Portosinusoidal Vascular Disorder: A Heretofore Unrecognized Manifestation of Sickle Cell Disease?

Portosinusoidal vascular disorder (PSVD) is a recently proposed histopathologic entity that encompasses a spectrum of often subtle hepatic microvascular lesions and related microarchitectural abnormalities. Clinical manifestations may arise years after histologic diagnosis and include extrahepatic portal vein thrombosis and portal hypertension. While the histopathologic features of PSVD have been associated with numerous clinical conditions, most notably prothrombotic/vasculopathic disorders, PSVD has not yet been described in sickle cell disease. This gap is striking given the central role of microvascular dysfunction in sickle cell disease and well-described patterns of hepatic injury and dysfunction in this population. This case series is the first to explore the prevalence and pathogenesis of PSVD in sickle cell disease. Forty-one diagnostically adequate liver biopsies from patients with sickle cell disease were identified across the archives of 5 tertiary medical centers. All biopsies exhibited at least 1 histopathologic feature associated with PSVD (mean 3.8 features/case). Overall, 90.2% of patients met the criteria for a diagnosis of PSVD based on the presence of specific histopathologic and/or clinical findings. Immunohistochemical stains for von Willebrand factor, CD34, and glutamine synthetase were performed on 36 cases (87.8%). Aberrant (centrilobular sinusoidal) CD34 and von Willebrand factor staining was present in 97.2% and 86.1% of cases, respectively. Glutamine synthetase reactivity was at least mildly decreased in zone 3 hepatocytes in 52.8% of cases. We posit that chronic erythrocyte sickling results in dysfunction and remodeling of the portal microvasculature, culminating in regression of zone 3 hepatocytes. The presence of PSVD may explain, at least in part, the hepatic dysfunction observed in this patient population. These patients may also benefit from extended clinical surveillance for portal hypertension and other complications. While subtle and prone to overdiagnosis, the features of PSVD should be carefully considered when interpreting liver biopsies from patients with sickle cell disease.

Clinicopathologic Features of Gastrointestinal Tract Langerhans Cell Histiocytosis.

Gastrointestinal (GI) tract involvement by Langerhans cell histiocytosis (LCH) is rare and its clinicopathologic characteristics have only been described in case reports and small series. We reviewed hematoxylin and eosin- and CD1a, S100, and Langerin immunohistochemical-stained slides from 47 patients with well-documented demographic and clinical findings. Our cases included 8 children and 39 adults, with a mean follow-up of 63 months. All pediatric patients had concurrent multisystem LCH, presented with GI symptoms, and showed non-polypoid lesions. Seven (88%) showed multifocal GI disease, including five with multiple GI organ involvement. All sampled lesions from children exhibited infiltrative growth. More than half had died of the disease or manifested persistent LCH at last follow-up. Twenty-five of 39 (64%) adults had LCH involving only the GI tract (single-system), with the remaining 14 (36%) exhibiting multi-system disease. Adult single-system GI LCH was typically encountered incidentally on screening/surveillance endoscopy (72%). Most exhibited isolated colorectal involvement (88%) as a solitary polyp (92%), with a well-demarcated/noninfiltrative growth pattern (70%), and excellent prognosis (100%). In comparison, adult patients with multi-system LCH more frequently presented with GI symptoms (92%, P<0.001), non-colorectal GI site involvement (50%, P=0.02), multifocal GI lesions (43%, P=0.005), non-polypoid lesions (71%, P<0.001), infiltrative histologic growth pattern (78%, P=0.04), and persistent disease (57%, P<0.001). Adult multi-system LCH patients appear to exhibit similar clinicopathologic features to those of pediatric patients. These results demonstrate that adults with single-system LCH involving the GI tract have an excellent prognosis, while multi-system LCH occurring at any age carries an unfavorable prognosis. High-risk features of GI LCH include pediatric age, GI symptomatology, non-colorectal GI involvement, multifocal GI disease, non-polypoid lesions, and infiltrative growth pattern.

Utility of Machine Learning to Detect Cytomegalovirus in Digital Hematoxylin and Eosin-Stained Slides.

