Evaluating Intestinal Infections: A Systematic Approach.

Endoscopic biopsies of the mucosa of the large and small intestines can present the pathologist with daunting challenges, in particular because of the breadth of the differential diagnosis, which may include neoplastic, ischemic, iatrogenic (notably medication related), autoimmune, idiopathic, and infectious entities. The purpose of the present study was to develop a logical and systematic approach to the diagnosis of mucosal infections by identifying several morphologic compartments in the intestinal mucosa, and establishing a differential diagnosis for the organisms that are associated with each compartment. The organisms involved may be identified by their appearances in histologic sections, or by the nature of the host reaction to their presence. The process of systematically examining each compartment of the mucosa and scanning for evidence of infection is performed subconsciously by many pathologists, and we have found this approach to be particularly appreciated by pathologists in training.

Identification of 'Candidatus Piscichlamydia salmonis' in Arctic charr Salvelinus alpinus during a survey of charr production facilities in North America.

Arctic charr Salvelinus alpinus production facilities, nonproduction water sources and effluents in the United States and Canada were sampled to determine if chlamydiae associated with epitheliocystis were present in water and were associated with inclusions of epitheliocystis in gill tissue. Gills from 607 fish from 13 sites were processed for histopathologic examination and DNA extraction. Water was collected from 21 locations for DNA testing. Eighteen fish from one location had inclusions of epitheliocystis with proliferative and inflammatory gill lesions. Inclusions were stained using the Gimenez technique and, at the ultrastructural level, consisted of intracytoplasmic membrane-bound vacuoles containing reticulate and intermediate bodies in a fibrillar matrix. PCR using Order Chlamydiales-specific primers performed on DNA extracts from 12 of 13 infected fish yielded amplicons that were identical to (GQ302988) or differed at one base from (GQ302987) the 16S ribosomal RNA gene signature sequence of 'Candidatus Piscichlamydia salmonis', which is the chlamydia that was previously identified in epitheliocystis inclusions of farmed Atlantic salmon. In situ hybridization using a approximately 1.5 kb riboprobe corresponding to the 'Candidatus Piscichlamydia salmonis' 16S rRNA genetic sequence (AY462244) confirmed its presence within Arctic charr gill inclusions. DNA isolated from water samples was tested by Chlamydiales-specific PCR and yielded 54 partial 16S rRNA genetic sequences spanning the signature region; however, no 16S rRNA genetic sequences associated with epitheliocystis were identified. This is the first report of 'Candidatus Piscichlamydia salmonis' associated with epitheliocystis in Arctic charr, the first identification of 'Candidatus Piscichlamydia salmonis' from a freshwater production location, and the first reported occurrence in North America.

Food group intake and risk of subtypes of esophageal and gastric cancer.

Incidence rates for adenocarcinomas of the esophagus and gastric cardia have been increasing rapidly, while rates for non-cardia gastric adenocarcinoma and esophageal squamous cell carcinoma have declined. We examined food group intake as a risk factor for subtypes of esophageal and gastric cancers in a multicenter, population-based case-control study in Connecticut, New Jersey and western Washington state. Associations between food groups and risk were estimated using adjusted odds ratios (OR), based on increasing intake of one serving per day. Total vegetable intake was associated with decreased risk of esophageal adenocarcinoma (OR = 0.85, 95% CI = 0.75, 0.96). Conversely, total meat intake was associated with increased risk of esophageal adenocarcinoma (OR = 1.43, 95% CI = 1.11, 1.83), gastric cardia adenocarcinoma (OR = 1.37, 95% CI = 1.08, 1.73) and noncardia gastric adenocarcinoma (OR = 1.39, 95% CI = 1.12, 1.71), with red meat most strongly associated with esophageal adenocarcinoma risk (OR = 2.49, 95% CI = 1.39, 4.46). Poultry was most strongly associated with gastric cardia adenocarcinoma (OR = 1.89, 95% CI = 1.15, 3.11) and noncardia gastric adenocarcinoma (OR = 1.90, 95% CI = 1.19, 3.03). High-fat dairy was associated with increased risk of both esophageal and gastric cardia adenocarcinoma. Higher intake of meats, particularly red meats, and lower intake of vegetables were associated with an increased risk of esophageal adenocarcinoma, while higher intake of meats, particularly poultry, and high-fat dairy was associated with increased risk of gastric cardia adenocarcinoma.

The pathology of diverticulitis.

