[Primary sarcomas and sarcoma metastases in the liver: morphological and molecular aspects]. / Primäre Sarkome und Sarkommetastasen in der Leber. Morphologische und molekulare Befunde.

The considerable progress made in radiology, in surgical management with curative intent, and in the identification of molecularly targeted small molecules, such as the tyrosine kinase inhibitor imatinib mesylate, in the treatment of gastrointestinal stromal tumors has greatly influenced the treatment of sarcoma manifestations within the liver. This requires not only the unequivocal pathomorphological differentiation of sarcomas from other tumor entities, e. g. spindle cell dedifferentiated/pleomorphic carcinomas, aggressive non-Hodgkin lymphomas or amelanotic malignant melanomas, but also an accurate subtyping of this complex group of tumors. Additionally to macroscopic and histological findings, the recognition of characteristic immunophenotypic constellations and, at least in some types of sarcoma, the identification of molecular signatures, have greatly expanded the diagnostic tools in pathology.

Preoperative high-frequency duplex scanning of potential pedal target vessels.

OBJECTIVE: The aim of this prospective study conducted at a tertiary referral center was to evaluate the efficacy of high-frequency duplex scanning in the preoperative evaluation of potential pedal target vessels. Material and methods The study population consisted of thirty-three consecutive diabetics suffering critical limb ischemia, with indications of infra-popliteal occlusive disease. Duplex ultrasound was performed by an angiologist unaware of any prior imaging procedures. The pedal vessels were divided into four segments. The inner diameter-, the grade of calcification (on a scale from 1-to-3), the maximal systolic velocity, and the resistance index ([V.max syst-V min syst]/V max syst), were assessed by using a 13-MHz probe, and the pedal target vessel best suited for surgery was identified. Results of duplex scanning were compared to (1) the results of selective digital subtraction angiography (DSA) and contrast-enhanced magnetic resonance angiography (CE-MRA) studies interpreted by two radiologists, (2) the site of distal anastomosis predicted by a vascular surgeon according to DSA and CE-MRA studies, (3) the definitive site of distal anastomosis, and (4) early postoperative results (patency at three months). RESULTS: Duplex scanning depicted significantly more pedal vascular segments than selective DSA- (P =.004, McNemar test). Agreement in predicting the site of distal anastomosis expressed as kappa value as follows: duplex versus DSA/CE-MRA, kappa 0.71;-DSA/CE-MRA versus definitive anastomosis, kappa 0.67; -and duplex versus definitive anastomosis kappa 0.82. Two patients were excluded from surgery as all three imaging modalities failed to demonstrate a pedal target vessel. Two patients had exploratory dissection of a pedal vessel (according to CE-MRA findings) that turned out to be occluded (as predicted by duplex scanning). In one patient the operation had to be terminated due to lack of autologous bypass material. In 31 patients who underwent pedal artery bypass, the resistance index could not be correlated to the run-off as assessed by intra-operative angiography. CONCLUSIONS: High-frequency duplex focusing on the vacular-morphology is a worthwhile diagnostic tool to evaluate-potential pedal target vessels and extremely helpful when contrast-related methods (selective DSA, CE-MRA) do not sufficiently depict the pedal vasculature.

Pedal artery bypass.

Pedal artery bypass has proven to be a safe, simple and durable procedure. Failure of a pedal artery reconstruction seldom results in an amputation that is more proximal than it would have been without previous attempted bypass. Thus an aggressive strategy in the revascularisation of the forefoot in case if critical ischemia based on tibial occlusive disease is worthwhile.

Emergency pedal artery bypass grafting.

