Clinical, laboratory and ultrasonographic findings differentiating low‐grade intestinal T‐cell lymphoma from lymphoplasmacytic enteritis in cats

Abstract

Background Low‐grade intestinal T‐cell lymphoma (LGITL) is the most common intestinal neoplasm in cats. Differentiating LGITL from lymphoplasmacytic enteritis (LPE) is challenging because clinical signs, laboratory results, diagnostic imaging findings, histology, immunohistochemistry, and clonality features may overlap. Objectives To evaluate possible discriminatory clinical, laboratory and ultrasonographic features to differentiate LGITL from LPE. Animals Twenty‐two cats diagnosed with LGITL and 22 cats with LPE based upon histology, immunohistochemistry, and lymphoid clonality. Methods Prospective, cohort study. Cats presented with clinical signs consistent with LGITL or LPE were enrolled prospectively. All data contributing to the diagnostic evaluation was recorded. Results A 3‐variable model (P < .001) consisting of male sex (P = .01), duration of clinical signs (P = .01), and polyphagia (P = .03) and a 2‐variable model (P < .001) including a rounded jejunal lymph node (P < .001) and ultrasonographic abdominal effusion (P = .04) were both helpful to differentiate LGITL from LPE. Conclusions and Clinical Importance Most clinical signs and laboratory results are similar between cats diagnosed with LGITL and LPE. However, male sex, a longer duration of clinical signs and polyphagia might help clinicians distinguish LGITL from LPE. On ultrasonography, a rounded jejunal lymph node, and the presence of (albeit small volume) abdominal effusion tended to be more prevalent in cats with LGITL. However, a definitive diagnosis requires comprehensive histopathologic and phenotypic assessment.

Intestinal S100/Calgranulin Expression in Cats with Chronic Inflammatory Enteropathy and Intestinal Lymphoma

“…The definition of a “normal intestinal microarchitecture” remains challenging in cats despite the WSAVA GI Standardization Group’s attempt to standardize the histologic assessment of GI biopsies with a grading scheme, evaluating cellular infiltration (e.g., lymphocytes/plasma cells, eosinophils, neutrophils, MΦ) and morphologic lesions (e.g., epithelial injury, crypt distention, lacteal dilation, villus blunting, fibrosis) on a scale from 0 (normal) to 3 (severely abnormal) [ 3 , 39 ]. The results of different observers still vary, and some investigators suggest simplifying the WSAVA grading scheme [ 47 ]. Cats defined as “normal” and used to establish the WSAVA guidelines were approximately 1.5 years old, specific pathogen-free (SPF) colony cats, which are hardly representative of the typical cat presented with GI signs in clinical practice.…”

“…antigen ELISA ( n = 20), and abdominal ultrasonography. Sonographic findings were evaluated based on the presence of increased total GI wall thickness (>2.5 mm for the duodenum and jejunum and >3.2 mm for the ileum; level of increase graded as normal, mildly increased, or markedly increased [ 46 ]), loss of GI wall layering, increased thickness of the muscularis layer (>0.3 mm for the duodenum, >0.4 mm for the jejunum, and >0.9 mm for the ileum; graded as normal, mildly increased, or markedly increased [ 46 ]), enlarged mesenteric lymph nodes, and the presence of (scant) ascites [ 47 ].…”

ACVIMconsensus statement guidelines on diagnosing and distinguishing low‐grade neoplastic from inflammatory lymphocytic chronic enteropathies in cats

“…In addition, concurrent inflammation in the same or other parts of the gastrointestinal tract has been documented in up to 60% of cats with LGITL 35‐39 . The duration of clinical signs has been documented to be significantly longer in cats with LGITL compared with LPE 40 . Epitheliotropism can be found in both entities 18,34,41,42 .…”

“…Interpretation of the pertinent literature is challenging because of inconsistent use of classification schemes. Recent studies imply that LGITL is very uncommon in cats under 8 years of age 40 . The role of breed is unclear.…”

“…To date, no specific association has been found consistently between breed and LGITL in cats, although domestic shorthair and Siamese breeds are over‐represented in some studies of AL 38,39,53 . Some studies also have mentioned an overrepresentation of male neutered cats 39,40,54 . Duration of clinical signs before presentation is generally chronic in both cats with LPE and LGITL.…”