment of stones and strictures. Intra-operative ultrasound and flexible choledochoscopy, combined with percutaneous transhepatic cholangioscopy and intraductal lithotripsy, facilitate stone removal. Balloon dilatation and biliary stenting serve to open the bile duct strictures. The creation of a hepaticocutaneous jejunostomy after conventional surgery allows atraumatic access to the biliary system for the removal of recurrent stones. The management of biliary parasites begins with conservative measures, including analgesics and anti-helminthic therapy. In refractory cases or patients with acute cholangitis, endoscopic biliary drainage and the extraction of worms may be necessary. Improvement in sanitation plays a crucial role in the epidemiological control of these biliary diseases.

Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease

BACKGROUND

Patients with Crohn's disease may have periods of remission, interrupted by relapses. Because fish oil has antiinflammatory actions, it could reduce the frequency of relapses, but it is often poorly tolerated because of its unpleasant taste and gastrointestinal side effects.

METHODS

We performed a one-year, double-blind, placebo-controlled study to investigate the effects of a new fish-oil preparation in the maintenance of remission in 78 patients with Crohn's disease who had a high risk of relapse. The patients received either nine fish-oil capsules containing a total of 2.7 g of n-3 fatty acids or nine placebo capsules daily. A special coating protected the capsules against gastric acidity for at least 30 minutes.

RESULTS

Among the 39 patients in the fish-oil group, 11 (28 percent) had relapses, 4 dropped out because of diarrhea, and 1 withdrew for other reasons. In contrast, among the 39 patients in the placebo group, 27 (69 percent) had relapses, 1 dropped out because of diarrhea, and 1 withdrew for other reasons (difference in relapse rate, 41 percentage points; 95 percent confidence interval, 21 to 61; P < 0.001). After one year, 23 patients (59 percent) in the fish-oil group remained in remission, as compared with 10 (26 percent) in the placebo group (P = 0.003). Logistic-regression analysis indicated that only fish oil and not sex, age, previous surgery, duration of disease, or smoking status affected the likelihood of relapse (odds ratio for the placebo group as compared with the fish-oil group, 4.2; 95 percent confidence interval, 1.6 to 10.7).

CONCLUSIONS

In patients with Crohn's disease in remission, a novel enteric-coated fish-oil preparation is effective in reducing the rate of relapse.

Primary dual defect of cholesterol and bile acid metabolism in liver of patients with intrahepatic calculi

BACKGROUND/AIMS

Intrahepatic calculi, which are characterized by cholesterol-rich pigment stones, are highly prevalent in East Asia. Their pathogenesis remains unknown. To elucidate the etiological factors underlying the formation of cholesterol-supersaturated bile, which leads to the formation of cholesterol-rich pigment stones cholesterol and bile acid de novo syntheses in the liver were studied.

METHODS

Liver specimens were assayed for the catalytic activities and steady-state messenger RNA levels of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and cholesterol 7 alpha-hydroxylase.

RESULTS

The activity of HMG-CoA reductase, consistent with the messenger RNA level, was significantly higher in 13 patients with intrahepatic grown pigment stones (11.2 +/- 1.3 pmol.min-1.mg protein-1 [mean +/- SEM; P < 0.0001] for affected hepatic lobes and 13.4 +/- 1.7 [P < 0.0001] for unaffected ones [P < 0.0001]) than in 19 control subjects (6.4 +/- 0.4) and in 29 patients with gallbladder cholesterol stones (2.1 +/- 0.1). On the other hand, the activity of 7 alpha-hydroxylase, consistent with the messenger RNA level, was significantly lower in patients with intrahepatic brown pigment stones (2.8 +/- 0.5 pmol.min-1.mg protein-1 [P < 0.0001] for affected lobes and 2.6 +/- 0.5 [P < 0.0001] for unaffected ones) than in control subjects (6.0 +/- 0.6) and in patients with cholesterol stones (5.1 +/- 0.5).

CONCLUSIONS

In intrahepatic calculi, the formation of supersaturated bile and cholesterol-rich pigment stones may be attributed to the primary dual defect of up-regulated cholesterogenesis and down-regulated bile acid synthesis in the liver.

Alterations of bile acid composition in gallstones, bile, and liver of patients with hepatolithiasis, and their etiological significance

A detailed comparison was made of the bile acid composition in gallstones (brown pigment stones) and paired bile and liver from both affected and unaffected lobes by gallstones, which were taken at operation from 16 patients with hepatolithiasis, with the aim of elucidating whether stone formation is derived from possible local disturbances limited to intrahepatic bile ducts. Brown pigment stones in the intrahepatic bile ducts, most of which were accompanied by bile with high cholesterol saturation, had significantly more cholesterol, and less calcium bilirubinate and bile acid than those found in the extrahepatic bile ducts. Intrahepatic gallstones had significantly lower amounts of secondary and unconjugated bile acids, the bile acids modified by bacterial intervention, than extrahepatic stones. Bile specimens from both affected and unaffected lobes showed significantly increased molar percentages of cholesterol and decreased percentages of bile acids than bile from controls. In contrast, liver specimens from both lobes showed significantly higher concentrations of total bile acids. Secondary bile acids were present in a much lower proportion in bile and liver from both lobes than in bile and liver from controls. On the other hand, unconjugated bile acids were present in a much higher proportion in bile and liver from patients and only in negligible amounts in bile from controls. Furthermore, the plasma levels of mevalonate and those of 7 alpha-hydroxy-4-cholestene-3-one were found to be significantly higher and lower in patients than in controls, respectively, indicating that in hepatolithiasis cholesterol synthesis might increase and bile acid synthesis might decrease in the liver. These findings suggested that alterations of bile acid composition in gallstones, bile, and liver of patients with hepatolithiasis may be attributed to not only secondary changes resulting from local disturbances limited to intrahepatic bile ducts but also possible primary alterations of hepatocyte metabolism, such as bile acid conjugation and primary defects in cholesterol and bile acid synthesis.

