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Updated: Sep 25, 2026
Intravital Imaging of Intraepithelial Lymphocytes in Murine Small Intestine
Published on: June 24, 2019
Feline epitheliotropic intestinal malignant lymphoma: 10 cases (1997-2000)
Janet K Carreras1, Micheal Goldschmidt, Martin Lamb
1Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Veterinary Teaching Hospital, Philadelphia, PA, USA. drcarreras@gcvs.com
Insights
Epitheliotropic intestinal malignant lymphoma (EIL) in cats involves increased intraepithelial lymphocytes. Treatment with prednisone showed variable outcomes, with a median survival time of 11 months.
Area of Science:
- Veterinary Pathology
- Oncology
- Immunology
Background:
- Epitheliotropic intestinal malignant lymphoma (EIL) is a challenging diagnosis in cats.
- Understanding the characteristics of EIL is crucial for effective treatment and prognosis.
Purpose of the Study:
- To describe the clinical, histopathologic, and immunohistochemical features of feline EIL.
- To compare intraepithelial lymphocytes in EIL cases with normal cats, inflammatory bowel disease (IBD), and non-EIL cases.
- To evaluate treatment outcomes and survival times for cats with EIL.
Main Methods:
- Histopathologic and immunohistochemical analysis of intestinal biopsies from 10 cats with EIL.
- Comparison with biopsies from 11 normal cats, 7 cats with IBD, and 9 cats with non-EIL.
- Immunophenotyping using CD3 and CD79a antibodies to differentiate T- and B-cells.
Main Results:
- EIL biopsies showed significantly higher intraepithelial lymphocyte counts than normal intestine and IBD samples.
- Intraepithelial lymphocytes in all groups were predominantly small- to intermediate-sized T cells.
- Nine of 10 EIL cats treated with prednisone had variable responses, with a median survival of 11 months.
Conclusions:
- Feline EIL is characterized by an increase in intraepithelial T lymphocytes.
- Clinical presentation can be nonspecific, mimicking IBD or other lymphomas.
- Further research is needed to optimize treatment strategies and understand EIL's relationship with IBD.
Abstract:
The clinical, histopathologic, and immunohistochemical features of 10 cats with epitheliotropic intestinal malignant lymphoma (EIL) are described. Intestinal biopsy samples were reviewed by 3 pathologists to confirm the diagnosis of EIL. These samples (n = 10) were compared to the intestinal biopsies of normal cats (n = 11), cats with inflammatory bowel disease (IBD; n = 7), and cats with non-EIL (n = 9) for quantification and immunophenotyping of intraepithelial lymphocytes. Immunophenotypic studies were performed with CD3 and CD79a antibody stains to assess for T- and B-cell immunoreactivity, respectively. EIL biopsies had markedly more intraepithelial lymphocytes than normal intestine (NRL) and samples from cats with IBD. However, no marked difference was observed in the number of intraepithelial lymphocytes in cats with non-EIL compared to cats with EIL. Regardless of the histologic diagnosis, the intraepithelial lymphocytes in all cats were small- to intermediate-sized T cells. Clinical findings and imaging studies in the cats identified minimal or nonspecific findings in affected cats. Most cats fit the typical profile of cats with IBD or alimentary malignant lymphoma. Nine of 10 cats with EIL were treated with prednisone with or without additional chemotherapy. Four cats were refractory to chemotherapy and were euthanized within 3.5 months. The remaining 5 cats had long-term survival times of 11 months or greater. The median survival time was 11 months. Additional studies are warranted to better characterize EIL and its relationship to IBD in cats and non-EIL and to identify optimal treatment strategies for this disease.