Polycystic liver disease: a study of cyst fluid constituents

EASL Clinical Practice Guidelines on the management of cystic liver diseases

The advent of enhanced radiological imaging techniques has facilitated the diagnosis of cystic liver lesions. Concomitantly, the evidence base supporting the management of these diseases has matured over the last decades. As a result, comprehensive clinical guidance on the subject matter is warranted. These Clinical Practice Guidelines cover the diagnosis and management of hepatic cysts, mucinous cystic neoplasms of the liver, biliary hamartomas, polycystic liver disease, Caroli disease, Caroli syndrome, biliary hamartomas and peribiliary cysts. On the basis of in-depth review of the relevant literature we provide recommendations to navigate clinical dilemmas followed by supporting text. The recommendations are graded according to the Oxford Centre for Evidence-Based Medicine system and categorised as 'weak' or 'strong'. We aim to provide the best available evidence to aid the clinical decision-making process in the management of patients with cystic liver disease.

Evidence for a "Pathogenic Triumvirate" in Congenital Hepatic Fibrosis in Autosomal Recessive Polycystic Kidney Disease

Autosomal recessive polycystic kidney disease (ARPKD) is a severe monogenic disorder that occurs due to mutations in the PKHD1 gene. Congenital hepatic fibrosis (CHF) associated with ARPKD is characterized by the presence of hepatic cysts derived from dilated bile ducts and a robust, pericystic fibrosis. Cyst growth, due to cyst wall epithelial cell hyperproliferation and fluid secretion, is thought to be the driving force behind disease progression. Liver fibrosis is a wound healing response in which collagen accumulates in the liver due to an imbalance between extracellular matrix synthesis and degradation. Whereas both hyperproliferation and pericystic fibrosis are hallmarks of CHF/ARPKD, whether or not these two processes influence one another remains unclear. Additionally, recent studies demonstrate that inflammation is a common feature of CHF/ARPKD. Therefore, we propose a "pathogenic triumvirate" consisting of hyperproliferation of cyst wall growth, pericystic fibrosis, and inflammation which drives CHF/ARPKD progression. This review will summarize what is known regarding the mechanisms of cyst growth, fibrosis, and inflammation in CHF/ARPKD. Further, we will discuss the potential advantage of identifying a core pathogenic feature in CHF/ARPKD to aid in the development of novel therapeutic approaches. If a core pathogenic feature does not exist, then developing multimodality therapeutic approaches to target each member of the "pathogenic triumvirate" individually may be a better strategy to manage this debilitating disease.

Spontaneous rupture of non-parasitic or non-neoplastic multiple and giant liver cysts: report of a case

Simple liver cysts occasionally cause pressure symptoms of the abdomen. We herein report an extremely rare case of spontaneous rupture of simple liver cysts. A 65-year-old woman suffered abdominal fullness and dyspnea. Laboratory examinations revealed general inflammation and mild hepatorenal dysfunction. Computed tomography revealed giant polycystic liver and ascites. Echinococcus antibody was not detected. Abdominal paracentesis provided dark brown transparent ascites in which any parasites or tumor cells were not observed. We diagnosed spontaneous rupture of isolated polycystic liver disease (PCLD) and continuously drained the ascites. After the symptoms and laboratory data were improved, resection of liver cysts and left lateral segmentectomy were performed. Histopathologically, simple columnar epithelia inside of cyst walls were observed. The patient remains well without recurrence of the symptoms 10 months after the surgery. We reviewed characteristics of PCLD and considered appropriate treatment for spontaneous rupture of simple liver cysts based on the previous case reports including the present case.

Evaluation of hepatic cystic lesions

Hepatic cysts are increasingly found as a mere coincidence on abdominal imaging techniques, such as ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). These cysts often present a diagnostic challenge. Therefore, we performed a review of the recent literature and developed an evidence-based diagnostic algorithm to guide clinicians in characterising these lesions. Simple cysts are the most common cystic liver disease, and diagnosis is based on typical USG characteristics. Serodiagnostic tests and microbubble contrast-enhanced ultrasound (CEUS) are invaluable in differentiating complicated cysts, echinococcosis and cystadenoma/cystadenocarcinoma when USG, CT and MRI show ambiguous findings. Therefore, serodiagnostic tests and CEUS reduce the need for invasive procedures. Polycystic liver disease (PLD) is arbitrarily defined as the presence of > 20 liver cysts and can present as two distinct genetic disorders: autosomal dominant polycystic kidney disease (ADPKD) and autosomal dominant polycystic liver disease (PCLD). Although genetic testing for ADPKD and PCLD is possible, it is rarely performed because it does not affect the therapeutic management of PLD. USG screening of the liver and both kidneys combined with extensive family history taking are the cornerstone of diagnostic decision making in PLD. In conclusion, an amalgamation of these recent advances results in a diagnostic algorithm that facilitates evidence-based clinical decision making.

