Extraskeletal Ewing Sarcoma of the Gastrointestinal and Hepatobiliary Tract: Deceptive Immunophenotype Commonly Leads to Misdiagnosis.

Ewing sarcoma (ES) is an uncommon mesenchymal neoplasm that typically develops as a bone mass, although up to 30% arise in extraskeletal sites. ES of the gastrointestinal (GI) and hepatobiliary tract is rare and may be misdiagnosed as other, more common neoplasms that occur in these sites. However, the correct classification of extraskeletal ES is important for timely clinical management and prognostication. We reviewed our experience of ES in the GI and hepatobiliary tract in order to further highlight the clinicopathologic features of these neoplasms and document the potential for misdiagnosis in this setting. The archives and consultation files of 6 academic institutions were retrospectively queried for cases of ES occurring in the GI and hepatobiliary tract. The histologic slides and ancillary studies were reviewed and clinical data were retrieved for each case through the electronic medical records, when available. Twenty-three patients with ES in the GI and/or hepatobiliary tract were identified from 2000 to 2022. Of these, 11 were women and 12 were men with a median age of 38 years (range, 2 to 64). Tumor locations included the pancreas (n=5), liver (n=2), stomach (n=3), colorectum (n=3), and small intestine (n=5), as well as tumors involving multiple organs, pelvis and retroperitoneum (n=5). Tumor size varied between 2 cm and 18 cm. Twenty were primary and 3 were metastases. Of the 23 cases, only 17% were initially diagnosed as ES. The most common misdiagnoses involved various forms of neuroendocrine neoplasia due to expression of synaptophysin and other neuroendocrine markers (22%). A wide variety of diagnoses including GI stromal tumor was considered due to aberrant CD117 expression (4%). The diagnosis of ES was ultimately confirmed by detection of the EWSR1 rearrangement in 22 cases. The remaining case was diagnosed using traditional immunohistochemistry. Follow-up information was available in 20 cases, with follow-up time varying between 2 and 256 months. Six patients with follow-up died of disease between 6 and 60 months following initial presentation. Our data indicate ES in the GI and hepatobiliary tract is commonly misdiagnosed leading to a delay in therapy. In light of the attendant therapeutic and prognostic implications, ES should be considered in the differential diagnosis of any GI or hepatobiliary tumor with epithelioid and/or small round cell morphology.

Milk fat globule-epidermal growth factor 8 (MFGE8) prevents intestinal fibrosis.

OBJECTIVE: Intestinal fibrosis is considered an inevitable consequence of chronic IBD, leading to stricture formation and need for surgery. During the process of fibrogenesis, extracellular matrix (ECM) components critically regulate the function of mesenchymal cells. We characterised the composition and function of ECM in fibrostenosing Crohn's disease (CD) and control tissues. DESIGN: Decellularised full-thickness intestinal tissue platforms were tested using three different protocols, and ECM composition in different tissue phenotypes was explored by proteomics and validated by quantitative PCR (qPCR) and immunohistochemistry. Primary human intestinal myofibroblasts (HIMFs) treated with milk fat globule-epidermal growth factor 8 (MFGE8) were evaluated regarding the mechanism of their antifibrotic response, and the action of MFGE8 was tested in two experimental intestinal fibrosis models. RESULTS: We established and validated an optimal decellularisation protocol for intestinal IBD tissues. Matrisome analysis revealed elevated MFGE8 expression in CD strictured (CDs) tissue, which was confirmed at the mRNA and protein levels. Treatment with MFGE8 inhibited ECM production in normal control HIMF but not CDs HIMF. Next-generation sequencing uncovered functionally relevant integrin-mediated signalling pathways, and blockade of integrin αvß5 and focal adhesion kinase rendered HIMF non-responsive to MFGE8. MFGE8 prevented and reversed experimental intestinal fibrosis in vitro and in vivo. CONCLUSION: MFGE8 displays antifibrotic effects, and its administration may represent a future approach for prevention of IBD-induced intestinal strictures.

Clinical and Pathological Correlation in Concomitant Celiac Disease and Eosinophilic Esophagitis Suggests Separate Etiologies.