OBJECTIVES: To determine the value of emergency pedal artery bypass. MATERIAL AND METHODS: Data were drawn from a prospective vascular database. Inclusion criteria were: acute onset of critical forefoot ischemia, emergency surgery, no pre-operative angiographic imaging of the pedal vasculature and attempted revascularisation of a pedal vessel. Follow-up was obtained from outpatient records. The grafts were considered patent if a pedal pulse was palpable. RESULTS: Eight out of 208 pedal vascular procedures performed between January 1996 and June 2002 were entered into the study. This cohort consisted of 3 women and 5 men (age 23-85 years, median 71). Operations were performed because of thrombo-embolic occlusion of the tibial vasculature (5 patients), severe tibial embolism following a percutaneous angioplasty of the superficial femoral artery, trash foot following aortic reconstruction and acute occlusion of tibial run-off vessels following a crural reconstruction. Two patients suffered an early graft occlusion, one of them resulting in major amputation. At a median follow up of 17 months (10-52 months) the remaining 6 grafts were patent. CONCLUSIONS: If catheter directed methods (local lysis, aspiration embolectomy) or surgical procedures (embolectomy, tibial bypass) fail to treat critical foot ischemia, pedal probatorial dissection and pedal bypass is worthwhile.

[Clinical usefulness and diagnostic value of percutaneous liver biopsy in patients with chronically elevated liver enzymes of non-viral origin]. / Klinischer Nutzen und diagnostische Bedeutung der Leberbiopsie bei chronisch erhöhten Leberwerten nicht viraler Genese.

BACKGROUND: In the context of increasing non-invasive diagnostic techniques the purpose of the present study was to determine the clinical usefulness and the diagnostic value of percutaneous liver biopsy in patients with chronically elevated liver enzymes of non-viral origin. PATIENTS AND METHODS: 100 patients from the outpatient clinic of the department of gastroenterology and hepatology who had a liver biopsy in the years 1996 to 1998 because of chronically elevated alanine-aminotransferase (ALT) and/or gamma-glutamyltransferase (gamma-GT) levels were included. Exclusion criteria were as follows: chronic hepatitis B or C infection, focal liver disease and clinical signs of hepatic decompensation. Retrospectively gained clinical data were independently evaluated by two experienced hepatologists. Initially, both examiners made a preliminary clinical diagnosis prior to knowing results from liver histology. With the results from liver histology both examiners were asked to make a final diagnosis. For each patient, the preliminary clinical diagnoses of both examiners were then correlated with the corresponding final diagnoses. RESULTS: Liver histology led in 71 % respectively 74 % of the patients to confirmation or specification of the clinical diagnosis. Liver biopsy was particularly helpful in differentiating non-decompensated liver cirrhosis, cryptogenic hepatitis, auto-immune hepatitis and biliary diseases. CONCLUSION: Despite improved non-invasive diagnostic tools including a broad spectrum of serologic tests liver biopsy is often indispensable for differentiating primary liver from biliary diseases and for the early detection of patients with liver cirrhosis.

Pedal artery imaging--a comparison of selective digital subtraction angiography, contrast enhanced magnetic resonance angiography and duplex ultrasound.

OBJECTIVE: to evaluate selective digital subtraction angiography (DSA), contrast-enhanced magnetic resonance angiography (CE-MRA) and duplex ultrasound (duplex) in preoperative pedal artery imaging. MATERIAL AND METHODS: DSA, CE-MRA and duplex were studied prospectively in 37 patients suffering from critical leg ischaemia. Two radiologists independently reviewed both the CE-MRA and DSA images. The pedal vessels were scored on a scale from 0 to III (0=vessel not visualised, I=vessel faintly visualised, II=stenosis >50%, III=vessel without relevant stenosis). Duplex ultrasound was performed by an angiologist blind to both the DSA and MRA findings and the pedal arteries were scored 0-III according to their diameter. Each examiner named the pedal artery best suitable for bypass surgery. Agreement in artery assessment was expressed as kappa values. Patency of the bypass at 30 days was used as validation of the artery's suitability as the run-off vessel. RESULTS: interobserver agreement for DSA (weighted Kappa 0.63, CI 0.53-0.73 and CE-MRA (weighted kappa 0.60, CI 0.5-0.7) was moderate to substantial. CE-MRA depicted significantly more vascular segments than DSA (p congruent with 0.0001).In the prediction of the distal outflow vessel duplex and CE-MRA proved to be superior to DSA. CONCLUSION: because of the moderate inter-observer agreement it may be questionable to regard selective DSA as gold standard imaging procedure in preoperative pedal artery imaging. CE-MRA and duplex are very helpful in assessing the pedal artery morphology and should be used if selective DSA does not sufficiently depict the pedal vasculature.