Biliary dysgenesis in the PCK rat, an orthologous model of autosomal recessive polycystic kidney disease

Hepatic polycystic disease occurs alone or in combination with polycystic kidney disease (PKD). In autosomal recessive PKD (ARPKD), liver lesions are the major cause of morbidity and mortality in older patients. ARPKD is caused by a mutation to PKHD1 and the PCK rat is an orthologous model of disease. Recently, we showed that fibrocystin, Pkhd1 protein, is localized to primary cilia in rat cholangiocytes and that disruption of its ciliary expression results in biliary cystogenesis. This study describes biliary phenotype in the PCK rat using micro-computed tomography scanning and three-dimensional reconstruction, and light, scanning, and transmission microscopy. Our results show that the biliary tree undergoes extensive remodeling resulting in bile duct dilatation, focal budding, and formation of cysts that are initially connected to bile ducts, but throughout time separate from them. Progressive liver enlargement results from massive cyst formation while liver parenchymal volume remains unchanged. Cilia in cystic cells are abnormal consistent with the notion that the primary defect in ARPKD resulting in cystogenesis may be linked to ciliary dysfunction. Our results suggest that the PCK rat is a useful model for studies of biliary cystogenesis and treatment options of inherited cystic liver disease.

Epithelial transport in polycystic kidney disease

In autosomal dominant polycystic kidney disease (ADPKD), the genetic defect results in the slow growth of a multitude of epithelial cysts within the renal parenchyma. Cysts originate within the glomeruli and all tubular structures, and their growth is the result of proliferation of incompletely differentiated epithelial cells and the accumulation of fluid within the cysts. The majority of cysts disconnect from tubular structures as they grow but still accumulate fluid within the lumen. The fluid accumulation is the result of secretion of fluid driven by active transepithelial Cl- secretion. Proliferation of the cells and fluid secretion are activated by agonists of the cAMP signaling pathway. The transport mechanisms involved include the cystic fibrosis transmembrane conductance regulator (CFTR) present in the apical membrane of the cystic cells and a bumetanide-sensitive transporter located in the basolateral membrane. A lipid factor, called cyst activating factor, has been found in the cystic fluid. Cyst activating factor stimulates cAMP production, proliferation, and fluid secretion by cultured renal epithelial cells and also is a chemotactic agent. Cysts also appear in the intrahepatic biliary tree in ADPKD. Normal ductal cells secrete Cl- and HCO3-. The cystic ductal cell also secretes Cl-, but HCO3- secretion is diminished, probably as the result of a lower population of Cl-/HCO3- exchangers in the apical membrane as compared with the normal cells. Some segments of the normal renal tubule are also capable of utilizing CFTR to secrete Cl-, particularly the inner medullary collecting duct. The ability of Madin-Darby canine kidney cells and normal human kidney cortex cells to form cysts in culture and to secrete fluid and the functional similarities between these incompletely differentiated, proliferative cells and developing cells in the intestinal crypt and in the fetal lung have led us to suggest that Cl- and fluid secretion may be a common property of at least some renal epithelial cells in an intermediate stage of development. The genetic defect in ADPKD may not directly affect membrane transport mechanisms but rather may arrest the development of certain renal epithelial cells in an incompletely differentiated, proliferative stage.

