Gastrointestinal Biopsies in the Patient Post-Stem Cell Transplant: An Approach to Diagnosis

Graft-versus-host disease (GVHD) is a major complication of hematopoietic stem cell transplantation (SCT), leading to a significant morbidity and mortality. Histologically, gastrointestinal GVHD is characterized by crypt apoptosis and dropout. However, similar histologic features can also be seen in drug-induced injury and opportunistic infection. Knowledge of the timing of biopsy, patient medications, evidence of infection, and presence of GVHD at other organ sites can aid in the correct diagnosis and subsequent management of these patients. This review focuses on the pathologic differential diagnosis of apoptosis in gastrointestinal biopsies obtained from SCT patients.

Histologic features of allograft livers in patients treated for rejection before biopsy

Liver biopsy is essential for management in liver transplant patients with clinical features suspicious for acute cellular rejection (ACR). As more patients are transplanted for noninfectious indications, it has become increasingly common for them to receive treatment for presumed ACR before biopsy. The effect of pretreatment on the classic histologic triad of ACR's mixed portal inflammation, endothelialitis, and bile duct damage is not well described. Here we report a retrospective study of 70 liver transplant biopsies performed on 53 patients for suspected ACR between 2018 and 2021. Thirty-seven biopsies had a clinical diagnosis of ACR after biopsy. Pretreatment with steroids, antithymocyte globulin, or other increased immunosuppression was given before biopsy in 17 of 37 cases; 20 not-pretreated cases acted as controls. A representative hematoxylin and eosin-stained slide from each biopsy was reviewed independently in a blinded fashion by 3 hepatic pathologists, graded according to the Banff system, assigned a Rejection Activity Index (RAI), and assessed for other histologic features. We found that pretreated biopsies had significantly less portal inflammation (P < .001), less endothelialitis (P < .001), lower RAI (P < .001), and less prominent eosinophils (P = .048) compared to not-pretreated biopsies. There was no significant difference for the other examined variables, including bile duct inflammation/damage (P = .32). Our findings suggest that portal inflammation and endothelialitis become less prominent with pretreatment, whereas bile duct inflammation/damage may take longer to resolve. When evaluating biopsies for suspected ACR, the finding of bile duct inflammation/damage should raise the possibility of partially treated ACR, even in the absence of endothelialitis and portal inflammation.

Immunisation with UB-312 in the Thy1SNCA mouse prevents motor performance deficits and oligomeric α-synuclein accumulation in the brain and gut

Alpha synuclein has a key role in the pathogenesis of Parkinson's disease (PD), Dementia with Lewy Bodies (LBD) and Multiple System Atrophy (MSA). Immunotherapies aiming at neutralising toxic αSyn species are being investigated in the clinic as potential disease modifying therapies for PD and other synucleinopathies. In this study, the effects of active immunisation against αSyn with the UB-312 vaccine were investigated in the Thy1SNCA/15 mouse model of PD. Young transgenic and wild-type mice received an immunisation regimen over a period of 6 weeks, then observed for an additional 9 weeks. Behavioural assessment was conducted before immunisation and at 15 weeks after the first dose. UB-312 immunisation prevented the development of motor impairment in the wire test and challenging beam test, which was associated with reduced levels of αSyn oligomers in the cerebral cortex, hippocampus and striatum of Thy1SNCA/15 mice. UB-312 immunotherapy resulted in a significant reduction of theαSyn load in the colon, accompanied by a reduction in enteric glial cell reactivity in the colonic ganglia. Our results demonstrate that immunisation with UB-312 prevents functional deficits and both central and peripheral pathology in Thy1SNCA/15 mice.

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.

