MYD88L265P augments proximal B-cell receptor signaling in large B-cell lymphomas via an interaction with DOCK8.

Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous disease with at least 5 recognized molecular subtypes. Cluster 5 (C5)/MCD tumors frequently exhibit concurrent alterations in the toll-like receptor (TLR) and B-cell receptor (BCR) pathway members, MYD88L265P and CD79B, and have a less favorable prognosis. In healthy B cells, the synergy between TLR and BCR signaling pathways integrates innate and adaptive immune responses and augments downstream NF-κB activation. In addition, physiologic TLR9 pathway engagement via MYD88, protein tyrosine kinase 2 (PYK2), and dedicator of cytokinesis 8 (DOCK8) increases proximal BCR signaling in healthy murine B cells. Although C5/MCD DLBCLs are selectively sensitive to Bruton tyrosine kinase (BTK) inhibition in in vitro studies and certain clinical trials, the role of mutated MYD88 in proximal BCR signaling remains undefined. Using engineered DLBCL cell line models, we found that concurrent MYD88L265P and CD79B alterations significantly increased the magnitude and duration of proximal BCR signaling, at the level of spleen tyrosine kinase and BTK, and augmented PYK2-dependent DOCK8 phosphorylation. MYD88L265P DLBCLs have significantly increased colocalization of DOCK8 with both MYD88 and the proximal BCR-associated Src kinase, LYN, in comparison with MYD88WT DLBCLs, implicating DOCK8 in MYD88L265P/proximal BCR cross talk. Additionally, DOCK8 depletion selectively decreased proximal BCR signaling, cellular proliferation, and viability of DLBCLs with endogenous MYD88L265P/CD79BY196F alterations and increased the efficacy of BTK blockade in these lymphomas. Therefore, MYD88L265P/DOCK8-enhanced proximal BCR signaling is a likely mechanism for the increased sensitivity of C5/MCD DLBCLs to BTK blockade.

Clinicopathologic and Molecular Characterization of Inflammatory Bowel Disease-Associated Neuroendocrine Carcinomas and Mixed Neuroendocrine-Non-Neuroendocrine Neoplasms.

The pathogenesis of neuroendocrine carcinoma (NEC) and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) in the gastrointestinal tract remains poorly understood. This study seeks to characterize the clinicopathologic and molecular features of NEC/MiNEN in patients with inflammatory bowel disease (IBD). Eighteen surgically resected IBD-associated intestinal carcinomas with a minimum of 30% neuroendocrine component were collected from 6 academic centers and compared to a control group of 12 IBD-associated carcinomas lacking neuroendocrine differentiation. Both groups exhibited a male predominance and similar age distribution. The NEC/MiNEN group was more likely to have a higher percentage of Crohn's disease (9/18 vs. 1/12, P=0.024), occur in the rectum (9/18 vs. 3/12) and small intestine (4/18 vs. 0/12) (P<0.01), be diagnosed on resection without a preceding biopsy (6/18 vs. 0/12, P=0.057), and have unidentifiable precursor lesions (10/18 vs. 1/12, P=0.018) than the control group. Synchronous carcinoma, advanced tumor stage (pT3 and pT4), and lymph node metastasis occurred at similar rates; however, the NEC/MiNEN group had a higher incidence of angiovascular invasion (14/18 vs. 4/12, P=0.024), distant metastasis (8/18 vs. 1/12, P=0.049), mortality (8/18 vs. 2/12, P=0.058), and worse survival (Kaplan-Meier, P=0.023) than the control group. All tested cases were mismatch repair proficient. A Ki-67 proliferation index ranged from 25% to 100%. Next-generation sequencing in 11 NEC/MiNEN cases revealed low tumor mutational burdens but complex genetic abnormalities commonly involving TP53 (9/11, 82%), FBXW7 (4/11, 36%), and APC (3/11, 27%), with the other genetic alterations randomly occurring in one or two cases. The neuroendocrine component, which shared similar molecular alterations as the non-neuroendocrine component, was subcategorized into intermediate (G3a)- and high-grade (G3b); the higher-grade correlated with more genetic alterations. In conclusion, IBD-associated NEC/MiNEN shows diverse histologic features, variable precursor lesions, intricate genetic abnormalities, and aggressive biologic behavior. The classification and grading of GI-NEC/MiNEN may be refined for better clinical management.