Introduction. Recently, an increased risk of celiac disease or eosinophilic esophagitis has been postulated among patients with either of these disorders, prompting some to suggest a common underlying mechanism, whereas others maintain that their co-existence is coincidental. Methods. We compared clinical and pathological features of 29 patients meeting criteria for both celiac disease and eosinophilic esophagitis to 26 celiac disease and 26 eosinophilic esophagitis controls to determine whether any distinguished study patients from controls. Results. Eight (28%) study patients presented with symptoms of both celiac disease and eosinophilic esophagitis, whereas 14 (48%) had celiac disease symptoms only and 5 had (17%) esophageal symptoms only. Study patients had similar autoimmune and atopic conditions seen in both control groups. Histological severity of disease, including Marsh II-III duodenal histology (study specimens: 87%; controls: 89%), mean peak esophageal eosinophil counts (study specimens: 55/400x field; controls: 80/400X field, P = .1), and presence of eosinophil microabscesses, scale crust, and subepithelial fibrosis were also similar to controls. Gluten-free diet resolved celiac disease-related symptoms (19 of 20, 95%) and histology (10 of 12, 83%), but not esophageal symptoms or eosinophilia in most study patients. Conclusion. Patients with concomitant celiac disease and eosinophilic esophagitis lack distinguishing features compared to controls with celiac disease or eosinophilic esophagitis alone. The occurrence of both disorders is likely coincidental in most cases.

Immunotactoid hepatopathy: A novel entity with histologically proven recurrence post liver transplantation.

Immunotactoid deposition is a rare fibrillary deposition disease that is primarily seen in the kidney and is associated with paraproteinemia. Here, we report a case of hepatic immunotactoid deposition in a 67-year-old male with a history of smoldering myeloma and chronic kidney disease who underwent liver transplantation for metabolic dysfunction-related cirrhosis. Immunotactoid deposition was first identified in the explanted liver and recurred in the allograft within only 7 weeks following transplantation, presenting as ascites with normal liver function tests. The patient's posttransplant course was complicated by proteinuria and renal failure requiring dialysis. Histologic examination of both native and allograft livers demonstrated pink amorphous material occupying sinusoidal spaces that were Congo-red negative and immunoglobulin M Kappa-restricted. Electron microscopy revealed characteristic deposits of electron-dense bundles of hollow microtubules with a 40 nm diameter within the sinusoids and space of Disse, consistent with immunotactoids. Therapy of the patient's underlying plasma-cell dyscrasia utilizing a daratumumab-based regimen showed decreased serum paraproteins, resolution of ascites, and improved kidney function, no longer requiring dialysis, without inducing rejection. The patient continues to respond to treatment 10 months posttransplant.

Random walk reduction in dithered ring laser gyroscope.

We experimentally demonstrated that the random walk in a dithered ring laser gyroscope caused by lock-in crossing can be eliminated by lock-in error compensation. Computer simulations demonstrated the effectiveness of this method. The experimental results show that the random walk coefficient can be reduced as predicted. Furthermore, gyroscopes with different random walk performances can achieve nearly the same random walk level after compensation, illustrating that the quantum limit can be approached after removing the lock-in error.

Stricturing Crohn's Disease Single-Cell RNA Sequencing Reveals Fibroblast Heterogeneity and Intercellular Interactions.

