Endoscopic Evaluation of PET/CT Abnormalities in the Gastrointestinal Tract: Yield and Approach.

BACKGROUND: Unexpected hypermetabolic activity is often encountered in the gastrointestinal tract when PET/CT is performed for various indications, prompting endoscopic evaluation. Our aim was to characterize the types of lesions seen in segments of the gastrointestinal tract with unexpected PET/CT abnormalities as well as clinically significant lesions seen on endoscopy which did not produce a PET/CT abnormality to guide the endoscopist tasked with evaluating these imaging findings. METHODS: We retrospectively reviewed a database of endoscopies performed at City of Hope Comprehensive Cancer Center between January 1, 2016 and September 30, 2021 for an indication of "abnormal PET." We divided the gastrointestinal tract into segments and defined categories of endoscopic/histologic findings for each segment. We counted the number of segments with an abnormal PET/CT finding and corresponding endoscopic/histologic abnormality as well as the number of segments with an endoscopic/histologic abnormality but normal PET/CT. RESULTS: PET/CT identified 209 segments with hypermetabolic activity, 109 of which had corresponding endoscopic/histologic abnormalities. In the jejunum and ileum, all corresponding lesions were malignant. Seventy-three percent of corresponding lesions in the stomach were H. pylori positive. PET/CT failed to detect 34.7% of clinically significant lesions diagnosed endoscopically, including 1 malignancy in the transverse colon and many inflammatory or low-risk premalignant lesions. CONCLUSION: PET/CT abnormalities seen in the small bowel should be evaluated urgently as nearly all correlates were malignant, while abnormalities in the stomach should prompt workup for H. pylori. Most lesions missed by PET/CT were inflammatory or low-risk premalignant yet clinically significant, confirming the need to inspect the entirety of the upper or lower gastrointestinal tract during endoscopy.

Pancreatic volume does not correlate with histologic fibrosis in adult patients with recurrent acute and chronic pancreatitis.

OBJECTIVES: Reduced pancreatic volume, often referred to as atrophy, is a commonly reported imaging feature of chronic pancreatitis (CP). This study evaluated whether there is an association between pancreatic volume and fibrosis, the criterion standard of CP, in patients undergoing total pancreatectomy with islet autotransplantation (TPIAT) for recurrent acute pancreatitis (RAP) and CP. METHODS: All adult patients who underwent TPIAT between 2010 and 2019 were categorized into 3 groups: RAP, definite CP and indeterminate CP. Pancreatic volume was calculated by summing up the areas from each thin section of the pancreas on 3D CT imaging. Excisional biopsies of the pancreatic head as well as body/tail region were obtained at the time of TPIAT. Two different fibrosis scores were used for histologic assessment. RESULTS: A total of 16, 29 and 15 patients underwent TPIAT for RAP, definite CP and indeterminate CP, respectively. The mean pancreatic volumes for patients with RAP, definite CP and indeterminate CP were 65.7 ± 28.5 cc, 54.9 ± 22.9 cc and 61.8 ± 23.6 cc, respectively (p = 0.3). The mean fibrosis scores were significantly higher in patients with definite CP compared to RAP (p < 0.001) and indeterminate CP (p < 0.001). Pancreatic volume was not associated with either fibrosis score after adjusting for age, gender, duration of disease, BMI and diabetes in the multivariable analysis. CONCLUSIONS: While the fibrosis scores were higher in definite CP compared to both RAP and indeterminate CP, there was no correlation between pancreatic volume and fibrosis. This suggests that atrophy alone cannot be used to diagnose CP.

Towards a "Net" generation of Pathologists: the pathCast online remote learning platform.

