The use of flow cytometry for immunophenotyping lymphoproliferative disorders in cats: a retrospective study of 19 cases.

Flow cytometric immunophenotyping is a useful step in the diagnosis of lymphoproliferative malignancies in human and veterinary medicine. The purpose of this study was to assess the usefulness of this technique for the diagnosis of lymphoproliferative disorders in cats. Nineteen cats were retrospectively enrolled in this study and allocated into two groups. Group 1 consisted of 13 cats with lymphoma, whereas group 2 consisted of 6 cats with non-neoplastic lymphoproliferative disorders. Fine-needle aspiration biopsies were analysed by flow cytometry in order to evaluate the immunophenotype. Flow cytometric analysis identified a neoplastic lymphoid population in 12 of the 13 cats of group 1, confirming the diagnosis of lymphoma and further characterizing it. The six cats in group 2 showed a mixed lymphoid population, which was not suggestive of a neoplastic disorder. Flow cytometry is a valuable and powerful tool for refining the diagnosis of feline lymphoproliferative disorders.