Diagnostic Pitfall of Gastric Signet-Ring Cells: How to Diagnose a Benign Signet-Ring Cell From a Malignant One

Sometimes non-neoplastic changes of the gastric mucosa mimic diffuse-type gastric carcinoma, specifically signet-ring cell adenocarcinoma. In fact, gastric epithelial cells undergoing signet-ring cell change have a cellular morphology that is almost identical to signet-ring cell adenocarcinoma, often leading to misdiagnosis. Accurate recognition of signet-ring cell change is essential to avoid overdiagnosis and overtreatment of signet-ring cell adenocarcinoma. Research on this topic is limited and clinicians lack formal diagnostic tools when signet-ring cells are detected in biopsy specimens. The aims of this study are 3-fold. Firstly, to increase the awareness of both clinicians and pathologists of this rare but highly significant entity. Secondly, to report 4 additional examples of signet-ring cell change and analyze them alongside signet-ring cell adenocarcinoma to compare their morphological and phenotypic features and their evolution over time. Finally, to highlight the potential utility of endoscopic resection to confirm the diagnosis. Cells in signet-ring cell change strongly express E-cadherin, show a wild-type p53 expression, and have a low Ki67 index. In contrast, cells in signet-ring cell adenocarcinoma strongly express p53, have high proliferation rates, and show either no or weak E-cadherin staining. Genetic analysis may be useful in identifying patients at risk of hereditary early diffuse gastric adenocarcinoma, which can mimic signet-ring cell change.

Auto-immune gastritis induced by pembrolizumab, an anti-PD-1, in a melanoma patient

We report a case of a 67-years-old woman presenting a severe acute lymphocytic gastritis induced by pembrolizumab, an immune check point inhibitor (ICI). This gastritis was her third auto-immune adverse event after 5 years of treatment with pembrolizumab, it was metabolically active at the PET Scan and confirmed by analysis of the gastric biopsies. Pembrolizumab treatment cessation and high doses of corticosteroids completely normalized the stomach clinically, endoscopically and histologically. This patient was in complete remission of her metastatic melanoma. Therefore, pembrolizumab therapy was not restarted and the patient is still in remission 6 months later. This strategy is supported by recent publications describing a relapse rate inferior to 10% in patients in complete remission after 2 years of immunotherapy. Particularities of this case are: rareness of this adverse event, late onset after introduction of pembrolizumab, evocative PET scan image, specific endoscopic aspect and histology. In addition, the favorable oncologic evolution of the patient after treatment cessation confirms the prolonged remission after immunotherapy.

Endoscopic features, pathological correlates and possible origin of foveolar gastric metaplasia presenting as a duodenal polyp

It has recently been shown that duodenal foveolar gastric metaplasia (FGM) sometimes presents as a polyp. The mechanism by which FGM develops into a polypoid lesion is unknown and it is unclear whether this form of FGM is indistinguishable from other polypoid lesions or whether endoscopists do not recognize it because they are unfamiliar with it. We identified and retrieved archival cases of FGM endoscopically suspicious for adenomatous polyp and examined their pathological, clinical and endoscopic features. Endoscopic features of the 13 identified FGMs presenting as polyps were heterogeneous and overlapping with those of adenomatous polyps. FGM was frequently associated with mucosal and submucosal Brunner's glands, but defining and recognizing hyperplasia of these glands remains difficult. Other pathological features could not explain the development of a polypoid lesion. The endoscopic features of FGM polyps are non-specific, overlapping with those of adenomatous polyps. FGM polyps probably acquire their polypoid aspect due to association with Brunner's gland hyperplasia (BGH), which also arises due to chronic inflammation and damage. Because BGH is ill-defined and difficult to recognize, while FGM is diagnosed easily, this type of polypoid lesions has until now only been recognized based on the presence of FGM, although FGM is most likely a secondary phenomenon and not the primary cause of the polyp.

Abstract P1-03-14: Assessment of stromal characteristics in ductal carcinoma in situ of the breast: An inter-observer variability study

Aim. Ductal carcinoma in situ (DCIS) is considered to be a non-obligate pre-invasive precursor of invasive ductal carcinoma. We previously showed that DCIS with a predominantly myxoid periductal stromal architecture is associated with an increased risk of both overall and invasive recurrence. The aim of this study is to determine a cut-off for the assessment of myxoid stroma and stromal inflammation in DCIS, based on inter-observer variability. Here, preliminary results of the histopathological analysis of 285 DCIS patients are presented, in which the consistency of assessment of stromal features is compared to the reproducibility of other morphological characteristics.

Methods. Hematoxylin/eosin stained tissue sections of 285 DCIS lesions were retrieved from the archives of the Department of Pathology of Leuven University Hospitals, Leuven, Belgium. The following characteristics were independently scored by two pathologists: nuclear grade, intraductal calcifications, extensive comedonecrosis, DCIS architecture, stromal architecture and stromal inflammation. Nuclear grade was scored as low, intermediate or high grade. Intraductal calcifications were scored as absent or present. Extensive comedonecrosis was defined as eosinophilic necrotic debris in >50% of ductal lumina. DCIS architecture was categorized as non-solid or solid, with a cut-off at 50% of ducts presenting with solid growth. Myxoid stroma was defined as loosely arranged collagen fibers interspersed with an amorphous, slightly basophilic substance. Stromal architecture was classified into 4 categories (0%, 1-33%, 33-66% or >66% myxoid stroma). By applying identical cut-offs, stromal inflammation was subdivided into absent, mild, moderate or extensive periductal inflammation. All features were dichotomized, using different cut-offs. Kappa values were determined to assess inter-observer variability.