In recent years, digital and communication technology has been changing the way to spread knowledge in Medicine. In the field of Pathology, several remote learning resources have been made available through multiple social media platforms (Facebook, Twitter and others), YouTube channels and dedicated Websites, with a growing number of freely available lectures or tutorials, broadcasted live and/or archived for on-demand viewing. All these internet-based resources enable the pursuit of a flexible, independent, self-motivated and self-directed way of learning that fits perfectly with the increasing limitations of time, space and speed of modern day learners.These resources have played a significant role in filling the void of conventional education during the ongoing Covid-19 pandemic. Moreover, with their widespread diffusion throughout communities of Pathologists from all over the world they help to reduce the educational gap between resource-rich and resource-poor countries, having the potential to become standardized knowledge-sharing platforms and to be incorporated into curricula at any level.pathCast is one of the most robust and reliable open-access online remote learning platforms for pathologists, which live-streams lectures across the world. In the present paper we describe its structure, its acceptance by the global community of pathologists, what innovation elements has introduced regarding methodologies for education and its powerful and positive impact for residency training and continuing life-long education of practicing pathologists. A comprehensive list of the pathCast lectures with the respective links is also provided along with a brief discussion on other freely accessible online educational resources for pathologists.

Nonneoplastic pathology of the appendix: A review article, based on the recent literature.

OBJECTIVES: The appendix, although considered a vestigial organ, is of considerable clinical importance because acute appendicitis is a common medical problem. There are also other disease processes involving the appendix. The appendix is among the first specimens that the pathologist (and surgeon) cuts one's teeth on. Thus, there may be a tendency to underestimate the clinically and prognostically significant appendiceal pathologies. METHODS: We provide a vade mecum of the pathologic features of a wide range of nonneoplastic appendiceal pathologies, with an emphasis on developing a practical approach to grossing, microscopy, and reporting-all with clinical and therapeutic implications. Much of this is based on literature on MEDLINE with reference to years 2008 to 2023, as well as on personal experiences and interpretations. RESULTS: The appendix can harbor a myriad of nonneoplastic pathologies, including infections, inflammations of varying etiologies (including interval appendectomy), endometriosis, diverticulosis, and so on. Chronic appendicitis, Crohn disease, and clinical audit are recurring themes while COVID-19 is a new entity. CONCLUSIONS: Most importantly, all pathologists should appreciate that the appendix is not as "routine" a specimen as one would want to believe.

Diffuse-Type Histology Is Prognostic for All Siewert Types of Gastroesophageal Adenocarcinoma.

PURPOSE: The optimal treatment for gastroesophageal junction adenocarcinoma (GEJA) remains controversial. We evaluated the treatment patterns and outcomes of patients with locally advanced GEJA according to the histological type. MATERIALS AND METHODS: We conducted a single-institution retrospective cohort study of patients with locally advanced GEJA who underwent curative-intent surgical resection between 2010 and 2020. Perioperative therapies as well as clinicopathologic, surgical, and survival data were collected. The results of endoscopy and histopathological examinations were assessed for Siewert and Lauren classifications. RESULTS: Among the 58 patients included in this study, 44 (76%) were clinical stage III, and all received neoadjuvant therapy (72% chemoradiation, 41% chemotherapy, 14% both chemoradiation and chemotherapy). Tumor locations were evenly distributed by Siewert Classification (33% Siewert-I, 40% Siewert-II, and 28% Siewert-III). Esophagogastrectomy (EG) was performed for 47 (81%) patients and total gastrectomy (TG) for 11 (19%) patients. All TG patients received D2 lymphadenectomy compared to 10 (21%) EG patients. Histopathological examination showed the presence of 64% intestinal-type and 36% diffuse-type histology. The frequencies of diffuse-type histology were similar among Siewert groups (37% Siewert-I, 36% Siewert-II, and 33% Siewert-III). Regardless of Siewert type and compared to intestinal-type, diffuse histology was associated with increased intraabdominal recurrence rates (P=0.03) and decreased overall survival (hazard ratio, 2.33; P=0.02). With a median follow-up of 31.2 months, 29 (50%) patients had a recurrence, and the median overall survival was 50.5 months. CONCLUSIONS: Present in equal proportions among Siewert types of esophageal and gastric cancer, a diffuse-type histology was associated with high intraabdominal recurrence rates and poor survival. Histopathological evaluation should be considered in addition to anatomic location in the determination of multimodal GEJA treatment strategies.

Severe Immune-Mediated Colitis Induced by Checkpoint Inhibitors in an Adolescent With Lynch Syndrome.