Ludwig symposium on biliary disorders--part I. Pathogenesis of ductal plate abnormalities

Intrahepatic bile ducts (IHBDs) develop from bipotential liver progenitor cells in contact with the mesenchyme of the portal vein and thus form the "ductal plates." The ductal plates are remodeled into mature tubular ducts. Lack of remodeling results in the persistence of periportal epithelial sleeves or "ductal plate malformation" (DPM). A proposal is that virtually all congenital diseases of IHBDs represent examples of DPM. Some early, severe types of extrahepatic bile duct atresia are characterized by DPM, a suggestion of a prenatal beginning of the disease. Several congenital diseases are characterized by dilatation of segments of IHBDs and variable degrees of fibrosis. Such "fibrocystic diseases" represent DPM at different levels of the biliary tree. Autosomal recessive polycystic kidney disease represents DPM of interlobular bile ducts, associated with tubular dilatation of collecting renal tubules. Congenital hepatic fibrosis may derive from the same type of liver lesion, through a superimposed destructive type of cholangiopathy associated with scarring fibrosis. Caroli's disease represents DPM of the larger IHBDs, whereas Caroli's syndrome combines the lesions of Caroli's disease and congenital hepatic fibrosis. von Meyenburg complexes represent DPM of smaller interlobular ducts; their dilatation gives rise to the liver cysts in autosomal dominant polycystic kidney disease. Finally, DPM is a component of the tissue abnormalities in so-called mesenchymal hamartoma.

Azotemia and extrarenal manifestations in old female Han:SPRD (cy/+) rats

In humans suffering from polycystic kidney disease (PKD) a gender difference is seen with males exhibiting a faster rate of progression of chronic renal failure than females. The aim of this study was to examine renal function in female rats suffering from autosomal dominant PKD [Han:SPRD (cy/+)] and to look for the occurrence of extrarenal organ manifestations of PKD. In young (2 months) as well as in old female rats (21 months) relative kidney weight was greater in affected than unaffected animals. In contrast, only the old affected female rats developed azotemia (serum urea 95 +/- 124 mg/dl) and severe cystic kidney transformation. Furthermore, old affected female rats exhibited liver cysts (affected 42%; unaffected 3%) and pancreatic cysts (affected 69%; unaffected 15%). Liver cyst epithelia stained positive for cytokeratin 19, a marker for bile duct epithelia. By immunohistochemistry liver cysts exhibited a similar extracellular matrix composition as observed in renal cysts of the same animals (staining positive for laminin, fibronectin and heparan sulfate proteoglycan, but not collagen I). This study proves PKD in the Han:SPRD (cy/+) rat model to be a truly multiorgan disease with a close resemblance of the human disease.

Polycystic kidney disease: etiology, pathogenesis, and treatment

Once viewed as hopelessly incurable disorders and the dustbin for careers in academic medicine, the polycystic kidney diseases have emerged as prime targets of pathophysiologic study and palliative and definitive treatment in the era of molecular medicine. Polycystic kidney disease (PKD) may be hereditary or acquired. The major inherited types are autosomal dominant (AD) and autosomal recessive (AR). ADPKD is caused by at least two (and possibly three) genes located on separate chromosomes, while ADPKD-1 is due to a 14 kb transcript in a duplicated region on the short arm of chromosome 16 very near the alpha-globin gene cluster and the gene for one form of tuberous sclerosis. ADPKD-2 has been assigned to the long arm of chromosome 4. ARPKD is due to a mutated gene on both copies of the long arm of chromosome 6. Cysts originate in renal tubules. Proliferation of tubule epithelial cells modulated by endocrine, paracrine, and autocrine factors is a major element in the pathogenesis of renal cystic diseases. In addition, fluid that is abnormally accumulated within the cysts is derived from glomerular filtrate and, to a greater extent, by transepithelial fluid secretion. Abnormal synthesis and degradation of matrix components associated with interstitial inflammation are additional features in the pathogenesis of renal cystic diseases. The ADPKD genotypes are characterized by bilateral kidney cysts, hypertension, hematuria, renal infection, stones, and renal insufficiency. ADPKD is a systemic disorder; cysts appear with decreasing frequency in the kidneys, liver, pancreas, brain, spleen, ovaries, and testis. Cardiac valvular disorders, abdominal and inguinal hernias, and aneurysms of cerebral and coronary arteries and aorta are also associated with ADPKD. Treatment is supportive: dietary regulation of salt and protein intake, control of hypertension and renal stones, and dialysis and transplantation at the end stage. ARPKD is a relatively rare disease that causes clinical symptoms at birth, with significant mortality in the first month of life. The cysts develop primarily in the collecting ducts because of a failure in the maturation process. Early complications include Potter's syndrome; excessive size of the kidneys, causing respiratory dysfunction; hypertension; and renal insufficiency. Hepatic fibrosis is an associated extrarenal problem that results in significant morbidity in young children and adolescents. Treatment includes supportive care, dialysis, and renal transplantation. Acquired cysts (solitary/simple) are commonplace in older persons. Multiple cysts may be seen in association with potassium deficiency, congenital disorders, metabolic diseases, and toxic renal injury.(ABSTRACT TRUNCATED AT 400 WORDS)

Liver resection and cyst fenestration in the treatment of severe polycystic liver disease

BACKGROUND/AIMS

There is limited information on treatment options for massive, highly symptomatic polycystic liver disease. The aim of the study was to analyze the immediate and long-term outcome of combined liver resection and fenestration.