Clinicopathologic features and diagnostic challenges of small cluster pattern appendiceal neuroendocrine tumors.

Appendiceal neuroendocrine neoplasms (NENs) can present with various growth patterns including the traditional triad of histologic patterns-insular, trabecular and tubular. A small cluster pattern was also found in this study and the literature on this specific morphology is limited. In this study, we conducted a comprehensive review of appendiceal NENs from our institution over a ten-year period. Clinical and demographic data were obtained from medical records. Immunohistochemical stains were performed with antibodies specific for synaptophysin, chromogranin, INSM1, CD56, serotonin and peptide YY. The small cluster pattern was found in 29.4 % of all cases evaluated. The tumor cells in these cases were predominantly located at the distal tip of the appendix, associated with fibrous obliteration. These tumors were smaller in size and tended towards less advanced tumor stage, with reduced incidence of lymphovascular and/or perineural invasion. Chromogranin expression was identified in 76 % of these cases. There is a heterogeneous hormone profile with 46.7 % serotonin and 33.3 % peptide YY. In conclusion, the small cluster pattern NENs present with unique histological features and hormone expression profile. Among the various neuroendocrine markers, INSM1 showed superior diagnostic performance, with high sensitivity and minimal non-specific staining.

Histology and clinical correlations in autoimmune hepatitis, primary biliary cholangitis, and autoimmune hepatitis-primary biliary cholangitis overlap syndrome.

OBJECTIVES: The diagnosis of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and AIH-PBC overlap syndrome (OS) relies on their histologic features and clinical findings. In this study, we aimed to identify specific morphologic features of these diseases and evaluate their clinical correlation. METHODS: We included initial biopsies from untreated patients with AIH (n = 14), PBC (n = 10), and OS (n = 7). Histologic features of the portal tract, portal-lobular interface, and hepatic lobule, fibrosis, as well as clinical data including serology, autoantibodies, treatment, and prognosis were reviewed and analyzed. RESULTS: Our results showed that several histologic features differed significantly between AIH and PBC (p < 0.05). Among these features, OS cases were more likely to present with bile duct-centered processes (presence of bile duct damage while absence of inflammation gradient from bile duct to interface, plasma cell cluster and pericentral inflammation) unlike those seen in AIH (p < 0.05), and interface-centered processes (unequivocal interface hepatitis, ductular reaction, and periportal fibrosis) which were not seen in PBC (p < 0.05). We observed a significant correlation between transaminase levels and lobular inflammation, including numbers of lymphocyte, plasma cell and eosinophil. Our study also found that anti-smooth muscle antibody positivity was associated with interface hepatitis (p < 0.01), while antimitochondrial antibody positivity was associated with duct damage (including ductopenia) and granulomas (p < 0.05). CONCLUSION: Our results highlight distinctive morphological features between AIH and PBC. The possibility of overlap syndrome should be considered when encountering AIH with bile duct-centered processes or PBC with interface-centered processes in morphology and correlation with autoantibodies.

Multitarget Stool RNA Test for Colorectal Cancer Screening.