Rapid and accurate cytomegalovirus (CMV) identification in immunosuppressed or immunocompromised patients presenting with diarrhea is essential for therapeutic management. Due to viral latency, however, the gold standard for CMV diagnosis remains to identify viral cytopathic inclusions on routine hematoxylin and eosin (H&E)-stained tissue sections. Therefore, biopsies may be taken and "rushed" for pathology evaluation. Here, we propose the use of artificial intelligence to detect CMV inclusions on routine H&E-stained whole-slide images to aid pathologists in evaluating these cases. Fifty-eight representative H&E slides from 30 cases with CMV inclusions were identified and scanned. The resulting whole-slide images were manually annotated for CMV inclusions and tiled into 300 × 300 pixel patches. Patches containing annotations were labeled "positive," and these tiles were oversampled with image augmentation to account for class imbalance. The remaining patches were labeled "negative." Data were then divided into training, validation, and holdout sets. Multiple deep learning models were provided with training data, and their performance was analyzed. All tested models showed excellent performance. The highest performance was seen using the EfficientNetV2BO model, which had a test (holdout) accuracy of 99.93%, precision of 100.0%, recall (sensitivity) of 99.85%, and area under the curve of 0.9998. Of 518,941 images in the holdout set, there were only 346 false negatives and 2 false positives. This shows proof of concept for the use of digital tools to assist pathologists in screening "rush" biopsies for CMV infection. Given the high precision, cases screened as "positive" can be quickly confirmed by a pathologist, reducing missed CMV inclusions and improving the confidence of preliminary results. Additionally, this may reduce the need for immunohistochemistry in limited tissue samples, reducing associated costs and turnaround time.

Non-conventional dysplasia is frequently associated with low-grade tubuloglandular and mucinous adenocarcinomas in inflammatory bowel disease.

There is limited information regarding the clinicopathological features of low-grade tubuloglandular (LGTGA) and mucinous (MAC) adenocarcinomas occurring in inflammatory bowel disease (IBD), especially with regard to their precursor lesions. METHODS AND RESULTS: Forty-six IBD colectomy specimens with LGTGA (n = 17) or MAC (n = 29) with adjacent precursor lesions were analysed. As controls, 12 IBD colectomy specimens with well- to moderately differentiated adenocarcinoma that lacked any mucinous, signet ring cell, low-grade tubuloglandular or serrated features were also analysed. Compared with MACs and controls, LGTGAs more often had a flat/invisible macroscopic appearance (LGTGAs = 88%, MACs = 34%, controls = 25%, P < 0.001). MACs were more likely to have high-grade differentiation (MACs = 31%, LGTGAs = 0%, controls = 0%, P = 0.002) and a higher pathological stage (pT3 and pT4 MACs = 76%, LGTGAs = 35%, controls = 33%, P = 0.007) than LGTGAs and controls. LGTGAs (70%) and MACs (53%) were more frequently associated with non-conventional dysplasia than controls (0%) (P < 0.001). Crypt cell (40%) and hypermucinous (34%) dysplasias were the most common non-conventional subtypes associated with LGTGAs and MACs, respectively. Synchronous dysplasia often demonstrated non-conventional features in the LGTGA (33%) and MAC (47%) groups (versus 0% for the control group, P = 0.074). Synchronous cancer frequently showed similar histological features as the main tumour (LGTGA group = 60%, MAC group = 38%, control group = 100%). CONCLUSIONS: Crypt cell and hypermucinous dysplasias are the most common precursor lesions associated with LGTGAs and MACs, respectively, and may serve as a marker of increased risk for these cancer subtypes.

Sex hormones regulate metainflammation in diet-induced obesity in mice.