Histologic mimics and diagnostic pitfalls of gastrointestinal endoscopic lifting media, ORISE™ gel and Eleview®

Synthetic lifting media, ORISE™ gel and Eleview®, are increasingly used in gastrointestinal endoscopy, but neither comparative features nor pitfalls are well-established. Media histopathology, morphologic mimics, and complications are described, along with helpful stains and endoscopist media preference. A 3-year retrospective search was performed. A total of 123 cases (108 endoscopies and 15 subsequent surgeries) were identified. ORISE gel was used in 86 (79.6%), Eleview in 20 (13.9%), and others in 7 (6.5%). ORISE gel was histologically identified in 58.1% (n = 50) of endoscopic specimens and all 15 resections. Eleview media were not detected histologically. ORISE gel mimicked mucin in hematoxylin and eosin-stained biopsies, concerning for adenocarcinoma misdiagnosis and/or upstaging, but did not stain for mucin. Acid-fast bacterial staining highlights ORISE gel for specific and definitive identification. In resections, ORISE evolves into an amorphous eosinophilic material, often with exuberant giant cell reaction and transmural bowel penetration. Polyp formation leads to polypectomy in one patient, and operative lesions concerning for adenocarcinoma resulted in frozen sections in two patients. ORISE gel mimics mucin, malignant masses, amyloid, pulse granulomata, elastofibromas, and infectious granulomata. No significant endoscopist media preference was identified. Recognition of ORISE gel in tissues eliminates multiple pitfalls. Eleview was not detectable, yielded none of the pitfalls seen with ORISE gel, and, on our survey, has equivalent endoscopist acceptance. In this largest published series to date, Eleview is clearly preferable to ORISE gel.

Impact of Subspecialty Sign-Out on Interobserver Variability and Accuracy in Gastrointestinal Pathology

Subspecialty sign-out is increasingly common in academic medical centers as well as some community practices. Reducing interobserver variability in anatomic pathology is desirable so that clinicians can select the appropriate therapy. Many departments that elect subspecialty sign-out do so with the assumption that it will improve diagnostic accuracy and interobserver variability-but does it? The literature is mixed.

The Cost-Effectiveness of Video Capsule Endoscopy

The development of video capsule endoscopy (VCE) has allowed for visualization of parts of the gastrointestinal tract generally not readily accessible by noninvasive means. Its ease of use has proved useful in diagnosing and managing various small bowel inflammatory disorders. Continued technological evolution of VCE has paved the way for use in small intestinal bleeding and in patients with acute gastrointestinal bleeding. A detailed analysis of costs associated with VCE has demonstrated its ability to promote efficient allocation of health care resources. Further work is needed regarding development of a universal infrastructure to handle the widespread use of VCE technology.

Sonographic assessment of infectious diseases of the gastrointestinal tract: from scanning to diagnosis

BACKGROUND

Sonography of the gastrointestinal (GI) tract is a practical, safe, inexpensive, and reproducible diagnostic tool for the evaluation, diagnosis, and follow-up of infectious bowel disease. The modality is rapidly gaining prominence among clinicians on a global scale. In the United States, however, ultrasound of the bowel remains underutilized primarily due to insufficient experience among radiologists and sonographers in performing sonographic bowel assessment. This lack of experience and knowledge results in misinterpretations, missed diagnoses, and underutilization of this modality in patients with acute abdomen, with the majority of GI pathology on sonography discovered incidentally.

OBJECTIVES

This article aims to demonstrate the characteristic sonographic findings associated with GI infectious processes as well as provide dedicated ultrasound protocols for evaluation of the GI tract.

CONCLUSION

This article serves a twofold purpose, raising awareness of the utility of this imaging modality within the radiology community and also providing practical teaching points for sonographic evaluation of infectious disorders of the GI tract.

Subtyping of intraductal papillary mucinous neoplasms - pitfalls of MUC1 immunohistochemistry

Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions of pancreatic ductal adenocarcinoma (PDAC). Current edition of WHO Classification of Tumors of the Digestive System recognizes four different subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) and recommends analysis of mucin expression (MUC1, MUC2, MUC5AC, MUC6) as well as evaluation of architectural and cell differentiation patterns for correct classification. However, there is no consensus on MUC1 expression of IPMN-lesions in the literature. Current recommendations are based on studies where antibodies against the core MUC1 protein or sialylated MUC1 (tumor associated MUC1), not the fully glycosylated MUC1 were used. We have recently reported that MUC1 is strongly expressed in both gastric and intestinal types IPMN specimens from the cystic wall, obtained by endoscopic ultrasound guided microbiopsy procedure. We have used a commercial MUC1 antibody, validated and recommended for diagnostic use, which recognizes fully glycosylated MUC1. Based on the above, we propose a revision of the WHO Classification, specifying that antibodies against tumor associated MUC1 should be used for IPMN subtyping.