Importance: Noninvasive tests for colorectal cancer screening must include sensitive detection of colorectal cancer and precancerous lesions. These tests must be validated for the intended-use population, which includes average-risk individuals 45 years or older. Objective: To evaluate the sensitivity and specificity of a noninvasive, multitarget stool RNA (mt-sRNA) test (ColoSense) test compared with results from a colonoscopy. Design, Setting, and Participants: This phase 3 clinical trial (CRC-PREVENT) was a blinded, prospective, cross-sectional study to support a premarket approval application for a class III medical device. A total of 8920 participants were identified online using social media platforms and enrolled from June 2021 to June 2022 using a decentralized nurse call center. All participants completed the mt-sRNA test, which incorporated a commercially available fecal immunochemical test (FIT), concentration of 8 RNA transcripts, and participant-reported smoking status. Stool samples were collected prior to participants completing a colonoscopy at their local endoscopy center. The mt-sRNA test results (positive or negative) were compared with index lesions observed on colonoscopy. Over the course of 12 months, individuals 45 years and older were enrolled in the clinical trial using the decentralized recruitment strategy. Participants were enrolled from 49 US states and obtained colonoscopies at more than 3800 different endoscopy centers. Main Outcomes and Measures: The primary outcomes included the sensitivity of the mt-sRNA test for detecting colorectal cancer and advanced adenomas and the specificity for no lesions on colonoscopy. Results: The mean (range) age of participants was 55 (45-90) years, with 4% self-identified as Asian, 11% as Black, and 7% as Hispanic. Of the 8920 eligible participants, 36 (0.40%) had colorectal cancer and 606 (6.8%) had advanced adenomas. The mt-sRNA test sensitivity for detecting colorectal cancer was 94%, sensitivity for detecting advanced adenomas was 46%, and specificity for no lesions on colonoscopy was 88%. The mt-sRNA test showed significant improvement in sensitivity for colorectal cancer (94% vs 78%; McNemar P = .01) and advanced adenomas (46% vs 29%; McNemar P < .001) compared with results of the FIT. Conclusions and Relevance: In individuals 45 years and older, the mt-sRNA test showed high sensitivity for colorectal neoplasia (colorectal cancer and advanced adenoma) with significant improvement in sensitivity relative to the FIT. Specificity for no lesions on colonoscopy was comparable to existing molecular diagnostic tests. Trial Registration: ClinicalTrials.gov Identifier: NCT04739722.

Constrictive and Hypertrophic Strictures in Ileal Crohn's Disease.

BACKGROUND & AIMS: Strictures in Crohn's disease (CD) are classically attributed to fibromuscular hypertrophy of the intestinal wall. We have identified and characterized CD-related ileal strictures that result instead from mural constriction (ie, reduced external circumference). METHODS: Twenty-four strictures and internal controls from 17 adults with obstructive CD were analyzed by cross-sectional morphometry. RESULTS: The stricture-to-control circumference ratios (CRs) ranged from 0.53 to 1.7. Six strictures with CR ≥1.0, designated hypertrophic, had concentrically thickened walls, mean 3-fold increases in cross-sectional area and stainable fibromucular tissue, and high transmural inflammation scores. In contrast, 18 strictures with CR <1.0, designated constrictive, had thin, pliant walls, cross-sectional areas and stainable fibromuscular tissue comparable with control values, and low transmural inflammation scores. Eight mildly constrictive strictures also showed mild fibromuscular mural expansion that fell short of statistical significance. Twelve of 18 constrictive strictures (67%) occurred multiply (2-4 strictures per specimen) in contrast with hypertrophic strictures, all of which occurred singly (P = .01). Constriction correlated quantitatively with circumferential serosal fat wrapping (P = .003) and was associated with myenteric lymphocytic plexitis (P = .02). Disease duration was shortest among subjects with constrictive strictures and correlated with increasing circumference (CR ≤0.8, 6.3 ± 6.2 years; CR >0.8, 8.7 ± 6.4 years; and CR ≥1.00, 13.7 ± 5.0 years, respectively; P = .03). CONCLUSIONS: Constrictive ileal strictures in CD differ pathologically and clinically from hypertrophic strictures, featuring little or no fibromuscular mural expansion, frequent multiplicity, and earlier onset. Mesenteric fat wrapping and myenteric plexitis may contribute to their pathogenesis. Pathologic manifestations of constriction and hypertrophy can coexist, suggesting that stricture heterogeneity may be shaped in part by the dynamics of constrictive and hypertrophic processes.

Surgery for pouch inflow limb-related complications: Crohn's disease or something else?

