Ikaros Inhibits Group 3 Innate Lymphoid Cell Development and Function by Suppressing the Aryl Hydrocarbon Receptor Pathway.

Group 3 innate lymphoid cells (ILC3s) expressing the transcription factor (TF) RORγt are important for the defense and homeostasis of host intestinal tissues. The zinc finger TF Ikaros, encoded by Ikzf1, is essential for the development of RORγt(+) fetal lymphoid tissue inducer (LTi) cells and lymphoid organogenesis, but its role in postnatal ILC3s is unknown. Here, we show that small-intestinal ILC3s had lower Ikaros expression than ILC precursors and other ILC subsets. Ikaros inhibited ILC3s in a cell-intrinsic manner through zinc-finger-dependent inhibition of transcriptional activity of the aryl hydrocarbon receptor, a key regulator of ILC3 maintenance and function. Ablation of Ikzf1 in RORγt(+) ILC3s resulted in increased expansion and cytokine production of intestinal ILC3s and protection against infection and colitis. Therefore, in contrast to being required for LTi development, Ikaros inhibits postnatal ILC3 development and function to regulate gut immune responses at steady state and in disease.

Multi-Institutional Study of Pathologist Reading of the Programmed Cell Death Ligand-1 Combined Positive Score Immunohistochemistry Assay for Gastric or Gastroesophageal Junction Cancer.

The assessment of the expression of programmed cell death ligand-1 (PD-L1) using immunohistochemistry (IHC) has been controversial since its introduction. The methods of assessment and the range of assays and platforms contribute to confusion. Perhaps the most challenging aspect of PD-L1 IHC is the combined positive score (CPS) method of interpretation of IHC results. Although the CPS method is prescribed for more indications than any other PD-L1 scoring system, its reproducibility has never been rigorously assessed. In this study, we collected a series of 108 gastric or gastroesophageal junction cancer cases, stained them using the Food and Drug Administration-approved 22C3 assay, scanned them, and then circulated them to 14 pathologists at 13 institutions for the assessment of interpretative concordance for the CPS system. We found that higher cut points (10 or 20) performed better than a CPS of <1 or >1. We used the Observers Needed to Evaluate Subjective Tests algorithm to assess how the CPS system might perform in the real-world setting and found that the cut points of <1 or >1 showed an overall percent agreement of only 30% among the pathologist raters, with a plateau occurring at 8 raters. The raters performed better at higher cut points. However, the best cut point of <20 versus that of >20 was still disappointing, with a plateau at an overall percent agreement of 70% (at 7 raters). Although there is no ground truth for CPS, we compared the score with quantitative messenger RNA measurement and showed no relationship between the score (at any cut point) and messenger RNA amount. In summary, we showed that CPS shows high subjective variability among pathologist readers and is likely to perform poorly in the real-world setting. This system may be the root cause of the poor specificity and relatively low predictive value of IHC companion diagnostic tests for PD-1 axis therapies that use the CPS system.

The Characteristics of Isolated Bulb Celiac Disease in Children.

OBJECTIVES: Mucosal injury in celiac disease (CD) patients can be patchy, and up to 12% of CD patients can have mucosal changes limited to the duodenal bulb. Hence, recent guidelines recommend obtaining bulb biopsies in addition to distal duodenum. This study aimed to describe a cohort of children with isolated bulb CD and assess the benefit of separating bulb biopsies. METHODS: A retrospective chart review between January 2011 and January 2022 at 2 medical centers was conducted. We included children with CD who underwent endoscopy with separated biopsies from the bulb and distal duodenum. A blinded pathologist performed Marsh-Oberhuber grading on selected cases. RESULTS: We identified 224 CD patients, of which 33 (15%) had histologically confirmed isolated bulb CD. Patients with isolated bulb CD were older at diagnosis (10 vs 8 years; P = 0.03). Median anti-tissue transglutaminase immunoglobulin A (TTG IgA) level was lower in isolate bulb CD (2.8 vs 16.7 times the upper limit of normal [ULN], P < 0.001). Almost 88% (29/33) of isolated bulb CD patients had an anti-TTG IgA value of less than 10 times the ULN. Time to anti-TTG IgA normalization (mean 14 months) was similar between the 2 groups. A pathologist review of diagnostic biopsies could not distinguish between the bulb and distal duodenum biopsies in approximately one-third of the reviewed samples. CONCLUSIONS: Separating bulb from distal duodenum biopsies can be considered during CD diagnosis, particularly in children with anti-TTG IgA levels less than 10 times the ULN. Larger prospective cohorts are needed to decide whether isolated bulb CD is a unique cohort or an early stage of the conventional CD.

