Ultrasonographic Evaluation of the Muscularis Propria in Cats with Diffuse Small Intestinal Lymphoma or Inflammatory Bowel Disease

Abstract

Background: An ultrasonographic pattern of thickened muscularis propria in the small intestine and lymphadenopathy have been associated with gastrointestinal lymphoma and inflammatory bowel disease (IBD) in cats.Objectives: To investigate the association of these imaging biomarkers with IBD and lymphoma in cats. Animals: One hundred and forty-two cats with a histologic diagnosis of normal small intestine (SI) (n 5 56), lymphoma (n 5 62), or IBD (n 5 24).Methods: Retrospective case review. Pathology records from 1998-2006 were searched for cats with a diagnosis of normal, IBD, or lymphoma, an ultrasonographic examination o28 days before surgery, and without ultrasonographic evidence of a mass. Multinomial regression analysis was used to determine the association of imaging biomarkers with disease status.Results: Cats with thickening of the muscularis propria detected by ultrasonographic examination were more likely to have lymphoma compared with normal SI cats (odds ratio [OR] 5 4.0, 95% confidence interval [95% CI] 1.2-13.1, P 5 .021) and those with IBD (OR 5 18.8, 95% CI 2.2-162.7, P 5 .008). Histologic samples of cats with muscularis propria thickening were more likely to have disease infiltrates in both the mucosal and submucosal layers (OR 5 8.1, 95% CI 1.7-38.4, P 5 .008) than cats with normal SI. Cats with ultrasonographic evidence of lymphadenopathy were more likely to have a diagnosis of lymphoma (OR 5 44.9, 95% CI 5.1-393.0, P 5 .001) or IBD (OR 5 10.8, 95% CI 1.1-106.3, P 5 .041) than normal SI. Fifty-six of 62 cats had confirmed or presumptive diagnosis of diffuse T-cell lymphoma.Conclusions and Clinical Relevance: Older cats with muscularis layer thickening are more likely to have T-cell lymphoma than IBD. The ultrasonographic pattern is associated with histologic infiltrates in the mucosal and submucosal layers of small intestine. Lymphadenopathy is associated with lymphoma or IBD.

Ultrasonographic thickening of the muscularis propria in feline small intestinal small cell T-cell lymphoma and inflammatory bowel disease

“…No cats in the IBD group had disease deeper than the mucosal layer. A relationship between the thickness of the muscularis layer and the extent of the neoplastic lymphocytic infiltration has been described previously, 7 with the muscularis thickening giving increased odds of transmural disease to the depth of the submucosa. This is supported by the current results in which the majority of bowel segments had transmural disease histologically.…”

Clinical characteristics and outcome in dogs with small cell T‐cell intestinal lymphoma

“…The reported ultrasonographic features of small cell intestinal lymphoma in cats include diffuse intestinal wall thickening (most specifically, a thickened muscularis propria) with or without preservation of wall layering and mesenteric lymph node enlargement(17,31). In the current study, these were also common findings in dogs.…”

Ultrasonographic evaluation of relative gastrointestinal layer thickness in cats without clinical evidence of gastrointestinal tract disease

“…Recent studies in cats have suggested that thickening of specific wall layers can occur in response to GI disease. 4,6,9 In one study, diagnoses of lymphocyticplasmocytic enteritis and foreign bodies were associated with thickening of the muscularis layer in four cats. 4 In a case report of small bowel infarction in a cat caused by an aortic thromboembolism, a series of US evaluations documented progressive, focal mucosal and submucosal layer prominence, with final loss of normal wall layering over a period of 48 h. 9 In these studies, normal GI layer thicknesses measurements were not reported, and the observation of layer thickening or prominence was subjectively assessed.…”