Significance of Crypt Atypia in Barrett's Esophagus: A Clinical, Molecular, and Outcome Study.

BACKGROUND & AIMS: The aim of this study was to characterize baseline morphologic features of crypts in nondysplastic Barrett's esophagus and correlate them with DNA content abnormalities and risk of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). METHODS: The morphologic features of nondysplastic crypts in baseline biopsy specimens from 212 BE patients (2956 biopsy specimens) were graded histologically using a 4-point scale (crypt atypia levels, 0-3). DNA content abnormalities were detected using flow cytometry. RESULTS: In patients who had dysplasia in their baseline biopsy specimens, dysplasia was associated significantly with increasing grades of crypt atypia in the background nondysplastic Barrett's esophagus (P < .001). In a subset of patients without dysplasia at baseline (N = 149), a higher grade of crypt atypia was associated with longer Barrett's esophagus segment length (5.5 vs 3.3 cm; P = .0095), and a higher percentage of cells with 4N DNA content (3.67 ± 1.27 vs 2.93 ± 1.22; P = .018). Crypt atypia was associated with the development of any neoplasia (low-grade dysplasia and HGD/EAC). Although no significant association was noted between the grade of crypt atypia and increased 4N, aneuploidy, or progression to HGD/EAC, only patients with grade 2 or 3 crypt atypia showed increased 4N, aneuploidy, or progression to HGD/EAC. CONCLUSIONS: Patients with Barrett's esophagus likely develop dysplasia via a progressive increase in the level of crypt atypia before the onset of dysplasia, and these changes may reflect some alteration of DNA content.

Colorectal dysplasia in chronic inflammatory bowel disease: a contemporary consensus classification and interobserver study.

The clinical management of patients with dysplasia in chronic inflammatory bowel disease (IBD) is currently guided by Riddell et al.'s grading system (negative, indefinite, low grade, high grade) from 1983 which was based primarily on nuclear cytoarchitectural characteristics. Although most dysplasia in IBD resembles sporadic adenomas morphologically, other distinctive potential cancer precursors in IBD have been described over time. Recognizing the need for a updated comprehensive classification for IBD-associated dysplasia, an international working group of pathologists with extensive clinical and research experience in IBD devised a new classification system and assessed its reproducibility by having each participant assess test cases selected randomly from a repository of electronic images of potential cancer precursor lesions. The new classification system now encompasses three broad categories and nine sub-categories: 1) intestinal dysplasia (tubular/villous adenoma-like, goblet cell deficient, crypt cell, traditional serrated adenoma-like, sessile serrated lesion-like and serrated NOS), 2) gastric dysplasia (tubular/villous and serrated), and 3) mixed intestinal-gastric dysplasia. In the interobserver analysis, 67% of the diagnoses were considered definitive and achieved substantial inter-rater agreement. The key distinctions between intestinal and gastric lesions and between serrated and non-serrated lesions achieved substantial and moderate inter-rater agreement overall, respectively, however, the distinctions among certain serrated sub-categories achieved only fair agreement. Based on the Riddell grading system, definite dysplasia accounted for 86% of the collective responses (75% low grade, 11% high grade). Based on these results, this new classification of dysplasia in IBD can provide a sound foundation for future clinical and basic IBD research.

Recent Advances in the Digestive, Metabolic and Therapeutic Effects of Farnesoid X Receptor and Fibroblast Growth Factor 19: From Cholesterol to Bile Acid Signaling.

