Peri-renal pseudocysts

Question 1

What is a peri-renal pseudocyst

Answer 1

A peri-renal pseudocyst corresponds to a peri-renal fluid accumulation
- it is not a common finding

Palpable cystic structures may be present around one or both kidneys, and there may be abdominal enlargement

Question 2

How could you suspect and diagnose peri-renal pseudocysts

Answer 2

Palpation of cystic structures on one or both kidneys

Non-painful kidney enlargement with an irregular outline

Radioggraphy reveals large soft-tissue densities around the kidney area

Ultrasonography or contrast radiographic studies will confirm the cystic nature

Question 3

What is the nature of the fluid

Answer 3

In most cases the fluid is a transudate, although in some cases it appears that part of the fluid may arise from the escape urine

Question 4

What is the etiology of peri-renal pseudocysts

Answer 4

The etiology of the condition is usually unknown
- it is most commonly seen in older cats

The fluid accumulation may be either intra- or extra-capsular
- in man, peri-renal pseudocysts most often arise after trauma to the kidney(s) or upper ureter

In most cases, the etiology of the pseudocysts is unknown, but the majority of cats have varying degrees of chronic interstitial nephritis

Rarely, peri-renal pseudocysts have been observed associated with renal lymphoma

Question 5

When is treatment indicated and how is treatment apply

Answer 5

Treatment is indicated if the pseudocysts are large

Treatment consists of surgical drainage and omentalization (if the existing CKD is not advanced)

Question 6

Give a differential diagnosis list for renomegaly

Answer 6

FIP

Lymphoma (or other neoplasia including carcinoma and metastatic tumors)

Hydronephrosis

Acute kidney injury

PKD

Peri-renal pseudocysts

Trauma and hemorrhage

Amyloidosis

Pyelonephritis

Acromegaly