BACKGROUND & AIMS: Fibroblasts play a key role in stricture formation in Crohn's disease (CD) but understanding its pathogenesis requires a systems-level investigation to uncover new treatment targets. We studied full-thickness CD tissues to characterize fibroblast heterogeneity and function by generating the first single-cell RNA sequencing (scRNAseq) atlas of strictured bowel and providing proof of principle for therapeutic target validation. METHODS: We performed scRNAseq of 13 fresh full-thickness CD resections containing noninvolved, inflamed nonstrictured, and strictured segments as well as 7 normal non-CD bowel segments. Each segment was separated into mucosa/submucosa or muscularis propria and analyzed separately for a total of 99 tissue samples and 409,001 cells. We validated cadherin-11 (CDH11) as a potential therapeutic target by using whole tissues, isolated intestinal cells, NanoString nCounter, next-generation sequencing, proteomics, and animal models. RESULTS: Our integrated dataset revealed fibroblast heterogeneity in strictured CD with the majority of stricture-selective changes detected in the mucosa/submucosa, but not the muscle layer. Cell-cell interaction modeling revealed CXCL14+ as well as MMP/WNT5A+ fibroblasts displaying a central signaling role in CD strictures. CDH11, a fibroblast cell-cell adhesion molecule, was broadly expressed and up-regulated, and its profibrotic function was validated using NanoString nCounter, RNA sequencing, tissue target expression, in vitro gain- and loss-of-function experiments, proteomics, and knock-out and antibody-mediated CDH11 blockade in experimental colitis. CONCLUSIONS: A full-thickness bowel scRNAseq atlas revealed previously unrecognized fibroblast heterogeneity and interactions in CD strictures and CDH11 was validated as a potential therapeutic target. These results provide a new resource for a better understanding of CD stricture formation and open potential therapeutic developments. This work has been posted as a preprint on Biorxiv under doi: 10.1101/2023.04.03.534781.

Gastric Glandular Siderosis but not Lamina Propria Siderosis is Associated With High Serum Ferritin Levels.

Three histologic patterns of gastric siderosis (GS) are described: pattern A (predominantly in lamina propria stromal cells-gastric lamina propria siderosis [GLPS]), pattern B (mostly extracellular crystalline iron) and pattern C (predominantly in glandular epithelium-gastric glandular siderosis [GGS]). This study aimed to analyze the association of GGS with clinicopathologic features using 3 cohorts. Cohort #1 consisted of 76 gastric siderosis cases. Upon classifying the cases into 3 groups by percentage of glandular involvement (negative, 1% to 5%, ≥5% GGS), the degree of GGS was positively associated with serum ferritin levels ( P =0.002), transferrin saturation ( P =0.003), and history of blood transfusion ( P =0.009). After excluding cases with coarse extracellular crystalline iron, cohort #1 was reclassified into 3 groups by degree of GLPS (no, rare [discernible at ×20 or ×40], overt [readily visible at low power]). The degree of GLPS was positively correlated with oral iron pill use ( P =0.01), but not serum ferritin levels or transferrin saturation. Cohort #2 contained 31 gastric samples from patients with hereditary hemochromatosis, most received phlebotomy treatment. GGS was identified in 2 (6.4%) patients; both had high ferritin levels. Cohort #3 included 38 gastric samples from patients with cirrhosis. Three (8%) cases showed GGS; serum ferritin level was available for 1 case and was elevated. These results indicate that GGS is associated with systemic iron overload, while GLPS is correlated with oral iron pill use. The identification of GGS, especially when it's ≥5%, should trigger further workup for potential systemic iron overload and underlying etiologies.

Stricturing Crohn's disease single-cell RNA sequencing reveals fibroblast heterogeneity and intercellular interactions.

Background: Fibroblasts play a key role in stricture formation in Crohn's disease (CD) but understanding it's pathogenesis requires a systems-level investigation to uncover new treatment targets. We studied full thickness CD tissues to characterize fibroblast heterogeneity and function by generating the first single cell RNA sequencing (scRNAseq) atlas of strictured bowel and providing proof of principle for therapeutic target validation. Methods: We performed scRNAseq of 13 fresh full thickness CD resections containing non-involved, inflamed non-strictured, and strictured segments as well as 7 normal non-CD bowel segments. Each segment was separated into mucosa/submucosa or muscularis propria and analyzed separately for a total of 99 tissue samples and 409,001 cells. We validated cadherin-11 (CDH11) as a potential therapeutic target by using whole tissues, isolated intestinal cells, NanoString nCounter, next generation sequencing, proteomics and animal models. Results: Our integrated dataset revealed fibroblast heterogeneity in strictured CD with the majority of stricture-selective changes detected in the mucosa/submucosa, but not the muscle layer. Cell-cell interaction modeling revealed CXCL14+ as well as MMP/WNT5A+ fibroblasts displaying a central signaling role in CD strictures. CDH11, a fibroblast cell-cell adhesion molecule, was broadly expressed and upregulated, and its pro-fibrotic function was validated by NanoString nCounter, RNA sequencing, tissue target expression, in vitro gain- and loss-of-function experiments, proteomics, and two animal models of experimental colitis. Conclusion: A full-thickness bowel scRNAseq atlas revealed previously unrecognized fibroblast heterogeneity and interactions in CD strictures and CDH11 was validated as a potential therapeutic target. These results provide a new resource for a better understanding of CD stricture formation and opens potential therapeutic developments.