Bile acids (BA) are amphiphilic molecules synthesized in the liver (primary BA) starting from cholesterol. In the small intestine, BA act as strong detergents for emulsification, solubilization and absorption of dietary fat, cholesterol, and lipid-soluble vitamins. Primary BA escaping the active ileal re-absorption undergo the microbiota-dependent biotransformation to secondary BA in the colon, and passive diffusion into the portal vein towards the liver. BA also act as signaling molecules able to play a systemic role in a variety of metabolic functions, mainly through the activation of nuclear and membrane-associated receptors in the intestine, gallbladder, and liver. BA homeostasis is tightly controlled by a complex interplay with the nuclear receptor farnesoid X receptor (FXR), the enterokine hormone fibroblast growth factor 15 (FGF15) or the human ortholog FGF19 (FGF19). Circulating FGF19 to the FGFR4/ß-Klotho receptor causes smooth muscle relaxation and refilling of the gallbladder. In the liver the binding activates the FXR-small heterodimer partner (SHP) pathway. This step suppresses the unnecessary BA synthesis and promotes the continuous enterohepatic circulation of BAs. Besides BA homeostasis, the BA-FXR-FGF19 axis governs several metabolic processes, hepatic protein, and glycogen synthesis, without inducing lipogenesis. These pathways can be disrupted in cholestasis, nonalcoholic fatty liver disease, and hepatocellular carcinoma. Thus, targeting FXR activity can represent a novel therapeutic approach for the prevention and the treatment of liver and metabolic diseases.

Hepatocyte ATF3 protects against atherosclerosis by regulating HDL and bile acid metabolism.

Activating transcription factor (ATF)3 is known to have an anti-inflammatory function, yet the role of hepatic ATF3 in lipoprotein metabolism or atherosclerosis remains unknown. Here we show that overexpression of human ATF3 in hepatocytes reduces the development of atherosclerosis in Western-diet-fed Ldlr-/- or Apoe-/- mice, whereas hepatocyte-specific ablation of Atf3 has the opposite effect. We further show that hepatic ATF3 expression is inhibited by hydrocortisone. Mechanistically, hepatocyte ATF3 enhances high-density lipoprotein (HDL) uptake, inhibits intestinal fat and cholesterol absorption and promotes macrophage reverse cholesterol transport by inducing scavenger receptor group B type 1 (SR-BI) and repressing cholesterol 12α-hydroxylase (CYP8B1) in the liver through its interaction with p53 and hepatocyte nuclear factor 4α, respectively. Our data demonstrate that hepatocyte ATF3 is a key regulator of HDL and bile acid metabolism and atherosclerosis.

Liver Steatosis, Gut-Liver Axis, Microbiome and Environmental Factors. A Never-Ending Bidirectional Cross-Talk.

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and parallels comorbidities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. Recent studies describe the presence of NAFLD in non-obese individuals, with mechanisms partially independent from excessive caloric intake. Increasing evidences, in particular, point towards a close interaction between dietary and environmental factors (including food contaminants), gut, blood flow, and liver metabolism, with pathways involving intestinal permeability, the composition of gut microbiota, bacterial products, immunity, local, and systemic inflammation. These factors play a critical role in the maintenance of intestinal, liver, and metabolic homeostasis. An anomalous or imbalanced gut microbial composition may favor an increased intestinal permeability, predisposing to portal translocation of microorganisms, microbial products, and cell wall components. These components form microbial-associated molecular patterns (MAMPs) or pathogen-associated molecular patterns (PAMPs), with potentials to interact in the intestine lamina propria enriched in immune cells, and in the liver at the level of the immune cells, i.e., Kupffer cells and stellate cells. The resulting inflammatory environment ultimately leads to liver fibrosis with potentials to progression towards necrotic and fibrotic changes, cirrhosis. and hepatocellular carcinoma. By contrast, measures able to modulate the composition of gut microbiota and to preserve gut vascular barrier might prevent or reverse NAFLD.

A novel GPER antagonist protects against the formation of estrogen-induced cholesterol gallstones in female mice.

