Depth of resection using two different endoscopic mucosal resection techniques.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) has been carried out for high-grade dysplasia (HGD) and intramucosal carcinoma (IMCA) in Barrett's esophagus using two different cap-assisted techniques, the "inject, suck, and cut" and the "band and snare." Previous work has demonstrated comparable specimen diameters. However, the two techniques have not been previously compared with respect to depth of resection. PATIENTS AND METHODS: From a database of patients with Barrett's esophagus, we identified 40 consecutive specimens removed using EMR from patients with HGD or IMCA, 20 each from the "inject, suck, and cut" and the "band and snare" techniques. Specimens were evaluated and measured separately by two pathologists for greatest diameter and depth, and for the presence of submucosa and muscularis propria at the deepest margin of resection. Follow-up data were collected regarding clinical outcome and stricture formation. RESULTS: The mean depth of the specimens from the two techniques was not significantly different (0.51 cm vs. 0.50 cm, P = 0.76). All specimens contained substantial submucosa, allowing accurate staging of the neoplastic lesions resected. Muscularis propria was identified at the base of 65% of the "band and snare" and 50% of the "inject, suck, and cut" specimens (P = 0.52). CONCLUSIONS: The "inject, suck, and cut" and "band and snare" techniques both yield equivalent adequate depth of histological specimens from Barrett's esophagus with HGD or IMCA, and both provide accurate pathological staging.

Insulin-like growth factor binding protein-3 inhibits colitis-induced carcinogenesis.

PURPOSE: Chronic inflammation in the setting of inflammatory bowel disease is thought to result in altered epithelial cell growth regulation and ultimately carcinogenesis. This loss in cell growth regulation may be partially caused by a decrease in circulating intact insulin-like growth factor binding protein-3 (IFGB-3) as a result of chronic inflammation. This study evaluates the effect of IFGB-3 on carcinogenesis in the setting of colitis. METHODS: A previously described animal model for colitis-induced carcinogenesis was used. Colitis was induced in both wild-type and IFGB-3 transgenic CD1 mice with a one-week oral exposure to dextran sodium sulfate (2 percent in drinking water). All mice received a single intraperitoneal administration (10 mg/kg body weight) of a genotoxic colonic carcinogen, azoxymethane. At Week 20, the animals were killed and their colons were excised. The colons were examined by a pathologist under blinded conditions. Criteria assessed included the severity of colitis, number of aberrant crypt foci per mouse colon, incidence of colonic adenomas, and mean size of colonic adenomas. RESULTS: A total of 20 mice (10 in each group) were included in the study. The severity of colitis was not significantly different between the two groups (mean colitis score wild-type = 13.2; IFGB-3 transgenic = 11; P = not significant). The average number of aberrant crypt foci per colon was significantly lower in the IFGB-3 transgenic mice compared with the wild-type mice (1.5 +/- 1.4 vs. 4.5 +/- 2.7, respectively; P < 0.0001). The number of adenomas per colon was significantly lower in IFGB-3 transgenic group (1.2 +/- 1.8) compared with the wild-type mice (3.7 +/- 2.7; P = 0.005). In addition the average size of adenomas was significantly smaller in IFGB-3 transgenic mice (1.4 +/- 1.3 mm) compared with the wild-type mice (2.6 +/- 2 mm; P = 0.013). CONCLUSIONS: IFGB-3 significantly reduces the development of colonic tumors and precursor lesions in the setting of induced murine colitis. It is possible that the loss of IFGB-3 as a result of chronic inflammation may be associated with an increased rate of carcinogenesis in the inflammatory bowel disease setting. Although further studies are necessary, in theory, inhibiting the depletion of IFGB-3 or replacement of IFGB-3 may serve as a novel treatment strategy to prevent the development of colitis-induced carcinogenesis.

Acidic fibroblast growth factor is expressed sequentially in the progression from Barrett's esophagus to esophageal adenocarcinoma.

Acidic fibroblast growth factor 1 (FGF-1) is sequentially accumulated in Barrett's esophagus and its expression in glandular dysplasias is independent of esophageal adenocarcinoma. This suggests that FGF-1 immunohistochemistry could be used as an adjunct to the routine histopathologic diagnosis of dysplasia in Barrett's esophagus. The data also underscore the important role of fibroblast growth factors in tumorigenesis.