A Low rectal GIST.

A man in his 70s presented with narrowing of his stool calibre and a palpable mass on rectal examination. Colonoscopy revealed a submucosal bulge without a mucosal lesion. CT and MRI demonstrated an 8×5.4×7 cm mass in lower rectum. Biopsy of the mass confirmed a rectal gastrointestinal stromal tumour (GIST). It was moderately sensitive to neoadjuvant imatinib and radiotherapy, which slightly downsized the tumour. He required abdominal perineal resection with curative intent. Uncommonly found in the rectum, when located here, GISTs are typically aggressive and are a rare cause of stool calibre narrowing. Rectal GISTs should be considered in patients presenting with this symptom.

Gastrointestinal stromal tumors (GISTs) arising in uncommon locations: clinicopathologic features and risk assessment of esophageal, colonic, and appendiceal GISTs.

Risk stratification of gastrointestinal stromal tumors (GISTs) is based on experience with tumors of the stomach, small bowel, and rectum, which are far more common than GISTs of other sites. In this study from 47 institutions, we analyzed GISTs of the esophagus (n = 102), colon (n = 136), and appendix (n = 27) for their size, mitotic rate, morphology, and outcome to determine which criteria predict their behavior. Esophageal GISTs were small (median: 2.5 cm) with spindle cell morphology and a low mitotic rate (mean: 3.6/5 mm2). Twelve (12%) tumors progressed, including 11 with a mitotic rate >5/5 mm2 and one large (6.8 cm) GIST with a mitotic rate of 2/5 mm2. Colonic GISTs were smaller (median: 1.4 cm) and presented with abdominal pain or bleeding in 29% of cases. Most (92%) were composed of spindle cells with a mean mitotic rate of 4.6/5 mm2. Sixteen (12%) tumors progressed: 14 had mitotic rates >5/5 mm2, and two were >5.0 cm with a mitotic rate <5/5 mm2. All but one appendiceal GIST measured <2.0 cm. These tumors were composed of spindle cells with low mitotic rates (<5/5 mm2), and none progressed. Our results suggest that progression risk among esophageal and colonic GISTs is associated with increased mitotic activity (>5/5 mm2) and size >5.0 cm. These findings support the use of size and mitotic rate for prognostication of GISTs in these locations, similar to tumors of the stomach, small bowel, and rectum.

B7-H3 and PD-L1 Expression Are Prognostic Biomarkers in a Multi-racial Cohort of Patients with Colorectal Cancer.

BACKGROUND: Immunotherapy has emerged as an effective and durable treatment modality for solid cancers. However, its use in colorectal cancer (CRC) is limited to deficient mismatch repair (dMMR) tumors. As such, assessing immune regulatory proteins from the B7-CD28 family, other than PD-1, PD-L1, and CTLA-4, is critical. This study aimed to evaluate the expression of novel protein regulators in a racially diverse population of patients with CRC. METHODS: A tumor microarray was created for 214 samples from a multiracial patient population with metastatic CRC, and expression of HHLA2, B7-H3, PD-L1, CK7, CK20, and CDX2 was determined. The expression pattern was scored as 0 to 12, based on tumor tissue prevalence and the intensity. Clinical information was obtained by chart review and vital statistics from the National Death Index. Associations between low and high expression groups for each protein by race/ethnic groups were assessed, and Kaplan-Meier curves were plotted to evaluate association with survival. RESULTS: The median age at diagnosis was 61 years, with a female predominance. The majority of the patients were diagnosed with de novo metastatic disease with left-sided, moderately differentiated tumors. There were no racial disparities in the expression of any protein. Overall, a high frequency of tumors had no expression of B7-H3 (62.5%) or PD-L1 (43.5%). Low expression of both PD-L1 and B7-H3 was a significant prognostic biomarker associated with better survival (median overall survival, 43.3 months vs. 24.6 months; P < .01). CONCLUSION: In this multiracial tumor microarray of CRC samples, low PD-L1 and B7-H3 expression was associated with an improved prognosis. There was no significant variation among races with respect to the relevant CRC protein markers.