Many clinical studies and epidemiological investigations have clearly demonstrated that women are twice as likely to develop cholesterol gallstones as men, and oral contraceptives and other estrogen therapies dramatically increase that risk. Further, animal studies have revealed that estrogen promotes cholesterol gallstone formation through the estrogen receptor (ER) α, but not ERß, pathway. More importantly, some genetic and pathophysiological studies have found that G protein-coupled estrogen receptor (GPER) 1 is a new gallstone gene, Lith18, on chromosome 5 in mice and produces additional lithogenic actions, working independently of ERα, to markedly increase cholelithogenesis in female mice. Based on computational modeling of GPER, a novel series of GPER-selective antagonists were designed, synthesized, and subsequently assessed for their therapeutic effects via calcium mobilization, cAMP, and ERα and ERß fluorescence polarization binding assays. From this series of compounds, one new compound, 2-cyclohexyl-4-isopropyl-N-(4-methoxybenzyl)aniline (CIMBA), exhibits superior antagonism and selectivity exclusively for GPER. Furthermore, CIMBA reduces the formation of 17ß-estradiol-induced gallstones in a dose-dependent manner in ovariectomized mice fed a lithogenic diet for 8 weeks. At 32 µg/day/kg CIMBA, no gallstones are found, even in ovariectomized ERα (-/-) mice treated with 6 µg/day 17ß-estradiol and fed the lithogenic diet for 8 weeks. In conclusion, CIMBA treatment protects against the formation of estrogen-induced cholesterol gallstones by inhibiting the GPER signaling pathway in female mice. CIMBA may thus be a new agent for effectively treating cholesterol gallstone disease in women.

Activation of Estrogen Receptor G Protein-Coupled Receptor 30 Enhances Cholesterol Cholelithogenesis in Female Mice.

BACKGROUND AND AIMS: Estrogen is an important risk factor for cholesterol gallstone disease because women are twice as likely as men to form gallstones. The classical estrogen receptor α (ERα), but not ERß, in the liver plays a critical role in the formation of estrogen-induced gallstones in female mice. The molecular mechanisms underlying the lithogenic effect of estrogen on gallstone formation have become more complicated with the identification of G protein-coupled receptor 30 (GPR30), an estrogen receptor. APPROACH AND RESULTS: We investigated the biliary and gallstone phenotypes in ovariectomized female GPR30-/- , ERα-/- , and wild-type mice injected intramuscularly with the potent GPR30-selective agonist G-1 at 0 or 1 µg/day and fed a lithogenic diet for 8 weeks. The activation of GPR30 by G-1 enhanced cholelithogenesis by suppressing expression of cholesterol 7α-hydroxylase, the rate-limiting enzyme for the classical pathway of bile salt synthesis. These metabolic abnormalities led to an increase in biliary cholesterol concentrations in company with hepatic hyposecretion of biliary bile salts, thereby inducing cholesterol-supersaturated gallbladder bile and accelerating cholesterol crystallization. G-1 also impairs gallbladder emptying, leading to sluggish gallbladder motility and promoting the development of biliary sludge in the early stage of gallstone formation. The prevalence rates of gallstones were 80% in wild-type and ERα-/- mice treated with G-1 compared to 10% in wild-type mice receiving no G-1. However, no gallstones were formed in GPR30-/- mice treated with G-1. CONCLUSIONS: GPR30 produces additional lithogenic actions, working independently of ERα, to increase susceptible to gallstone formation in female mice; both GPR30 and ERα are potential therapeutic targets for cholesterol gallstone disease, particularly in women and patients exposed to high levels of estrogen.

Microscopic/"Backwash" Ileitis and Its Association With Colonic Disease in New Onset Pediatric Ulcerative Colitis.

BACKGROUND: Microscopic ileitis and its association with pancolitis in adults with ulcerative colitis (UC) have been described. The incidence of ileitis and associations with colonic disease in pediatric UC have, however, not been thoroughly investigated. This study was undertaken to examine the prevalence of microscopic ileal inflammation at the time of initial diagnosis in a cohort of children with UC. METHODS: We reviewed colonoscopy and biopsy data at time of diagnosis from 105 children and young adults with treatment naïve UC; ileal and colonic mucosal biopsies were available on all patients. Ileal mucosal biopsies were examined for the presence and severity of ileal inflammation, and other histologic features. Concurrently obtained colonic mucosal biopsies were assessed to define the severity, distribution, and extent of disease; endoscopic and clinical follow-up data were reviewed. RESULTS: A total of 107 ileal mucosal biopsies and 693 corresponding colonic mucosal biopsies were examined. Seventeen of 105 patients (16%) were found to have ileal inflammation (mean age = 10.4 years, 59% girls), 14 (82%) of whom had histologic pancolitis. The presence of ileal inflammation was significantly associated with endoscopic pancolitis (P = 0.02). The association between histologic pancolitis, severity of active inflammation in the cecum, and ascending colon suggested a possible association with ileal inflammation (P = 0.06, 0.07, and 0.08 respectively), but did not reach statistical significance. CONCLUSION: Patients with new onset UC may have microscopic ileal inflammation at time of diagnosis, even if the terminal ileum appears macroscopically normal. The presence of endoscopic pancolitis is associated with the presence of histologic ileitis. In contrast to existing studies in adults, an association between the presence of ileitis and the histologic severity or the histologic extent of colitis was not observed. Children with microscopic ileitis in the context of UC do not need to be reclassified as "indeterminate colitis" or Crohn disease.