Men have a statistically higher risk of metabolic and cardiovascular disease than premenopausal women, but the mechanisms mediating these differences are elusive. Chronic inflammation during obesity contributes to disease risk and is significantly more robust in males. Prior work demonstrated that compared with obese males, obese females have reduced proinflammatory adipose tissue macrophages (ATMs). Given the paucity of data on how sex hormones contribute to macrophage responses in obesity, we sought to understand the role of sex hormones in promoting obesity-induced myeloid inflammation. We used gonadectomy, estrogen receptor-deficient alpha chimeras, and androgen-insensitive mice to model sex hormone deficiency. These models were evaluated in diet-induced obesity conditions (high-fat diet [HFD]) and in vitro myeloid assays. We found that ovariectomy increased weight gain and adiposity. Ovariectomized females had increased ATMs and bone marrow myeloid colonies compared with sham-gonadectomized females. In addition, castrated males exposed to HFD had improved glucose tolerance, insulin sensitivity, and adiposity with fewer Ly6chi monocytes and bone marrow myeloid colonies compared with sham-gonadectomized males, although local adipose inflammation was enhanced. Similar findings were observed in androgen-insensitive mice; however, these mice had fewer CD11c+ ATMs, implying a developmental role for androgens in myelopoiesis and adipose inflammation. We concluded that gonadectomy results in convergence of metabolic and inflammatory responses to HFD between the sexes, and that myeloid estrogen receptor alpha contributes minimally to diet-induced inflammatory responses, whereas loss of androgen-receptor signaling improves metabolic and inflammatory outcomes. These studies demonstrate that sex hormones play a critical role in sex differences in obesity, metabolic dysfunction, and myeloid inflammation.

Transient Lymphocytic Colitis After SARS-CoV2 mRNA Vaccine.

This is the first scientific report describing lymphocytic colitis after administration of the Pfizer severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) messenger RNA (mRNA) vaccine. The patient developed liquid stools, abdominal pain, and nausea within 24 hours of receiving the second dose. Symptoms were persistent for 3 months but improved 113 days after onset. Laboratory profiles and gastrointestinal polymerase chain reaction were normal. Esophagogastroduodenoscopy and colonoscopy performed 98 days after onset revealed patchy erythema in the descending colon and rectosigmoid. Mucosal evaluation revealed lymphocytic colitis. Review of the Vaccine Adverse Event Reporting System revealed 5 cases of microscopic colitis after the second mRNA dose. This report and Vaccine Adverse Event Reporting System cases suggest providers should consider microscopic colitis in the differential diagnosis of patients with severe, persistent diarrhea after the SARS-CoV2 mRNA vaccine.

Metallothionein immunohistochemistry has high sensitivity and specificity for detection of Wilson disease.

Diagnosis of Wilson disease (WD) can be difficult because of its protean clinical presentations, but early diagnosis is important because effective treatment is available and can prevent disease progression. Similarly, diagnosis of WD on liver biopsy specimens is difficult due to the wide range of histologic appearances. A stain that could help identify WD patients would be of great value. The goal of this study was to use mass spectrometry-based proteomics to identify potential proteins that are differentially expressed in WD compared to controls, and could serve as potential immunohistochemical markers for screening. Several proteins were differentially expressed in WD and immunohistochemical stains for two (metallothionein (MT) and cytochrome C oxidase copper chaperone (COX17)) were tested and compared to other methods of diagnosis in WD including copper staining and quantitative copper assays. We found diffuse metallothionein immunoreactivity in all liver specimens from patients with WD (n = 20); the intensity of the staining was moderate to strong. This staining pattern was distinct from that seen in specimens from the control groups (none of which showed strong, diffuse staining), which included diseases that may be in the clinical or histologic differential of WD (steatohepatitis (n = 51), chronic viral hepatitis (n = 40), autoimmune hepatitis (n = 50), chronic biliary tract disease (n = 42), and normal liver (n = 20)). COX17 immunostain showed no significant difference in expression between the WD and control groups. MT had higher sensitivity than rhodanine for diagnosis of WD. While the quantitative liver copper assays also had high sensitivity, they require more tissue, have a higher cost, longer turnaround time, and are less widely available than an immunohistochemical stain. We conclude that MT IHC is a sensitive immunohistochemical stain for the diagnosis of WD that could be widely deployed as a screening tool for liver biopsies in which WD is in the clinical or histologic differential diagnosis.

The histological spectrum of ARB-induced gastritis.

