International study group on rectal cancer regression grading: interobserver variability with commonly used regression grading systems.

The aim of this study was to ascertain the level of concordance among gastrointestinal pathologists for regression grading in rectal cancers treated with neoadjuvant chemoradiation. Seventeen gastrointestinal pathologists participated using the Mandard, Dworak, and modified rectal cancer regression grading systems to grade 10 representative slides that were selected from 10 cases of rectal cancer treated with long-course neoadjuvant chemoradiation. The slides were scanned with a whole-slide scanner generating dynamic digitized images. The results showed very little concordance across the 3 grading systems, with κ values of 0.28, 0.35, and 0.38 for the Mandard, Dworak, and modified rectal cancer regression grading systems, respectively. In only 1 of 10 study cases was there unanimous grading concordance using the modified rectal cancer regression grading system. It was felt that these systems lacked precision and clarity for reproducible, accurate regression grading. The study concluded that there was a need for a simple, reproducible regression grading system with clear criteria, a cumulative or composite score taking into account all sections of the tumor bed that is sampled rather than the worst section (highest grade), and there should be a uniform method of sampling of these specimens.

Iatrogenic deep epithelial misplacement ("gastritis cystica profunda") in a gastric foveolar-type adenoma after endoscopic manipulation: a diagnostic pitfall.

Gastritis cystica profunda (GCP) is analogous to the more commonly encountered colitis cystic profunda. Both conditions are associated with polypoid and/or ulcerative mucosal lesions with or without previous surgery. Typically, the misplaced glands in GCP are encountered in the submucosa. The case described occurred in a 62-year-old man with a fundic foveolar adenoma containing foci of low-grade dysplasia. Three attempts at endoscopic removal were attempted before a sleeve gastrectomy was performed. Remnants of the foveolar adenoma were identified in the resection specimen. However, the striking feature in the gastrectomy specimen was the presence of GCP and cystically dilated glands within the muscularis propria. Such deep misplacement of glands in GCP has not been described previously and simulates adenocarcinoma. The glands were devoid of cytologic atypia, noninfiltrative, and surrounded by lamina propria. These features, together with the history of multiple attempts at removal, distinguish this lesion from adenocarcinoma. It is most likely due to iatrogenically induced defects in the gastric wall from multiple previous attempts at endoscopic removal of the polyp. These previous surgical procedures facilitated the deep misplacement of gastric glands into the muscularis propria.