Renal Lymphoma

Allison Zwingenberger

University of California, Davis

Publication Date: 2012-03-12

History

3 year old male neutered domestic long haired cat. Outdoor cat noted to have anorexia, and bumps seen on abdomen.

Question

1. What organ system is enlarged?

   a	Reproductive Incorrect.
   b	Gastrointestinal Incorrect
   c	Mesenteric lymph nodes Incorrect. The enlargement is bilateral.
   d	Renal Correct. The displacement of the colon ventrally indicates the masses are originating from the retroperitoneal space.

Findings

On images of the abdomen, there is poor peritoneal detail due to a mid abdominal mass effect. The cat is in thin body condition, also contributing to poor detail. There are two oval soft tissue masses in the region of the kidneys. They are displacing the colon ventrally on the lateral projection, and medially on the v/d projection. There is possible mineralization in the left kidney. The kidneys are markedly enlarged and irregular in shape. The remainder of the abdominal organs are displaced peripherally. The spleen appears enlarged.

DDX

• renal lymphoma
• polycystic kidney disease
• bilateral perirenal pseudocysts are less likely
• granulomatous disease such as FIP

Diagnosis

Ultrasound examination revealed enlarged, irregular kidneys with distorted architecture and a prominent subcapsular collection of fluid or cells. The cat was treated for lymphoma, diagnosed from cytology. On necropsy, the immunohistochemistry suggested an NK cell type (Non-B, non-T cell).