Reciprocal expression of ERalpha and ERbeta is associated with estrogen-mediated modulation of intestinal tumorigenesis.

Menopausal hormone replacement therapy has been widely used to alleviate the symptoms of menopause and to decrease the detrimental effects of ovarian hormone loss on bone density and cardiovascular health. Multiple studies of colorectal cancer epidemiology also support a role for hormone replacement therapy in prevention of colorectal cancer. We studied the effect of ovariectomy and estrogen replacement on tumor formation in C57BL/6J-Min/+ (Min/+) mice, animals that bear a germline mutation in murine Apc. These mice develop multiple intestinal tumors that show loss of wild-type Apc protein. After ovariectomy, intestinal adenomas in Min/+ mice increased by 77% (P = 0.0004). Ovariectomized Min/+ mice that were treated with a replacement dose of 17beta-estradiol had the same number of tumors as Min/+ mice that were neither castrated nor treated with estrogen replacement (P = 0.85). Examination of estrogen receptor (ER) levels in intestinal tissue by immunoblot showed changes in relative expression levels of ERalpha and ERbeta, with highest ERalpha and lowest ERbeta expression in the normal-appearing intestine of Min/+ mice, and lowest ERalpha and highest ERbeta expression in the enterocytes of animals that received 17beta-estradiol. These results suggest that endogenous estrogens protect against Apc-associated tumor formation and that tumor prevention by 17beta-estradiol is associated with an increase in ERbeta and a decrease in ERalpha expression in the target tissue.

P53 mutations in primary tumors and subsequent liver metastases are related to survival in patients with colorectal carcinoma who undergo liver resection.

BACKGROUND: The appearance of p53 mutations in colorectal carcinoma was determined, independent of differentiation and tumor stage of the primary tumors, in relation to the survival of patients who were scheduled to undergo liver resection. METHODS: Tumor material was analyzed for p53 mutations in primary colorectal tumors and subsequent liver metastases from 41 consecutive patients who were scheduled to undergo surgical liver resection. DNA sequencing and immunohistochemical staining of p53 protein within tumor nuclei were performed. RESULTS: Primary tumors displayed p53 mutations within exons 5-9 in 41% of patients. No mutations were found in exons 4, 10, or 11. Forty-one percent of metastatic lesions had the same single mutation that was found in the primary tumor, whereas 11% of metastatic lesions had one additional mutation within exons 5-9; 22% had mutations only in their liver metastases, whereas corresponding primary tumors displayed wild-type p53. None of the patients had mutated p53 in their primary tumor and wild type in their metastases. Survival after undergoing liver resection was correlated negatively (P < 0.05-0.01) with Duke Stages A-D classification of the primary tumors, tumor differentiation, and radicality (> 0.7-0.8 mm) of resected liver metastases. CONCLUSIONS: The presence of p53 mutations in patients with metastatic lesions was related significantly (P < 0.003) to better survival after the patients underwent liver resection compared with patients with wild type p53 in their metastatic lesions. This finding was not related to covariates, such as Duke classification, tumor differentiation, type of liver metastasis, or metastatic radicality during resections. Explanations for this unexpected finding remain unclear, although the authors speculate that occult tumor cells with p53 mutations may be less responsive to growth factor(s) exposure during hepatic regeneration after resection.

Eosinophilic hepatic necrosis in hypereosinophilic syndrome.

Hypereosinophilic syndrome has been reported to be associated with liver disease, predominantly in men, in the form of acute and chronic active hepatitis with an inflammatory infiltrate that is mainly composed of eosinophils. We describe a female patient with peripheral blood and bone marrow eosinophilia, in whom liver biopsy displayed areas of necrosis with eosinophilic inflammation, with other regions showing features of chronic hepatitis. The patient also had antimitochondrial antibodies in serum. She responded favorably to immunosuppressive therapy.

Characterization of Cyp2d22, a novel cytochrome P450 expressed in mouse mammary cells.