Results. Nuclear grade was dichotomized as low grade versus intermediate/high grade (κ 0,500), and as grade low/intermediate versus high grade (κ 0,507). The kappa value for scoring myxoid stromal architecture was highest by dichotomization with a cut-off at 33% (κ 0,566), compared to κ 0,454 and κ 0,501 when using 1% and 66% as a cut-off, respectively. A similar analysis for stromal inflammation revealed that the highest kappa value was obtained by dichotomization as 'absent to mild' versus 'moderate to extensive' inflammation (κ 0,724). Dichotomization with cut-offs of 1% and 66% resulted in lower kappa values of κ 0,564 and κ 0,670, respectively. Scores for extensive comedonecrosis showed substantial agreement (κ 0,604). Scores for solid versus non-solid DCIS architecture (κ 0,507), and presence or absence of calcifications (κ 0,664) showed moderate and substantial agreement, respectively.

Conclusions. Adequate prognostic markers require robustness of assessment, i.e. low inter-observer variability and thus high reproducibility. The dichotomous assessment of stromal features in DCIS resulted in similar or even higher kappa values compared to the dichotomous scoring of other histopathological characteristics. This study demonstrates the robustness of dichotomous assessment of both stromal architecture and stromal inflammation.

Citation Format: Van Bockstal M, Lambein K, Smeets A, Nevelsteen I, Neven P, Christiaens M-R, Libbrecht L, Floris G. Assessment of stromal characteristics in ductal carcinoma in situ of the breast: An inter-observer variability study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-14.

IgG4-related cholangitis: Case report and literature review

CASE PRESENTATION

We describe a case of a patient who presents with jaundice, elevated cholestatic liver enzymes, an extreme weight loss and a midcholedochal stricture very suspect for a cholangiocarcinoma. In the conviction of malignancy, although the absence of anatomopathological prove, the patient underwent a choledochal resection. The anatomopathological specimen revealed no malignancy. In the year following resection, the patient keeps presenting with bile duct strictures and further weight loss. Ultimately the diagnosis of Ig G4-related cholangitis is withheld. Therapy with corticosteroids is initiated with a spectacular clinical, biochemical and radiographical result.

DISCUSSION

IgG4-related cholangitis is the biliary presentation of IgG4-related disease, a recently discovered entity of fibroinflammatory masses which can affect virtually every organ in the body. It is characterized by a dense lymphoplasmacytic infiltrate, storiform fibrosis, obliterative phlebitis and a presence of > 30 IgG4-positive plasma cells per high power field. Main differential diagnosis contains cholangiocarcinoma and primary sclerosing cholangitis. Corticoids are cornerstone of therapy, with azathioprine frequently used as a maintenance in case of relapse.

CONCLUSIONS

With this case we want to draw the attention to a rather uncommon cause of biliary obstruction, easily mistaken for a cholangiocarcinoma.

Calciphylaxis: a rare complication in alcoholic liver disease

Calciphylaxis, or calcific uremic arteriolopathy (CUA) is a rare but well described entity in patients with endstage renal disease (ESRD) and/or hyperparathyroidism. CUA is characterized by systemic acute calcification of the small and intermediate dermal vasculature that can lead to epidermal ischemia, ulceration, and necrosis. Cutaneous lesions of calciphylaxis characteristically begin as tender, violaceous, livedoid discolorations. The mechanisms of disease remain poorly understood although abnormal bone and mineral metabolism and hyperparathyroidism can contribute to CUA. Therapeutic strategies are of unproven benefit and mortality remains high. Calciphylaxis has also been extremely rarely reported in patients without ESRD and/or hyperparathyroidism. We report an unusual case of calciphylaxis in a patient with alcoholic liver cirrhosis and normal renal function, without any alteration in the phosphocalcic and parathyroid hormone (PTH) metabolisms.

Value of DCE-MRI and FDG-PET/CT in the prediction of response to preoperative chemotherapy with bevacizumab for colorectal liver metastases

Background:

The purpose of this study was to assess the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and ¹⁸F-fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) for evaluation of response to chemotherapy and bevacizumab and for prediction of progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC) with potentially resectable liver lesions.

Methods:

A total of 19 mCRC patients were treated with FOLFOX/FOLFIRI and bevacizumab followed by surgery. Dynamic contrast-enhanced magnetic resonance imaging and FDG-PET/CT were performed before treatment and after cycle 5. PET results were quantified by calculating maximum standardised uptake value (SUV_max) whereas area under the enhancement curve (AUC), initial AUC (iAUC) and the endothelial transfer constant (K^trans) were used to quantify DCE-MRI. Pathological analysis of the resection specimen was performed, including measurement of microvessel density (MVD) and proliferation index.