AIMS: Olmesartan, an angiotensin receptor blocker (ARB) used for hypertension management, is known to cause a sprue-like enteropathy in a subset of patients. Rare cases of gastritis occurring with ARB use have also been reported, but the histological features of ARB-induced gastritis and the response to drug cessation have not been examined in a dedicated case-series. METHODS AND RESULTS: Cases of suspected ARB-induced gastritis were identified from the pathology archives of four institutions. Haematoxylin and eosin (H&E) slides from gastric biopsies were reviewed. Fifteen patients (14 female, one male) were identified. The most common presenting symptoms were diarrhoea (10) and weight loss (six). Gastric biopsies commonly showed a full-thickness active chronic gastritis with surface epithelial injury involving the antrum and body. Glandular atrophy, intra-epithelial lymphocytosis and/or subepithelial collagen thickening were also present in some cases. Duodenal involvement, including villous atrophy, intra-epithelial lymphocytosis and/or collagenous sprue, was identified in 11 of 13 cases with concurrent duodenal biopsies. Following drug cessation, symptomatic improvement occurred in all 11 cases for which follow-up data were available. Histological resolution occurred in five of eight cases with follow-up gastric biopsies, with improvement seen in the remaining three biopsies. CONCLUSION: ARB-induced gastritis typically presents as active chronic gastritis, frequently with associated surface epithelial injury. Glandular atrophy, intra-epithelial lymphocytosis and/or subepithelial collagen thickening may also be present. These gastric changes can be seen without associated duodenal injury in rare cases, and they should alert the pathologist to the possibility of ARB-induced injury. Drug cessation results in marked symptomatic and histological improvement.

Measuring depth of invasion of submucosa - invasive adenocarcinoma in oesophageal endoscopic specimens: how good are we?

AIMS: Emerging data support that submucosa-invasive (pT1b) esophageal adenocarcinomas are cured via endoscopic resection, provided that invasion measures ≤500 µm, they lack other histological features predictive of nodal metastasis and have negative margins. Hence, pathologists' measurement of the depth of submucosal invasion in endoscopic resections may dictate further management (i.e. endoscopic follow-up versus oesophagectomy). In this study, we assessed the interobserver agreement in measuring the depth of submucosal invasion in oesophageal endoscopic resections. METHODS AND RESULTS: Six subspecialised gastrointestinal (GI) pathologists from five academic centres independently measured the depth of submucosal invasion in µm from the deepest muscularis mucosae on 37 oesophageal endoscopic resection slides (round 1 scoring). A consensus meeting with a systematic approach for measuring and discussion of pitfalls was undertaken and remeasuring (round 2 scoring) was conducted. Interobserver agreement was assessed by the intraclass correlation coefficient (ICC) and Cohen's kappa statistics. A lack of agreement was seen among the six reviewers with a poor ICC for both rounds: 1 [0.40, 95% confidence interval (CI) = 0.26-0.56] and 2 (0.49, 95% CI = 0.34-0.63). When measurements were categorised as < or >500 µm, the overall agreement among the six reviewers was only fair for both rounds: 1 (kappa = 0.37, 95% CI = 0.22-0.53) and 2 (kappa = 0.29, 95% CI = 0.12-0.46). CONCLUSIONS: Our study shows a lack of agreement among gastrointestinal pathologists in measuring the depth of submucosal invasion in oesophageal endoscopic resections despite formulating a consensus approach for scoring. If important management decisions continue to be based upon this parameter, more reproducible and concrete guidelines are needed.

Histologic features of colonic infections.

BACKGROUND: The histopathologic diagnosis of infectious colitis remains relevant despite recent advances in microbiologic techniques. OBJECTIVE: This article aims to describe the histologic features of selected infectious diseases of the colon. MATERIALS AND METHODS: Existing reports on histopathologic and clinical aspects of colonic infectious agents were reviewed. RESULTS: While histology alone may not be as sensitive as current microbiologic methods, tissue identification of infectious agents still plays an important role in patient care. Infectious colitis can have a variety of clinical manifestations, ranging from strongyloidiasis, which can cause a smoldering, subclinical infection for decades, to syphilis, which can clinically mimic cancer or inflammatory bowel disease. Therefore, the histopathologic identification of infection as the cause of a patient's colitis has a considerable impact on treatment decisions. Morphologic overlap can occur between infection and other diseases, however. Moreover, some infections can elicit various tissue responses beyond acute colitis. Immunosuppressed patients may not mount an inflammatory response to pathogens such as cytomegalovirus or adenovirus. Sexually transmitted proctocolitis can cause plasma-cell-rich inflammation. Gastrointestinal histoplasmosis is more likely to cause diffuse histiocyte infiltration rather than the expected granuloma formation. In some cases, ancillary tests are useful, but equivocal results can cause diagnostic dilemmas. CONCLUSION: Given the range with which colonic infectious disorders can manifest, pathologists should be aware of the typical features of infectious colitis, as well as findings beyond the classic morphologies.