Endogenous steroids and numerous environmental agents have potent effects on mammary development and carcinogenesis. Locally produced cytochrome P450 enzymes that modify such molecules are therefore likely to be important regulators of these processes. Here we describe the characterization of a novel mouse gene, termed Cyp2d22, that is highly expressed in the mammary tumor derived cell line RIII/Prl. Cyp2d22 is expressed at intermediate levels in the weakly tumorigenic cell line RIII/MG, whereas expression is low or absent in all normal mouse mammary epithelial cell lines tested and three C3H mammary tumor derived cell lines. Immunoblot analysis of mouse tissues with highly specific antisera indicates that 2D22 protein levels are most abundant in liver, while intermediate levels of expression are seen in adrenal, ovary, and mammary gland. Immunohistochemical staining of liver sections with these antisera demonstrates that 2D22 is most abundant in the first layer or two of parenchymal cells surrounding the central vein, with virtually no expression detected in periportal cells. Interestingly, sequence similarity and functional data suggest that Cyp2d22 may be the mouse ortholog of human CYP2D6. These observations support the hypothesis that 2D22 mediates a distinct, biologically significant activity in relation to other mouse 2D family members.

Objective ranking of fibrosis in standard histologic sections of human neonatal liver: applicability to alpha1-antitrypsin deficiency.

BACKGROUND: The etiologic heterogeneity of fibrotic liver disease has resulted in the formulation of diverse, often disease-specific, classification systems for biopsy assessment, based on tissue morphology and staining. Their qualitative nature and observer dependency remain a concern, and no classification exists for several significant conditions--for example, alpha1-antitrypsin deficiency (alpha1-ATD). The authors propose a disease- and morphology-independent numeric ranking system to objectively quantify fibrosis in a standard histologic section, based on its content of protein amino acids. This PNC system is applied to two cases of alpha1-ATD liver fibrosis. METHODS: High-performance liquid chromatography separation of the 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC)-labeled acid hydrolysate of an individual needle biopsy section, followed by the calculation of specific amino acid ratios to eliminate confounding variables. RESULTS: As required by the PNC system, three numeric values were identified per tissue section, one increasing (P quotient), one decreasing (N quotient), one constant (C quotient) as fibrosis progresses, assessed by calibration against Knodell-staged samples. Generated for the alpha1-ATD sections, these three coordinates numerically referenced the degree of fibrosis in a manner that in each case was consistent with the histologic evaluation, the laboratory values, and the clinical course. CONCLUSIONS: Numeric, objective referencing of the degree of fibrosis in routine liver biopsy sections, based on the PNC system, is technically possible.

Cholangiocarcinoma in primary sclerosing cholangitis: K-ras mutations and Tp53 dysfunction are implicated in the neoplastic development.

BACKGROUND/AIM: Cholangiocarcinoma is a feared complication of primary sclerosing cholangitis (PSC). Neoplastic bile duct strictures may be difficult to differentiate cholangiographically from the non-neoplastic bile duct irregularities characteristic of this disorder, and the diagnosis of cholangiocarcinoma may be difficult to establish with certainty, even in tissue samples. Thus, new methods which can improve the diagnostic accuracy of cholangiocarcinoma in PSC are needed. METHODS: We investigated the occurrence of K-ras codon 12 and 13 mutations, p53 protein accumulation, and Ki-67 expression in tumor tissue from PSC patients (n=33) who had developed cholangiocarcinoma, using bile duct specimens exised at liver transplantation of PSC patients without cholangiocarcinoma (n=15) as controls RESULTS: K-ras mutations were present in 11 (33%) of the cholangiocarcinoma samples and significantly more frequent in females. Nine tumors carried a codon 12 mutation, and 2 had a codon 13 mutation. The most frequent substitutions in codon 12 were GGT-->GAT (n=5) and GGT-->TGT (n=3). None of the control bile ducts had K-ras mutations. p53 protein was accumulated in 10 (31%) of the tumors, as opposed to negative findings in all the control samples. Sixteen (48%) tumors revealed either K-ras mutation or p53 accumulation. Ki-67 positivity was significantly higher in cholangiocarcinomas than in the non-neoplastic bile ducts (median 29% vs 12%, respectively; p=0.011). CONCLUSION: We conclude that K-ras mutations and p53 dysfunction are implicated in tumorigenesis of cholangiocarcinomas arising in PSC patients and that these abnormalities together with increased Ki-67 index may indicate neoplastic progression of bile ducts in these patients.