METHODS

Information was abstracted from medical records. Follow-up was obtained by mailed questionnaire. Liver volume was quantified by computed tomography.

RESULTS

Thirty-one patients underwent liver resection and fenestration between July 1985 and June 1993. Mean liver volume was 9357 mL before and 3567 mL after surgery. There was one death from postoperative intracerebral bleed. Eighteen patients experienced complications, usually transient pleural effusions or transient ascites. Twenty-eight of 29 surviving patients with adequate follow-up have experienced immediate and sustained relief of symptoms and improvement in quality of life. After median follow-up of 2.4 years (range, 0.2 to 7.9 years), most patients have not had clinically significant enlargement of the liver. Sequential computed tomography scans before and after surgery suggest that hepatic enlargement in the age range of the patients in the study mainly resulted from the expansion of existing cysts rather than from the development of new cysts.

CONCLUSIONS

Selected patients with severe symptomatic polycystic liver disease and favorable anatomy benefit from liver resection and fenestration with acceptable morbidity and mortality. The extent of hepatic resection and fenestration is important for the long-term effectiveness of this procedure.

Fenestration in the management of polycystic liver disease

Thirteen patients with symptomatic polycystic liver disease who were selected for fenestration were reviewed. The main preoperative complaints that related to polycystic liver disease were severe abdominal pain, respiratory distress, clinical ascites, or leg edema. All symptoms disappeared after operation, and the number and size of the cysts were smaller. Five patients developed transient but massive ascites during the postoperative period, and long-term follow-up demonstrated a moderate recurrence of hepatomegaly in two patients. These postoperative complications and failures appeared to be at least partly related to a more extensive evolution of the disease in the patients in whom it developed.

Polycystic liver disease with obstructive jaundice: treatment with ultrasound-guided cyst aspiration

A 59-year-old woman with polycystic liver (PCLD) and kidney disease (PCKD) presented with jaundice, fever, and abdominal pain. A computered tomographic (CT) scan performed immediately after an endoscopic retrograde cholangiopancreatogram (ERCP) clearly demonstrated a hepatic cyst obstructing the biliary system. The cyst was then aspirated under ultrasound guidance with complete relief of obstruction.

Cystic dilatation of peribiliary glands in livers with adult polycystic disease and livers with solitary nonparasitic cysts: an autopsy study

Cystic dilatation of peribiliary glands of intrahepatic and extrahepatic bile ducts was investigated in autopsied livers with adult polycystic disease (n = 8), in autopsied livers with solitary nonparasitic cysts (n = 18) and in normal autopsied livers (n = 23). In normal livers, cystic dilatation of intrahepatic peribiliary glands was absent or slight, when present. In livers with solitary nonparasitic cysts, cystic dilatation of intrahepatic peribiliary glands was present in varying degrees. In livers with adult polycystic disease, intrahepatic peribiliary glands showed frequent and severe cystic dilatation so marked that it was grossly recognizable. In contrast, peribiliary glands of the extrahepatic bile ducts showed no cystic dilatation in most cases, regardless of the three conditions examined. Liver parenchymal cysts were numerous in livers with adult polycystic disease, few in livers with solitary nonparasitic cysts and nonexistent in normal livers. Von Meyenburg complexes were present in 87.5% of livers with adult polycystic disease, in 16.7% of livers with solitary nonparasitic cysts and in 4.3% of normal livers. These findings suggest that intrahepatic peribiliary glands undergo cystic dilatation in livers with adult polycystic disease-and, to a lesser degree and frequency in livers with solitary nonparasitic cysts, probably because of congenital or genetic factors-and that these cystic changes may comprise a part of numerous cysts of adult polycystic disease.

