Primary epitheliotropic alimentary T-cell lymphoma with hepatic involvement in a dog.

The anatomic forms of lymphoma are multicentric, alimentary, thymic, cutaneous, and leukemic. Correlations between cell type and topographic distribution of lymphomas is not well documented, but there are more plasmacytoid tumors in the gut, skin, and spleen, which suggests that these are areas of malignant transformation preceded by a period of benign immune hyperplasia. Alimentary forms of lymphoma can be preceded by lymphocytic-plasmacytic enteritis. In the present case, an epitheliotropic alimentary form of T-cell lymphoma with hepatic involvement and concomitant lymphocytic-plasmacytic enteritis was diagnosed in an 8-year-old male Labrador Retriever. The lymphoma was characterized by the accumulation of atypical lymphocytes in the lamina propria and mucosal epithelium of the jejunum. The lymphocytes were identified as T-cell lineage using a polyclonal rabbit antisera to the human pan-T-cell determinant CD-3. The "homing" nature of the neoplasm resembles the epidermotropic form of cutaneous T-cell lymphoma.