Canine lymphoma: cytologic study and response to therapy

The prevalence of cytomorphologic types of canine lymphoma is described for the first time in Slovenia as well as their response to selected chemotherapeutic protocols. Fine-needle aspiration was used as routine diagnostic method in attempt to estimate more accurately first remission and survival time in lymphoma affected dogs. In a retrospective study including 39 dogs with lymphoma we have explored the occurrence of different cytomorphologic types of canine lymphoma and evaluated the influence of clinical stage, choice of therapy and sex on survival time of treated dogs. One dog (2.6 %) had a low grade lymphoma classified as the small lymphocytic type, in 13 dogs (33.3 %) intermediate grade lymphoma (mixed, large and small cleaved) were observed, and in 25 dogs (64.1 %) high grade tumours (lymphoblastic, immunoblastic, small noncleaved) were determined. The survival times of the dogs with high-grade tumours were better than of those with low-grade, due to more complete responses to the therapy and longer remission times. Cytomorphologic evaluation of fine-needle aspirates of affected lymph nodes is suitable for a routine morphological diagnostics, however it can contribute to a more accurate prognosis only in the association with other known prognostic factors.