Results:

Both AUC and iAUC were significantly decreased following bevacizumab therapy (median change of 22% (P=0.002) and 40% (P=0.001) for AUC and iAUC, respectively). Progression-free survival benefit was shown for patients with >40% reduction in K^trans (P=0.019). In the group of radiological responders, the median baseline SUV_max was 3.77 (IQR: 2.88–5.60) compared with 7.20 (IQR: 4.67–8.73) in nonresponders (P=0.021). A higher follow-up SUV_max was correlated with worse PFS (P=0.012). Median MVD was 10.9. Progression-free survival was significantly shorter in patients with an MVD greater than 10, compared with patients with lower MVD (10 months compared with 16 months, P=0.016).

Conclusion:

High relative decrease in K^trans, low follow-up SUV_max and low MVD are favourable prognostic factors for mCRC patients treated with bevacizumab before surgery.

Symptomatic bilateral choroidal metastasis from breast cancer as first clinical sign of advanced metastatic tumor disease 31 years after diagnosis

We report a 62-year-old caucasian woman with bilateral choroidal metastases as only clinical presenting sign of advanced metastatic tumour disease. She presented with decreased vision in the left eye since 5 days. She was treated for breast cancer 31 years before. Fundoscopy and ultrasound analysis showed a large choroidal metastasis in the left eye and one asymptomatic lesion in the right eye. Systemic screening revealed multiple lung and bone metastases. Health practitioners should be aware that choroidal metastasis from breast carcinoma can present throughout life. Small asymptomatic lesions may be detected that still can be treated effectively.

P4-18-06: Relationship between Pathological Features, Her2 Protein Expression, and HER2 and CEP17 Copy Numbers in DCIS

Background Previous studies in which HER2 status in ductal carcinoma in situ (DCIS) was evaluated yielded conflicting results. The reported prevalences of HER2 overexpression and amplification vary remarkably. These discrepancies might partly be due to differences in assessment methods, i.e. FISH or immunohistochemistry (IHC) and usage of tissue microarray or whole mount slides. To further investigate this issue, we performed both FISH and IHC for HER2, evaluated HER2 and CEP17 copy numbers and correlated these data with histopathological findings.

Methods 61 DCIS cases were studied, of which 55 pure DCIS and 6 DCIS with micro-invasion. Pathological features were evaluated and included: architecture, nuclear atypia, necrosis, calcifications, stromal inflammation, stromal morphology, extent of lesion, margin width, Van Nuys Prognostic Index and Pinder classification. Her2 IHC and HER2 dual probe FISH analysis were performed and scored according to ASCO/CAP guidelines. HER2/CEP17 ratio and HER2 and CEP17 copy numbers were separately analysed. IHC for estrogen and progesterone receptor (ER and PR) was also performed. Whole mount slides were used for all analyses.

Results 15 cases (25%) were scored negative (1+), 10 cases (16%) equivocal (2+) and 36 cases (59%) positive (3+) using Her2 IHC. According to FISH analysis, 34 of 60 cases (57%) showed HER2 amplification; there was insufficient tissue for FISH analysis in one case.

The amplification status of the DCIS lesions correlated with the IHC score (p<0,001). 30 of all 34 amplified cases were assigned a 3+ IHC score, and remarkably, all these cases showed HER2 clusters on FISH analysis (88%).

Amplified lesions showed more frequently nuclear atypia grade 3 (p=0.0335), extensive comedonecrosis (p=0.002) and stromal inflammation (p=0.003). HER2 amplification correlated with the presence of micro-invasion (p=0.0218)%. There was no correlation with hormone receptor status or other pathological variables.

In the amplified group, high-grade nuclear atypia was associated with a higher mean HER2 copy number (p=0.0026) and HER2/CEP17 ratio (p=0.0356), while this was not the case in the non-amplified group. CEP17 copy numbers did not correlate with nuclear atypia. Conclusions

The correlation between HER2 amplification and adverse pathological features, including micro-invasion and the association in amplified DCIS between HER2 copy number and high-grade nuclear atypia, underscore that HER2 is a driver of DCIS aggressiveness and possibly of recurrence in the form of non-invasive cancer. However, the prevalence of HER2 overexpression, amplification and cluster formation was much higher than in invasive carcinoma, suggesting that HER2 might play a less important role in transition from DCIS to frankly invasive cancer. Further studies should evaluate non-invasive and invasive recurrence of resected DCIS separately.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-18-06.

The multicenter Belgian survey on liver transplantation for hepatocellular failure after bariatric surgery

The prevalence of obesity has grown dramatically over the last decades, with nonalcoholic steatohepatitis increasingly observed. Therapeutic options for morbid obesity include bariatric surgery. Fatal liver failure (LF) has been recorded after jejunoileal bypass (JIB) but is controversial after biliopancreatic diversion (BPD, Scopinaro operation). We performed a survey on the frequency of liver transplantation (LT) after bariatric surgery in Belgium. An enquiry was sent to all Belgian liver transplant centers to investigate the occurrence of subacute and chronic LF after bariatric surgery. After weight-reduction surgery, 10 patients in 3 Belgian transplant centers were listed for LT due to severe hepatocellular failure. Nine of them had undergone a Scopinaro operation and 1 a jejunoileal bypass. The median time to develop LF was 5 years. The patient with JIB developed chronic LF after 25 years. Seven patients were transplanted; two died awaiting a graft and one is still on the waiting list. After LT, 1 patient developed rapid reappearance of LF at 10 months, requiring retransplantation. Two recipients died after LT because of multiorgan failure shortly after transplantation. In another case, a de novo cancer was fatal at 6 years' follow-up. The remaining recipients were doing well. According to this survey, the BPD operation carries a potential risk of LF. However, because there were only 10 cases, we remain unaware of the actual incidence of Scopinaro operation-induced LF. We advise strict follow-up of liver function and timely dismantling of BPD.

