Case Study

Left renal mass suggestive of round cell neoplasia by cytology, in a 9 year old MN Miniature Poodle dog

This 9 year old MN Miniature Poodle dog presented with a history of weight loss.

CBC: wnl; Chem: mild elevation in ALT

This 9 year old MN Miniature Poodle dog presented with a history of weight loss.

CBC: wnl; Chem: mild elevation in ALT

DX

Left renal mass, round cell tumor suggesting histolytic proliferation.

Sonographic Differential Diagnosis

Left renal mass. Undefined subtle, hepatic nodules. FNA of the liver would be recommended. Three view chest radiographs and echocardiogram are recommended.
Suspect renal carcinoma or sarcoma. It is recommended that the kidney not be sampled at this
time, as the left kidney capsule appears to be containing the pathology. Therefore,
compromising that could theoretically allow for micrometastasis. FNA of
the liver is recommended to ensure that minor heterogenous parenchymal changes are benign. No other
evidence of potential metastatic disease was noted. An
echocardiogram is recommended to ensure that right auricular appendage and pericardium are free of
evident pathology as the sonographic appearance of the left kidney mass appears to be
that of sarcoma. Hemangiosarcoma is the primary differential or other sarcoma as well
as renal carcinoma. Guarded prognosis. If the hepatic aspirates and other screening
procedures are free of evident pathology then left nephrectomy is recommended.

Image Interpretation

The left kidney in this patient presented a mixed, hypoechoic mass that was deriving
from the mid caudal body. The mass was expansive and nodular. There was no
evidence of capsular escape noted. However, significant capsular stretch and expansion
was present. The mass extended caudally into the retroperitoneal space; however, it
still appears to be free moving and resectable. Target lesions were noted within the
mass itself. The right kidney was structurally unremarkable and was normal in size and
contour. The right kidney measured approximately 5.0 cm. There was no evidence of
pathology. Mildly increased cortical echogenicity was noted, which is largely an age
related change.
The liver was largely normal with very subtle, hypoechoic nodules noted without
disruption of architecture. FNA of the left liver could be considered as a screening
measure prior to surgical intervention. However, these are common changes in older dogs and not overtly neoplastic.

Clinical Differential Diagnosis

Weight loss – GI tract (IBD, neoplasia, ulceration), pancreas (chronic pancreatitis, neoplasia), neoplasia
Liver – neoplasia, chronic-active hepatopathy, nodular regeneration