Cross-Talk Between Bile Acids and Gastro-Intestinal and Thermogenic Hormones: Clues from Bariatric Surgery

Obesity is rapidly increasing and has reached epidemic features worldwide. It´s linked to insulin resistance, systemic low-grade inflammation and common pathogenic pathways with a number of comorbidities (including cancer), leading to high mortality rates. Besides change of lifestyles (diet and physical exercise) and pharmacological therapy, bariatric surgery is able to rapidly improve several metabolic and morphologic features associated with excessive fat storage, and currently represents an in vivo model to study the pathogenic mechanisms underlying obesity and obesity-related complications. Studies on obese subjects undergoing bariatric surgery find that the effects of surgery are not simply secondary to gastric mechanical restriction and malabsorption which induce body weight loss. In fact, some surgical procedures positively modify key pathways involving the intestine, bile acids, receptor signaling, gut microbiota, hormones and thermogenesis, leading to systemic metabolic changes. Furthermore, bariatric surgery represents a suitable model to evaluate the gene-environment interaction and some epigenetic mechanisms linking obesity and insulin resistance to metabolic diseases.

Evidence that the adenosine triphosphate-binding cassette G5/G8-independent pathway plays a determinant role in cholesterol gallstone formation in mice.

UNLABELLED: The adenosine triphosphate-binding cassette (ABC) sterol transporter, Abcg5/g8, is Lith9 in mice, and two gallstone-associated variants in ABCG5/G8 have been identified in humans. Although ABCG5/G8 plays a critical role in determining hepatic sterol secretion, cholesterol is still secreted to bile in sitosterolemic patients with a defect in either ABCG5 or ABCG8 and in either Abcg5/g8 double- or single-knockout mice. We hypothesize that in the defect of ABCG5/G8, an ABCG5/G8-independent pathway is essential for regulating hepatic secretion of biliary sterols, which is independent of the lithogenic mechanism of the ABCG5/G8 pathway. To elucidate the effect of the ABCG5/G8-independent pathway on cholelithogenesis, we investigated the biliary and gallstone characteristics in male wild-type (WT), ABCG5(-/-)/G8(-/-), and ABCG8 (-/-) mice fed a lithogenic diet or varying amounts of cholesterol, treated with a liver X receptor (LXR) agonist, or injected intravenously with [(3) H]sitostanol- and [(14) C]cholesterol-labeled high-density lipoprotein (HDL). We found that ABCG5(-/-)/G8(-/-) and ABCG8 (-/-) mice displayed the same biliary and gallstone phenotypes. Although both groups of knockout mice showed a significant reduction in hepatic cholesterol output compared to WT mice, they still formed gallstones. The LXR agonist significantly increased biliary cholesterol secretion and gallstones in WT, but not ABCG5(-/-)/G8(-/-) or ABCG8 (-/-), mice. The 6-hour recovery of [(14) C]cholesterol in hepatic bile was significantly lower in both groups of knockout mice than in WT mice and [(3) H]sitostanol was detected in WT, but not ABCG5(-/-)/G8(-/-) or ABCG8 (-/-), mice. CONCLUSIONS: The ABCG5/G8-independent pathway plays an important role in regulating biliary cholesterol secretion, the transport of HDL-derived cholesterol from plasma to bile, and gallstone formation, which works independently of the ABCG5/G8 pathway. Further studies are needed to observe whether this pathway is also operational in humans. (Hepatology 2016;64:853-864).

The deletion of the estrogen receptor α gene reduces susceptibility to estrogen-induced cholesterol cholelithiasis in female mice.