A unique combination of celiac disease, mesenteric lymph node cavitation, splenic atrophy and necrotizing hepatitis

We report on a patient who was diagnosed six years before with celiac disease, with a current combined problem of asplenism, mesenteric cysts and elevated liver function tests. The implications of splenic atrophy mimic those of post-splenectomy patients. Mesenteric lymph node cavitation is a rare complication of celiac disease that is most often associated with splenic atrophy. The pathogenesis is unknown. The clinical implications of the cavitated mesenteric lymph nodes are unclear. The association of celiac disease with liver disease was reported many years ago, but only recently these associations have been more clearly defined. Liver involvement shows a clinical spectrum varying from nonspecific reactive hepatitis, chronic active hepatitis, steatohepatitis to frank cirrhosis. Associations with autoimmune hepatitis, autoimmune cholangitis, primary biliary cirrhosis and primary sclerosing cholangitis have been described. In our patient, we found no obvious cause for the necrotizing hepatitis and the negative auto-antibodies made it impossible to firmly establish the diagnosis of autoimmune hepatitis. The causal relationship with celiac disease, if any, remains unproven.

The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin

AIMS

Cytokeratin (CK) 7 and CK19 expression, present in hepatic progenitor cells (HPCs) and in cholangiocytes but not in normal hepatocytes, has been reported in some hepatocellular carcinomas (HCCs); however, the incidence and relevance of this expression in HCC in Caucasians is not known. Therefore, our aim was to study the occurrence and clinicopathological characteristics of HCC expressing CK7 and/or CK19 in 109 Caucasian patients.

METHODS AND RESULTS

The expression of hepatocellular differentiation markers (Hepar, canalicular polyclonal carcinoembryonic antigen), biliary/progenitor cell markers (CK7, CK19), alpha-fetoprotein (AFP), p53 and beta-catenin in HCC was semiquantitatively assessed by immunohistochemistry. Of 109 HCCs, 78 were CK7-/CK19- (72%), 13 CK7+/CK19- (12%), seven CK7-/CK19+ (6%), 11 CK7+/CK19+ (10%). CK19 expression was significantly associated with elevated serum AFP (400 ng/ml) (P = 0.023), tumour AFP expression (P < 0.0001), presence in serum of anti-hepatitis B core (P = 0.016), less fibrosis in non-neoplastic parenchyma (P = 0.009) and less nuclear beta-catenin expression (P = 0.021). CK7 expression was significantly associated with elevated serum bilirubin (> 2 mg/dl) (P = 0.0005) and less nuclear beta-catenin expression (P = 0.003). HCC expressing CK19 had a higher rate of recurrence (P = 0.009, hazard ratio 12.5, n = 31) after liver transplantation compared with CK19- tumours.

CONCLUSIONS

In our series, 28% of HCCs contained cells expressing CK7 and/or CK19. They potentially derive from HPCs. The higher recurrence rate of CK19+ HCC after transplantation suggests a worse prognosis for these HCCs compared with CK19- HCC.

A stable model of cirrhotic portal hypertension in the rat: thioacetamide revisited

BACKGROUND

Cirrhotic animal models are vital to investigate complications of chronic liver disease. We chronologically characterized the effect of thioacetamide, administrated orally and adapted weekly to weight changes, focusing on the optimal moment to obtain all typical features of portal hypertension and cirrhosis.

MATERIALS AND METHODS

Male Wistar rats, 200-250 g, were intoxicated for 6, 12 or 18 weeks (n = 8 per group), respectively, and compared with age-matched controls (n = 4 per group). An in-situ perfusion model was used to evaluate intrahepatic resistance and endothelial function. Splanchnic blood flow and portosystemic shunting were assessed by a perivascular flow probe.

RESULTS

Rats intoxicated for 6 or 12 weeks had no mortality and histologically showed hepatitis and advanced fibrosis, respectively. At 18 weeks, mortality was 16% (on a total of 56 animals) and only at that moment all animals showed homogenous macronodular cirrhosis with signs of high-grade hepatocellular dysplasia. Portal hypertension was present at 12 weeks (11 +/- 0.4 vs. 5.9 +/- 0.4 mmHg, P < 0.001), but was not associated with the hyperdynamic state until 18 weeks (12.1 +/- 0.8 vs. 5.6 +/- 0.5 mmHg, P < 0.001). At this latter time-point, we also observed increased intrahepatic resistance associated with endothelial dysfunction, hyperresponsiveness to vasoconstrictors, splanchnic hyperaemia and portosystemic shunting. These alterations were associated with increased systemic levels of nitrate/nitrite and thromboxane A(2).

