Small bowel adenocarcinomas (SBAs) are often associated with poor prognosis and have limited therapeutic options. Programmed cell death protein-1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway blockade is an effective treatment in many microsatellite instability-high (MSI-H) solid tumors. We aimed at investigating PD-L1 and PD-1 expression in nonhereditary, non-ampullary SBAs, associated with celiac disease (CeD), Crohn's disease (CrD), or sporadic, recruited through the Small Bowel Cancer Italian Consortium. We assessed PD-L1 and PD-1 by immunohistochemistry in a series of 121 surgically resected SBAs, including 34 CeD-SBAs, 49 CrD-SBAs, and 38 sporadic SBAs. PD-L1 and PD-1 expression was correlated with several clinico-pathological features, such as the etiology, microsatellite instability status, and tumorinfiltrating lymphocyte (TIL) density. The prevalence of PD-L1 positivity according to combined positive score (CPS) was 26% in the whole cohort of SBAs, with significantly (p = 0.001) higher percentage (35%) in both CeD-SBAs and CrD-SBAs in comparison with sporadic SBAs (5%). CPS ≥ 1 SBAs were significantly (p = 0.013) more frequent in MSI-H cases (41%) than in non-MSI-H ones (18%); however, 15 CPS ≥ 1 microsatellite stable SBAs were also identified. CPS ≥ 1 SBAs showed higher TIL and PD-1 + immune cell density, more frequently medullary histotype, as well as a better outcome in comparison with CPS < 1 cases. This study demonstrates an increased proportion of PD-L1 + cases in both CeD-SBAs and CrD-SBAs in comparison with sporadic SBAs. In addition, the identification of a subset of PD-L1 + microsatellite stable SBAs supports the need to ascertain additional biomarkers of response to immune checkpoint inhibitors along with MSI-H.

Background Small bowel adenocarcinoma is a relatively rare cancer, often diagnosed in an advanced stage. In localized and resectable disease, surgery alone or in combination with adjuvant chemotherapy is the mainstay of treatment. In the recently published National Comprehensive Cancer Network Clinical Practice guidelines, criteria for selecting patients with stage II small bowel adenocarcinoma to receive adjuvant chemotherapy are provided, and they are mainly extrapolated from studies on colorectal cancer. Patients and Methods In the present study, we aimed to verify whether mismatch repair deficiency phenotype, high-risk pathologic features (including T4, positive resection margins and a low number of lymph nodes harvested), as well as tumor histologic subtype, were associated with cancer-specific survival in 66 stage II non-ampullary small bowel adenocarcinoma patients, collected through the Small Bowel Cancer Italian Consortium. A central histopathology review was performed. Mismatch repair deficiency was tested by immunohistochemistry for MLH1, MSH2, MSH6 and PMS2, and confirmed by polymerase chain reaction for microsatellite instability. Results We identified mismatch repair deficiency, glandular/medullary histologic subtype, and celiac disease as significant predictors of favorable cancer-specific survival using univariable analysis with retained significance in bivariable models adjusted for pT stage. Among the high-risk features, only T4 showed a significant association with an increased risk of death; however, its prognostic value was not independent of mismatch repair status. Conclusions Mismatch repair protein expression, histologic subtype, association with celiac disease, and, in the mismatch repair proficient subset only, T stage, may help identify patients who may benefit from adjuvant chemotherapy. Graphic Abstract

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Introduction: In this study, we report on our experience using digital pathology to overcome the severe limitations imposed on health care by the Covid-19 outbreak in Northern Italy. Social distancing had a major impact on public transportation, causing it to run with reduced timetables. This resulted in a major challenge for hospital commuters. To limit the presence in our hospital of no more than two pathologists at a time out of four, a web-based digital pathology system (DPS) was employed to work remotely. Subjects and Methods: We used a DPS in which a scanner, a laboratory information system, a storage device, and a web server were interfaced so that tissue slides could be viewed over the Internet by whole-slide imaging (WSI). After a brief internal verification test, the activity on the DPS was recorded, taking track of a set of performance and efficiency indicators. At the end of the study, 405 cases were signed out remotely. Results: Of 693 cases, 58.4% were signed out remotely by WSI, while 8.4% needed to be kept on hold to return to the original microscope slide. In three cases, at least one slide had to be rescanned. In eight cases, one slide was recut. Panel discussion by WSI was necessary in 34 cases, a condition in which all pathologists were asked for their opinion. A consultation with a more experienced colleague was necessary in 17 cases. Conclusions: We show that WSI easily allows pathologists to overcome the problems caused by the severe social distancing measures imposed by the Covid-19 pandemic. Our experience shows that soon there will not be alternatives to digital pathology, given that there is no assurance that other similar outbreaks will not occur.

Author 'Marco Vincenzo Lenti' was listed in the original article as given name: 'Marco', family name: 'Vincenzo Lenti'. However, this should be listed as given name: 'Marco Vincenzo', family name: 'Lenti'. This has been addressed by means of this correction article as well as an update to the original article. 1234567890();,: 1234567890();,:

We describe a solitary peduncolated polypoid lesion with a bilobated head in the transverse colon mucosa of a 51-year-old Caucasian man. Histologically, the lesion was consistent with juvenile polyp (JP), but showing a few dysplastic glands and a focus of intramucosal adenocarcinoma. This finding suggests that, at least in adults, even the sporadic JPs might carry an inherent potential for malignancy, which has so far only been pointed out for syndromic lesions. Additionally, we observed p53 overexpression in both the dysplastic lesions and in the invasive cells but not in the remaining epithelium. We can argue that p53 immunohistochemistry may be helpful in differentiating hyperplastic regenerative atypia of the epithelium, frequently found in JPs, from true dysplasia, a much more rare change in the sporadic JPs.

Summary Objective A common source of concern about digital pathology (DP) is that limited resolution could be a reason for an increased risk of malpractice. A frequent question being raised about this technology is whether it can be used to reliably detect Helicobacter pylori (HP) in gastric biopsies, which can be a significant burden in routine work. The main goal of this work is to show that a reliable diagnosis of HP infection can be made by DP even at low magnification. The secondary goal is to demonstrate that artificial intelligence (AI) algorithms can diagnose HP infections on virtual slides with sufficient accuracy. Methods The method we propose is based on the Warthin-Starry (W-S) silver stain which allows faster detection of HP in virtual slides. A software tool, based on regular expressions, performed a specific search to select 679 biopsies on which a W-S stain was done. From this dataset 185 virtual slides were selected to be assessed by WSI and compared with microscopy slide readings. To determine whether HP infections could be accurately diagnosed with machine learning. AI was used as a service (AIaaS) on a neural network-based web platform trained with 468 images. A test dataset of 210 images was used to assess the classifier performance. Results In 185 gastric biopsies read with DP we recorded only 4 false positives and 4 false negatives with an overall agreement of 95.6%. Compared with microscopy, defined as the “gold standard” for the diagnosis of HP infections, WSI had a sensitivity and specificity of 0.95 and 0.96, respectively. The ROC curve of our AI classifier generated on a testing dataset of 210 images had an AUC of 0.938. Conclusions This study demonstrates that DP and AI can be used to reliably identify HP at 20X resolution.

We here demonstrated neuroendocrine cell hyperplasia in pouch mucosa. Further studies are needed to clarify the pathophysiological implication of this finding.