Pedal artery imaging using DSA, CE-MRA and duplex.

Diabetic macroangiopathy is associated with a typical disease pattern, mostly affecting the tibial but sparing the pedal arteries. Bypass grafts to these patent pedal vessels have evolved into a feasible technique. Restoring a palpable pulse in the ischemic foot they create the prerequisite to heal an ulcer or gangrene. Preoperative evaluation of pedal arteries demands a detailed depiction of the entire pedal vascular system. At present, the main options for preoperative pedal artery imaging are selective DSA contrast enhanced MRA and Duplex ultrasound. The aim of this review article is to give a survey of these three techniques and to determine their potential to depict pedal run off vessels. Selective DSA is still the standard diagnostic tool in preoperative pedal artery imaging. CE MRA offers high contrast related resolution but in-plane resolution is inferior to the concurrent imaging techniques. Duplex is the preferable method to evaluate a pedal artery's diameter and morphology. Both, CE MRA and Duplex are worthwhile additional imaging techniques in case DSA did not sufficiently depict the pedal vasculature.

Expression of the multidrug resistance proteins MRP2 and MRP3 in human hepatocellular carcinoma.

Treatment of hepatocellular carcinoma (HCC) by chemotherapy is often impeded by the intrinsic multidrug resistance (MDR) of this frequent primary cancer of the liver. The MDR phenotype can be caused by ATP-dependent export of chemotherapeutic drugs across the plasma membrane being mediated by transporters of the MDR P-glycoprotein family or of the multidrug resistance protein (MRP) family. To elucidate the role of MRP family members in HCC, we analyzed the expression and subcellular localization of MRP1 (ABCC1), MRP2 (ABCC2) and MRP3 (ABCC3); all 3 isoforms have been shown to confer resistance to chemotherapeutic drugs. Semiquantitative RT-PCR demonstrated that MRP2 and MRP3 mRNA expression in HCC was at least 10-fold higher than MRP1 mRNA expression. MRP2 immunostaining was observed in 87% (33/38) of HCC samples. MRP2 was localized in the plasma membrane in a polarized fashion, either in trabecular structures resembling the canalicular membrane or in the luminal membrane when cells had a pseudoglandular arrangement. MRP3 was detected in all samples examined (9/9) by RT-PCR and by immunofluorescence microscopy. MRP3 was localized to the basolateral membrane of carcinoma cells. Double-label immunofluorescence microscopy with antibodies specific for MRP2 or MRP3 indicated that carcinoma cells expressed both MRP isoforms simultaneously. When MRP1 was detected by immunofluorescence microscopy, it was localized on the intracellular membranes of carcinoma cells. Thus, plasma membrane expression of MRP2 and MRP3, but not of MRP1, can contribute to the MDR phenotype of HCC.

Hepatic failure with neonatal tissue siderosis of hemochromatotic type in an infant presenting with meconium ileus. Case report and differential diagnosis of the perinatal iron storage disorders.

We report on a female preterm infant with hepatic failure and neonatal tissue siderosis of hemochromatotic type diagnosed by using both histochemistry and atomic absorption spectroscopy. The infant presented with meconium ileus, signs of rapidly progressive hepatic failure, and hyperferritinemia (7132 ng/ml). Despite surgery and intensive care the infant died 32 days after birth. Postmortem examination showed a wrinkled liver with extensive collapse of the hepatic architecture and regenerating nodules as well as hepatic and extrahepatic iron accumulation of hemochromatotic type, sparing the reticuloendothelial system. Atomic absorption spectroscopy confirmed an increase in the iron content of various organs: liver, heart, pancreas, oral salivary gland, kidney, and adrenal gland. The increase in the iron content of various organs was determined by comparing the analysis of the propositus with those of 5 gestationally age-related preterm infants who had died in the intensive care unit: 2 died of meconium aspiration syndrome, the other 3 of hyaline membrane disease, bronchopulmonary dysplasia, and immaturity, respectively. We also compared the analysis of 15 fetuses having a a condition predisposing to iron accumulation (trisomy 21, trisomy 18, cytomegalovirus, amnion infection syndrome, Rhesus- and ABO-incompatibility, congenital hemolysis, anti-phospholipid syndrome, congenital heart disease). Delta F508, the most frequent mutation seen in cystic fibrosis patients, was excluded by gene sequencing. Different noxae causing iron accumulation in the neonatal period have led to the statement that neonatal hemochromatosis may collect different etiologies, such as metabolic disorders, infections, chromosomal aberrations, and immunological disorders. In this study, we report the singular evidence of neonatal iron accumulation of hemochromatotic type in an infant presenting with meconium ileus and propose a classification of the neonatal disorders associated with iron accumulation.