CONCLUSION

Thioacetamide, adapted to weekly weight changes, leads to a homogenous, reproducible model of cirrhosis in the rat in 18 weeks, which is associated with all the typical characteristics of portal hypertension, including endothelial dysfunction.

Microscopic colitis with giant cells

AIMS

Collagenous colitis and lymphocytic colitis are the two types of microscopic colitis with specific morphological features. In this report we describe a new histopathological subtype of microscopic colitis.

METHODS AND RESULTS

Colonoscopy in four patients with chronic watery diarrhoea showed no macroscopic abnormalities. The random biopsies from the colon showed subepithelial multinucleated giant cells in combination with the features of collagenous colitis in three patients and lymphocytic colitis in one patient. These multinucleated giant cells were positive for CD68. The density of macrophages was highest in the most superficial part of the lamina propria. In one patient, a previous biopsy showed features consistent with collagenous colitis without multinucleated giant cells. Treatment with budesonide led to the disappearance of diarrhoea in all four patients.

CONCLUSIONS

The clinical and histopathological features of the four presented patients indicate that there exists a histopathological subtype of microscopic colitis characterized by the presence of subepithelial multinucleated giant cells, which probably arise from fusion of subepithelial macrophages. Analysis of more patients with this histopathological subtype of microscopic colitis is necessary to determine whether they also form a clinically distinct group.

Hepatic progenitor cells in hepatocellular adenomas

Hepatocellular adenoma is a benign tumor of the liver that has a small but not negligible risk of malignant transformation into hepatocellular carcinoma. In analogy with the established role of oval cells in hepatocarcinogenesis in rodent models, human hepatic progenitor cells may have a function in the development of liver tumors. To investigate this issue, we performed immunohistochemistry on biopsies of 10 consecutively resected hepatocellular adenomas using markers for hepatic progenitor cells. Sections of paraffin-embedded and frozen biopsies were stained using antibodies against cytokeratins 7, 8, 18, and 19, chromogranin-A, OV-6, and neural cell adhesion molecule. Hepatic progenitor cells were observed in five of 10 hepatocellular adenomas. These five tumors also contained cells with an immunohistochemical phenotype intermediate between hepatic progenitor cells and hepatocytes. Hepatic progenitor cells and intermediate hepatocyte-like cells were scattered throughout the tumors with a density that varied from area to area. Ultrastructural examination confirmed the presence of hepatic progenitor cells. Our study shows that hepatic progenitor cells are present in a considerable proportion of hepatocellular adenomas, supporting the hypothesis that human hepatic progenitor cells can play a role in the development of hepatocellular tumors.

Expression of neural cell adhesion molecule in human liver development and in congenital and acquired liver diseases

In the liver, neural cell adhesion molecule (NCAM) is a marker of immature cells committed to the biliary lineage and is expressed by reactive bile ductules in human liver diseases. We investigated the possible role of NCAM in the development of intrahepatic bile ducts and aimed at determining whether immature biliary cells can contribute to the repair of damaged bile ducts in chronic liver diseases. Therefore, we performed immunohistochemistry for NCAM and bile duct cell markers cytokeratin 7 and cytokeratin 19 on frozen sections of 85 liver specimens taken from 14 fetuses, 10 donor livers, 18 patients with congenital liver diseases characterized by ductal plate malformations (DPMs), and 43 cirrhotic explant livers. Duplicated ductal plates and incorporating bile ducts during development showed a patchy immunoreactivity for NCAM, while DPMs were continuously positive for NCAM. Bile ducts showing complete or patchy immunoreactivity for NCAM were found in cirrhotic livers, with higher frequency in biliary than in posthepatitic cirrhosis. Our results suggest that NCAM may have a function in the development of the intrahepatic bile ducts and that NCAM-positive immature biliary cells can contribute to the repair of damaged bile ducts in chronic liver diseases.

Alpha B-crystallin expression in human and rat hepatic stellate cells

BACKGROUND/AIMS

We searched for factors implicated in early hepatic stellate cell (HSC) activation in diseased liver, by means of suppression subtractive hybridization (SSH).

METHODS

SSH was performed between messenger RNA (mRNA) from normal rat HSC and mRNA from HSC, isolated from rats with acute D-galactosamine (Gal)-induced hepatitis.

RESULTS

One of the potentially upregulated factors which we found was alpha B-crystallin (ABCRYS), a small heat-shock protein and a chaperone known to protect the cell against protein degradation in conditions of cellular stress and known to associate with various types of intermediate filaments. Upregulation of ABCRYS mRNA in HSC, following Gal-intoxication (3.5-fold) as well as by culturing the HSC on plastic (20-30-fold), was confirmed by quantitative real-time reverse transcription polymerase chain reaction. The expression of ABCRYS protein in human and rat HSC was demonstrated by immunohistochemistry, in vitro and in vivo, in normal and diseased liver. Double-staining co-localized ABCRYS immunoreactivity with alpha-smooth muscle actin immunoreactivity in human liver and with desmin immunoreactivity in rat liver. In vivo upregulation of ABCRYS protein following Gal-intoxication was also shown, by comparison with desmin expression.

CONCLUSIONS

Human and rat HSC express ABCRYS mRNA and protein. Both are rapidly upregulated following HSC activation.

