Féline-Abdomen : A case of renal and nervous lymphoma in a cat
Persian cat male castrated. Presented for chronic lameness of the right hind limb with marked muscle atrophy. At clinical exam a mass effect is felt in the abdomen.
An ovoid mass of soft tissue opacity, homogeneous, with ill-defined edge is visible in the craniodorsal abdomen to the right of the spine. It generates a significant mass effect on the caudal edge of the stomach, intestines including colon that is displaced ventrally. The right kidney is not visible on the VD. The liver extendends caudal to the rib cage and has rounded edges. A loss of contrast is visible across the abdomen.
Considering the mass effect on the colon and localisation plus the fact that the right kidney is not discernible, the mass is a retroperitoneal mass and most likely arising from the right kidney. Another possibility, less likely is the adrenal gland.
Differential diagnosis: severe unilateral renomegaly:
1) hydronephrosis due to obstruction
2) renal tumor such as carcinoma, lymphoma less likely (it is usually bilateral)
3) perirenal cyst
The ultrasound showed a hyperechoic kidney and hypoechoic subcapsular halo characteristic of lymphoma. A necropsy confirmed renal lymphoma. Lung metastases and peripheral nerve sheath tumor were also found.