Lymphoma in Young Cats

Sandra Bechtel, DVM, DACVIM, University of Florida

ArticleLast Updated December 20232 min read
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In the Literature

Rogato F, Tanis JB, Pons Gil B, Pittaway C, Johnston CA, Guillén A. Clinical characterisation and long-term survival of paediatric and juvenile lymphoma in cats: 33 cases (2008-2022). J Small Anim Pract. 2023. doi:10.1111/jsap.13667

The Research …

Lymphoma most often occurs in the GI tract of older cats; however, a subset of cases occurs in younger cats, with disease distribution primarily in the mediastinum and peripheral lymph nodes.1,2 Chemotherapy may elicit a different response in young cats due to their age and site distribution; toxicity and long-term adverse effects are unknown.  

This study aimed to describe the clinical presentation, characteristics, response to therapy, and adverse effects of treatment of cats (n = 33) ≤18 months of age with lymphoma. Median age at diagnosis was 12 months (range, 3-18 months). All cats had intermediate or large cell lymphoma diagnosed via cytology or histopathology. The most common clinical signs were dyspnea and lethargy, and the most common anatomic forms were mediastinal, disseminated (including peripheral lymph node involvement), and renal. FeLV and FIV were tested for in 29 cats; 3 cats were positive for FeLV, and all were negative for FIV.  

Multiagent chemotherapy protocols were variable, and the overall response rate was 96%, with 46% of cats having a complete response. Late-term toxicoses (ie, chronic disease, stunted growth, second cancer) from chemotherapy were not reported in any cat during the follow-up period. Median progression-free survival for all cats that responded to therapy was 133 days; cats that achieved complete remission had a significantly longer median progression-free interval (868 days) compared with cats with partial remission (63 days). Overall median survival time was 268 days.

… The Takeaways

Key pearls to put into practice:

  • Although the majority of feline lymphoma cases are diagnosed in the GI tract of older cats, young cats can develop lymphoma, most commonly in the mediastinum, in the peripheral lymph nodes, and disseminated throughout the body. Lymphoma should be a differential diagnosis for mediastinal masses and enlarged lymph nodes in young cats. 

  • Fine-needle aspiration and cytology can often successfully diagnose large cell lymphoma. 

  • Multiagent chemotherapy is the treatment of choice in young cats with lymphoma and can be administered safely at therapeutic doses. Young cats have a high treatment response rate. Cats that achieved complete remission in the current study had a long progression-free survival; however, it is not possible to predict which cats will respond to chemotherapy prior to starting therapy.