Loss of CD95 expression is linked to most but not all p53 mutants in European hepatocellular carcinoma.

Experimental data have shown p53-dependent CD95 induction to be associated with increased levels of apoptosis after cytostatic treatment in hepatoma cells. A study of Japanese hepatocellular carcinoma (HCC) has reported an inverse correlation between CD95 and p53 expression. To examine the interaction of p53 and CD95 in tumors we investigated which alterations in p53 can be linked to loss of CD95 expression in European HCC. In 39 tumors we analyzed CD95 by immunohistochemistry and assessed the correlation between the findings of the p53 status as determined by immunohistochemistry and single-strand conformation polymorphism with polymerase chain reaction sequencing. In 10 of 14 tumors with evidence of p53 aberration there was also loss of CD95 expression, compared to 6 of 25 samples with apparent wild-type p53 (P<0.01). Three tumors with p53 mutations but sustained CD95 expression showed single base substitutions mapping to a narrow region of 20 codons in p53. A significant correlation with differentiation status of the tumor was found for the p53 aberration but not for CD95 expression. This is the first study to link loss of CD95 expression to specific p53 alterations in HCC. Functional p53 appears to be a major factor for CD95 expression in hepatocytes, the loss of which could contribute to chemoresistance and possibly immune evasion in hepatocellular carcinoma. Sustained CD95 expression in tumors with certain p53 aberrations may indicate functional heterogeneity of p53 mutants.

[Pathohistological findings in liver metastases]. / Pathohistologische Befunde bei Lebermetastasen.

Metastatic tumors are the most common malignancies of the liver. The frequency distribution of the primary tumor location site closely resembles the frequency distribution of primary cancers in general. Yet, due to the liver's filter function of the portal blood-stream, metastatic tumors of the gastrointestinal tract are overrepresented. Most metastatic tumors show a nodular growth pattern with a demarcation of the tumor by inflammatory or fibrous reactive tissue; a diffuse metastatic tumor spread within the sinusoids is uncommon. Metastatic liver tumors may be the first clinically detectable manifestation of an unknown primary tumor. In these cases, the histological and immunohistochemical pattern of the metastatic tumor cells may give a clue of the location of the corresponding primary tumor.

Extrapulmonary sarcoidosis primarily diagnosed in the liver.

Sarcoidosis is a relatively common, chronic, multisystem disease of unknown origin characterized by the presence of noncaseating epithelioid granulomas. Although an array of organs may be affected by the disease, the commonest site of affection is the lung. We describe a 73-year-old patient admitted to our hospital because of fatigue, weight loss, and an increased alkaline phosphatase level. In conjunction with clinical presentation, laboratory variables, and imaging analysis, a liver biopsy finally confirmed the diagnosis of a systemic sarcoidosis without affection of the lung or mediastinal lymph nodes. Treatment with ursodeoxycholic acid before diagnosis did not improve clinical symptoms and cholestasis indicators. After prednisone treatment, liver enzyme values normalized and remained normal during follow-up for 2 years after diagnosis. The literature on hepatic manifestation of sarcoidosis, its diagnosis, treatment, and prognosis is reviewed. This single case of sarcoidosis presented to the clinician almost exclusively with liver enzyme abnormalities. The consideration of sarcoidosis in such cases is of utmost importance, since the differential diagnosis of hepatic granulomas includes infectious diseases in which treatment with corticosteroids could be fatal.

