The combination of lomustine and corticosteroids is a valid chemotherapeutic option in cats with presumptive central nervous system lymphoma.

Objective: To describe the clinical outcomes of 10 cats diagnosed with CNS lymphoma treated with lomustine and corticosteroids.

Animals: Clinical records of privately owned cats diagnosed with CNS lymphoma and presented to a neurological veterinary center were reviewed. Inclusion criteria were MRI, CSF analysis, treatment with corticosteroids and lomustine, and availability of detailed follow-up data. Cats with incomplete data, alternative diagnoses, or concomitant intracranial conditions as well as those improving after corticosteroid treatment before the diagnosis were excluded. Ten cats met the inclusion criteria.

Clinical presentation: The median duration of clinical signs was 7 days. All patients presented with locomotor deficits; 90% exhibited ataxia. Paresis was observed in 60%, and spinal pain on palpation was also described in 60% of the cats. Cranial nerve abnormalities were identified in 30% and epileptic seizures were reported in 20% of the cats.

Results: MRI revealed intracranial lymphoma in 40% and spinal lymphoma in 60% of the cases and contrast-enhancing lesions with meningeal involvement in most of the cases. One cat had elevated CSF cell counts; the others showed normal cell counts but atypical lymphocytes. Seven cats (70%) were still alive at the 3-month follow-up, with 3 (30%) maintaining improvement at 6 and 12 months. The treatment did not result in any significant adverse effect.

Clinical relevance: The combination of lomustine and corticosteroids is a valid chemotherapeutic option in cats with CNS lymphoma. Larger prospective studies are warranted to compare efficacy of this treatment with that of other chemotherapeutic protocols.