Predictive value of liver cell dysplasia for development of hepatocellular carcinoma in patients with non-cirrhotic and cirrhotic chronic viral hepatitis

AIMS

Hepatocellular carcinoma (HCC) frequently develops in patients with chronic viral hepatitis, especially in the cirrhotic stage. We retrospectively studied whether the presence of the putative preneoplastic lesions large liver cell dysplasia (LLCD) and/or small liver cell dysplasia (SLCD) in a needle liver biopsy of these patients are a risk factor for the development of HCC.

METHODS AND RESULTS

The presence of LLCD and SLCD in the needle liver biopsy taken at the initial work-up of 115 patients with chronic hepatitis B or C was assessed retrospectively. LLCD and SLCD were present in the initial biopsy of, respectively, 35 (30%) and 25 patients (22%). During a mean follow-up of 107 months, 16 patients (14%) developed HCC and this occurred significantly more frequently in patients with cirrhosis, age > or = 55 years, LLCD or SLCD. Cirrhosis and LLCD were independent risk factors for HCC development.

CONCLUSIONS

Our findings indicate that the presence of LLCD in a needle liver biopsy of patients with viral-induced chronic liver disease is an independent risk factor for the development of HCC. If these results are confirmed, the presence of LLCD can be used to identify a subgroup of patients at high risk for HCC requiring more intensive screening.

A novel N-ras mutation in malignant melanoma is associated with excellent prognosis

Mutations in the ras gene are key events in the process of carcinogenesis; in particular, point mutations in codon 61 of exon 2 of the N-ras gene occur frequently in malignant melanoma (MM). We searched for point mutations in the N-ras gene in a large series of primary and metastatic MM from 81 different retrospectively selected patients using the very sensitive denaturing gradient gel electrophoresis technique, followed by sequencing. The classical codon 12 and codon 61 mutations were found in 21 and 17% of the cases, respectively. No codon 13 mutation was found. A novel mutation at codon 18 of exon 1, consisting of a substitution of alanine (GCA) by threonine (ACA), was found in 15% of the primary MMs but in none of the metastatic MMs. All of the other cases were free of mutations. Using microdissected cells from distinctive MM growth phases as source of DNA for mutation analysis, this particular N-ras exon 1 mutation at codon 18 was already present in the radial growth phase and preserved throughout the successive growth phases; it was also found in a dysplastic nevi in continuity with a MM, indicating a clonal relationship between both lesions. Our findings also illustrate the clonal relationship between the distinctive growth phases in MM and suggest the codon 18 mutation to occur early in MM development. The MM in patients with this mutation were significantly thinner than those without a codon 18 mutation (P = 0.0257). Statistical analysis, comparing the group of codon 18 patients with the group of patients with the classical mutations and without mutations, revealed a highly significant difference in overall outcome. The cumulative probability of developing metastasis was significantly lower for the group patients with a codon 18 mutation (P = 0.0130). We can thus conclude that this codon 18 mutation identifies a group of patients with better prognosis than patients with melanoma that harbor wild-type sequence or classical activating point mutations in codon 12 or 61. Preliminary nucleotide binding measurements could not detect a difference between wild-type Ras protein and the mutant Ras(A18T) protein. However, for a precise elucidation of the role of the N-Ras(A18T) mutant in melanoma, additional studies aimed to measure the affinity to guanine nucleotide exchange factors and GTPase-activating proteins are needed.

Expression of neurotrophins and their receptors in pigment cell lesions of the skin

The neurotrophins (NTs) are a group of growth factors involved in the development of the nervous system and presumed to play a role in neural crest-derived tumours. The expression of three NTs (NGF, BDNF, and NT-3) and their receptors (NTRs; i.e. low-affinity pan-NT receptor p75, Trk-B, and Trk-C) was studied in frozen sections of benign and malignant cutaneous pigment cell lesions, using immunohistochemistry. In order to understand the possible role of these growth factors and their receptors in the progression of primary cutaneous malignant melanomas (PCMMs), their distribution in the radial (RGP) and vertical (VGP) growth phases was particularly studied. While most of the common acquired naevi were unreactive, Spitz and blue naevi showed scattered immunoreactive cells, especially for the p75 NTR. Dysplastic naevi, but not common naevi, expressed NT-3 in their junctional component. PCMM and melanoma metastases often showed a diffuse pattern of immunostaining. NT-3 was significantly more frequently expressed in the RGP of PCMMs than in the junctional component of benign naevi, whereas more extensive immunoreactivity for NGF was found in the VGP of PCMMs, compared with the RGP; metastases more frequently expressed NGF, BDNF, and Trk-B than PCMMs. Interestingly, neurotropic melanoma expressed all NTs/NTRs except Trk-B. These immuunohistochemical data confirm suggestions from previous in vitro studies that autocrine loops of certain NTs and their respective receptors may be involved in melanoma progression; in addition, NT-3 may be involved in the junctional growth of dysplastic naevi. The precise role of these growth factors in melanoma, however, will await further functional studies.

Deep intralobular extension of human hepatic 'progenitor cells' correlates with parenchymal inflammation in chronic viral hepatitis: can 'progenitor cells' migrate?