Lynch syndrome is a hereditary colorectal cancer caused by mutations in DNA mismatch repair genes. Immune checkpoint therapies have shown promise in treating Lynch syndrome-associated cancers but can lead to immune-related adverse events, such as colitis. In this report, we present a severe case of immune-mediated colitis (IMC) induced by checkpoint inhibitors in a young patient with Lynch syndrome. This 20-year-old male with Lynch syndrome and a history of glioblastoma underwent dual checkpoint therapy, after initial treatment with systemic steroids. Despite this, his condition worsened, resulting in complications, such as toxic megacolon and small bowel obstruction. He was subjected to various treatments, including infliximab and vedolizumab, but ultimately required total abdominal colectomy with J-pouch creation. This case highlights the challenges of managing severe IMC in patients with Lynch syndrome. The patient's suboptimal response to standard treatments and the development of complications emphasizes the need for a better understanding and alternative therapeutic options for IMC. This case also calls into question whether a subset of patients with IMC should be "treated to target," even though the current standard of care for IMC is guided by symptom response, and if so, further research is necessary to identify potential therapeutic targets. Further research is also required to understand the mechanisms of IMC and develop effective treatment strategies tailored to patients with Lynch syndrome and immune-related adverse events.

Decline of case reports in pathology and their renewal in the digital age: an analysis of publication trends over four decades.

AIMS: We investigated the trend in case reports (CRs) publication in a sample of pathology journals. Furthermore, we proposed an alternative publishing route through new digital communication platforms, represented by the 'social media case report'. METHODS: 28 pathology journals were selected from SCImago database and searched in PubMed to identify the number of published CRs. Four reference decades (1981-2020) were selected. The 5-year impact factor (IF) was retrieved from the Academic Accelerator database. RESULTS: CRs increased during the first three decades (6752, 8698 and 11148, respectively; mean values: 355, 27.3%; 334, 26.4%; 398, 28.8%) as the number of CR-publishing journals (19, 26 and 28, respectively). In the last decade, CRs significantly decreased (9341; mean 334, 23.6%) without variation in the number of CR-publishing journals (28). Half of the journals reduced CRs (from -1.1% to -37.9%; mean decreasing percentage -14.7%), especially if active since the first decade (11/14, 79%); the other half increased CRs (from +0.5% to +34.2%; mean increasing percentage +11.8%), with 8/14 (57%) starting publishing in the first decade. The 5-year IF ranged from 0.504 to 5.722. Most of the journals with IF ≥2 (10/14, 71%) reduced the CRs number, while 71% of journals with IF <2 increased CRs publication (especially journals with IF <1, +15.1%). CONCLUSIONS: CRs publication decreased during the last decade, especially for journals which are older or have higher IF. Social media CRs may represent a valid alternative and by using standardised templates to enter all relevant data may be organised in digital databases and/or transformed in traditional CRs.

Complete response to chemoimmunotherapy with bevacizumab in synchronous multiple primary cancers: pulmonary adenocarcinoma and sarcomatoid carcinoma.

A small percentage of patients have multiple synchronous primary cancers at presentation. In the last five years, many regimens associated with immunotherapy and chemotherapy were approved for first-line metastatic non-small-cell lung cancer (NSCLC) and other solid tumors, but the study of immunotherapy when multiple cancers are present in one patient remains incomplete. Next-generation sequencing biomarkers and immunotherapy markers including PD-L1 can be effectively utilized in the diagnosis and treatment plan for multiple synchronous primary cancers. Immune biomarkers and PD-L1 expression warrant individualized treatments in synchronous primary adenocarcinoma and pulmonary sarcomatoid carcinoma. We describe the case of a patient with pulmonary sarcomatoid carcinoma and lung adenocarcinoma, metastatic to brain de novo. The patient achieved a complete response after only three cycles of carboplatin, paclitaxel, bevacizumab, and atezolizumab and remains free of any evidence of disease after 18 mo of maintenance therapy.

Follicular dendritic cell sarcoma of gastrointestinal tract with two emerging distinct subtypes: a case report and systemic review.