Suppression of apoptosis does not foster neoplastic growth in Barrett's esophagus.

Esophageal adenocarcinoma often arises in association with metaplastic and dysplastic mucosa in Barrett's esophagus. Derangements in cell cycle control and apoptosis regulation might be responsible for the progression from metaplasia to dysplasia and adenocarcinoma We tested this hypothesis by performing cell cycle analysis, in situ detection of apoptosis, and evaluation for the immunohistochemical expression of proteins involved in proliferation (Ki-67), the control of apoptosis (bcl-2, bcl-x and bax), and cell cycle regulation (retinoblastoma and cyclin D1). We studied 17 randomly selected paraffin-embedded esophagectomy specimens that contained intestinal metaplasia without dysplasia, low-grade dysplasia, high-grade dysplasia, and esophageal adenocarcinoma Compared with gastric controls and intestinal metaplasia without dysplasia, high-grade dysplasia and esophageal adenocarcinoma demonstrated greater numbers of cells in S phase and G2 phase. Comparison of the proliferation index and the apoptotic rate in intestinal metaplasia without dysplasia, low-grade dysplasia, high-grade dysplasia, and esophageal adenocarcinoma showed a statistically significant trend that linked an increasing proliferation index and apoptotic rate with increasing histologic severity (P = .006 and P = .0002, respectively). A statistically significant linear association was found between bcl-x expression, bax expression, and the bcl-2-to-bax expression ratio versus increasing histologic severity (P = .0004, P = .007, and P = .03, respectively). These data support the hypothesis that neoplastic transformation of intestinal metaplastic epithelium in the esophagus might result from sequential changes in the expression of proteins involved in the control of apoptosis and the cell cycle. Furthermore, suppression of apoptosis does not seem to foster neoplastic growth in Barrett's esophagus. These observations will lead to a better understanding of the pathogenesis of esophageal adenocarcinoma and might contribute to enhancing the diagnostic accuracy when presented with dysplastic lesions.

Role of immunosuppressive therapy in refractory sprue-like disease.

Patients with malabsorption and histological findings consistent with celiac disease, who are unresponsive to gluten free diet, and in whom other causes of flat mucosa have been excluded, are considered to suffer from so called unclassified or refractory sprue. Although the true nature of this condition needs to be further elucidated, it is known to represent a difficult therapeutical problem with potentially fatal course. Herein, we report a patient with refractory sprue-like disease who after failing to respond to corticosteroids and TPN was in a critical condition. He responded promptly to cyclosporine and made a remarkable recovery. In contrast to previous reports, the cyclosporine treatment in this patient was pursued only for 1 month, whereupon the patient turned responsive to steroids. Subsequent treatment with azathioprine allowed corticosteroids to be reduced to a low maintenance dose and eventually all drugs could be discontinued without reappearance of symptoms. Cyclosporine therapy might be lifesaving in occasional patients with refractory sprue-like disease and it may result in reversal of steroid resistance. Moreover, azathioprine seems to have a steroid sparing effect in this setting. Short term immunosuppressive treatment may have an advantage of lower risk for drug related side effects.

CHOP is implicated in programmed cell death in response to impaired function of the endoplasmic reticulum.

Cellular stress, particularly in response to toxic and metabolic insults that perturb function of the endoplasmic reticulum (ER stress), is a powerful inducer of the transcription factor CHOP. The role of CHOP in the response of cells to injury associated with ER stress was examined in a murine deficiency model obtained by homologous recombination at the chop gene. Compared with the wild type, mouse embryonic fibroblasts (MEFs) derived from chop -/- animals exhibited significantly less programmed cell death when challenged with agents that perturb ER function. A similar deficit in programmed cells death in response to ER stress was also observed in MEFs that lack CHOP's major dimerization partner, C/EBPbeta, implicating the CHOP-C/EBP pathway in programmed cell death. An animal model for studying the effects of chop on the response to ER stress was developed. It entailed exposing mice with defined chop genotypes to a single sublethal intraperitoneal injection of tunicamycin and resulted in a severe illness characterized by transient renal insufficiency. In chop +/+ and chop +/- mice this was associated with the early expression of CHOP in the proximal tubules followed by the development of a histological picture similar to the human condition known as acute tubular necrosis, a process that resolved by cellular regeneration. In the chop -/- animals, in spite of the severe impairment in renal function, evidence of cellular death in the kidney was reduced compared with the wild type. The proximal tubule epithelium of chop -/- animals exhibited fourfold lower levels of TUNEL-positive cells (a marker for programmed cell death), and significantly less evidence for subsequent regeneration. CHOP therefore has a role in the induction of cell death under conditions associated with malfunction of the ER and may also have a role in cellular regeneration under such circumstances.