[Ulcers of the colon in association with nonsteroidal anti-inflammatory drugs (NSAID)--a rare cause of gastrointestinal bleeding? Report of 3 cases]. / Kolonulzera nach der Einnahme nichtsteroidaler Antiphlogistika--eine seltene Ursache gastrointestinaler Blutungen? Bericht von 3 Fällen.

Although adverse side effects of nonsteroidal anti-inflammatory drugs (NSAID) can affect the whole gastrointestinal tract, most reports refer to upper gastrointestinal tract complications. We report on 3 patients with lower gastrointestinal bleeding (patient 1 and 2) respectively detectable fecal blood loss (patient 3) after the use of NSAID. Patient 1 and 3 were taking NSAID over at least 6 months for the treatment of rheumatic diseases while patient 2 reported a single use of 2 g acetylsalicylic acid. Colonoscopy showed a single ulcer of the colon in patients 1 and 2. Due to acute bleeding patient 1 required interventional endoscopic treatment. Colonoscopy of patient 3 revealed multiple colonic ulcerations. Gastroduodenoscopy also detected adverse NSAID-effects on the upper gastrointestinal tract in patient 1 and 3 (ulcers of the stomach, erosive duodenitis). NSAID-medication was discontinued in all patients and, additionally, mesalazine was administered to patient 3. Consecutively, symptoms and lesions disappeared. Our cases stress the clinical importance of NSAID-toxicity distal to the small intestine which may exist concomitantly to lesions of the upper gastrointestinal tract and is not obligatory dose-dependent.

Localization of the Wilson's disease protein in human liver.

BACKGROUND & AIMS: Wilson's disease is an autosomal-recessive disorder of copper metabolism that results from the absence or dysfunction of a copper-transporting P-type adenosine triphosphatase that leads to impaired biliary copper excretion and disturbed holoceruloplasmin synthesis. To gain further insight into the role of the Wilson's disease protein in hepatic copper handling, its localization in human liver was investigated. METHODS: By use of a specific antibody, localization of the Wilson's disease protein was studied in liver membrane fractions and liver sections by immunoblotting, immunohistochemistry, and double-label confocal scanning laser microscopy. RESULTS: The 165-kilodalton protein, found by immunoblotting, was most abundant mainly in isolated plasma membrane fractions enriched in canalicular domains. Immunohistochemistry revealed intracellular punctuate staining of hepatocytes in certain regions of the liver, whereas a canalicular membrane staining pattern was observed in other regions. Double-labeling studies showed that in the latter regions the transporter is present mainly in vesicular structures just underneath the canalicular membrane that are positive for markers of the trans-Golgi network. A weak staining of the canalicular membrane, identified by staining for P-glycoprotein, was observed. CONCLUSIONS: These results show that in human liver the Wilson's disease protein is predominantly present in trans-Golgi vesicles in the pericanalicular area, whereas relatively small amounts of the protein appear to localize to the canalicular membrane, consistent with a dual function of the protein in holoceruloplasmin synthesis and biliary copper excretion.

Immunocytochemical investigation of catalase and peroxisomal lipid beta-oxidation enzymes in human hepatocellular tumors and liver cirrhosis.

A significant reduction of catalase activity, a peroxisomal marker enzyme, occurs in human hepatic neoplasias, but no information is available on other peroxisomal proteins. We have studied by means of immunohistochemistry four specific proteins of peroxisomes (catalase and three enzymes of lipid beta-oxidation) in human hepatocellular tumors of various differentiation grades from adenoma to anaplastic carcinoma. In all tumors, except the adenomas, the tumor cells contained fewer peroxisomes than extrafocal hepatocytes and the reduction of antigenic sites in the tumor types generally correlated with the degree of tumor dedifferentiation as assessed by classical histopathological criteria. Two poorly differentiated tumors had no detectable peroxisomes at all. There were no major differences in the intensities of the immunocytochemical staining for all four studied peroxisomal antigens in different tumors, suggesting that the neoplastic transformation affects the biogenesis of the entire organelle and not merely the individual peroxisomal enzyme proteins. Some tumors exhibited a distinct peripheral distribution of peroxisomes. In cases with associated liver cirrhosis, the hepatocytes in the adjacent liver showed marked peroxisome proliferation, forming large perinuclear aggregates, occupying occasionally the entire cytoplasm. Taken together, our observations indicate that peroxisomes are significantly altered in both hepatocellular tumors and liver cirrhosis and, thus, could be responsible for some of the metabolic derangements observed in those disease processes.