PURPOSE: A total proctocolectomy with subsequent creation of an ileal-pouch, such as a J-pouch or a Kock pouch, has been the most common surgery performed for ulcerative colitis (UC). A small portion of these patients will develop complications with the inflow limb into the pouch requiring operative intervention. The objective was to establish a better understanding as to the pathological mechanism by which these pouch inflow limb problems develop. METHODS: This was a retrospective cohort study conducted at a single tertiary care inflammatory bowel disease (IBD) center. A database was created of all the patients who underwent pouch-related procedures, following completion of their original pouch, between 2006 and 2018. The patients requiring operative resection for inflow limb complications were identified among this cohort. Operative and pathological data were collected. RESULTS: One hundred seventy-eight UC patients underwent surgeries on their pouches between 2006 and 2018. Sixteen patients required operative resection for inflow limb problems. Reoperations for inflow limb problems included inflow limb resection with pouch excision (n = 4) and inflow limb resection with pouch revision (n = 12). The pathology findings of the inflow limb were consistent with Crohn's disease in 9 patients (56%). Two other patients (total 69%) were eventually diagnosed with Crohn's disease due to other pathological specimens or perianal pathology. The remaining patients had chronic, non-specific enteritis/serositis. CONCLUSIONS: A small proportion of pouch patients will eventually require surgery for inflow limb complications. Among these, there was a high rate of Crohn's disease of the inflow limb and overall change in diagnosis to Crohn's disease (Plietz et al. in Official Journal of the American College of Gastroenterology | ACG 114:S453, 2019).

Baseline Histological Findings Do Not Predict the Risk of Subsequent Extension in Patients with Limited Ulcerative Colitis.

BACKGROUND: Among patients with limited ulcerative colitis (UC), 30% ultimately extend to pancolitis and are at increased risk of adverse clinical outcomes. Risk of endoscopic extension has been found to correlate with clinical features such as early age of onset. AIMS: We sought to determine whether histologic features correlate with disease extension. METHODS: The study population consisted of 40 patients with UC from two large academic centers diagnosed between 2006 and 2017. Eligible cases had a diagnosis of endoscopically limited UC (Montreal E1 or E2) at baseline and ≥ 2 subsequent endoscopic examinations with biopsies. Severity of inflammation was scored using both the Mount Sinai Activity Index and Nancy Histological Index. RESULTS: Patients were divided into two cohorts: those who progressed to pancolitis (Montreal E3) were defined as "Extenders" (n = 21), whereas "Non-extenders" (n = 19) were cases without progression in the follow-up period. The median follow-up time was 58.4 months. The histologic scores in the endoscopically involved mucosa of the index biopsies were not associated with subsequent extension of disease, overall. However, among extender cohort, the index histology scores correlated with biopsy scores at extension (r = 0.455, P = 0.044) and index severity was associated with a shorter time to extension (r = - 0.611, P = 0.003). Furthermore, female patients had a shorter time to extension (P = 0.013). CONCLUSIONS: Histological severity of limited UC is not an independent predictor of extension in UC. However, among patients who subsequently extend, severe inflammation at baseline correlates with shorter progression time and severe inflammation when extension occurs. Patients with limited UC but severe histologic inflammation may warrant more frequent endoscopic surveillance.

Bone marrow morphologic features, MyPRS, and gene mutation correlations in plasma cell myeloma.

Genetics has played an important role in risk stratification for plasma cell myeloma patients, providing therapeutic guidance. In this study, we investigated the correlation of bone marrow morphologic features and genetic aberrations, including gene expression profiles, translocations, and gene mutations. For the first time we show that high plasma cell volume, diffuse sheet growth pattern, immature cell morphology, high mitotic index, and increased reticulin fibrosis, significantly correlates with high risk disease determined by MyPRS gene expression profiles. Furthermore, we show the association between MyPRS risk stratification and chromosomal alterations and specific gene mutations. We also demonstrate the combinational effect of TP53 mutation and 17p loss on the histological changes in bone marrow.

Mutation profile of high-grade appendiceal mucinous neoplasm.

