Case Study

Lymphoma in a 16 year old FS DSH cat with weight loss

A 16-year-old spayed female DSH cat was presented for weight loss. No abnormalities were noted on the physical exam other than poor body condition. The CBC was within normal limits. The blood chemistry profile revealed elevations of the urea, creatinine, bilirubin, lipase, and magnesium.

DX

Renal lymphoma

Sonographic Differential Diagnosis

Infiltrative renal neoplasia – lymphoma probable, possible carcinoma. Chronic pyelonephritis possible but unlikely.

Image Interpretation

Severe disruption of renal architecture with loss of corticomedullary definition is noted. A hypoechoic cortical mass can be seen at the medial caudal aspect of the kidney. A hypoechoic subcapsular rim is also present; this often develops in cases of renal lymphoma, and represents tissue proliferation rather than fluid.

Outcome

The patient was euthanized one month after the diagnosis was obtained.

Clinical Differential Diagnosis

Azotemia – chronic renal insufficiency, pre-renal azotemia. Weight loss – neoplasia (lymphoma, adenocarcinoma, leiomyoma, leiomyosarcoma, mast cell tumor), pancreatitis, inflammatory bowel disease, cholangitis, cholangiohepatitis, triaditis, apathetic hyperthyroidism.

Sampling

Ultrasound-guided FNA of kidney. Cytological analysis revealed a highly cellular sample with the majority of cells being intermediate to large lymphocytes, suggestive of lymphoma.