Pre- and neonatal imaging of gastrointestinal complications in congenital diaphragmatic hernia

The initial outcome in infants with congenital diaphragmatic hernia is mainly related to the associated lung hypoplasia. However, these patients frequently present with additional gastrointestinal pathology that also influences their quality of life and final prognosis. Congenital gastrointestinal anomalies are often observed and the displacement of the liver, the stomach and/or the intestines into the thorax may cause distortion of the vascular axis of these organs, increasing the risk of congestion and/or ischemia. Some of these gastrointestinal complications are already visible at imaging studies performed in utero and/or in newborns.This pictorial essay describes the imaging findings of the most frequently detected gastrointestinal complications in fetuses and infants with congenital diaphragmatic hernia, focusing on prenatal exams.

The Apoptotic Crypt Abscess: An Underappreciated Histologic Finding in Gastrointestinal Pathology

OBJECTIVES

To differentiate apoptotic crypt abscesses (ACAs) from neutrophilic crypt abscesses (NCAs).

METHODS

Cases with crypt abscesses were classified as containing ACAs, NCAs, or mixed crypt abscesses (MCAs) by H&E staining. Sections were stained with cleaved caspase 3 and myeloperoxidase and recategorized.

RESULTS

Fifty-nine cases were reviewed: inflammatory bowel disease (IBD; n = 33), acute cellular rejection (n = 5), graft vs host disease (GVHD; n = 14), cytomegalovirus (n = 5), and drug reaction (n = 2). Concordance was seen in 59%, with most reclassifications resulting from a change of ACAs to MCAs. When cases were classified as having NCA vs those with apoptosis (ACA and MCA), there was 85% agreement (P < .01). NCAs were present in IBD (96%) and not in GVHD or drug injury. Crypt abscesses with apoptosis were seen in 18% of IBD and 96% of non-IBD cases.

CONCLUSIONS

ACAs and MCAs can be distinguished from NCAs and may be a diagnostically useful finding.

Histopathology of Graft-vs-Host Disease of Gastrointestinal Tract and Liver: An Update

OBJECTIVES

Graft-vs-host disease (GVHD) is a donor T-cell-mediated disorder affecting the recipient's skin, gastrointestinal tract, lungs, and liver. It complicates up to 70% of hematopoietic cell transplantation and is associated with high morbidity and mortality rates.

METHODS

An extensive review of the literature has been performed to include the most current consensus on the histopathologic diagnosis of gastrointestinal and liver GVHD.

RESULTS

In this review, we present an overview of GVHD, with emphasis on the histopathologic evaluation of gastrointestinal and liver specimens, including the most important differential diagnoses and possible pitfalls.

CONCLUSIONS

Histopathologic examination remains the mainstay of diagnosis of gastrointestinal and liver GVHD and is interpreted in conjunction with clinical and laboratory data.

Primary Amyloidosis with Gastric Involvement

Amyloidosis can involve all the segments of the gastrointestinal system (GIS) from mouth to anal canal. We present a case of amyloidosis that is detected by gastric biopsy taken in esophagogas-troduodenoscopy (EGD) performed to investigate the etiology of weight loss, nausea and vomiting. It is worth emphasizing that random gastric biopsy is important in gastric evaluations.

How to cite this article: Borazan S, Coşkun A, Yavaşoğlu İ, Yeniçerioğlu Y, Meteoğlu i, Yaşa MH, Karaoğlu AOÖ. Primary Amyloidosis with Gastric Involvement. Euroasian J Hepato-Gastroenterol 2014;4(2):107-109.

New Endoscopic Techniques: Challenges and Opportunities for Surgical Pathologists

In recent years, significant clinical and technological advances have been made in endoscopic methods for diagnosis and treatment of early gastrointestinal neoplasms. However, essential information related to these novel techniques and their implications for practicing surgical pathologists have largely been missing in the general pathology literature. This article provides a general introduction to these novel therapeutic and diagnostic methods, and discusses their indications, contraindications, and potential limitations. The article aims to enable surgical pathologists to interact more efficiently with basic scientists and clinical colleagues to help implement and improve the existing clinical methods and to advance the new technologies.