Coordinated co-migration of CCR10+ antibody-producing B cells with helper T cells for colonic homeostatic regulation.

In the intestine, IgA antibody-secreting B cells (IgA-ASCs) and helper T cells coordinate to maintain local homeostasis while their dysregulation could lead to development of intestinal inflammatory diseases. However, mechanisms underlying the coordinated localization and function of the B and T cells into the intestine, particularly the colon, are poorly understood. We herein report the first evidence that the gut-homing chemokine receptor CCR10+ IgA-ASCs form conjugates with helper T cells, preferentially regulatory T cells, at their differentiation sites of gut-associated lymphoid organs for their coordinated co-localization into the colon to promote local homeostasis. In CCR10-knockout mice, defective migration of IgA-ASCs also resulted in defective T-cell migration and homeostasis, and development of inflammatory symptoms in the colon. Antigen-specific interaction of CCR10+ IgA-ASCs and T cells is crucial for their homeostatic establishment in the colon. On the other hand, in IgA-knockout mice, preferential expansion of CCR10+ IgG1-ASCs with regulatory functions compensated for CCR10+ IgA-ASCs to help maintain colonic homeostasis. The preferential expansion of specific subclasses of CCR10+ IgG-ASCs with regulatory functions was also found in asymptomatic IgA-deficient patients. These findings suggest coordinated cell migration as a novel mechanism underlying localization and function of B and T cells in colonic homeostatic regulation.

Preferential Perinatal Development of Skin-Homing NK1.1+ Innate Lymphoid Cells for Regulation of Cutaneous Microbiota Colonization.

Proper immune cell development at early ontogenic stages is critical for life-long health. How resident immune cells are established in barrier tissues at neonatal stages to provide early protection is an important but still poorly understood question. We herein report that a developmentally programmed preferential generation of skin-homing group 1 innate lymphoid cells (ILC1s) at perinatal stages helps regulate early skin microbiota colonization. We found that a population of skin-homing NK1.1+ ILC1s was preferentially generated in the perinatal thymi of mice. Unique thymic environments and progenitor cells are responsible for the preferential generation of skin-homing NK1.1+ ILC1s at perinatal stages. In the skin, NK1.1+ ILC1s regulate proper microbiota colonization and control the opportunistic pathogen Pseudomonas aeruginosa in neonatal mice. These findings provide insight into the development and function of tissue-specific immune cells at neonatal stages, a critical temporal window for establishment of local tissue immune homeostasis.

Hepatotoxicity From Immune Checkpoint Inhibitors: A Systematic Review and Management Recommendation.

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies targeting immune checkpoint molecules. ICIs are an immunotherapy for the treatment of many advanced malignancies. The advent of ICIs has been a major breakthrough in the field of oncology, a fact recognized by the 2018 Nobel Prize in Physiology or Medicine being awarded for the discovery. The Food and Drug Administration approved the first ICI, ipilimumab, in 2011 for the treatment of metastatic melanoma. Seven ICIs are now used in clinical practice, including nivolumab and pembrolizumab for treatment of advanced hepatocellular carcinoma. ICIs are increasingly used across the spectrum of hepatobiliary neoplasia. The utility of ICI therapy has been limited by immune-related adverse reactions (irAEs) affecting multiple organ systems. Hepatotoxicity is an important irAE, occurring in up to 16% of patients receiving ICIs. Optimizing outcomes in patients receiving ICI therapy requires awareness of and familiarity with diagnosing and management of ICI-induced immune-mediated hepatotoxicity (IMH), including approaches to treatment and ICI dose management. The aim of this review article is to (1) provide a comprehensive, evidence-based review of IMH; (2) perform a systematic review of the management of IMH; and (3) present algorithms for the diagnosis and management of IMH.