Collagenous Gastritis: Characteristics and Response to Topical Budesonide.

BACKGROUND AND AIMS: Collagenous gastritis (CG) is a rare disorder characterized by subepithelial collagen deposition in the stomach. Standard medications have been only moderately successful in treating CG. We report results of a large, retrospective, open-label noncontrolled study of topical budesonide for CG, with an aim of establishing an alternative therapy for the disease. METHODS: We identified patients treated for CG at Mayo Clinic (2000-2017) with topically targeted budesonide (TTB) in 2 formulations: open-capsule budesonide or compounded immediate-release budesonide capsule. Demographic, clinical, biochemical, and histologic variables were assessed for all patients before and after treatment. RESULTS: We identified 64 patients with CG (50 adults, 14 children). Most were female (68%), mean age was 41 ± 22.8 years, and body mass index was 23.1 ± 5.9 kg/m2. In most pediatric patients, CG presented with abdominal pain and anemia; in adults, CG presented more often with weight loss (P < .001). Collagenous sprue or colitis were more common in patients >50 years of age (83%) vs those 19-50 years of age (27%) or <19 years of age (50%) (P < .001). Of the patients treated with TTB, 89% had a clinical response to TTB (42% complete, 46% partial), and 88% had a histologic response (53% complete, 33% partial). CONCLUSIONS: Adults and children with CG have a wide variety of symptoms, and notably, TTB therapy produced clinical and histologic improvement after other therapy had failed.

Group 3 innate lymphoid cells inhibit T-cell-mediated intestinal inflammation through aryl hydrocarbon receptor signaling and regulation of microflora.

Aryl hydrocarbon receptor (Ahr) is crucial for the maintenance and function of group 3 innate lymphoid cells (ILCs), which are important in gut immunity. Because Ahr promotes T helper 17 (Th17) cell differentiation in vitro, it is reasonable to expect that Ahr would enhance Th17 cells in vivo. Instead, we show that Ahr deficiency caused increased intestinal Th17 cells, raising the possibility that group 3 ILCs could negatively regulate Th17 cells. Reduced innate interleukin-22 (IL-22) in Ahr-deficient mice allowed expansion of commensal segmented filamentous bacteria (SFB), known to promote Th17 cells. Compared to Rorc(+/+)Ahr(-/-) mice, Rorc(gfp/+)Ahr(-/-) mice had further reduced group 3 ILCs and were prone to spontaneous colitis with increased SFB and Th17 cells. Innate expression of Ahr played a protective role in T-cell-mediated experimental colitis by suppressing pathogenic Th17 cells. Our data reveal an intricate balance between ILCs and Th17 cells regulated by Ahr and commensal flora.

Dichotomous regulation of group 3 innate lymphoid cells by nongastric Helicobacter species.

Intestinal innate lymphoid cells (ILCs) contribute to the protective immunity and homeostasis of the gut, and the microbiota are critically involved in shaping ILC function. However, the role of the gut microbiota in regulating ILC development and maintenance still remains elusive. Here, we identified opposing effects on ILCs by two Helicobacter species, Helicobacter apodemus and Helicobacter typhlonius, isolated from immunocompromised mice. We demonstrated that the introduction of both Helicobacter species activated ILCs and induced gut inflammation; however, these Helicobacter species negatively regulated RORγt+ group 3 ILCs (ILC3s), especially T-bet+ ILC3s, and diminished their proliferative capacity. Thus, these findings underscore a previously unknown dichotomous regulation of ILC3s by Helicobacter species, and may serve as a model for further investigations to elucidate the host-microbe interactions that critically sustain the maintenance of intestinal ILC3s.

The aryl hydrocarbon receptor regulates gut immunity through modulation of innate lymphoid cells.