Diverticulosis of the left colon is an acquired condition that is associated with aging. The diverticula arise at the points of penetration of the circular layer of the muscularis propria by the blood vessels supplying the submucosa and mucosa. They are outpouchings of mucosa invested by wisps of muscularis mucosae, which are believed to result from elevated intraluminal pressure in the left colon, associated with degenerative changes in the collagen and elastin content of the colonic wall. Pathologically, diverticulitis occurs when the mucosa of diverticula becomes inflamed. This may result from obstruction of the diverticulum, for example, by inspissated feces or a fecolith, leading to bacterial overgrowth, gas and toxin production, and mucosal injury. The flat mucosa of the colon between the orifices of the diverticula is also commonly inflamed, with changes of varying severity indistinguishable from those of ulcerative colitis or Crohn's disease. Such mucosal changes include a dense lymphoplasmacytic infiltrate, mucin depletion, cryptitis, crypt abscesses, architectural distortion, gland dropout, Paneth cell metaplasia, and ulceration. Complications of diverticulitis include bleeding (the diverticula are in intimate contact with the penetrating blood vessels which may become eroded), ulceration, abscess formation, penetration, perforation, fistulas, stricture formation, and pylephlebitis.

Mycophenolate mofetil for drug-induced vanishing bile duct syndrome.

Amoxicillin/clavulanate is associated with liver injury, mostly of a cholestatic pattern. While outcomes are usually benign, progression to cirrhosis and death has been reported. The role of immunosuppressive therapy for patients with a protracted course is unclear. We report the case of an elderly patient who developed prolonged cholestasis secondary to amoxicillin/clavulanate. Vanishing bile duct syndrome was confirmed by sequential liver biopsies. The patient responded to prednisone treatment, but could not be weaned off corticosteroids, even when azathioprine was added. Complete withdrawal of both prednisone and azathioprine was possible by using mycophenolate mofetil, an inosine monophosphate dehydrogenase inhibitor. Sustained remission has been maintained for more than 3 years with low-dose mycophenolate mofetil.

Characterization of a Neochlamydia-like bacterium associated with epitheliocystis in cultured Arctic charr Salvelinus alpinus.

Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic charr Salvelinus alpinus. To characterize a bacterium associated with epitheliocystis in cultured charr, gills were sampled for histopathologic examination, conventional and immunoelectron microscopy, in situ hybridization, 16S ribosomal DNA (rDNA) amplification, sequence analysis and phylogenetic inference. Sampling was conducted at the Freshwater Institute (Shepherdstown, West Virginia, USA) during outbreaks of epitheliocystis in April and May 2002. Granular, basophilic, cytoplasmic inclusions in charr gill were shown to stain with Macchiavello, Lendrum's phloxine-tartrazine and Gimenez histochemical techniques. Ultrastructurally, inclusions were membrane-bound and contained round to elongate reticulate bodies that were immunoreactive to an antibody against chlamydial lipopolysaccharide, suggesting the presence of similar epitopes. DNA extracted from gills supported amplification of the most polymorphic and phylogenetically relevant region of the 16S rRNA gene, which had 97 to 100% identity with several uncultured clinical Neochlamydia spp. (order Chlamydiales) Clones WB13 (AY225593.1) and WB258 (AY225594.1). Sequence-specific riboprobes localized to inclusions during in situ hybridization experiments. Taxonomic affiliation was inferred by distance- and parsimony-based phylogenetic analyses of the 16S sequence, which branched with Neochlamydia hartmannellae in the order Chlamydiales with high confidence. This is the first molecular characterization of a chlamydia associated with epitheliocystis in Arctic charr and the fourth Neochlamydia spp. sequence to be associated with epitheliocystis. Presence of a clinical neochlamydial sequence, first identified from a cat, in Arctic charr suggests a possible mammalian and piscine host range for some environmental chlamydiae.

Diffuse Alveolar Hemorrhage in Systemic Lupus Erythematosus: Histopathologic Features and Clinical Correlations.

The case of a 16-year-old African-American girl with systemic lupus erythematosus, who developed diffuse alveolar hemorrhage with fatal consequences, is described. Diffuse alveolar hemorrhage is a rare but serious complication of systemic lupus. It occurs in three distinct but overlapping phenotypes, acute capillaritis, bland pulmonary hemorrhage, and diffuse alveolar damage, each of which is associated with a different group of underlying conditions. Diffuse alveolar hemorrhage is a medical emergency: choice of treatment depends on early diagnosis and determination of the underlying etiology. Acute infection, superimposed on diffuse alveolar hemorrhage in the setting of immune compromise, is often a terminal event, as in this case.

Focal hepatic glycogenosis associated with metastatic insulinoma presenting as mass lesions.

