To round out the year, we have an ultrasound case for you to look at. It’s a 1 year old Boxer with polyuria and polydipsia. Take a look and post your interpretations in the comments section.
Case originally posted on September 18, 2008
Both kidneys appear with complete loss of normal echogenicity and echotexure, abnormal shape and cystic components. Large cystic part of the lt kidney cranial pole with debris and thick walls, possibly related with the pelvis. Splenomegaly.
dd: Bilateral renal tumor (hystiocytoma…), Nephritis with abscessation from systemic illness, cystic renal dysplasia
Since the hypoechoic area in the cranial pole of the left kidney is not completely unechoic other differntials would be an abscess, a mass or hematoma. This area does contain fluid most likely, since there is a distal acoustic enhancement associated with it.
Both kidneys have a complete loss of the normal renal architectures, with dilated pelvises.
The liver, spleen, adrenals and kidneys all seem to be hyperechoic.
I would suspect an infiltrative neoplastic process such as LSA or hystiocytosis. More rare diseases like amyloidosis could also be considered.
FNAs or biopsies are required for the final diagnosis.
Right. You’ve both pointed out that there are changes involving both kidneys, pointing to a global renal disease. But, there is a large focal abnormality in the left kidney that may be a second or a different disease process. Thinking of the DAMNIT scheme, what would you rank as your top differentials for the bilateral renal changes?
Neoplastic is likely (e.g bilateral renal LSA), with a focal necrosis of the L kidney?
It would also be helpful to know what was the size of these kidneys
The left kidney is about 6 cm but is likely distorted by the focal lesion. The right kidney is 4.6 cm in length which I would call small for a Boxer.
I think it could be a Polycystic kidney disease (PKD), a slowly progressive, irreversible, inherited kidney disease that can result in renal failure. It is relatively uncommon in dogs.
The disorder is often present at birth. Multiple small cysts slowly grow in size, causing the kidney to enlarge dramatically. The cysts replace the normal kidney tissue, while kidney function continuously declines. PKD often progresses to cause clinical signs of kidney failure. This dog has been polyuric and polydipsic since being acquired as an 8 week old puppy.
Clinical signs of PKD are non-specific and are similar to those seen in dogs with chronic renal failure of any cause. These include depression, decreased appetite or anorexia, excessive drinking, excessive urination, weight loss and sporadic vomiting.
Polycystic disease as it concerns my experience especially in cats is a progressive proccess of normal parenchymal alternation to thin wall cysts but in this case there is no normal renal parenchyma. The top dd could be: Familial nephropathy/ Renal dysplasia/ CA/ Chronic toxic stimulated nephropathy associated with secondary abscessation. Some echogenic areas in the hepatic parenchyma (polycystemic disease) could bring familial disease such amyloidosis or toxicity first in the dd list.
I would not consider neoplasia at all in this case. On both sides I see hyperechoic renal cortices, loss of corticomedullary junction definition, dilated pelves and irregularly shaped small kidneys. Cystic structures are also present.Based on appearance and signalment the most likely diagnosis in this case is Boxer Juvenile Nephropathy, a form of Renal dysplasia with pericapsular and interstitial fibrosis, inflammatory cell infiltration, dilated tubules, sclerotic glomeruli and dystrophic calcification, observed in Boxers less than 5 years of age. The clinical presentation and ultrasonography in this case are very typical for this condition, though biopsy is required to establish the diagnosis.
Great discussion everyone! I think that considering the age and breed of the dog, we can narrow it down to congenital/developmental conditions and then use what we know about breed-related diseases to come to a diagnosis. The cystic structures and perirenal fluid could be considered as degenerative/inflammatory/developmental lesions. Check back on Monday when the answers will be available within the case. Just click on the link in the original post to access it.
Would you like to see more ultrasound cases? Since this one generated so much interest, let me know what you’d like to see in the Case of the Day.
It would be nice to see more cases
Ultrasound area would be very interesting!
Both kidneys are irregular and smaller than normal with increased cortical echogenicity and almost total loss of corticomedullary junction definition. Mild dilatation of the pelvis. Cystic structure (anechoic thin wall) within the parenchyma and one large roundish structure in the cranial pole of left kidney. The structure is fluid filled with a thick wall. The fluid contains a lot of cells. The urine contains lot of cells as well.
There are very few visible vessels in the liver parenchyma.
The renal ultrasonography is most consistent with chronic renal failure – probably congenital and than secondary abscess in left kidney pole most likely related to ascending infection (cystitis).
Polycystic kidney disease is less likely because cysts are quite common in chronic renal failure. And Boxers are known for congenital inherited renal disease (at least in Europe).