Innate lymphoid cells (ILCs) expressing the nuclear receptor RORγt are essential for gut immunity presumably through production of interleukin-22 (IL-22). The molecular mechanism underlying the development of RORγt(+) ILCs is poorly understood. Here, we have shown that the aryl hydrocarbon receptor (Ahr) plays an essential role in RORγt(+) ILC maintenance and function. Expression of Ahr in the hematopoietic compartment was important for accumulation of adult but not fetal intestinal RORγt(+) ILCs. Without Ahr, RORγt(+) ILCs had increased apoptosis and less production of IL-22. RORγt interacted with Ahr and promoted Ahr binding at the Il22 locus. Upon IL-23 stimulation, Ahr-deficient RORγt(+) ILCs had reduced IL-22 expression, consistent with downregulation of IL-23R in those cells. Ahr-deficient mice succumbed to Citrobacter rodentium infection, whereas ectopic expression of IL-22 protected animals from early mortality. Our data uncover a previously unrecognized physiological role for Ahr in promoting innate gut immunity by regulating RORγt(+) ILCs.

Early cancer diagnoses through BRCA1/2 screening of unselected adult biobank participants.

PurposeThe clinical utility of screening unselected individuals for pathogenic BRCA1/2 variants has not been established. Data on cancer risk management behaviors and diagnoses of BRCA1/2-associated cancers can help inform assessments of clinical utility.MethodsWhole-exome sequences of participants in the MyCode Community Health Initiative were reviewed for pathogenic/likely pathogenic BRCA1/2 variants. Clinically confirmed variants were disclosed to patient-participants and their clinicians. We queried patient-participants' electronic health records for BRCA1/2-associated cancer diagnoses and risk management that occurred within 12 months after results disclosure, and calculated the percentage of patient-participants of eligible age who had begun risk management.ResultsThirty-seven MyCode patient-participants were unaware of their pathogenic/likely pathogenic BRCA1/2 variant, had not had a BRCA1/2-associated cancer, and had 12 months of follow-up. Of the 33 who were of an age to begin BRCA1/2-associated risk management, 26 (79%) had performed at least one such procedure. Three were diagnosed with an early-stage, BRCA1/2-associated cancer-including a stage 1C fallopian tube cancer-via these procedures.ConclusionScreening for pathogenic BRCA1/2 variants among unselected individuals can lead to occult cancer detection shortly after disclosure. Comprehensive outcomes data generated within our learning healthcare system will aid in determining whether population-wide BRCA1/2 genomic screening programs offer clinical utility.

A prospective pilot comparison of wet and dry heparinized suction for EUS-guided liver biopsy (with videos).

BACKGROUND AND AIMS: As EUS-guided liver biopsy sampling (EUS-LB) becomes more widely used, further studies have investigated ways to improve tissue yields. Use of a heparin-primed needle may lead to less clotting of blood within the needle, improve tissue recovery, and decrease fragmentation. The purpose of this study was to prospectively evaluate wet suction using a heparin-primed needle for EUS-LB. METHODS: This was a prospective crossover study evaluating wet suction for EUS-LB in parenchymal liver disease. The primary outcome was specimen adequacy, defined by an aggregate specimen length ≥15 mm and ≥5 complete portal tracts (CPTs). Secondary outcomes included number of CPTs, length of the longest piece, aggregate specimen length, and number of small (≤4 mm), medium (5-8 mm), and large (≥9 mm) fragments. Adverse events were tracked at 7 and 30 days. RESULTS: One hundred twenty biopsy specimens were collected from 40 participants (3 specimens per patient). Specimen adequacy occurred in 39 wet heparin (98%), 37 dry heparin (93%), and 30 dry needle biopsy samples (80%; 95% confidence interval [CI], .14-.18; P = .01). There was no difference between dry needle techniques. Length of the longest piece was 8.9 mm for wet heparin and 5.8 mm for dry techniques (95% CI, .33-1.53; P = .003). Aggregate specimen length was 49.2 mm for wet heparin and 23.9 mm for dry heparin (95% CI, -46.34 to 44.94; P = .003). Mean CPT count was 7.0 for wet heparin versus 4.0 for dry (95% CI, .74-6.26; P = .01). There were more medium (2.0 vs 1.0; 95% CI, .06-1.24; P = .03) and large (1.0 versus 0.0; 95% CI, .33-1.53; P = .003) fragments with wet suction with no difference in small fragments between groups. CONCLUSIONS: The use of wet suction EUS-LB demonstrated improved tissue adequacy compared with dry needle techniques. (Clinical trial registration number: NCT03103997.).