One of the important functions of the liver is glycogen storage. Most processes associated with increased hepatic glycogen, or glycogenoses, are metabolic and affect the entire liver leading to diffuse glycogenosis. We present a case in which the liver contained multiple small pale nodules that on initial assessment were recognized to be composed of glycogenated hepatocytes. Most of the known causes of hepatic glycogenosis were not pertinent to this case. After cutting many deeper levels and obtaining additional sections, small foci of insulinoma were revealed in the center of each of these lesions. The glycogenosis surrounding the foci of insulinoma can be best explained as a local effect of insulin on the hepatocytes, a phenomenon that has been previously described in primate models, but not in human subjects. Here, we report the first case of metastatic insulinoma causing local hepatic glycogenosis.

Nonsteroidal anti-inflammatory drug use associated with reduced incidence of adenocarcinomas of the esophagus and gastric cardia that overexpress cyclin D1: a population-based study.

This study was undertaken to determine whether selected risk factors for esophageal and gastric cancer are associated with tumors that overexpress cyclin D1. Archived tumor tissue was available for 630 esophageal and gastric cancer patients who participated in a population-based case-control study. Patients were categorized into case groups based on whether protein overexpression of the cyclin D1 gene, as assessed by immunohistochemistry, was present (cyclin D1+, n = 285) or not (cyclin D1-, n = 345) in the tumor. The distribution of risk factors in each of these case groups was then compared with the distribution among the 695 controls. Multivariate-adjusted odds ratios (OR) for esophageal adenocarcinoma were reduced in relation to use of aspirin and other nonsteroidal anti-inflammatory drug (NSAID) use but only among patients with cyclin D1+ tumors (0.45, 95% confidence interval [CI] = 0.26, 0.79) and not among those with cyclin D1- tumors (1.12, 95% CI = 0.67, 1.86). A similar pattern was observed for gastric cardia adenocarcinomas. In contrast, ORs for esophageal squamous cell carcinoma and noncardia gastric adenocarcinomas in relation to NSAID use were reduced, regardless of cyclin D1 status. ORs did not vary with cyclin D1 status in relation to alcohol, body size, or cigarette smoking, with the following exception; for noncardia gastric adenocarcinomas the cyclin D1- tumors showed a 2-fold elevation in the OR with ever smoking. These data suggest that the reduction in risk associated with NSAID use may be restricted to those esophageal and gastric cardia adenocarcinomas that overexpress cyclin D1.

Distribution of Peyer's patches in the distal ileum.

BACKGROUND AND AIMS: Peyer's patches play a major role in intestinal immunity, are portals of entry for significant pathogens, and may be important in Crohn's disease. Whereas their microscopic anatomy and immune function are well described, surprisingly little is known of their macroscopic anatomy and distribution. Our aim was to assess their number, area, and distribution in the normal distal ileum, with particular reference to patient age. METHODS: Distal ilea (200 cm) obtained at autopsy from 55 adults without intestinal disease were opened along the mesenteric border, fixed in acetic acid, and transilluminated. Peyer's patches were counted, and the length, breadth, and distance from the ileocecal valve were recorded. RESULTS: Patches were most numerous in the terminal 10-15 cm where they formed a lymphoid ring. More proximal patches were oval, antimesenteric, and irregularly spaced. By area, 46% of patch tissue occurred in the terminal 25 cm. The mean number of patches ranged from 29.4 +/- 5.4 in the youngest group studied, to 19.0 +/- 3.0 in the oldest. Total patch area was greatest in the group aged 21-30 (47.4 +/- 1.0 cm2). CONCLUSION: Peyer's patches are concentrated in the distal 25 cm of ileum but extend proximally for 200 cm. The variation in their size, shape, and distribution in different individuals is greater than often appreciated and may influence the presentation of diseases centered on these structures.

Stellate-cell lipidosis in liver biopsy specimens. Recognition and significance.

Hepatic stellate-cell lipidosis due to hypervitaminosis A can lead to cirrhosis, which can be averted by restricting vitamin A intake. Other causes, including the use of synthetic retinoids, have been postulated. We studied the frequency and etiology of stellate-cell lipidosis in patients undergoing liver biopsy for reasons other than vitamin A abuse. Fourteen cases (1.1%) were identified retrospectively among 1,235 nontransplant liver biopsy specimens examined from January 1995 through December 1999. Diagnostic criteria included the following: lipid-laden cells in the space of Disse; small, dark, crescent-shaped nuclei with inconspicuous nucleoli; and wispy cytoplasmic strands separating fat droplets. Patient details, reason for biopsy, and medication use were studied. Reasons for biopsy included hepatitis C (10 cases), abnormal liver enzyme levels (2 cases), methotrexate use (1 case), and alcohol abuse (1 case). Hypervitaminosis A was not suspected clinically in the 5 patients who used oral vitamin A or 3 who used topical tretinoin (Retin-A). In 6 patients, no cause of stellate-cell lipidosis was discerned. Stellate-cell lipidosis should be reported to alert clinicians to a potentially preventable form of liver injury.