Transient elastography versus liver biopsy: discordance in evaluations for fibrosis and steatosis from a pathology standpoint.

Vibration-controlled transient elastography (VCTE) is a non-invasive method of evaluating liver fibrosis and steatosis. It can easily be performed in the outpatient setting and has been suggested as an alternative to liver biopsy. However, VCTE and biopsy discrepancies commonly occur. Patient characteristics, procedure performance, and liver features can impact the reliability of VCTE results. We identified 82 patients who received VCTE and biopsy within one month to assess how frequently major discrepancies occur and to determine the role of the liver biopsy in this workup. In our study, 35.4% of patients had a major fibrosis discrepancy, which was defined as advanced fibrosis or cirrhosis by VCTE and no to minimal fibrosis on biopsy. This was significantly associated with increased BMI, and liver features including steatohepatitis, inflammation, congestion, and cholestasis were important contributors to discrepancies. All patients with advanced fibrosis or cirrhosis on liver biopsy were appropriately detected by VCTE (n = 28). Detection of steatosis was less sensitive as 19% (n = 4 of 21) of patients with moderate to severe steatosis on biopsy were missed by VCTE. Liver biopsy has been traditionally performed for diagnosis, but with the emergence of non-invasive tools to evaluate for liver fibrosis and steatosis, biopsies are now additionally being performed to confirm findings from noninvasive procedures. Although VCTE is a highly sensitive tool for liver fibrosis, it is not as specific, and therefore, the liver biopsy remains the gold standard for accurate fibrosis assessment.

Clinical significance of pathologic abnormalities in biopsy samples from the appendiceal orifice.

AIMS: Appendiceal orifice mucosa often appears inflamed endoscopically, even when other colonic segments appear normal. Histological findings in biopsy samples taken from endoscopically abnormal mucosa may simulate a variety of inflammatory colitides. We performed this study to evaluate the clinical implications of inflammatory changes isolated to the appendiceal orifice. METHODS AND RESULTS: In this double cohort study, biopsy samples from 26 histologically abnormal appendiceal orifices were reviewed. Twenty-five control cases were culled from endoscopically normal (n = 11) and abnormal (n = 14) appendiceal orifices that were histologically normal. Histological findings were correlated with presentation, medication history, findings at other colonic sites and clinical outcomes. Study cases displayed active inflammation (n = 12), chronic active inflammation (n = 13) or features simulating collagenous colitis (n = 1). Eighteen patients had biopsies taken from other colonic sites; these revealed benign polyps (n = 10) or displayed active (n = 4) or chronic active (n = 4) inflammation. All patients with findings isolated to the appendiceal orifice were asymptomatic at most recent clinical follow-up. Four of eight (50%) of the patients with inflammation in other biopsy samples were ultimately diagnosed with ulcerative colitis, in keeping with the well-established role of the appendix as a 'skip lesion' in that disorder. Control patients presented for screening colonoscopy (n = 19), iron deficiency anaemia (n = 3) or change in bowel habits (n = 3) and none reported gastrointestinal symptoms upon follow-up, regardless of the endoscopic appearance of the appendiceal orifice. CONCLUSION: Isolated inflammation of the appendiceal orifice mucosa should not be regarded as a feature of evolving inflammatory bowel disease or other types of chronic colitis.

Diagnostic challenges of focal nodular hyperplasia: interobserver variability, accuracy, and the utility of glutamine synthetase immunohistochemistry.