Restriction of IL-22-producing T cell responses and differential regulation of regulatory T cell compartments by zinc finger transcription factor Ikaros.

Proper immune responses are needed to control pathogen infection at mucosal surfaces. IL-22-producing CD4(+) T cells play an important role in controlling bacterial infection in the gut; however, transcriptional regulation of these cells remains elusive. In this study, we show that mice with targeted deletion of the fourth DNA-binding zinc finger of the transcription factor Ikaros had increased IL-22-producing, but not IL-17-producing, CD4(+) T cells in the gut. Adoptive transfer of CD4(+) T cells from these Ikaros-mutant mice conferred enhanced mucosal immunity against Citrobacter rodentium infection. Despite an intact in vivo thymic-derived regulatory T cell (Treg) compartment in these Ikaros-mutant mice, TGF-ß, a cytokine well known for induction of Tregs, failed to induce Foxp3 expression in Ikaros-mutant CD4(+) T cells in vitro and, instead, promoted IL-22. Aberrant upregulation of IL-21 in CD4(+) T cells expressing mutant Ikaros was responsible, at least in part, for the enhanced IL-22 expression in a Stat3-dependent manner. Genetic analysis using compound mutations further demonstrated that the aryl hydrocarbon receptor, but not RORγt, was required for aberrant IL-22 expression by Ikaros-mutant CD4(+) T cells, whereas forced expression of Foxp3 was sufficient to inhibit this aberrant cytokine production. Together, our data identified new functions for Ikaros in maintaining mucosal immune homeostasis by restricting IL-22 production by CD4(+) T cells.

Rotating shift and BMI increase among healthcare workers in a military hospital: pre- and post-pandemic analysis in Taiwan.

Background: The increasing prevalence of high body mass index (BMI) emphasizes the need for action. Understanding of BMI factors among military hospital healthcare workers remains limited. This study aims to address this gap by analyzing BMI risk factors and changes pre- and post-coronavirus 2019 pandemic among military hospital healthcare workers in central Taiwan from 2019 to 2021. Methods: Conducted at a military hospital in central Taiwan, this study analyzed anonymized health examination data from 2019 to 2021 for 483 healthcare workers. We performed generalized estimating equations to investigate trends in BMI and its association with various factors, including age, sex, job titles, military status, job tenure, work shifts, and lifestyle habits. Results: The risk of increased BMI was higher in 2021 compared to 2019 (risk ratio [RR]: 1.008, 95% confidence interval [CI]: 1.001-1.014). Individuals on rotating shifts had a higher risk of increased BMI compared to day shift workers (RR: 1.021; 95% CI: 1.008-1.035) and higher odds of obesity (odds ratio: 1.546; 95% CI: 1.099-2.175). Among obese individuals, BMI in soldiers was approximately 4.9% lower than in non-soldiers (RR: 0.951; 95% CI: 0.915-0.988). Conclusions: This study identified a significant post-pandemic increase in BMI among healthcare workers in a Taiwanese military hospital, with rotating shifts being a key risk factor for both increased BMI and obesity. Work-related factors influenced BMI changes among obese individuals, while non-work-related factors were significant for non-obese individuals. These findings highlight the broader effects of the pandemic and the specific impact of work-related factors on obese healthcare workers.

Morphological findings in different subtypes of hepatic amyloid.

The classic findings have been well described for light-chain amyloid involving the liver. In addition to light chain, however, many additional proteins are now known to be amyloidogenic and can involve the liver. A total of 58 surgical pathology specimens with amyloid deposits were analyzed for patterns of amyloid deposition, including amyloid from light chain lambda (N = 17), light chain kappa (N = 15), transthyretin (N = 15), serum amyloid A (N = 4), apolipoprotein A1 (N = 4), fibrinogen alpha (N = 2), LECT2 (N = 1). Amyloid deposits predominately targeted the liver vasculature, including the walls of the hepatic arteries, portal veins, and sinusoids. While there was overlap, light chain amyloid predominately involved the sinusoids, while transthyretin amyloid predominately targeted the hepatic arteries, especially the larger ones in the hilum and larger portal tracts. Serum amyloid A formed nodular deposits that started in the portal vasculature but then extended into the portal tract stroma, leading to large, bulbous, portal-based amyloid deposits. Apolipoprotein A amyloid also formed large portal-based nodules. Fibrinogen was mild and subtle on H&E and predominately affected portal veins. Amyloid deposits in hilar nerves were prominent with amyloid light chain, transthyretin, and apolipoprotein A1. In conclusion, the histology of hepatic amyloid is diverse and shows several distinct clusters of findings that can aide in recognition in surgical pathology specimens.