Multiplex DNA short tandem repeat analysis. A useful method for determining the provenance of minute fragments of formalin-fixed, paraffin-embedded tissue.

A tiny fragment of high-grade carcinoma was found in histologic sections and in the paraffin block of a benign cervical polyp from a patient with no clinical evidence of malignancy. Thus, it raised the suspicion of block contamination. No malignant tumor was processed the same day as the polyp; however, a similar tumor had been processed 6 days earlier. Multiplex DNA short tandem repeat analysis was applied to paraffin-extracted tissue samples obtained from the polyp, the suspected contaminant, the patient's additional cervical biopsy specimen, and the putative source of contamination. The results demonstrated that the suspected contaminant and the patient's cervical tissue could not have come from the same patient and that the suspected contaminant derived from the tumor processed earlier, without reasonable doubt. We hypothesize that this friable tumor escaped from cassettes into the processor and contaminated the polyp specimen. Multiplex DNA short tandem repeat analysis can be applied to determine the provenance of minute tissue samples in surgical pathology.

Diet and lifestyle factors and risk of subtypes of esophageal and gastric cancers: classification tree analysis.

PURPOSE: Although risk factors for squamous cell carcinoma of the esophagus and adenocarcinomas of the esophagus (EA), gastric cardia (GC), and other (noncardia) gastric (OG) sites have been identified, little is known about interactions among risk factors. We sought to examine interactions of diet, other lifestyle, and medical factors with risks of subtypes of esophageal and gastric cancers. METHODS: We used classification tree analysis to analyze data from a population-based case-control study (1095 cases, 687 controls) conducted in Connecticut, New Jersey, and western Washington State. RESULTS: Frequency of reported gastroesophageal reflux disease symptoms was the most important risk stratification factor for EA, GC, and OG, with dietary factors (EA, OG), smoking (EA, GC), wine intake (GC, OG), age (OG), and income (OG) appearing to modify the risk of these cancer sites. For esophageal squamous cell carcinoma, smoking was the most important risk stratification factor, with gastroesophageal reflux disease, income, race, noncitrus fruit, and energy intakes further modifying risk. CONCLUSION: Various combinations of risk factors appear to interact to affect risk of each cancer subtype. Replication of these data mining analyses are required before suggesting causal pathways; however, the classification tree results are useful in partitioning risk and mapping multilevel interactions among risk variables.

Principal component analysis of dietary and lifestyle patterns in relation to risk of subtypes of esophageal and gastric cancer.

PURPOSE: To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers. METHODS: We evaluated risk factors for esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). Impact of the resultant scores on cancer risk was estimated through logistic regression. RESULTS: PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study increased with rising meat/nitrite score. Risk of EA increased with increasing GERD/BMI score, and risk of ESCC rose with increasing smoking/alcohol score and decreasing gastroesophageal reflux disease (GERD)/body mass index (BMI) score. Fruit/vegetable scores were inversely associated with EA, ESCC, and GCA. CONCLUSIONS: PCA may provide a useful approach for summarizing extensive dietary/lifestyle data into fewer interpretable combinations that discriminate between cancer cases and controls. The analyses suggest that meat/nitrite intake is associated with elevated risk of each cancer under study, whereas fruit/vegetable intake reduces risk of EA, ESCC, and GCA. GERD/obesity were confirmed as risk factors for EA and smoking/alcohol as risk factors for ESCC.

Alcohol dehydrogenase 3 and risk of esophageal and gastric adenocarcinomas.