BACKGROUND: Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm of mesenchymal origin. FDCS of gastrointestinal tract (GI) are exceedingly uncommon. CASE PRESENTATION: We report the first case of classic type FDCS in a 34-year-old male with Birt-Hogg-Dubé syndrome, which presented as a mass at the ileo-cecal junction. He received no further treatment after resection and remained disease free for 3.5 years. We further analyze and review the clinical and pathologic findings of 33 cases of GI tract FDCS reported in the literature. CONCLUSIONS: There are two distinct subtypes of FDCS in the GI tract: the classic type occurs in relatively younger patients (mean = 45.3 years) without Epstein-Barr virus (EBV) association, and behaves more aggressively; the inflammatory subtype presents as colonic polypoid tumor in older patients (mean = 60.7 years) and is EBV positive. The clinical outcome in the latter group appears favorable although mortality rate is not necessarily low.

Potentiating effect of reovirus on immune checkpoint inhibition in microsatellite stable colorectal cancer.

The majority of colorectal cancers (CRCs) are microsatellite stable (MSS) and resistant to immunotherapy. The current study explores the possibility of using oncolytic reovirus to sensitize MSS CRC to immune checkpoint inhibition. While reovirus reduced metabolic activity among KRAS Mut cells, microarray/computational analysis revealed microsatellite status-oriented activation of immune-response pathways. Reovirus plus anti-PD-1 treatment increased cell death among MSS cells ex vivo. Reduced tumorigenicity and proliferative index, and increased apoptosis were evident among CT26 [MSS, KRAS Mut], but not in MC38 [microsatellite unstable/MSI, KRAS Wt] syngeneic mouse models under combinatorial treatment. PD-L1-PD-1 signaling axis were differentially altered among CT26/MC38 models. Combinatorial treatment activated the innate immune system, pattern recognition receptors, and antigen presentation markers. Furthermore, we observed the reduction of immunosuppressive macrophages and expansion of effector T cell subsets, as well as reduction in T cell exhaustion. The current investigation sheds light on the immunological mechanisms of the reovirus-anti-PD-1 combination to reduce the growth of MSS CRC.

pathCast: An Interactive Medical Education Curriculum That Leverages Livestreaming on Facebook and YouTube.

PROBLEM: Global connectivity and awareness have significantly increased over the past 3 decades, yet medical education remains mostly unchanged in its delivery-local didactic teaching, supplemented with hands-on clinical experiences. APPROACH: Beginning in 2016, the authors leveraged the livestreaming capabilities of Facebook and YouTube to create a platform called pathCast to broadcast pathology lectures to an international community of medical professionals. An interactive pathology curriculum was designed to address challenging topics across various subspecialties. Expert pathologists were invited to deliver 60-minute lectures using digital or glass slides or traditional slide decks. Remote (online) attendees interacted with lecturers in real time using the broadcasts' chat interface. Facebook's and YouTube's analytics were evaluated to assess the performance of all lectures. OUTCOMES: From June 2016 to December 4, 2019, 53 speakers delivered 87 lectures representing 18 pathology subspecialties in 9 different languages (with 78 [89.7%] in English only) and from various geographic regions. The lectures hosted on the Facebook channel have garnered 8,333 followers and 52,171 views for a total of 386,200 minutes of watch time, and the lectures hosted on the YouTube channel have accumulated 5,891 subscribers and 292,735 views for a total of 50,674 hours of watch time. The lectures have been viewed by users from 1,093 unique cities across 124 countries. NEXT STEPS: The authors will continue to develop the curriculum to further disseminate pathology education on a global scale.

Russell Body Barrett's Esophagus.

We report an unusual case of Barrett's esophagus with prominent intramucosal Russell bodies, also known as Russell body Barrett's esophagus. We present this case to emphasize the importance of recognizing this unusual entity. It also represents a potential diagnostic pitfall because the distended plasma cells may be mistaken for signet ring cells of gastric adenocarcinoma or low-grade lymphoma. Hence, an awareness of this entity is important to avoid diagnostic confusion.

Correlations of morphology and molecular alterations in traditional serrated adenoma.