Ductular reaction and putative progenitor cells (or 'progenitor cells'), which are presumed to be the human counterpart of the oval cells in rat liver, have been discerned in various human liver diseases, including chronic viral hepatitis. Since in experimental models of chronic hepatitis the activation of oval cells is correlated with the inflammatory infiltrate, this study investigated whether there is a correlation in chronic viral hepatitis between the number of 'progenitor cells' extending into the lobule and the severity of parenchymal inflammation, on the one hand, and the extent of ductular reaction and the severity of interface hepatitis, on the other hand. Liver biopsies of 55 patients with chronic hepatitis B and/or C were used. The severity of parenchymal inflammation and of interface hepatitis was semiquantitatively graded on a haematoxylin and eosin-stained paraffin section, while the number of 'progenitor cells' and the extent of the ductular reaction were assessed on a serial section stained for cytokeratin (CK) 7. In addition, more extensive phenotyping of 'progenitor cells' was performed on sections from frozen material from five patients, using antibodies against CK7, CK8, CK18, CK19, chromogranin-A, and the rat oval cell marker OV-6. The number of more centrally located 'progenitor cells' correlated significantly with the severity of the parenchymal inflammation, while the extent of the ductular reaction correlated significantly with the severity of interface hepatitis. These findings suggest that in chronic viral hepatitis, inflammation plays a role in 'progenitor cell' activation and its topography. In cases with moderate and severe lobular inflammation, 'progenitor cells' were strikingly scattered throughout the parenchyma and surrounded by intermediate hepatocyte-like cells, suggesting their migration into the parenchyma and their differentiation towards the hepatocytic lineage.

Deep intralobular extension of human hepatic 'progenitor cells' correlates with parenchymal inflammation in chronic viral hepatitis: can 'progenitor cells' migrate?

Ductular reaction and putative progenitor cells (or 'progenitor cells'), which are presumed to be the human counterpart of the oval cells in rat liver, have been discerned in various human liver diseases, including chronic viral hepatitis. Since in experimental models of chronic hepatitis the activation of oval cells is correlated with the inflammatory infiltrate, this study investigated whether there is a correlation in chronic viral hepatitis between the number of 'progenitor cells' extending into the lobule and the severity of parenchymal inflammation, on the one hand, and the extent of ductular reaction and the severity of interface hepatitis, on the other hand. Liver biopsies of 55 patients with chronic hepatitis B and/or C were used. The severity of parenchymal inflammation and of interface hepatitis was semiquantitatively graded on a haematoxylin and eosin-stained paraffin section, while the number of 'progenitor cells' and the extent of the ductular reaction were assessed on a serial section stained for cytokeratin (CK) 7. In addition, more extensive phenotyping of 'progenitor cells' was performed on sections from frozen material from five patients, using antibodies against CK7, CK8, CK18, CK19, chromogranin-A, and the rat oval cell marker OV-6. The number of more centrally located 'progenitor cells' correlated significantly with the severity of the parenchymal inflammation, while the extent of the ductular reaction correlated significantly with the severity of interface hepatitis. These findings suggest that in chronic viral hepatitis, inflammation plays a role in 'progenitor cell' activation and its topography. In cases with moderate and severe lobular inflammation, 'progenitor cells' were strikingly scattered throughout the parenchyma and surrounded by intermediate hepatocyte-like cells, suggesting their migration into the parenchyma and their differentiation towards the hepatocytic lineage.

Deep intralobular extension of human hepatic 'progenitor cells' correlates with parenchymal inflammation in chronic viral hepatitis: can 'progenitor cells' migrate?

Ductular reaction and putative progenitor cells (or 'progenitor cells'), which are presumed to be the human counterpart of the oval cells in rat liver, have been discerned in various human liver diseases, including chronic viral hepatitis. Since in experimental models of chronic hepatitis the activation of oval cells is correlated with the inflammatory infiltrate, this study investigated whether there is a correlation in chronic viral hepatitis between the number of 'progenitor cells' extending into the lobule and the severity of parenchymal inflammation, on the one hand, and the extent of ductular reaction and the severity of interface hepatitis, on the other hand. Liver biopsies of 55 patients with chronic hepatitis B and/or C were used. The severity of parenchymal inflammation and of interface hepatitis was semiquantitatively graded on a haematoxylin and eosin-stained paraffin section, while the number of 'progenitor cells' and the extent of the ductular reaction were assessed on a serial section stained for cytokeratin (CK) 7. In addition, more extensive phenotyping of 'progenitor cells' was performed on sections from frozen material from five patients, using antibodies against CK7, CK8, CK18, CK19, chromogranin-A, and the rat oval cell marker OV-6. The number of more centrally located 'progenitor cells' correlated significantly with the severity of the parenchymal inflammation, while the extent of the ductular reaction correlated significantly with the severity of interface hepatitis. These findings suggest that in chronic viral hepatitis, inflammation plays a role in 'progenitor cell' activation and its topography. In cases with moderate and severe lobular inflammation, 'progenitor cells' were strikingly scattered throughout the parenchyma and surrounded by intermediate hepatocyte-like cells, suggesting their migration into the parenchyma and their differentiation towards the hepatocytic lineage.

Fas and Fas ligand: strong co-expression in human hepatocytes surrounding hepatocellular carcinoma; can cancer induce suicide in peritumoural cells?