Compelling evidence has demonstrated that estrogen is a critical risk factor for gallstone formation and enhances cholesterol cholelithogenesis through the hepatic estrogen receptor α (ERα), but not ERß. To study the lithogenic mechanisms of estrogen through ERα, we investigated whether the deletion of Erα protects against gallstone formation in ovariectomized (OVX) female mice fed a lithogenic diet and treated with 17ß-estradiol (E2) at 0 or 6µg/day for 56days. Our results showed that the prevalence of gallstones was reduced from 100% in OVX ERα (+/+) mice to 30% in OVX ERα (-/-) mice in response to high doses of E2 and the lithogenic diet for 56days. Hepatic cholesterol secretion was significantly diminished in OVX ERα (-/-) mice compared to OVX ERα (+/+) mice even fed the lithogenic diet and treated with E2 for 56days. These alterations decreased bile lithogenicity by reducing cholesterol saturation index of gallbladder bile. Immunohistochemical studies revealed that ERα was expressed mainly in the gallbladder smooth muscle cells. High levels of E2 impaired gallbladder emptying function mostly through the ERα and cholecystokinin-1 receptor pathway, leading to gallbladder stasis in OVX ERα (+/+) mice. By contrast, gallbladder emptying function was greatly improved in OVX ERα (-/-) mice. This markedly retarded cholesterol crystallization and the growth and agglomeration of solid cholesterol crystals into microlithiasis and stones. In conclusion, the deletion of Erα reduces susceptibility to the formation of E2-induced gallstones by diminishing hepatic cholesterol secretion, desaturating gallbladder bile, and improving gallbladder contraction function in female mice.

Reporting thyroid FNA before and after implementation of the Bethesda system-one institution's experience.

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology was published in 2008 and was implemented at Beth Israel Deaconess Medical Center (BIDMC) in June, 2010. Prior to this date, our diagnostic scheme was similar to the Bethesda System, except for the category of "Atypia/Follicular Lesion of Undetermined Significance" (AUS). This study evaluates the impact of the Bethesda System on the rate and the positive predictive value (PPV) of the diagnostic categories at BIDMC. METHODS: We performed a retrospective review of all thyroid fine-needle aspirations (FNAs) during the time periods January, 2006 to November, 2008 and June, 2010 to July, 2011 and the subsequent thyroidectomy specimens. RESULTS: Post-Bethesda System, diagnoses that are equivocal for diverse reasons and which have wide-ranging PPVs are now all grouped into the AUS category, and the proportion of cases that are in the atypical/AUS category rose from 3.7% in the pre-Bethesda period to 12% in the post-Bethesda period. CONCLUSION: The AUS category has a PPV approaching 50% in our lab. This creates uncertainty regarding the appropriate management for this category and may cause unnecessary overuse of molecular testing for cases in the AUS category.

Cytologic rapid on-site evaluation of transthoracic computed tomography-guided lung needle biopsies: who should perform ROSE? A cross-institutional analysis of procedural and diagnostic outcomes.

INTRODUCTION: Cytologic rapid on-site evaluation (ROSE) during minimally invasive biopsy procedures is an increasingly important service provided by cytopathology to increase diagnostic yield and appropriately triage cellular material. Although ROSE can be performed by cytopathologists, cytotechnologists, or cytopathology fellows, few studies have directly compared both procedural and diagnostic outcome measures among different ROSE personnel. MATERIALS AND METHODS: We evaluated all transthoracic computed tomography (CT)-guided lung biopsies in which ROSE was performed during a 1-year period at 2 academic institutions with similar patient populations and procedural methods: Dartmouth-Hitchcock Medical Center (DHMC) (where ROSE is performed by cytopathologists) and the Beth Israel Deaconess Medical Center (BIDMC) (where ROSE is rendered by either cytotechnologists or cytopathology fellows). RESULTS: A total of 273 CT-guided transthoracic lung biopsies (190 DHMC, 83 BIDMC) were analyzed. There was no major difference in procedure time with respect to ROSE personnel. The repeat procedure rate for nondiagnostic biopsies was similar at DHMC (cytopathologists) and BIDMC (cytotechnologists or cytology fellows) (2.1% versus 2.3%, P = 1.0). Adequacy rates for cytopathologists, cytotechnologists, and cytopathology fellows were comparable (P = 0.23). ROSE assessments by cytopathologists were more concordant with the final diagnosis (87%) than those by cytotechnologists (82%) or cytopathology fellows (79%); this difference was not statistically significant (P = 0.28). CONCLUSIONS: ROSE procedural and diagnostic outcomes for transthoracic CT-guided lung biopsies were similar among cytopathologists, cytotechnologists, and cytopathology fellows.

