Feline Epitheliotropic Intestinal Malignant Lymphoma: 10 Cases (1997–2000)

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.

Intestinal T-Cell Lymphoma with Severe Hypereosinophilic Syndrome in a Cat

“…One immunohistological study [27] indicates that infiltration of either T-or B-lymphocytes was observed in the intestine of cats with alimentary lymphoma, whereas both lymphocytic populations infiltrated the intestine of patients with inflammatory bowel disease (IBD). However, another immunohistological study [3] showed that most of the intraepithelial lymphocytes in the intestines were T-cells regardless of whether the cats were histologically diagnosed to have alimentally lymphoma or IBD. Therefore, to confirm the diagnosis of intestinal lymphoma in cats, not only immunohistochemical analysis but also careful morphological evaluation of the degree of mucosal injury and/ or polymerase chain reaction-based clonality assessment of infiltrating lymphocytes are required [13].…”

Immunophenotypic and Histologic Classification of 50 Cases of Feline Gastrointestinal Lymphoma

“…Lymphoma is the most common neoplasm in cats, 4,9,12,19,25,28,30,38 accounting for 50 to 90% of all feline hematopoietic neoplasms. 37 Further, since the widespread implementation of test/euthanize and vaccination programs for the control of feline leukemia virus (FeLV), 21,37,38 the gastrointestinal tract (GIT) has been reported by several authors to be the most frequently recognized anatomic location of disease.…”

“…37 Further, since the widespread implementation of test/euthanize and vaccination programs for the control of feline leukemia virus (FeLV), 21,37,38 the gastrointestinal tract (GIT) has been reported by several authors to be the most frequently recognized anatomic location of disease. 4,12,17,19,28 Cats with GIT lymphoma have a median age of 12 years, 37 and they are generally FeLV negative. 28,37 Most authors report that within the GIT, B-cell tumors predominate over T-cell tumors and tumors of large granular lymphocytes (LGLs).…”

Endoscopic Findings on Alimentary Lymphoma in 7 Dogs

“…The alimentary form is common in cats [1,5,9,10], but uncommon in dogs, accounting for only 5 to 7% of all lymphomas [2,8]. It is generally believed that full thickness biopsy of the intestine is necessary to diagnose alimentary lymphoma as the lesions are usually deep-seated and invade the serosa.…”