OBJECTIVES: Alcohol increases esophageal squamous carcinoma risk but has been less consistently associated with esophageal adenocarcinoma. Alcohol dehydrogenase catalyzes the oxidation of approximately 80% of ethanol to acetaldehyde, a carcinogen. The alcohol dehydrogenase gene has several polymorphisms which may lead to faster conversion of ethanol to acetaldehyde, which may increase cancer risk. METHODS: We undertook a study to examine whether a common polymorphism in the alcohol dehydrogenase 3 gene was associated with a higher risk of esophageal adenocarcinoma using data and biological samples collected for the Esophageal and Gastric Cancer Study (n = 114 esophageal and gastric cardia adenocarcinoma, n = 60 non-cardia gastric carcinoma, n = 23 cases of esophageal squamous cell carcinoma and 160 controls). RESULTS: Individuals homozygous for ADH ( 3 ) (1-1) had a higher risk of each tumor type compared to individuals who had ADH ( 3 ) (2-2) or ADH ( 3 ) (1-2) genotype (OR = 1.7, 95% CI = 1.0-2.9 for esophageal and gastric cardia adenocarcinomas; OR = 1.7, 95% CI = 0.7-4.3 for esophageal squamous cell carcinoma; and OR = 2.8, 95% CI = 1.5-5.1 for non-cardia gastric cancer). The elevation in risk from homozygosity of the ADH ( 3 ) (1) allele was seen in drinkers and nondrinkers, although the risk estimate was only significant for drinkers, particularly of liquor. CONCLUSION: These data suggest ADH3 genotype may be associated with risk of esophageal and gastric cardia adenocarcinomas.

Carbonated soft drink consumption and risk of esophageal adenocarcinoma.

Carbonated soft drinks (CSDs) have been associated with gastroesophageal reflux, an established risk factor for esophageal adenocarcinoma. As both CSD consumption and esophageal adenocarcinoma incidence have sharply increased in recent decades, we examined CSD as a risk factor for esophageal and gastric cancers in a U.S. multicenter, population-based case-control study. Associations between CSD intake and risk were estimated by adjusted odds ratios (ORs), comparing the highest versus lowest quartiles of intake. All statistical tests were two-sided. Contrary to the proposed hypothesis, CSD consumption was inversely associated with esophageal adenocarcinoma risk (highest versus lowest quartiles, OR = 0.47, 95% confidence interval = 0.29 to 0.76; Ptrend = .005), due primarily to intake of diet CSD. High CSD consumption did not increase risk of any esophageal or gastric cancer subtype in men or women or when analyses were restricted to nonproxy interviews. These findings indicate that CSD consumption (especially diet CSD) is inversely associated with risk of esophageal adenocarcinoma, and thus it is not likely to have contributed to the rising incidence rates.

Hepatocellular carcinoma in the cirrhotic liver: gadolinium-enhanced 3D T1-weighted MR imaging as a stand-alone sequence for diagnosis.

PURPOSE: To retrospectively assess the usefulness of contrast material-enhanced T1-weighted magnetic resonance (MR) imaging alone and with T2-weighted MR imaging in the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A waiver of informed consent and institutional review board approval for this retrospective study were granted. The study was HIPAA compliant. Twenty-eight men (mean age, 49 years; range, 23-70 years) and 10 women (mean age, 53 years; range, 42-72 years) with cirrhosis underwent T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5 T within 90 days of liver transplantation. Three readers reviewed the T1-weighted images alone and then the T2-weighted and T1-weighted images together. Lesion detection, characterization, and reader confidence levels were recorded. RESULTS: At liver explantation, 57 lesions were present in 18 patients: 19 HCCs, 33 dysplastic nodules, and five cysts. Contrast-enhanced T1-weighted imaging depicted 13 of 19 HCCs with an overall sensitivity of 68.4% (13 of 19) and specificity of 65.7% (23 of 35). The sensitivity and specificity for detection of dysplastic nodules (sensitivity, 9%; specificity, 68.4%) and HCCs (sensitivity, 68.4%; specificity, 65.7%) were nearly identical for T1-weighted images read alone or read with T2-weighted images. The only difference was the specificity for T1-weighted images read alone (65.7%) and read with T2-weighted images (62.9%). The addition of T2-weighted images altered the diagnosis in one of 90 (1.1%) cases and provided an increase in diagnostic confidence in four of 258 (1.6%) cases for independent readers and three of 90 (3.3%) cases at consensus reading. CONCLUSION: Contrast-enhanced T1-weighted imaging can be used as a stand-alone sequence for the diagnosis of HCC in patients with cirrhosis prior to liver transplantation.

Interobserver agreement in hepatitis C grading and staging and in the Banff grading schema for acute cellular rejection: the "hepatitis C 3" multi-institutional trial experience.

CONTEXT: Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. OBJECTIVE: To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the "Hepatitis C 3" trial. DESIGN: The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin-stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. RESULTS: Statistically significant agreement was found among all participating pathologists (P < .001). On kappa analysis, the degree of agreement was rated "moderate" for HCV grade and stage and ACR global grading (kappa = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (kappa = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (kappa = 0.76 "almost perfect" for HCV and 0.62 "substantial" for ACR). CONCLUSIONS: An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.