Surgical experience with nonparasitic cysts of the liver--the characteristics and constituents of cyst fluid

Fifteen patients with nonparasitic hepatic cysts underwent surgery to relieve abdominal complaints, at the First Surgical Department, Tokyo University Hospital between 1966 and 1989. Total removal of the cyst was carried out in 14 of the patients, while puncture and aspiration only were performed in the other patient in whom a cyst had ruptured spontaneously, after which hemoperitoneum was observed at emergency laparotomy. The size of the cysts varied from 7-19 cm with a mean of 12.4 cm. Histological study revealed a congenital cyst in 14 patients and a cystadenoma in one. The epithelium lining of the internal surface of the congenital cysts was highly atrophic and desolated and often disappeared. Examination of the cyst fluid revealed the same concentration of electrolytes as in the serum. Hepatic enzyme levels were usually lower than in the serum, but lactic dehydrogenase and aminotransferase levels were elevated in a few cases. Tumor marker levels of the cyst fluid were higher than those in the serum in four of five patients examined.

Evidence against a requisite role for defective virus in the establishment of persistent hepadnavirus infections

The factors involved in the establishment of persistent hepadnavirus infection are poorly understood. Recent findings demonstrate that the sequence of the genome of hepatitis B virus (HBV) is variable in infected individuals and that, in some cases, virus mutants predominate. Our objectives in the present study were to analyze the variability of woodchuck hepatitis virus (WHV) genomes in an infected animal and to determine whether sequence heterogeneity played a critical role in the ability of WHV to induce chronic infection. We cloned and determined the complete nucleotide sequence of three supercoiled genomes from an animal that became infected after inoculation with a standardized WHV serum pool (i.e., the WHV7 virus pool). We found that there were four nucleotide substitutions among the three genome sequences as well as a 73-nucleotide deletion in one of the recombinants. DNA transfection experiments revealed that only one of the three recombinants was capable of independent replication. These data suggest that a significant proportion of replicative templates in woodchucks that are infected with WHV are defective virus genomes. Next, we compared the outcome of acute infection after inoculation with a serum pool containing a uniform population of replication competent virus (i.e., the WHV7R pool) with a serum pool composed of WHV genomes of variable sequence. The WHV7R serum pool originated from a woodchuck that became a chronic carrier after in vivo transfection of the liver with the infectious WHV7 recombinant. Neonatal woodchucks were inoculated with 5 x 10(6) WHV genome equivalents of either the WHV7 pool or the WHV7R pool. All animals in the study became acutely infected with WHV. Of the animals infected with the WHV7 serum pool, 65% became chronic carriers, while 80% of the animals infected with the WHV7R serum pool developed chronic infection. Thus, infection of woodchucks with a serum pool containing defective virus resulted in a rate of chronic WHV infection that was similar to, or even lower than, a rate from a pool containing only wild-type virus. This suggests that the presence of defective virus in the inoculum is not a prerequisite for the establishment of persistent hepadnavirus infections.

Autosomal dominant polycystic kidney disease--more than a renal disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disease, affecting a half million Americans. The clinical phenotype can result from at least two different gene defects. One gene that can cause ADPKD has been located on the short arm of chromosome 16. This discovery has made possible new methods for diagnosing the disorder in gene carriers prior to the development of renal cysts. Although renal cysts are clearly an important manifestation of the gene defect, other systemic manifestations are both common and clinically important. Cardiac valvular lesions, intracranial aneurysms, hepatic cysts, and diverticula are included in the array of systemic manifestations. Moreover, renal cysts are only one of a myriad of renal manifestations. Although ADPKD was long considered an adult cystic disease, it is also a common cause of childhood cystic disease and must be considered in the differential diagnosis in that setting.

Hepatic cysts in autosomal dominant polycystic kidney disease

Hepatic cysts are one of several extrarenal manifestations of the ADPKD gene. Several factors, including age, gender, pregnancy, the degree of renal cystic disease, and the extent of renal functional impairment, may modify the expression of hepatic cystic disease. With advances in medical care, such as improvement in the management of end-stage renal disease, hemodialysis, and renal transplantation, patients with ADPKD will experience an increased life expectancy. As a result, complications associated with hepatic cysts may become more common, and physicians may encounter an increasing number of patients with ADPKD who have infected hepatic cysts. Several issues in the management of this complication remain unresolved, but the article by Telenti and associates in this issue of the Proceedings addresses some of the critical issues that physicians who are responsible for the care of these patients will certainly confront in future years.