Artificial intelligence in anatomical pathology: building a strong foundation for precision medicine.

With the convergence of digital pathology (DP) and artificial intelligence (AI), anatomic pathology practice has been experiencing an exciting paradigm shifting. Pathologists will be provided with an augmented ability to improve diagnostic accuracy, efficiency, and consistency. There will be subvisual morphometric features discovered and multiomics data integrated to provide better prognostic and theragnostic information to guide individual patients' management. The perspective for future precision medicine is promising. However, there are many challenges before AI-assisted DP diagnostic workflows can be successfully implemented. Herein, we briefly review some examples of AI application in anatomic pathology with an emphasis on the subspecialty of gastrointestinal pathology and discuss potential challenges for clinical implementation.

Histologic evaluation in the diagnosis and management of celiac disease: practical challenges, current best practice recommendations and beyond.

Celiac disease (CD) is an immunoallergic enteropathy affecting genetically susceptible individuals upon dietary exposure to gluten. In current clinical practice, the diagnosis of CD is based on a combination of clinical, serologic, and histologic factors with the possible exception of pediatric patients. Histopathologic evaluation of small intestinal tissue plays a critical role in the disease diagnosis and management, despite many practical challenges. Recently published best practice guidelines help to standardize biopsy sample procurement, tissue preparation, histology interpretation, and reporting, to optimize patient care. In addition, an increasing demand for monitoring the disease course, particularly demonstrating the efficacy of dietary and nondietary interventions for disease management, calls for the use of quantitative histology. With the advent of a gradual transition toward digital pathology in routine diagnostic practice, quantitative histopathologic evaluation in CD shows a promising future.

Berberine oleanolic acid complex salt grafted hyaluronic acid/silk fibroin (BOA-g-HA/SF) composite scaffold promotes cartilage tissue regeneration under IL-1ß caused stress.

Since inflammatory cytokines cause stress to chondrocytes and the failure of cartilage defects repair with cartilage tissue engineering, it is necessary to develop a scaffold to maintain cartilage regeneration under inflammatory factors caused stress. Following a berberine-oleanolic acid (OA) complex salt (BOA) was grafted to hyaluronic acid (HA) to obtain water soluble BOA-g-HA, it mixed with silk fibroin (SF) to prepared 4 solutions, which contained 30 mg/mL SF and 0.75, 1.5, 2.25, and 3.0 mg/mL BOA-g-HA respectively. They were lyophilized to fabricate BOA-g-HA/SF-1, BOA-g-HA/SF-2, BOA-g-HA/SF-3, and BOA-g-HA/SF-4 composite scaffolds respectively. All prepared scaffolds displayed porous network structure and exhibited promising mechanical properties for tissue engineering applications. Among them, the BOA-g-HA/SF-3 composite scaffold showed the highest influence on maintaining chondrocytic phenotype of chondrocytes under IL-1ß induced stress. Following SF, HA/SF, and BOA-g-HA/SF-3 composite scaffolds with seeded chondrocytes were treated with IL-1ß induction for 1 week, specimens were incubated with cell culture medium for 3 week or were subcutaneously implanted into nude mice for 4 weeks. The results demonstrated that the BOA-g-HA/SF-3 composite scaffold promotes cartilage tissue regeneration in vitro and in vivo under IL-1ß caused stress, suggesting that it can be potential applied for repairing cartilage defects in osteoarthritis patients.

The interventional direct peroral cholangioscopy toolbox for endoscopic snare resection of a high-grade biliary intraductal neoplasia.

Video 1Demonstration of techniques for performing direct peroral cholangioscopy.

Hepatic Angiosarcomas With Sinusoidal Growth Patterns.