AIMS: The diagnosis of focal nodular hyperplasia (FNH) and the interpretation of glutamine synthetase (GS) staining can be challenging on biopsies. We aimed to evaluate the reproducibility of needle biopsy diagnosis of FNH, the effect of GS immunohistochemistry on FNH diagnosis, and which histological features are most useful for the diagnosis of FNH. METHODS AND RESULTS: The study included virtual needle biopsies generated from 75 resection specimens (30 FNHs, 15 hepatocellular adenomas, 15 hepatocellular carcinomas, and 15 non-lesional liver specimens). Pathologists were reasonably accurate (83.1%) in the diagnosis of FNH with haematoxylin and eosin alone. Ductular reaction and nodularity had the highest sensitivity for a diagnosis of FNH (88.1% and 82.2%, respectively), whereas central scar was the most specific feature (90.6%). The presence of two or more of the classic histological features had 89.6% sensitivity and 86.2% specificity for a diagnosis of FNH. Diagnostic accuracy was significantly higher with the addition of a GS stain. A map-like GS staining pattern was highly specific (99.3%) for FNH. However, GS staining was interpreted as non-map-like in 14.4% of reviews of true FNH cases, and overall interobserver agreement for interpretation of the GS staining pattern was only moderate (kappa = 0.42). CONCLUSIONS: Pathologists are reasonably accurate in the diagnosis of FNH on virtual biopsies, and GS staining improves accuracy. However, a subset of FNH cases remain challenging. Steatosis and a pseudo-map-like GS staining pattern were associated with increased difficulty. Therefore, although a map-like GS staining pattern is useful for confirmation of a diagnosis, the lack of a map-like GS staining pattern on needle biopsy does not necessarily exclude a diagnosis of FNH.

Varying practices in tumor regression grading of gastrointestinal carcinomas after neoadjuvant therapy: results of an international survey.

Tumor regression grading is routinely performed on neoadjuvantly treated gastrointestinal cancer resections. Challenges in tumor regression grading include grossing standards, multiple grading systems, and difficulty interpreting therapy-induced changes. We surveyed gastrointestinal pathologists around the world for their practices in handling neoadjuvantly treated gastrointestinal cancer specimens and reporting tumor regression using a 23-question online survey. Topics addressed grossing, histologic work-up, tumor regression grading systems, and degree of difficulty identifying and estimating residual cancer within treatment effect. Two-hundred three responses were received, including 173 participants who completed the entire questionnaire. Fifty percent of the participants were from Europe, 29% from North America, 10% from Australia, and 11% from other continents. Ninety-five percent routinely report a tumor regression grade and 92% have standardized grossing and histologic work-up: 27% always completely embed the entire tumor bed, 54% embed the complete tumor site if not a grossly apparent, large mass. Fifty-nine percent use hematoxylin & eosin alone for assessment; the remaining use additional stains. In North America and Australia, the American Joint Committee on Cancer (AJCC)/College of American Pathologists (CAP)/Ryan system is routinely used for gastroesophageal (71%) and rectal carcinomas (77%). In Europe, the Mandard system is common (36%) for gastroesophageal tumors, followed by AJCC/CAP/Ryan (22%), and Becker (10%); for rectal CA, the Dworak system (30%) is followed by AJCC/CAP/Ryan (24%) and Mandard (14%). This regional differences were significant (p < 0.001 each). Fifty-one percent prefer a four-tiered system. Sixty-six percent think that regressive changes in lymph nodes should be part of a regression grade. Sixty-nine percent consider identifying residual tumor straight-forward, but estimating therapy-induced fibrosis difficult (57%). Free comments raised issues of costs for work-up and clinical relevance. In conclusion, this multinational survey provides a comprehensive overview of grossing and histologic work-up with regards to tumor regression grading in gastrointestinal cancers with partly significant regional differences particularly between North America and Europe.

Challenges with colorectal cancer staging: results of an international study.

Challenges exist with standardized colorectal cancer reporting despite adoption of the American Joint Committee on Cancer-Staging Manual 8th edition. We performed this study to gauge current practice patterns among a diverse group of surgical pathologists. A web-based questionnaire depicting problematic issues and images related to colorectal carcinoma staging was circulated among 118 surgical pathologists and their responses were correlated with their geographic location (North America vs. Europe vs. others), nature of practice (academic vs. community), the sign-out model (gastrointestinal subspecialty vs. general surgical pathology), and years of professional experience. We found that a substantial number of practicing pathologists ignore recommended-staging criteria in specific settings, particularly with respect to assessment of advanced T stage. Tumors that communicated with the serosa through inflammatory foci were staged as pT3 (49%) or pT4a (51%) by nearly equal numbers of pathologists regardless of level of experience, the sign-out model, or geographic location. Only 65% assigned T stage and margin status based on extent of viable tumor in the neoadjuvant setting. One-third of pathologists, particularly those in Europe (p = 0.015), classified acellular mucin deposits as N1 disease when detected in treatment-naive cases. Nearly 50% of pathologists classified isolated tumor cells (i.e., deposits <0.2 mm) in lymph nodes as metastatic disease (i.e., pN1, p = 0.02). Our results suggest that pathologists ignore recommendations that are based on insufficient data and apply individualized criteria when faced with situations that are not addressed in the American Joint Committee on Cancer Staging Manual 8th edition. These variations in practice limit the ability to compare outcome data across different institutions and draw attention to areas that require further study.