Functional similarities of hepatic cystic and biliary epithelium: studies of fluid constituents and in vivo secretion in response to secretin

Hepatic cysts are a frequent manifestation of autosomal dominant polycystic kidney disease, but little is known about their functional characteristics. The goals of our study were to define the composition of hepatic cyst fluid and to determine whether hepatic cysts secrete in response to intravenously administered secretin. We percutaneously punctured five hepatic cysts and one proximal renal cyst from six subjects with autosomal dominant polycystic kidney disease and one solitary hepatic cyst from a subject without autosomal dominant polycystic kidney disease. Most fluids had an electrolyte composition similar to serum. Fluid from all hepatic cysts had glutamyltranspeptidase concentrations above those found in serum [( cyst]/[serum] = 4.93 +/- 5.92), contained secretory component (the epithelial receptor for polymeric IgA) and had glucose concentrations less than 15 mg/dl. Fluid from both hepatic and renal cysts of subjects with autosomal dominant polycystic kidney disease, but not from the subject with the solitary hepatic cyst, demonstrated extensive changes in the electrophoretic mobility of several serum proteins. Initial intracystic pressures ranged from 16 to 40 cm H2O, were reduced 57% to 97% after aspiration of a portion of cyst fluid and were held constant during the secretion study. Within 8 min of the intravenous administration of secretin, secretion of fluid increased in two of three hepatic cysts and in the renal cyst. The electrolyte composition of cyst fluids was not altered by secretin. These data suggest that hepatic cystic epithelium has functional characteristics of biliary epithelium and that secretion by both hepatic and renal cysts may be hormonally regulated.

Highly symptomatic adult polycystic disease of the liver. A report of fifteen cases

Fifteen patients were evaluated because of highly symptomatic adult polycystic liver disease. All of them had abdominal pain, two patients had obstructive jaundice, one had ascites and a large right-sided pleural effusion, and one had oesophageal varices. In 4 patients percutaneous aspiration of the largest cysts was performed, but this form of treatment only provided temporary relief. In 9 patients a fenestration operation was carried out. One of these patients died per-operatively due to irreversible shock. The abdominal complaints disappeared post-operatively in 7 of the other 8 patients, although a decrease of the liver span was uncommon. In the two patients with obstructive jaundice the serum bilirubin level normalized after the operation, and in the patient with oesophageal varices this abnormality disappeared post-operatively. Biochemical analysis of cyst fluid was performed in 7 of the cases. The mean ratios of the levels of most of the non-protein-bound inorganic ions and other small molecules in cyst fluid and serum were about 1, whereas those of all proteins and protein-bound constituents were generally far below 1.

Lymphoid cells in the spleens of woodchuck hepatitis virus-infected woodchucks are a site of active viral replication

Lymphoid cells were purified from the spleens of 15 woodchucks and examined for the presence of woodchuck hepatitis virus (WHV). Lymphoid cells from the spleens of eight of eight chronically infected animals contained high levels of WHV RNA and DNA. A 100-fold lower level of WHV DNA was found in the spleen from one of five animals that had recovered from acute WHV infections 2 years before this analysis. No WHV nucleic acids were observed in either of two uninfected animals. WHV DNA patterns in the lymphoid cells from the spleens of the chronically infected animals, which included the presence of single-stranded DNA and RNA-DNA hybrid molecules, were identical to those observed in WHV-infected liver. WHV DNA in these cells was present in intact, 27-nm core particles which also contained the endogenous DNA polymerase activity. These results indicate that the spleen is a site of active WHV DNA replication and is most likely a major source of WHV-infected cells in the circulating lymphoid cell population.

MR imaging of multiple hepatic cysts in a patient with polycystic liver disease

We report a case of a 55-year-old woman with polycystic liver disease that we examined with magnetic resonance (MR) imaging, CT and ultrasound. The MR images demonstrated varying intensities in the cyst contents which we believe is due to different degrees and age of hemorrhage. Such variability among the cysts was not seen on the CT or ultrasound images.