AIMS: High-grade appendiceal mucinous neoplasm (HAMN) was recently proposed as a disease entity histologically analogous to low-grade appendiceal mucinous neoplasm (LAMN), but characterised by high-grade cytological atypia. The pathogenesis and clinical features of HAMN have not been fully elucidated. METHODS AND RESULTS: Nine cases of HAMN, eight LAMN, 10 appendiceal mucinous adenocarcinomas (MACA) and five appendiceal serrated polyps resected between 2008 and 2017 contributed by three medical centres underwent targeted next-generation sequencing of 50 cancer-related genes. The patients in each category had similar profiles with respect to gender, age, tumour stage and follow-up intervals. Both LAMN and HAMN harboured mutations of KRAS [nine of nine and eight of eight (100%), respectively] and GNAS [five of eight (63%) and five of nine (56%), respectively] in significantly higher proportions than MACA [KRAS, seven of 10 (70%, P = 0.04); GNAS: one of 10 (10%, P = 0.02)] and serrated polyps [KRAS, one of five (20%, P = 0.0007); GNAS: none of five (0%, P = 0.04)]. Four cases of HAMN, but none of LAMN, harboured mutations of TP53 [four of nine (44%)] and/or ATM [two of nine (22%)]. Three cases of HAMN (33%) showed extra-appendiceal spread with retention of the same mutational profiles in the intra- and extra-appendiceal components. The 10 cases of MACA harboured a similar prevalence of TP53 mutations (n = 5, 50%) as HAMN but, unlike LAMN and HAMN, some harboured mutations in PIK3CA, APC, FBXW7, PTEN and SMAD4. CONCLUSIONS: HAMN and LAMN share high rates of KRAS and GNAS co-mutations supporting a common histogenesis and distinguishing them from MACA. Acquisition of TP53 or ATM mutations by HAMN may drive its progression to a more advanced phenotype.

CXCR4 upregulation is an indicator of sensitivity to B-cell receptor/PI3K blockade and a potential resistance mechanism in B-cell receptor-dependent diffuse large B-cell lymphomas.

B-cell receptor (BCR) signaling pathway components represent promising treatment targets in multiple B-cell malignancies including diffuse large B-cell lymphoma (DLBCL). In in vitro and in vivo model systems, a subset of DLBCLs depend upon BCR survival signals and respond to proximal BCR/phosphoinositide 3 kinase (PI3K) blockade. However, single-agent BCR pathway inhibitors have had more limited activity in patients with DLBCL, underscoring the need for indicators of sensitivity to BCR blockade and insights into potential resistance mechanisms. Here, we report highly significant transcriptional upregulation of C-X-C chemokine receptor 4 (CXCR4) in BCR-dependent DLBCL cell lines and primary tumors following chemical spleen tyrosine kinase (SYK) inhibition, molecular SYK depletion or chemical PI3K blockade. SYK or PI3K inhibition also selectively upregulated cell surface CXCR4 protein expression in BCR-dependent DLBCLs. CXCR4 expression was directly modulated by fork-head box O1 via the PI3K/protein kinase B/forkhead box O1 signaling axis. Following chemical SYK inhibition, all BCR-dependent DLBCLs exhibited significantly increased stromal cell-derived factor-1α (SDF-1α) induced chemotaxis, consistent with the role of CXCR4 signaling in B-cell migration. Select PI3K isoform inhibitors also augmented SDF-1α induced chemotaxis. These data define CXCR4 upregulation as an indicator of sensitivity to BCR/PI3K blockade and identify CXCR4 signaling as a potential resistance mechanism in BCR-dependent DLBCLs.

Keratometric measurements and IOL calculations in pseudophakic post-DSAEK patients.

BACKGROUND: To compare different K readings in pseudophakic patients post-Descemet's stripping automated endothelial keratoplasty (DSAEK) and evaluate corresponding prediction errors in intraocular lens (IOL) power calculations. METHODS: Subjects that underwent cataract surgery and DSAEK surgery at least 3 and 6 months prior, respectively, and IOL implantation in the capsular bag were included in this study. Manifest refraction and IOL information were recorded. A Scheimpflug keratometer (Pentacam) was used for corneal measurements, including the mean anterior and posterior radii of curvature, simulated keratometer (SimK), true net power (TNP), and equivalent K reading (EKR) at the 4.0-mm zone. Conventional keratometry was acquired using the IOLMaster (KMaster). The four K measurements were evaluated for calculating the predicted refraction. RESULTS: The study included 20 eyes from 19 subjects. The ratio of the posterior to the anterior corneal radius was 74.1 ± 3.24%. Comparison of the four keratometric methods (KMaster, SimK, EKR, and TNP) revealed statistically significant differences among all the methods besides KMaster and SimK. Of the four IOL calculation methods(KMaster, SimK, EKR and TNP method),the arithmetic prediction error of the KMaster, SimK, and EKR methods featured nonsignificant differences from zero(p = 0.07, 0.19 and 0.84 respectively); the EKR method calculated the highest percentage of eyes with IOLs within the prediction error. CONCLUSIONS: IOL calculations in post-DSAEK eyes using KMaster, SimK, and EKR can yield small refractive errors after surgery. The EKR (4.0-mm diameter) method was found to be the most accurate.