Gastrointestinal pacemaker cell tumor (GIPACT): gastrointestinal stromal tumors show phenotypic characteristics of the interstitial cells of Cajal.

The interstitial cells of Cajal (ICC) form a complex cell network within the gastrointestinal tract wall where they function as a pacemaker system. Expression of the kit proto-oncogene is essential for the development of this system. The aim of our study was to examine the hypothesis that gastrointestinal stromal tumors differentiate toward cells with an ICC phenotype. Ultrastructurally, 58 stromal tumors were characterized and found to share many features with ICC. Seventy-eight stromal tumors were immunophenotyped, particularly with regard to the kit receptor. All 78 tumors revealed strong, homogeneous immunoreactivity for the kit receptor as did ICC of adjacent and control gastrointestinal walls. Focal hyperplasia and hypertrophy of kit receptor positive cells were also observed in the gastrointestinal wall adjacent to the tumors. CD34 immunoreactivity observed in interstitial cells surrounding Auerbach's ganglia suggests that a subpopulation of ICC is CD34 positive and may explain why 56 of 78 stromal tumors were CD34 positive. Thirty control tumors, including gastrointestinal leiomyomas and leiomyosarcomas, were all negative for the kit receptor. We conclude that gastrointestinal stromal tumors show striking morphological and immunophenotypic similarities with ICC and that they may originate from stem cells that differentiate toward a pacemaker cell phenotype. We propose that the noncommittal name "gastrointestinal stromal tumor" be replaced by gastrointestinal pacemaker cell tumor.

Spontaneous regression of hepatocellular carcinoma.

AIMS: To determine the clinical and histopathological features of a case of a spontaneous regression of hepatocellular carcinoma (HCC). CASE DETAILS: HCC was found incidentally in a 73-year-old man during a laparotomy for evaluation of gastric retention. Despite no treatment being given, he improved gradually with no sign of tumour as evidenced by coeliac angiography 15 months later, as well as by explorative laparotomy after another 2 years. The patient died 15 years after the primary diagnosis of HCC, without known evidence of tumour recurrence. The patient's clinical records were reviewed, and paraffin-embedded liver tissue was re-evaluated. Both histological and immunohistochemical features were compatible with the diagnosis of a well differentiated HCC. Conceivable causes of the spontaneous regression of this and other reported cases are discussed, but the phenomenon remains enigmatic. CONCLUSIONS: This case with a histologically proven HCC and a very long follow-up time confirms that spontaneous regression does occur. Since the case was found incidentally our report also implies that this may not be as rare as reported.

Dual carcinoid/epithelial neoplasia of the appendix.

We report a series of 13 lesions of the human vermiform appendix in which a carcinoid component was associated with a separate non-carcinoid epithelial component that included an adenoma-like lesion of the mucosal epithelium. We use the term dual carcinoid/epithelial neoplasia to describe this phenomenon. The carcinoid component was insular/trabecular in nine cases, tubular in one case and of goblet cell type in three. The epithelial component was a mucinous cystadenoma in four, a mucinous tumour of uncertain malignant potential in three, and a mucinous cystadenocarcinoma in six. No intermediate cell population was seen and in three cases the carcinoid and epithelial components were in different parts of the appendix, leading us to suggest that these lesions may be true 'collision' tumours in which two neoplasms have arisen in the same organ. The prognosis appears to be no worse than for either of the components alone, but conclusions regarding these lesions must be guarded on account of their rarity and the small numbers available for study.