Lymphoma
Lymphoma is the most common malignancy in cats, accounting for approximately 30% of all feline cancers. It is a cancer of lymphocytes -- immune cells that travel throughout the body via the lymph system. Because lymphoma is rarely localized, chemotherapy is the primary treatment rather than surgery or radiation.
Key Facts
- Most common cancer in cats
- Classified by anatomical location: intestinal (most common in cats), renal, mediastinal, nasal, and multicentric
- feline-leukemia-virus was historically the chief cause; vaccination shifted the predominant form to intestinal lymphoma
- Grading (high-grade vs low-grade) affects prognosis and treatment response
- Species: cats primarily (dogs get multicentric form more often)
Connections (29)
Related Conditions
Renal lymphoma produces CKD-like symptoms (poor appetite, excessive thirst, weight loss) and can directly damage kidney tissue.
Cutaneous lymphoma is one of the anatomic forms
Common trigger in cats
— FeLV is a major cause; vaccination changed predominant lymphoma form
Most common cause of hypercalcemia in dogs (via PTH-rP)
Low-grade intestinal lymphoma behaves like severe IBD and treatment is similar.
— differential for subcutaneous lumps
— differential diagnosis
Lymphoma relies on this process to progress from localized nodes to systemic disease.
Oral lymphosarcoma is one type of oral cancer
One of several anatomical forms of feline lymphoma.
Symptoms
Diarrhea is a frequent sign of intestinal lymphoma.
Swollen and hardened lymph nodes are the hallmark physical presentation of this malignancy.
Nasal lymphoma can cause epistaxis
Mediastinal lymphoma is the primary cause in cats.
Variable appetite in lymphoma, also seen in advanced CKD.
Common in intestinal lymphoma, also seen in CKD and hyperthyroidism.
Shared symptom across intestinal, renal, and other lymphoma forms, and across CKD and hyperthyroidism.
Treatments
Medications
Part of the standard treatment for low-grade intestinal form.
Highly effective against lymphoid malignancies in dogs and cats.
Key oral medication for low-grade intestinal lymphoma.
Provides symptomatic relief and direct anti-lymphoma activity.
Diagnostics
Definitive diagnosis requires tissue confirmation.
Blood work may reveal secondary organ changes.
Staging is a critical diagnostic step for determining the extent of lymphoma spread.
Key diagnostic tool for intestinal lymphoma.