[Post operation complications analysis and their treatment of Descemet's stripping automated endothelium keratoplasty].

OBJECTIVE: To summarize intra and post operation complications and their treatment of Descemet's Stripping Automated Endothelium Keratoplasty (DSAEK), and provide our experience for its development in China. METHODS: Retrospective case study. Forty-seven eyes of 42 patients underwent DSAEK performed by one surgeon. Indications include: Pseudophakic or aphakic Bullous Keratopathy, 27 eyes (57.4%); Fuchs Endothelial Dystrophy, 7 eyes (14.9%); endothelial decompensation post vitrectomy, 3 eyes (6.4%); iridocorneal endothelial syndrome (ICE), 3 eyes (6.4%); congenital glaucoma, 3 eyes (6.4%); graft failure post endothelial keratoplasty, 3 eyes (6.4%); endothelial decompensation after open ocular injury and intraocular foreign body, 1 eye (2.1%). Nineteen eyes underwent single DSAEK (40.4%); eight combined phacoemulsification and intraocular lens implantation (17.0%); eight combined anterior chamber IOL (AC-IOL) removal plus anterior segment vitrectomy and posterior chamber IOL (PC-IOL) implantation (17.0%); eight combined anterior segment vitrectomy and PC-IOL suspension (17.0%); two combined cataract extraction and anterior segment vitrectomy (4.3%); two failed in DSAEK and underwent penetrating keratoplasty (4.3%). RESULTS: Dislocation is the most common postoperative complications. Ten eyes underwent dislocation in 47 eyes (21.3%), which was solved by air and viscoelastic agent injection. High intraocular pressure happened in 12 eyes (25.5%), in 11 of which had a history of glaucoma and 1 with ICE. After drug treatment, ten patients had stable intraocular pressure and two patients underwent ciliary body photocoagulation surgery (1 case with anterior chamber intraocular lens, 1 case with ICE). Reactions happened in 2 cases (4.3%) patients, including 1 case with anterior chamber IOL (AC-IOL) rehabilitating after drug treatment and the other with Fuch's corneal endothelial dysfunction being regrafted. CONCLUSION: Dislocation is the most common complication after corneal endothelial keratoplasty, and air injection in anterior chamber is a common and effective method; High intraocular pressure is the second postoperative complication. Preoperative history of glaucoma is closely related to postoperative high intraocular pressure.

Intestinal "Piggybacking Lipoma", A Unique Lipoma Composed of Lipoma and Overlying Epithelial Lesions: A Case-control Study and Review of Literature.

BACKGROUND/AIM: Lipomas are rare but the most common benign mesenchymal lesions of the gastrointestinal (GI) tract, composed of mature adipose cells. The "piggybacking lipoma" is formed by lipomas with overlying polypoid epithelial lesions, such as sessile serrated lesion, tubular adenoma, or hyperplastic polyp, and the literature on these lesions is limited. In this study, we systematically investigated the clinical, endoscopic, and pathologic characteristics of these unique lipomas. PATIENTS AND METHODS: This is a single-institution retrospective study of gastrointestinal tract lipomas diagnosed from 2016-2021. Those with concurrent polypoid epithelial or mesenchymal lesions during the same endoscopic episode were included and reviewed in this study, and the lipomas were classified as "piggybacking lipoma" or "non-piggybacking lipoma" depending on whether the concurrent lesion was overlying the lipoma or was at a different location in the intestine. Demographic, clinical, and endoscopic data were obtained from electronic medical records. RESULTS: A total of 100 lipomas with concurrent epithelial or mesenchymal lesions were included in this study. Among them, 21 cases were classified as "piggybacking lipoma" and 79 were classified as "non-piggybacking lipoma". Patients with piggybacking lipomas showed a female predilection, and were more likely to be symptomatic and less likely to exhibit classic endoscopic features of lipoma. Histologically, the piggybacking polyps showed overlying sessile serrated lesions (SSL) (76.2%) and tubular adenoma (TA) (19%), whereas the non-piggybacking group had differing characteristic lesions with TA (57.5%) and SSL (6.0%). CONCLUSION: Piggybacking lipomas are rare lipomas with overlying polypoid epithelial lesions, most commonly SSL. They present different clinical, endoscopic, and pathologic features compared to non-piggybacking lipomas.