Ezetimibe prevents the formation of oestrogen-induced cholesterol gallstones in mice.

BACKGROUND: Oestrogen is an important risk factor for cholesterol cholelithiasis not only in women of childbearing age taking oral contraceptives and postmenopausal women undergoing hormone replacement therapy, but also in male patients receiving oestrogen therapy for prostatic cancer. In women, hormonal changes occurring during pregnancy markedly increase the risk of developing gallstones. We investigated whether the potent cholesterol absorption inhibitor ezetimibe could prevent the formation of oestrogen-induced cholesterol gallstones in mice. DESIGN: Following ovariectomy, female AKR mice were implanted subcutaneously with pellets releasing 17ß-estradiol at 6 µg/day and fed a lithogenic diet supplemented with ezetimibe in doses of 0 or 8 mg/kg/day for 8 weeks. Cholesterol crystallization and gallstone prevalence, lipid concentrations and composition in bile, and biliary lipid output were analysed by physical-chemical methods. Intestinal cholesterol absorption efficiency was determined by faecal dual-isotope ratio methods. RESULTS: Ezetimibe inhibited intestinal cholesterol absorption, while significantly reducing hepatic secretion of biliary cholesterol. Consequently, bile was desaturated through the formation of numerous unsaturated micelles and gallstones were prevented by ezetimibe in mice exposed to high doses of oestrogen and fed the lithogenic diet. Ezetimibe did not influence mRNA levels of the classical oestrogen receptors α (ERα) and ERß, as well as a novel oestrogen receptor the G protein-coupled receptor 30 (GPR30) in the liver. CONCLUSIONS: Ezetimibe protects against the oestrogen-mediated lithogenic actions on gallstone formation in mice. Our finding may provide an efficacious novel strategy for the prevention of cholesterol gallstones in high-risk subjects, especially those exposed to high levels of oestrogen.

Assessment of breast pathologies using nonlinear microscopy.

Rapid intraoperative assessment of breast excision specimens is clinically important because up to 40% of patients undergoing breast-conserving cancer surgery require reexcision for positive or close margins. We demonstrate nonlinear microscopy (NLM) for the assessment of benign and malignant breast pathologies in fresh surgical specimens. A total of 179 specimens from 50 patients was imaged with NLM using rapid extrinsic nuclear staining with acridine orange and intrinsic second harmonic contrast generation from collagen. Imaging was performed on fresh, intact specimens without the need for fixation, embedding, and sectioning required for conventional histopathology. A visualization method to aid pathological interpretation is presented that maps NLM contrast from two-photon fluorescence and second harmonic signals to features closely resembling histopathology using hematoxylin and eosin staining. Mosaicking is used to overcome trade-offs between resolution and field of view, enabling imaging of subcellular features over square-centimeter specimens. After NLM examination, specimens were processed for standard paraffin-embedded histology using a protocol that coregistered histological sections to NLM images for paired assessment. Blinded NLM reading by three pathologists achieved 95.4% sensitivity and 93.3% specificity, compared with paraffin-embedded histology, for identifying invasive cancer and ductal carcinoma in situ versus benign breast tissue. Interobserver agreement was κ = 0.88 for NLM and κ = 0.89 for histology. These results show that NLM achieves high diagnostic accuracy, can be rapidly performed on unfixed specimens, and is a promising method for intraoperative margin assessment.