Hepatobiliary fibropolycystic diseases. A clinical and histological review of 51 patients

The clinical, radiological and hepatic histological features of 51 patients with hepatobiliary fibropolycystic disease were reviewed. Many of the patients had more than one of the diseases; the combination of both congenital hepatic fibrosis (CHF) and Caroli's disease was most striking. Twelve patients with CHF (50% male) presented at 6 +/- 2 years of age (mean +/- SEM) with hepatosplenomegaly or variceal bleeding. Their main problems were recurrent variceal bleeds and renal disease. Polycystic kidneys and renal stones were present in 79% and chronic renal failure in 30%. Six of the 8 patients with Caroli's disease were male (75%) and presented later (aged 37 +/- 8 years) with hepatomegaly or cholangitis. Recurrent cholangitis developed in most (7/8) and 2 had polycystic kidneys. Twelve patients had a combination of CHF and Caroli's disease presenting with hepatosplenomegaly, bleeding or cholangitis. As in Caroli's disease, most (83%) were male, but the age of presentation (15 +/- 4 years), and the incidence of polycystic kidneys (42%) and renal failure (8%) was intermediate between CHF and Caroli's disease. In these patients, bleeds always predated cholangitis. Histologically, acute cholangitis was superimposed on the changes of CHF. Adult polycystic liver disease (10 patients) presented later (43 +/- 3 years) in females (90%) with pain, a mass or incidentally; polycystic kidneys were present in 33%. Microhamartomas (10 patients), which were usually incidental findings, were diagnosed latest (50 +/- 6 years). Three choledochal cysts were seen. The hazard of cancer in these diseases was reflected by 2 bile duct cancers and 1 pancreatic cancer (incidence 6%). This study has confirmed that hepatobiliary fibropolycystic diseases form part of a family and are often associated together. However, the diseases are of greatly differing severity and the prognosis in an individual patient is determined by the fibropolycystic diseases present.

Duck hepatitis B virus DNA in liver and serum of Chinese ducks: integration of viral DNA in a hepatocellular carcinoma

The presence of duck hepatitis B virus (DHBV) DNA in liver and serum and its state (integrated vs. free) were studied in 23 ducks from Chi-tung county in China by spot hybridization and Southern blot hybridization, respectively. In 16 of 23 (70%), DHBV DNA was detected in serum and/or in liver tissue. These infected ducks showed a variety of pathological changes including advanced chronic disease in the liver. In contrast, none of the virus-negative ducks had advanced hepatic changes. One DHBV DNA-seropositive duck had a large hepatocellular carcinoma. Southern blot analysis demonstrated integrated DHBV DNA in neoplastic tissue and abundant episomal DHBV DNA in non-neoplastic tissue of the liver. In one noninfected duck with a small adenoma, no viral DNA was detected in tumor or non-neoplastic tissue. The detection of integrated DHBV DNA in hepatocellular carcinoma suggests that DHBV behaves like human and woodchuck hepatitis viruses in relation to chronic liver disease and hepatocarcinogenesis.

Liver disease associated with duck hepatitis B virus infection of domestic ducks

The liver disease associated with duck hepatitis B viremia was investigated in naturally infected ducks from Chi-tung county in China and in both naturally and experimentally infected ducks from the United States. Liver and serum specimens of adult Chinese ducks were examined for duck hepatitis B virus (DHBV) DNA by dot and gel blot hybridization. DHBV was found in serum and (in episomal form only) in livers of 6 of 11 birds exhibiting various degrees of chronic hepatitis. In 1 bird with hepatocellular carcinoma, DHBV DNA was detected at the limit of assay sensitivity and in another not at all, contrasting with findings in humans and woodchucks. In work with California Pekin and Khaki Campbell ducks, known amounts of DHBV were injected into the egg 10 days before, or into ducklings 1 day after, hatching and the livers were examined 6 weeks later. The majority of the injected ducklings had viremia detectable by hybridization 1 or 2 weeks after injection. The presence but not the amount of viremia correlated with incidence and degree of hepatitis, determined under code. The most severe instances of hepatitis, all in Pekin ducks, resembled the hepatitis in adult Chinese ducks of Chi-tung county. Severe and moderate hepatitis were found only in indoor-caged injected animals with viremia and in some uninjected birds without viremia that had been kept in outdoor flocks. The latter hepatitis, as some hepatitis in adult Chinese ducks, may not be related to DHBV. Mild and insignificant hepatitis were also found in injected and noninjected ducklings, some of which had the vertically transmitted spontaneous viremia previously described. The good correlation of experimentally induced viremia with incidence and severity of hepatitis in the Pekin duckling provides a simple, rapid, and relatively inexpensive model to study the relation of lesions to hepatitis B family infection in nonprimates.