Expression of PSMA in Tumor-Associated Vasculature Predicts Poorer Survival in Patients With Hepatocellular Carcinoma and Is Likely Associated With PD-L1.

BACKGROUND: PSMA (prostate-specific membrane antigen) is a type II transmembrane glycoprotein recently found to be expressed in hepatocellular carcinoma (HCC). We aimed to characterize the expression pattern of PSMA in HCC and its association with clinicopathologic parameters and other biomarkers. METHODS: Immunohistochemical studies for PSMA were performed on a previously established tissue microarray of 103 surgically resected HCC. RESULTS: Conceivable PSMA expression in ≥5% tumor-associated vasculature (TAV) was considered positive, and was identified in 56 (54.4%) tumors. Eight (7.8%) tumors also showed membranous/cytoplasmic and/or canalicular staining in tumor cells. By chi-square tests, only PSMA-positive TAV was associated with moderate-to-poorly differentiated HCC and the modified higher tumor stage (P < .05). PSMA-positive TAV was not associated with age, sex, or expression of glypican-3, keratin 7, CD3, CD8, HHLA-2, but marginally correlated with programmed death-ligand 1 (PD-L1) expression (P = .052). Kaplan-Meier survival analysis revealed PSMA-positive TAV as an independent risk factor for poorer disease-specific survival (P = .008). Co-expression of PD-L1 did not ameliorate the adverse prognostication of PSMA-positive TAV. Membranous/cytoplasmic/canalicular expression of PSMA alone was not prognostically significant. CONCLUSIONS: Our study confirmed that PSMA-positive TAV is a prospective diagnostic and prognostic biomarker for HCC. Co-expression of PSMA with PD-L1 may suggest potential crosstalk between the 2 proteins, likely regulating the tumor microenvironment.

Confined Low Grade Appendiceal Mucinous Neoplasm With Coexisting Distant Metastasis.

BACKGROUND/AIM: Appendiceal mucinous neoplasms (AMNs) are tumors with dysplastic mucinous epithelium, a pushing growth pattern but no infiltrative invasion to the appendiceal wall. Some AMNs are associated with pseudomyxoma peritonei, characterized by intraperitoneal mucinous involvement. Recent studies have demonstrated that LAMNs confined to the appendix have low or no risk for disease recurrence, progression, and peritoneal involvement during follow up. CASE REPORT: Here, we present two extremely rare cases with confined low grade appendiceal mucinous neoplasm (pTis and pT3) and simultaneous extraperitoneal subcutaneous or ovary involvement at the time of diagnosis. CONCLUSION: Our cases demonstrate that although the primary tumor is limited to the appendix, coexisting distant metastasis may occur on very rare occasions.

Digital Pathology in the Detection of Infectious Microorganisms: An Evaluation of Its Strengths and Weaknesses Across a Panel of Immunohistochemical and Histochemical Stains Routinely Used in Diagnostic Surgical Pathology.