Fas (Apo-1, CD95), a member of the nerve growth factor/tumour necrosis factor receptor superfamily, mediates apoptosis in response to agonistic antibodies or Fas ligand (Fas-L) binding. Fas has been shown to be present on hepatocyte membranes in normal liver and in chronic hepatitis C. At the present time, very limited data are available on the expression of Fas-L. This paper describes a study of 20 cases of active chronic hepatitis of different aetiologies, 20 hepatocellular carcinomas (HCCs) and the adjacent non-tumoural liver parenchyma, and five normal livers. The immunohistochemical expression of Fas and Fas-L was determined using specific monoclonal antibodies. In normal liver, Fas was faintly expressed on membranes of hepatocytes and bile duct cells, while Fas-L was negative. In active chronic hepatitis, Fas expression in hepatocytes was enhanced, resulting in a diffuse honeycomb pattern. Fas-L showed cytoplasmic positivity in hepatocytes in areas of interface hepatitis. Strong expression of Fas as well as Fas-L in the hepatocytes immediately adjacent to HCC was a constant finding. Within the HCCs, Fas-L expression was variable, but present only in a minority of cells. Fas varied from a diffuse honeycomb pattern to focal positivity in occasional cells. There was no correlation between Fas and Fas-L expression in the tumours. In conclusion, hepatocytes can co-express Fas and Fas-L in areas of interface hepatitis and adjacent to HCC, suggesting that they have the ability to induce apoptosis in an autocrine or paracrine way. Within the tumour, the Fas-Fas-L apoptosis pathway seems to be little involved.

The immunohistochemical phenotype of dysplastic foci in human liver: correlation with putative progenitor cells

BACKGROUND/AIMS

In previous studies we found strong evidence for the existence and activation in human liver of putative progenitor cells resembling oval cells in rat liver. In view of the known role of rat oval cells in regeneration and hepatocarcinogenesis, we investigated a possible correlation between human putative progenitor cells and different types of dysplastic foci.

METHODS

We determined the immunohistochemical phenotype of dysplastic foci found in 20 cirrhotic liver explants of various etiology, using specific antibodies against hepatocyte-type cytokeratin (CK) 8 and CK18, bile duct-type CK7 and CK19, chromogranin-A (chrom-A) and rat oval cell marker OV-6.

RESULTS

All 12 foci of large cell dysplasia had a phenotype similar to that of surrounding parenchyma. Oncocytic foci showed a strong cytoplasmic staining for CK7. Three out of six of these foci contained "progenitor cells", which are small cells immunoreactive for CK18, CK7, CK19, OV-6, chrom-A and stained more intensely for CK8 than surrounding hepatocytes. Four out of eight glycogen-storing foci contained CK7-positive intermediate hepatocyte-like cells and "progenitor cells". Sixteen out of 29 small cell dysplastic foci consisted of "progenitor cells" and intermediate hepatocyte-like cells which were immunoreactive for CK7, CK18, OV-6, chrom-A and showed a stronger cytoplasmic positivity for CK8 than surrounding hepatocytes.

CONCLUSIONS

Foci of large cell dysplasia show no correlation with putative progenitor cells. Half of the oncocytic and glycogen-storing foci contain "progenitor cells", while more than half of the foci of small cell dysplasia consist of small cells with the same immunohistochemical phenotype as putative progenitor cells and intermediate hepatocyte-like cells, suggesting that differentiating putative progenitor cells can give rise to foci of small cell dysplasia.

Fas and Fas ligand: strong co-expression in human hepatocytes surrounding hepatocellular carcinoma; can cancer induce suicide in peritumoural cells?

Fas (Apo-1, CD95), a member of the nerve growth factor/tumour necrosis factor receptor superfamily, mediates apoptosis in response to agonistic antibodies or Fas ligand (Fas-L) binding. Fas has been shown to be present on hepatocyte membranes in normal liver and in chronic hepatitis C. At the present time, very limited data are available on the expression of Fas-L. This paper describes a study of 20 cases of active chronic hepatitis of different aetiologies, 20 hepatocellular carcinomas (HCCs) and the adjacent non-tumoural liver parenchyma, and five normal livers. The immunohistochemical expression of Fas and Fas-L was determined using specific monoclonal antibodies. In normal liver, Fas was faintly expressed on membranes of hepatocytes and bile duct cells, while Fas-L was negative. In active chronic hepatitis, Fas expression in hepatocytes was enhanced, resulting in a diffuse honeycomb pattern. Fas-L showed cytoplasmic positivity in hepatocytes in areas of interface hepatitis. Strong expression of Fas as well as Fas-L in the hepatocytes immediately adjacent to HCC was a constant finding. Within the HCCs, Fas-L expression was variable, but present only in a minority of cells. Fas varied from a diffuse honeycomb pattern to focal positivity in occasional cells. There was no correlation between Fas and Fas-L expression in the tumours. In conclusion, hepatocytes can co-express Fas and Fas-L in areas of interface hepatitis and adjacent to HCC, suggesting that they have the ability to induce apoptosis in an autocrine or paracrine way. Within the tumour, the Fas-Fas-L apoptosis pathway seems to be little involved.