Hepatic angiosarcomas are aggressive malignant tumors of the liver with variable morphology. One of the rare morphologies is that of the sinusoidal growth pattern, which is challenging to diagnose because of its subtle imaging and morphologic findings. This retrospective study characterizes the clinical, histologic, and immunohistochemical features of sinusoidal hepatic angiosarcomas. Thirteen cases were included in the study, comprising 12 (92.3%) needle core biopsies and 1 wedge biopsy; one of the needle biopsies also had a subsequent resection specimen available for review. Multiple biopsies were needed to make the diagnosis in 4 cases. At least moderate sinusoidal dilatation was seen in 53.8% of cases. Increased cellularity within the sinusoids was seen at both low-power and high-power magnification (69.2% and 84.6%, respectively). Cytologic atypia ranged from mild to marked. Multinucleated tumor cells were present in most cases (10/13 cases) but were often sparse. Mitotic activity was identified in 5/13 cases. ERG immunostains were more reliable than CD31 and CD34 in identifying the tumor cells. Ki-67 proliferative index ranged from 5% to 30%. p53 immunostains were available in 9 cases and c-MYC in 7 cases; they were positive in 62.5% and 33.3% of cases, respectively and had a mutually exclusive staining pattern. In summary, this rare pattern of hepatic angiosarcoma is challenging to diagnose but has distinctive morphologic findings that can be supplemented with immunostains to establish the diagnosis.

CRP Versus SAA for Identification of Inflammatory Hepatic Adenomas.

Subtyping hepatic adenomas is important for patient management due to differing complication risks. Immunohistochemical staining with C-reactive protein (CRP) and serum amyloid-A (SAA) is widely accepted as a surrogate for molecular classification to identify inflammatory hepatocellular adenomas. Limited data, however, has been published on how these 2 stains compare for sensitivity. We conducted a large, multicenter, retrospective study to examine the sensitivity and staining characteristics of CRP and SAA in inflammatory hepatic adenomas, with focal nodular hyperplasia (FNHs) as a control group. Inflammatory adenomas were identified in 133 patients (average age 37 years, 109 were female). In all, 69.9% of cases were resection specimens and 90.2% of all cases showed positive staining for both CRP and SAA; 10 (7.5%) were positive for CRP only and 3 (2.3%) were positive for SAA only. CRP was more sensitive than SAA (97.74% vs. 92.48%, P -value = 0.0961) and showed more extensive and intense staining, with a significantly higher modified H-score ( P <0.001). Focal nodular hyperplasia can also show positive CRP and SAA staining but with a lower modified H-score ( P <0.0001). Based on beta-catenin and glutamine synthetase staining, 26 of inflammatory adenomas also had beta-catenin activation (19.5%). All 3 cases with positive SAA and negative CRP staining were beta-catenin activated. In contrast, the proportion of cases that were CRP positive and SAA negative was similar regardless of beta-catenin activation. The data affirms the strategy of using both CRP and SAA immunostains for hepatic adenoma subtyping and raises the awareness of the highly variable nature of SAA staining characteristics.

Unique Morphologic Findings in the Liver After Stereotactic Radiation for Cholangiocarcinoma.

Newer radiotherapy techniques, such as stereotactic body radiation, have been increasingly used as part of the treatment of cholangiocarcinomas, particularly as a bridge to liver transplantation. Although conformal, these high-dose therapies result in tissue injury in the peritumoral liver tissue. This retrospective study characterized the morphologic changes in the liver after stereotactic body radiation in a series of liver explant specimens with perihilar cholangiocarcinoma. The morphologic changes in the irradiated zone were compared against the nonirradiated background liver parenchyma to control for chemotherapy-related changes. Of the 21 cases studied, 16 patients (76.2%) had underlying primary sclerosing cholangitis, and 13 patients (61.9%) had advanced liver fibrosis. The average duration between completion of radiotherapy and liver transplantation was 33.4 weeks (range: 6.29 to 67.7). Twelve patients (57.1%) had no residual tumor in the liver. The most frequent histologic changes in the peritumoral irradiated liver tissue were sinusoidal congestion (100%), sinusoidal edematous stroma (100%), and hepatocellular atrophy (100%), followed by partial/complete occlusion of central veins (76.2%), sinusoidal cellular infiltrates (76.2%), and hepatocyte dropout (66.7%). The findings in the radiated areas were more extensive than in the background liver ( P <0.01). Sinusoidal edematous stroma was striking and dominated the histologic findings in some cases. Over time, there was less sinusoidal congestion but more hepatocyte dropout (r s =-0.54, P =0.012 and r s =0.64, P =0.002, respectively). Uncommon findings, such as foam cell arteriopathy in the liver hilum, were also observed. In summary, postradiation liver specimens have distinctive morphologic findings.