CONTEXT.­: The diagnosis of some infectious diseases requires their identification in tissue specimens. As institutions adopt digital pathology for primary diagnosis, the limits of microorganism detection from digital images must be delineated. OBJECTIVE.­: To assess the reliability of microorganism detection from digitized images of histochemical and immunohistochemical stains commonly used in pathology. DESIGN.­: Original glass slides from 620 surgical pathology cases evaluated for the presence of infectious microorganisms were digitized. Immunohistochemical stains included those for herpes simplex virus (n = 100), cytomegalovirus (n = 100), Helicobacter pylori (n = 100), and spirochetes (n = 80). Histochemical stains included mucicarmine for Cryptococcus spp (n = 20), Grocott methenamine silver for fungi (n = 100), Giemsa for H pylori (n = 100), and Ziehl-Neelsen for acid-fast bacilli (n = 20). The original diagnosis based on the glass slides was regarded as the reference standard. Six pathologists reviewed the digital images. RESULTS.­: Digital review was generally associated with high (ie, ≥90%) specificity and positive predictive value owing to a low percentage of false positive reads, whereas a high percentage of false negatives contributed to low sensitivity and negative predictive value for many stains. Fleiss κ showed substantial interobserver agreement in the interpretation of Grocott methenamine silver and immunostains for herpes simplex virus, H pylori, and cytomegalovirus; moderate agreement for spirochete, Ziehl-Neelsen, and mucicarmine; and poor agreement for Giemsa. CONCLUSIONS.­: Digital immunohistochemistry generally outperforms histochemical stains for microorganism detection. Digital interpretation of Ziehl-Neelsen and mucicarmine stains is associated with low scores for interrater reliability, accuracy, sensitivity, and negative predictive value such that it should not substitute for conventional review of glass slides.

MYC overexpression in inflammatory bowel disease-associated conventional dysplasia and association of subsequent low-grade dysplasia in follow-up biopsies.

OBJECTIVE: Diagnosis of inflammatory bowel disease (IBD)-associated dysplastic lesions can be challenging. This study aims to evaluate MYC immunohistochemistry (IHC) as a potential biomarker for IBD-associated dysplasia and compare its effectiveness with p53 IHC. METHODS: The study cohort included resections from 12 IBD patients with carcinoma and concurrent conventional low-grade dysplasia (LGD), as well as biopsies from 21 patients with visible conventional LGD, which were followed up for 2 years with subsequent endoscopic examination. MYC and p53 IHC and MYC-FISH analysis were performed. RESULTS: Sensitivity for LGD detection was 67% (8/12) and 50% (6/12) for MYC and p53, respectively, but the difference was not statistically significant (p = 0.2207). MYC and p53 overexpression were not always mutually exclusive, nor were they always present simultaneously. Patients who presented dysplasia in subsequent biopsies (7/21) were found to be more likely present with multiple LGD polyps and MYC-overexpressed LGD in the initial biopsies, compared to those without subsequent dysplasia (p < 0.05). These dysplastic lesions were commonly associated with chronic colitis (p = 0.0614). The distribution of LGD sites did not show a significant difference between patients with and without subsequent LGD. In MYC overexpressed cases, homogeneously strong nuclear expression was not identified in all dysplastic epithelial cells, and no MYC amplification was found in these cases by FISH. CONCLUSION: MYC IHC can complement p53 IHC as an adjunct biomarker for diagnosing IBD-associated conventional LGD and can be used for the prediction of subsequent LGD in the follow-up biopsies combined with endoscopic features.

Further prognostic stratification of intestinal type of gastric adenocarcinoma by CDX2 expression pattern.

Gastric cancer is one of the most deadly malignancies worldwide. It is routinely divided into 2 common histologic subtypes by the Lauren classification, intestinal type and diffuse type. In recent years, the intestinal type of gastric cancer has been found to represent a heterogeneous disease with divergent prognosis. Our objective was to investigate the CDX2/CK7 immunohistochemical pattern and its role in further stratifying this type of gastric cancer. Gastrectomy cases with a diagnosis of the intestinal type of gastric adenocarcinoma from a single large institution between 2008 and 2022 were collected. Forty-four cases with available blocks and enough tumor tissue were included in this study. Four different immunohistochemical patterns were identified: CDX2+/CK7+ (40.9%), CDX2-/CK7+ (34.1%), CDX2+/CK7- (18.2%), and CDX2-/CK7- (6.8%). Compared to CDX2-negative cases, CDX2-positive ones are more likely to present better prognostic histopathological features including early stage, less perineural and lymphovascular invasion, and lower nodal metastasis. In addition, CDX2 expression was associated with specific molecular features like HER2 overexpression and genetic alterations of receptor tyrosine kinase (TRK) genes including EGFR, ERBB2, ERBB3, DDR2, and MET. In conclusion, according to the CDX2 expression pattern, the intestinal type of gastric cancer could be further divided into 2 subgroups, which have different histopathological and molecular features and different prognosis.