Traditional serrated adenoma was first reported by Longacre and Fenoglio-Presier in 1990. Their initial study described main features of this lesion, but the consensus diagnostic criteria were not widely adopted until recently. Traditional serrated adenoma presents with grossly protuberant configuration and pinecone-like appearance upon endoscopy. Histologically, it is characterized by ectopic crypt formation, slit-like serration, eosinophilic cytoplasm and pencillate nuclei. Although much is now known about the morphology and molecular changes, the mechanisms underlying the morphological alterations are still not fully understood. Furthermore, the origin of traditional serrated adenoma is not completely known. We review recent studies of the traditional serrated adenoma and provide an overview on current understanding of this rare entity.

Are Upfront Levels for Colon "Polyps" Necessary? A Pragmatic Review.

INTRODUCTION: Colon biopsies are among the most frequently examined specimens by pathologists. Many pathology practices, ours included, review upfront levels on all gastrointestinal biopsies. In our experience, when a lesion is present on specimens labeled "colon polyp," it is readily identified on the first level. To test our hypothesis, we re-reviewed 500 cases in which a lesion was identified histologically and determined if the diagnosis could be made on the first level. Furthermore, we examined 50 additional cases of high-grade dysplasia/carcinoma to determine if the higher-grade component was also present on the first level. MATERIALS AND METHODS: Cases were retrieved for lesions that could account for a colon polyp clinically, and the first level was examined to determine if lesional tissue was present on the first level. Fifty additional cases of higher-grade lesions were included to ensure higher-grade lesions were present on the first level. RESULTS: Overall, 497/500 (99.4%) of the non-high-grade lesions were present on the first level, whereas 3/500 (0.6%) required the additional level for diagnosis. All 50 high-grade lesions were present on the first level examined. DISCUSSION: Many pathology practices routinely order upfront levels on all gastrointestinal biopsies, often generating 2 or 3 slides. Additional slides increase costs, increase the likelihood of laboratory-generated errors, and can waste limited tissue on small biopsies for which ancillary studies may be necessary. Our study showed that a single level is sufficient in the overwhelming majority of cases in which a lesion is identified histologically.

Long-term survivor of primary malignant melanoma of the esophagus treated with surgical resection.

INTRODUCTION: Primary malignant melanoma of the esophagus is a rare diagnosis with only a few hundred cases reported in the literature. Due to the aggressive nature of this disease, long-term survivors are exceedingly rare with only a handful of case reports. PRESENTATION OF CASE: We report the case of a 38 year old man who presented with chest and back pain. Workup revealed a mediastinal mass and the patient was diagnosed with primary malignant melanoma of the esophagus and treated with radical resection. Despite the poor prognosis associated with primary malignant melanoma of the esophagus, he remains disease free for over 7 years. DISCUSSION: Initially primary malignant melanoma of the esophagus was a controversial diagnosis until the demonstration of normal melanocytes in healthy patients. It is an aggressive disease that is nearly uniformly fatal. Review of the literature shows that treatment with radical surgical resection extends prognosis by months while treatment with adjuvant chemotherapy is controversial. CONCLUSION: Primary malignant melanoma of the esophagus is a rare and aggressive disease that should be treated with surgical resection when feasible. We report the rare case of a long term survivor over 7 years since diagnosis.

Autoimmune Pancreatitis: A Multiorgan Disease Presenting a Conundrum for Clinicians in the West.

Autoimmune pancreatitis (AIP), a clinical entity originally described in East Asia and more recently recognized in the United States and Europe, poses a diagnostic conundrum for clinicians in the West due to immunoglobulin G4 seronegativity. Although expert panels classify this disease into 2 types, it remains difficult to stratify the disease given that both types share most clinical, biochemical, and imaging characteristics. The classic presentation of AIP can mimic that of pancreatic carcinoma, which increases the urgency of evaluation, diagnosis, and treatment. In this article, we elucidate the differences between the 2 types of AIP, highlight the shortcomings of the current classification system, and propose a more inclusive view of the disorder.

Erythema annulare centrifugum with autoimmune hepatitis.

Erythema annulare centrifugum (EAC) is a rare disease entity characterized by dense perivascular lymphocytic infiltrates in dermis. It has been associated with a few conditions, though its etiology is largely unknown. To our knowledge there has been no reported association with autoimmune hepatitis described earlier. This child also was positive for hepatitis C virus antibodies, though HCV RNA was negative. We should keep in mind the false positivity of hepatitis C antibodies before deciding on its therapy.