CDKN2 mutation is infrequent in german hepatocellular carcinoma.

For hepatocellular carcinoma, only scarce and controversial data on CDKN2 alterations are available. A high rate of mutations in a Chinese study contrasts with a low rate found in Japanese tumors and a CDKN2 germline mutation in 4/26 Swiss tumors examined. We analyzed 23 hepatocellular carcinomas from German patients for homozygous deletions of CDKN2 by coamplification with the human tyrosine hydroxylase (TH) gene and for CDKN2 mutations by PCR-single strand conformation polymorphism analysis and direct DNA sequencing. Our results indicate the lack of homozygous deletions. In one tumor, DNA sequencing showed a GCG-ACG (alanine-threonine) substitution at codon 148, a polymorphism in exon 2 of CDKN2. We conclude that the alteration of CDKN2 by deletion or mutation appears not to be a frequent event in hepatocarcinogenesis in German patients.

Thermodiffusion for continuous quantification of hepatic microcirculation--validation and potential in liver transplantation.

Hepatic microcirculation is a main determinant of reperfusion injury and graft quality in liver transplantation. Methods available for the quantification of hepatic microcirculation are indirect, are invasive, or preclude postoperative application. The aim of this study was the validation of thermodiffusion in a new modification allowing long-term use in the clinical setting. In six pigs Doppler flowmeters were positioned around the hepatic artery and portal vein for the measurement of total liver blood flow. Liver perfusion was quantified by thermodiffusion and compared to H(2) clearance as an established technique under baseline conditions, during different degrees of portal venous obstruction and during occlusion of the hepatic artery. Thermodiffusion measurements were recorded for five days postoperatively followed by histological evaluation of the hepatic puncture site. Perfusion data obtained by thermodiffusion were significantly correlated to H(2) clearance (r = 0.94, P < 0. 001) and to liver blood flow (r = 0.9, P < 0.05). The agreement between thermodiffusion and H(2) clearance was excellent (mean difference -2.1 ml/100 g/min; limits of agreement -12.5 and 8.3 ml/100 g/min). Occlusion of the portal vein or hepatic artery was immediately detected by thermodiffusion, indicating a decrease of perfusion by 64 +/- 7% or 27 +/- 5% of baseline, respectively. Perfusion values at baseline and during vascular occlusion were reproducible during the entire observation period. Histological changes of the liver tissue adjacent to the thermodiffusion probes were minute and did not influence long-term measurements. In vivo validation proved that enhanced thermodiffusion is a minimally invasive technique for the continuous, real-time quantification of hepatic microcirculation. Changes in liver perfusion can be safely detected over several days postoperatively. The implication for liver transplantation has led to the clinical application of thermodiffusion.

Beta-catenin accumulation and mutation of the CTNNB1 gene in hepatoblastoma.

Hepatoblastoma is a rare malignant tumor of the liver that occurs in children at an average age of 2 to 3 years. Epidemiologic studies have shown an increased frequency of this tumor type in families affected by adenomatous polyposis coli. In addition to the epidemiologic data, molecular genetic studies suggest that inactivation of the APC tumor suppressor may be involved in hepatoblastoma tumorigenesis. A major function of APC is the downregulation of beta-catenin, a transcription-activating protein with oncogenic potential. In an ongoing immunohistochemical study of beta-catenin expression in sporadic cases of tumor types that are associated with adenomatous polyposis coli, we observed increased beta-catenin levels in the cytoplasm and in the nuclei of three investigated hepatoblastomas. Sequencing of exon 3 of the beta-catenin gene (CTNNB1) revealed an activating mutation in one of the tumor samples. Our data indicate for the first time that beta-catenin accumulation may play a role in the development of hepatoblastoma and that activating mutations of the beta-catenin gene may substitute biallelic APC inactivation in this tumor type. Genes Chromosomes Cancer 25:399-402, 1999.