Concordance of the Histopathologic Diagnosis of Concurrent Duodenal and Ileal Biopsy Specimens in Dogs

Abstract

Histopathologic discordance between gastrointestinal (GI) locations in canine chronic inflammatory enteropathy (CIE) has prompted recommendations to biopsy both the duodenum and ileum, while further evaluation is required for non-CIE. We aimed to determine the concordance of histopathologic diagnosis between duodenal and ileal endoscopic or full-thickness biopsy specimens for all dogs with CIE and GI neoplasia and to assess the association between histopathologic discordance between GI locations with clinicopathologic variables. Seventy-nine dogs were eligible, with endoscopic (74) or full-thickness (5) biopsy specimens. Clinicopathological data were recorded for all dogs. Concordance of histopathologic diagnosis was retrospectively assessed for concurrent duodenal and ileal biopsy specimens by a single board-certified veterinary pathologist using the modified World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group guidelines. Sixty-seven dogs were diagnosed with CIE and 5 with enteric-associated T-cell lymphoma-2 (EATL-2). Concordance of histologic diagnosis between duodenal and ileal sites was similar between endoscopic (73.0%) and full-thickness (80.0%) biopsy groups. For the CIE cases, lymphoplasmacytic enteritis had the highest concordance (73.0%) and eosinophilic enteritis the least (16.7%). Of the 5 neoplastic cases, 5/5 (100%) were present at the duodenum but only 3/5 (60%) in the ileum. No clinicopathologic variables demonstrated a statistically significant association with discordance. We conclude that the level of discordance necessitates concurrent biopsy of both duodenum and ileum in all dogs with chronic GI signs. The rate of EATL-2 was lower than rates reported for cats.

Relationship between serum cobalamin concentration and endoscopic ileal appearance and histology in dogs with chronic inflammatory enteropathy

“…An early study in dogs found that the concordance of histologic diagnosis between duodenal and ileal sites was high for lymphoplasmacytic enteritis (73%) but low for eosinophilic enteritis (17%). 3 The same study also confirmed the discordance between upper and lower gastrointestinal biopsies for smallcell lymphoma in dogs. 3 In our opinion, these are compelling reasons to perform ileoscopy.…”

“…3 The same study also confirmed the discordance between upper and lower gastrointestinal biopsies for smallcell lymphoma in dogs. 3 In our opinion, these are compelling reasons to perform ileoscopy. Nevertheless, in those cases in which CIE was the diagnosis and endoscopy did not include ileoscopy, this study and cobalamin concentration might provide the clinician with insight into the ileum's condition.…”

“…1 Endoscopy and biopsy sampling of the digestive tract is a crucial tool in the diagnosis of CIE. During the examination, ileoscopy is recommended due to the extreme disparity between ileal, duodenal, or colonic histopathologic findings. 2,3 Nevertheless, the tendency is to explore and biopsy only the stomach, duodenum, and colon due to the difficulty of ileal intubation. 4,5 In those cases, possible injuries to the ileum might have been overlooked.…”

Association of fecal and serummicroRNAprofiles with gastrointestinal cancer and chronic inflammatory enteropathy in dogs

“…Thus, the quality and extent of pinch biopsies are inferior to that of full-thickness biopsies, potentially leading to incorrect diagnoses. [76][77][78] Dogs in all groups had biopsies evaluated by a pathologist at a reference laboratory, however, we did not have a single pathologist review all samples. Even though the interobserver variation between pathologists can be significant, 79 histopathologic scoring was not an objective of this study, and was not pursued further.…”

“…Though endoscopy is noninvasive and might facilitate localization of lesions, the endoscope is rarely able to access the jejunum, and in some dogs, it can be challenging to gain access to and obtain biopsies from the ileum. Thus, the quality and extent of pinch biopsies are inferior to that of full‐thickness biopsies, potentially leading to incorrect diagnoses 76‐78 . Dogs in all groups had biopsies evaluated by a pathologist at a reference laboratory, however, we did not have a single pathologist review all samples.…”