Aims Immune checkpoint inhibitors (ICIs) improve survival across a range of malignancies but are also associated with a spectrum of gastrointestinal (GI) immune‐related adverse events (GI‐irAEs). The aims of this study were to explore the diagnostic value of gastric and duodenal biopsies and to address considerations in the differential diagnosis. Methods and results We identified 39 patients who were treated with ICIs and had a subsequent upper GI biopsy. We recorded clinical data and endoscopic findings, and reviewed their gastric, duodenal and colonic biopsies. Twenty‐one (54%) patients were treated with an anti‐programmed cell death protein 1 (PD‐1)/anti‐programmed cell death ligand 1 antibody alone, and 17 (44%) patients were treated with a combination of anti‐cytotoxic T‐lymphocyte‐associated protein‐4 and anti‐PD‐1 antibodies. Thirty‐two (82%) patients presented with diarrhoea. Gastric alterations included periglandular inflammation and granulomas, and duodenal changes included villous blunting, intraepithelial lymphocytosis, granulomas, and neutrophilic activity. We recognised four patterns of colonic injury: (i) acute self‐limiting colitis; (ii) lymphocytic colitis; (iii) collagenous colitis; and (iv) apoptosis‐only. Twenty‐nine (74%) and 10 (26%) patients were diagnosed clinically as positive and negative for GI‐irAEs, respectively. Gastric periglandular inflammation (P = 0.004) and an increased number of colonic lamina propria mononuclear cells (P = 0.04) correlated with the clinical diagnosis of a GI‐irAE. Histological alterations associated with ICI injury were more often identified in upper GI biopsies (71%) than in colonic biopsies (65%). Conclusions The morphological spectrum of ICI‐related GI disease is broad, and mimics a range of infectious and inflammatory diseases. Gastric periglandular inflammation represents one of the more characteristic histological features of GI‐irAEs. The study underscores the importance of a comprehensive review of upper and lower GI biopsies for the diagnosis of GI‐irAEs.

BACKGROUND:The Paris System for Reporting Urinary Cytology (TPS) has defined nuclear-to-cytoplasmic (N:C) ratio cutoff values for several of its risk-stratified diagnostic categories. However, because pathologists are not trained to recognize strict N:C ratio cutoff values, a previously designed survey was used to determine whether pathologists could accurately identify N:C ratios according to TPS standards. METHODS: Participants were instructed to estimate the N:C ratio of ideal (line drawing) and real (cell photograph) images presented via an online survey. Actual N:C ratios ranged from 0.3 to 0.8, and 3 answer choices were available: < 0.5, 0.5 and <0.7, and 0.7. The resulting data were analyzed to determine the accuracy and performance of the subgroups. RESULTS: A total of 137 individuals completed the survey.Approximately 24.1% were cytopathologists, 18.2% were pathologists without formal cytopathology training, 18.2% were cytotechnologists, 24.1% were pathology residents, and 15.3% were nonmorphologists. Overall, 70.0%, 67.6%, and 93.3% of responses, respectively, were correct for images with an N:C ratio of < 0.5, 0.5 and < 0.7, and 0.7. For images with an actual N:C ratio < 0.5 and 0.5 and < 0.7, 30.0% and 25.0% of responses, respectively, overestimated the N:C ratio. Furthermore, for images with an N:C ratio of 0.4 and 0.6, > 40.0% of responses overestimated the N:C ratio. As a whole, morphologists were significantly more accurate than nonmorphologists (P 5.030). CONCLUSIONS: Morphologists tended to overestimate the N:C ratio, particularly at ratios close to TPS-recommended cutoff values. Additional training regarding N:C ratio estimation may help pathologists to adapt to this new system.

Background-Cataract and glaucoma are leading causes of blindness worldwide, and their coexistence is common in elderly people. Glaucoma surgery can accelerate cataract progression, and performing both surgeries may increase the rate of postoperative complications and compromise the success of either surgery. However, cataract surgery may independently lower intraocular