On endocytoscopy and posttherapy pathologic staging in esophageal cancers, and on evidence-based methodology.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the value of endocytoscopy to replace biopsy histology for squamous cell carcinoma and the clinical significance of posttherapy pathologic stage in patients with esophageal adenocarcinoma following preoperative chemoradiation; a short discussion of evidence-based methodology is also included.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): an overview and update for the cytopathologist.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a minimally invasive technique for evaluating the mediastinum and staging patients with lung cancer. In the hands of an experienced operator, the procedure is safe and provides excellent sensitivity, specificity, and predictive diagnostic values. In conjunction with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), a nearly complete mediastinal evaluation can be performed in a minimally invasive fashion. This strategy results in improved lymph node staging, markedly reduced need for mediastinoscopy, and fewer futile thoracotomies compared with a traditional surgical staging procedure. The procedure is cost effective and provides excellent cytologic specimens that have proven well suited for ancillary testing, such as immunohistochemistry and tumor genotyping. EBUS-TBNA, initially used as a tool to sample the lymph nodes adjacent to the airway walls, has now become instrumental in sampling lesions in the mediastinum, hilum, and lung parenchyma, where previously more than 1 procedure would have been necessary. Looking forward, expanded use of this procedure is likely to revolutionize the access to cytology-proven staging and restaging of lung cancer and other thoracic malignancies in a minimally invasive fashion.

Histologic features in colon biopsies can discriminate mycophenolate from GVHD-induced colitis.

Mycophenolate mofetil (MMF) is a T-cell inhibitor frequently used in the treatment of acute allograft rejection. MMF may cause colitis that clinically and histologically resembles graft-versus-host disease (GVHD). The aim of this study was to evaluate a wide range of histologic features that may help differentiate MMF from GVHD-induced colitis and to validate significant features on a cohort of bone marrow transplant patients who were also taking MMF as part of their immunosuppressive regimen and developed a diarrheal illness due to colitis. Routinely processed colonic biopsies from 17 patients with MMF colitis and 40 patients with GVHD-induced colitis were evaluated for the overall grade of colitis (grades 1 to 4) and histologically for a wide range of inflammatory, epithelial, and architectural changes in a blinded manner. Statistically significant features were then tested in a cohort of 20 bone marrow transplant patients who also received MMF, and later developed a diarrheal illness. Both univariate and multivariate analyses (including receiver operating characteristic analysis) were performed. Morphologic features shown to be independently associated with MMF include the presence and quantity of lamina propria eosinophils and endocrine cell aggregates and the presence and quantity of apoptotic microabscesses, hypereosinophilic (degenerated) crypts, and crypt distortion. Eosinophils were present in all MMF patients, but apoptotic microabscesses were present in none and endocrine cell aggregates in only 1 case. When a grade-by-grade comparison was made between MMF and GVHD, grade 1 or 2 MMF also showed an increased prevalence rate and quantity of lamina propria neutrophils in comparison with grade 1 or 2 GVHD. By receiver operating characteristic analysis, a combination of lamina propria eosinophils >15 per 10 HPF, combined with a lack of endocrine cell aggregates and apoptotic microabscesses, revealed sensitivity, specificity, and positive and negative predictive values of 76%, 93%, 81%, and 90%, respectively, for identification of MMF colitis. On the basis of these data, we conclude that a variety of histologic features, in particular, eosinophils >15 per 10 HPF, lack of endocrine cell aggregates in the lamina propria, and lack of apoptotic microabscesses, can be used by pathologists to help separate MMF from GVHD-induced colitis in routine clinical practice.

The esophageal mucosa and submucosa: immunohistology in GERD and Barrett's esophagus.

This paper presents commentaries on the microscopic morphology of esophageal squamous epithelium; the frequency of duplication of the muscularis mucosae (MM) in Barrett's esophagus (BE); the significance of multilayered epithelium; whether cells in the lamina propria reflect those in the epithelium; how stem cells are identified in the squamous esophagus; dilated intercellular spaces; the metastasizing potential of early carcinoma-dependent, molecular or immunohistochemical tests that improve diagnosis; the role of immunohistochemistry IHC in grading of neoplasia in Barrett's esophagus and defining the risk of progression to adenocarcinoma; the roles of CDX1 and CDX2 in squamous and cardiac mucosa; and the role of desmosomal cadherins and lectins in squamous and cardiac mucosa.