Case Of the Month

Disseminated lymphoma in an 11-year-old FS DSH cat: Our Case Of The Month January 2012

Lymphoma Does What Lymphoma Does.

Anorexia, weight loss, “not doin’ right” are the usual signs in cats that make us suspect lymphoma or similar neoplasia but have us hope for pancreatitis, biliary disease, obstructive urolithiasis, orthopedic disease and other treatable disease with similar vague signs. However, when the uncontrolled cell growth of lymphoma strikes and causes every affected organ to “burst at the seams,” this is what the organs under the probe present like which we then sample accordingly. Dr, Marty Henderson of www.sonovet.us teams up with the amazing Claudia Barton DACVIM (Oncology) for the lymphoma diagnosis in this cat for the January, 2012 SonoPath Case of the month.

Sonogram (Liver): Lizzie

History: A 11-year-old female neutered DSH was presented with a history of anorexia and weight loss. The only abnormality on urinalysis is an inappropriate urine specific gravity ( 1.016). Azotemia is present on serum biochemistry.

Outcome

No further outcome.

Comments

(Barton DACVIM): This cat clearly has disseminated lymphoma in all areas sampled, and one would presume that the other organs that were abnormal on the sonogram are also affected. Palliative prednisone or a chemotherapy protocol would be the treatment for this tumor, but the prognosis is very guarded to poor given the renal involvement. Many renal lymphomas in the cat spread fairly rapidly to the CNS, and thus lomustine/prednisolone might be a reasonable chemotherapy choice. Even with a ‘good’ response to chemotherapy, one would expect that remission duration would be 6 months or less, given the propensity of large-cell lymphoma in the cat to become chemotherapy drug resistant. The presence of numerous eosinophils among the neoplastic lymphocytes is interesting; it is likely that the lymphoid tumor cells are synthesizing interleukin 5. IL-5 is a key player in the coordination and orchestration of eosinophil-based inflammatory processes. There are occasional lymphomas in the cat in which the tumor cells apparently produce this cytokine, since the tumor tissue contains a very large number of eosinophils.

Clinical Differential Diagnosis

(Lobetti DECVIM http://www.sonopath.com/specialists_lobetti.asp):

Anorexia/weight loss – renal/hepatic/cardiac/pancreatitic disease, pyothorax, neoplasia, hyperthyroidism
Renal disease – chronic kidney disease, neoplasia, pyelonephritis, hydronephrosis, renoliths, ureteroliths

Sampling

The right kidney and the liver were aspirated and slides are submitted for cytology review.

Sonographic Differential Diagnosis

(Henderson DVM): Kidney Mass – the findings are severe -DDx: primary renal carcinoma, primary renal TCC, renal lymphosarcoma – may appear as diffuse disease or focal mass. Less likely: renal malignant histiocytosis or mastocytosis, malignant osteosarcoma, hemangiosarcoma .
2) Liver – the findings are moderately-severe – DDx:
a) Hepatic lipidosis / Cholangiohepatitis
b) Infiltrative neoplasia (lymphoma – probable in this case)
c) Chronic vs. Acute hepatitis or cholangiohepatitis (bacterial vs. sterile vs. toxin)
3) Lymph nodes – the findings are moderate – DDx: infiltrative neoplasia is likely vs. reaction
Due to the involvement of the liver, gastrointestinal tract, and multiple enlarged lymph nodes, lymphosarcoma is a highly likely.