Smooth muscle tumors of the gastrointestinal tract: an analysis of prognostic features in 407 cases.

Smooth muscle tumors represent the second most common mural mesenchymal neoplasm in the gastrointestinal tract, but established criteria for prognostic assessment of these tumors are lacking. A large cohort of surgically resected intramural gastrointestinal smooth muscle tumors from 31 institutions was analyzed to identify potential prognostic features. Pathologic features were assessed by expert gastrointestinal and/or soft tissue pathologists at each center. Immunohistochemical confirmation was required. A total of 407 cases from the esophagus (n = 97, 24%), stomach (n = 180, 44%), small bowel (n = 74, 18%), and colorectum (n = 56, 14%) were identified. Patients ranged in age from 19 to 92 years (mean 55 years), with a slight female predominance (57%). Mean tumor size was 5.4 cm, with the largest tumor measuring 29 cm. Disease progression following surgery, defined as local recurrence, metastasis, or disease-related death, occurred in 56 patients (14%). Colorectal tumors were most likely to progress, followed by small bowel and gastric tumors. None of the esophageal tumors in this series progressed. Receiver operator characteristic analysis identified optimal cutoffs of 9.8 cm and 3 mitoses/5 mm2 for discriminating between progressive and non-progressive tumors. Histologic features strongly associated with progression by univariate analysis included moderate-to-severe atypia, high cellularity, abnormal differentiation (defined as differentiation not closely resembling that of normal smooth muscle), tumor necrosis, mucosal ulceration, lamina propria involvement, and serosal involvement (P < 0.0001 for all features). Age, sex, and margin status were not significantly associated with progression (P = 0.23, 0.82, and 0.07, respectively). A risk assessment table was created based on tumor site, size, and mitotic count, and Kaplan-Meier plots of progression-free survival for each subgroup revealed progression-based tiers. Based on our findings, it appears that nonesophageal gastrointestinal smooth muscle tumors measuring >10 cm and/or showing ≥3 mitoses/5 mm2 may behave aggressively, and therefore close clinical follow-up is recommended in these cases.

Training the Next Generation of Pathologists: A Novel Residency Program Curriculum at Montefiore Medical Center/Albert Einstein College of Medicine.

Pathology residency training is currently a time-intensive process, frequently extending up to 6 years in duration as residents complete 1 or 2 fellowships following graduation. Innovative training curricula may help address the impending changes in the health-care landscape, particularly future shortfalls in pathology staffing and changing health-care models that incorporate more work within interdisciplinary teams. Montefiore has created a novel residency training program aimed at accelerating the acquisition of competency in pathology, preparing residents for independent practice at the completion of residency training, and providing residents with the requisite adaptability and consultative skills to excel wherever they choose to practice. We describe the implementation of this novel pathology residency training curriculum at Montefiore Medical Center/Albert Einstein College of Medicine and the perception of residents in both the old curriculum and the new curriculum.

Utilization of spectrins ßI and ßIII in diagnosis of hepatocellular carcinoma.

Spectrins are a group of cytoskeletal proteins which participate in many important cellular functions. It has been suggested that loss of spectrin isoforms may be associated with tumorigenesis of lymphoma, leukemia, gastric cancer and hepatocellular carcinoma (HCC). We recently reported that ßI spectrin expression was present in normal hepatocytes but lost in HCC cells, which suggested that spectrins may be helpful markers in diagnosis of HCC. In this study, using immunohistochemical staining, we further investigated the expression pattern of four spectrin isoforms (αII, ßI-III) on different benign and malignant liver tumors including focal nodular hyperplasia (FNH), hepatic adenoma (HA), HCC, and cholangiocarcinoma (CC). The results revealed that ßI spectrin was moderately to strongly positive in FNH and HA tissues, but was only weakly positive or lost in HCC cases and was weakly positive in all CC cases. In addition, the ßIII spectrin, majority of which was moderately positive in both FNH and HA tissues, was mostly lost in poorly differentiated HCC but remained at least moderately positive in most CC cases. These results suggest that spectrins ßI and ßIII may be used to differentiate well differentiated HCC from FNH or HA, and poorly differentiated HCC from CC, respectively.