Utility of glutamine synthetase immunohistochemistry in identifying features of regressed cirrhosis.

The prevailing view that cirrhosis is irreversible has been challenged. It has been proposed that varying degrees of fibrosis regression can be achieved if the injurious agent is removed. In the normal liver, glutamine synthetase immunostaining is present around central veins. In regressed cirrhosis, although fibrous bands between portal tracts and central veins may largely be resorbed, the abnormal portal tract-central vein adherence often remains. Hence, we hypothesized that aberrant glutamine synthetase positivity adjacent to portal tracts would help identify regressed cirrhosis. We performed glutamine synthetase immunohistochemistry on 49 liver specimens (16 regressed cirrhosis, 18 cirrhotic, and 15 normal livers). Qualification for regressed cirrhosis required the following histologic features: curved, delicate incomplete septa, portal tract-central vein adhesions, and portal tract "remnants" (portal tracts with no venous branch). Out of 16, 14 regressed cirrhosis cases had baseline cirrhosis established based on previous biopsy or signs of cirrhosis based on physical exam, laboratory, and radiological findings. All regressed cirrhosis cases (100%) had areas of aberrant glutamine synthetase positivity adjacent to portal tracts, indicating that portal tract-central vein approximation had occurred (p < 0.001 compared to all other categories). No normal cases had glutamine synthetase positivity adjacent to portal tracts, and half of cirrhosis cases had areas showing features of regression, with focal glutamine synthetase positivity adjacent to portal tracts. Overall, glutamine synthetase expression showed highly significant differences among the three categories (p < 0.001). This study shows that aberrant glutamine synthetase positivity adjacent to portal tracts is present in regressed cirrhosis and can be useful in identifying regressed cirrhosis when it is histologically suspected.

Increased Frequency of Heterozygous Alpha-1-Antitrypsin Deficiency in Liver Explants From Nonalcoholic Steatohepatitis Patients.

Cirrhotic explanted livers occasionally have unexpected periodic acid-Schiff-diastase (PASD)-positive globules within the hepatocyte cytoplasm. It is often unclear whether this finding is a nonspecific consequence of cirrhosis or is indicative of an underlying alpha-1-antitrypsin deficiency (A1ATD) contributing to the cirrhosis. In this study, explanted livers were retrospectively evaluated for histopathology (including PASD status with confirmatory alpha-1-antitrypsin [A1AT] immunohistochemistry [IHC]), and chart review provided etiology of liver failure and general clinical parameters. Real-time polymerase chain reaction was used to detect A1AT genotype (SERPINA1 S and Z alleles) by melting curve analysis on liver explant tissue from selected cases. Of 196 explanted livers, 21 (11%) had PASD+ globules, which were significantly enriched in patients with a clinical diagnosis of nonalcoholic steatohepatitis (NASH; 47%) compared with other causes (P < 0.001). IHC confirmed all PASD+ globules were A1AT+, with 20 of 21 cases demonstrating diffuse A1AT staining. In an expanded NASH cohort, 42% (14/33) of explants had PASD+ globules, 92% of which were homozygous (n = 1) or heterozygous (n = 11) for the SERPINA1 Z allele, corresponding to nearly 40% of all NASH patients. Overall, the Z allele was present in 10% of all tested liver explants, with 85% of PASD+ cases genotyping homozygous (n = 2) or heterozygous (n = 20), which is far in excess of the estimated 2% in the general population. These results indicate PASD+ A1AT globules (with confirmatory genotyping showing at least 1 Z allele) are commonly observed in NASH, suggesting a synergistic relationship toward liver fibrosis. In addition, the high frequency of SERPINA1 Z alleles in liver transplantation patients supports the utility of pretransplant genotyping.