Ursodeoxycholic acid treatment of primary hepatolithiasis in Caroli's syndrome

Congenital cystic dilation of the intrahepatic bile ducts (Caroli's syndrome) is a rare cause of chronic cholestasis and hepatolithiasis in young adults. Long-term prognosis is poor even with surgical drainage. We treated twelve patients who had Caroli's syndrome and intrahepatic stones with ursodeoxycholic acid (UDCA), 10-20 mg/kg daily. The duodenal bile of these patients contained cholesterol crystals, which suggests that the stones were cholesterol rich. UDCA led to sustained clinical remission, return to normal liver function, and dissolution of intrahepatic stones on ultrasound in all patients (nine partial, three complete) after 48 (range 12-114) months' follow-up. Litholytic therapy is indicated for intrahepatic stones in Caroli's syndrome.

Histological features and interphase nucleolar organizer regions in hyperplastic, dysplastic and neoplastic epithelium of intrahepatic bile ducts in hepatolithiasis

Neoplastic transformation occurs in the intrahepatic biliary tree in hepatolithiasis. The present study aimed to clarify the neoplastic processes by correlating the histological features of the bile duct lesions with counts of interphase argyrophilic nucleolar organizer regions (AgNORs), which reflect cell proliferative activity. We studied 55 cases of hepatolithiasis and 25 normal autopsy livers. The biliary epithelial lesions in hepatolithiasis were divisible into hyperplasia, dysplasia and neoplasia. These lesions were found in bile ducts containing calculi. All cases of hepatolithiasis showed a varied degree of hyperplasia. Additionally, eight cases showed dysplasia, five non-invasive intraductal adenocarcinoma and 10 invasive adenocarcinoma. Cases of non-invasive and invasive carcinoma frequently harboured areas of dysplasia, and areas of dysplasia and non-invasive carcinoma, respectively. The mean and standard deviation of the number of interphase AgNORs in the normal and abnormal biliary epithelium showed a step-wise increase in the following order: normal (1.32 +/- 0.36), hyperplasia (1.52 +/- 0.37), dysplasia (2.28 +/- 0.56), non-invasive carcinoma (3.23 +/- 1.00), and invasive carcinoma (3.72 +/- 0.77). These histological and cell kinetic observations suggest that, in hepatolithiasis, carcinogenesis in bile duct epithelial cells progresses in a multi-step manner, through hyperplasia, dysplasia, non-invasive adenocarcinoma and invasive adenocarcinoma.

Cell kinetic analyses and expression of carcinoembryonic antigen, carbohydrate antigen 19-9 and DU-PAN-2 in hyperplastic, pre-neoplastic and neoplastic lesions of intrahepatic bile ducts in livers with hepatoliths

We evaluated cell proliferative activity and expression of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9) and DU-PAN-2 in various bile duct lesions in livers with hepatoliths, using histochemical and immunohistochemical methods. Histologically, the bile duct lesions were divisible into hyperplasia, dysplasia, adenocarcinoma in situ and invasive adenocarcinoma. All cases showed mucosal hyperplasia in stone-bearing bile ducts. Livers with invasive adenocarcinoma frequently contained adenocarcinoma in situ and dysplasia, and livers with adenocarcinoma in situ occasionally harboured dysplasia. Proliferating cell nuclear antigen (PCNA) labelling index was low in hyperplasia (mean +/- SD = 20.5 +/- 8.7%), intermediate in dysplasia (35.4 +/- 15.9%), and high in adenocarcinoma in situ (46.4 +/- 9.3%). The mean number of argyrophilic nucleolar organizer regions (AgNORs) was low in hyperplasia (1.52), intermediate in dysplasia (2.26) and high in adenocarcinoma in situ (2.69). There was a significant positive correlation between PCNA labelling index and AgNORs count. CEA was expressed on invasive adenocarcinoma cells and adenocarcinoma in situ cells in most cases and on dysplastic cells in about a half, while CEA was never present in hyperplastic epithelia. Expression of CA 19-9 was low in adenocarcinoma, intermediate in dysplasia and rather high in hyperplasia. There was no significant difference in DU-PAN-2 expression among these bile duct lesions. These data suggest that cell replicative activity is low in hyperplasia, intermediate in dysplasia and high in adenocarcinoma in situ, and that CEA appears in the following order: dysplasia, adenocarcinoma in situ, invasive adenocarcinoma. We suggest that carcinogenesis in biliary epithelial in livers with stones is a multi-step process through hyperplasia, dysplasia and adenocarcinoma in situ to invasive adenocarcinoma.