Rapid tissue processing using a temperature-controlled collection device to preserve tumor biomarkers.

Precision tissue diagnostics rely on high quality input specimens so that assay results are not affected by artifact, but advances in collection and processing of tissue specimens have lagged behind innovations in diagnostic assay development. Therefore, we have designed and evaluated a novel surgical tissue collection device that maintains and monitors sample temperature and motion throughout transport so that the major preanalytical variable of tissue temperature can be controlled and measured. This device, in combination with an improved cold-hot tissue fixation protocol affords optimal biomarker preservation in less overall time, thereby simultaneously improving diagnostic quality and turnaround time. We collected 50 primary and metastatic liver tumors using a novel transport device. Tissue was fixed using a rapid cold-hot fixation protocol and immunohistochemical assays were used to assess the performance of the device, in comparison to control tissue preserved using standard clinical fixation protocol. Two pathologists evaluated the IHC studies in a blinded fashion to determine the immunophenotype of each tumor. The observed IHC staining intensities and the clinical impressions of the immunophenotypes did not differ between tissue collected with the novel device and control tissue, while improvements in processing time were achieved. The novel cold transport device and rapid fixation protocol can be successfully and safely combined and used to monitor specimen conditions, thus preserving the diagnostic utility of specimens and improving the overall turn-around time of the diagnostic process.

Centrilobular ductular reaction correlates with fibrosis stage and fibrosis progression in non-alcoholic steatohepatitis.

There is increasing interest in the role of ductular reaction as part of the pathogenesis and characteristic histology of non-alcoholic steatohepatitis. However, earlier studies did not separately assess the contribution of periportal and centrilobular zone ductular reaction over the spectrum of non-alcoholic steatohepatitis, and their clinical significance remains unclear. We herein analyzed the character of ductular reaction in each hepatic zone in non-alcoholic steatohepatitis biopsies and for the first time evaluated the prognostic value of ductular reaction in baseline biopsies as a predictor of progression of fibrosis in subsequent biopsies. A total of 90 non-alcoholic steatohepatitis liver biopsies were included in the cohort. The relationships among ductular reaction, grade, stage, and other common histopathologic findings in non-alcoholic steatohepatitis were analyzed in a cross-sectional manner. Among these patients, a total of 47 patients underwent sequential liver biopsies in the absence of effective treatment. The frequency of ductular reaction and the other histopathologic parameters in the initial biopsies were analyzed as predictors of progression of fibrosis in the second biopsies in a longitudinal analysis. Centrilobular ductular reaction was identified in 90% of patients and 38% of centrilobular zones. The prevalence of centrilobular ductular reaction increased as non-alcoholic steatohepatitis grade increased (P=0.0002) and also as stage of fibrosis increased (P<0.0001) in the cross-sectional study. In the longitudinal study, the frequency of centrilobular ductular reaction in the initial biopsies was significantly higher in the group of progressors and correlated with the rate of fibrosis progression (P=0.02). Centrilobular ductular reaction is common in non-alcoholic steatohepatitis and its presence correlates significantly with increasing necroinflammatory activity and fibrosis stage. Development of centrilobular ductular reaction appears to predict progression of fibrosis in subsequent biopsies.

Pathological assessment of gastrointestinal biopsies from patients with idelalisib-associated diarrhea and colitis.

AIM: Idelalisib (IDELA) treatment is associated with diarrhea/colitis (incidence of ∼15% grade ≥3). We performed a retrospective analysis of gastrointestinal biopsies from 29 patients treated with IDELA across nine clinical trials. METHODS: A central core laboratory performed histopathologic review, immunohistochemistry, and droplet digital PCR viral studies. These results were correlated with tissue immune profiling data and morphologic features per modified Geboes score. RESULTS: Out of 29 eligible patients with abdominal pain or diarrhea, 24 (82.8%) had reported adverse event terms of diarrhea and/or colitis. Infectious pathogens were detected in 9/29 samples. Most biopsies presented with mixed/inflammatory infiltrates and contained increased numbers of FOXP3+ cells versus normal controls. CONCLUSION: This study revealed evidence of T-cell dysregulation and a substantial infectious component in association with IDELA-related diarrhea/colitis.