Case Study

Renal calculi, biliary calculi, common bile duct obstruction, and right adrenal mass in a 12 year old FS Yorkshire Terrier

A 12-year-old FS Yorkshire Terrier was presented for sudden onset aggression. Two years previous to this visit, calcium oxalate uroliths were removed via cystotomy. Current diet was U/D, and current therapy included Enacard. On urinalysis, an inappropriate specific gravity, 3+ protein, hematuria, and elevated urine protein:creatinine ratio were present. CBC was within normal limits, but serum biochemistry showed elevated ALT and elevated ALP activity, hypercalcemia, and elevated lipase. T4 was low.

DX

Renal calculi, biliary calculi, common bile duct obstruction, right adrenal mass

Sonographic Differential Diagnosis

Common bile duct calculi and obstruction with inflamed common bile duct and inspissated debris. Small calculus embedded at the duodenal papilla. Surgical intervention is highly recommended. Concurrent right adrenal gland mass, which does not appear invasive. Potential myelolipoma or benign hyperplasia of the right adrenal gland. Given that the patient is not persistently PU/PD, this may represent a benign myelolipoma. Other possibilities include non-functional adenocarcinoma, pheochromocytoma or benign hyperplasia. Given that the urine specific gravity is persistently greater than 1.020, blood pressure measurements would be warranted. Renal fibrosis and calculi are evident, so urine culture and sensitivity would be warranted as well as blood pressure measurements. Eventual surgical intervention to liberate the common bile duct would be recommended. It does appear to have adequate integrity. CT evaluation may be warranted to evaluate the extent of the right adrenal tumor. However, no overt evidence of invasion into the vena cava was noted in this patient.

Image Interpretation

Both kidneys had a diffuse, interstitial nephrosis pattern with corticomedullary and medullary calculi. This is consistent with calcium oxalate given the history and sonographic appearance. Occasional cortical cysts were noted. The left kidney measured 4.2 cm. The right kidney measured 4.4 cm. The left adrenal gland was normal in size and contour and measured 2 x 0.5 cm.. However, the right adrenal gland contained a mass that measured 3.5 x 2.7 cm with mixed, hyperechoic changes. This mass is expansive upon the right kidney, but no overt invasion into the vena cava was noted on these views. This appears resectable with some effort. Blood pressure monitoring would be recommended. The liver in this patient presented multiple lobar calculi with common bile duct calculi and significant dilation of the common bile duct. It measured 0.9 cm with echogenic debris and large calculus localized in the entrance of the cystic duct into the common bile duct. The distal aspect of the common bile duct also presented calculus at the duodenal papilla that appears to be obstructing. The calculus at the entrance to the common bile duct measured 1.4 cm, but multiple other small calculi were noted. Around the common bile duct, there were some areas of inflammation. The remainder of the liver presented minor, degenerative changes.

Outcome

The patient was lost to follow up.

Clinical Differential Diagnosis

Aggression – Neurological (GME, neoplasia, cyst, abscess, metabolic encephalopathy), behavioral, pain (orthopedic, neoplasia, urolith), liver disease, renal disease. Hypercalcemia – neoplasia, renal disease, toxicity, granulomatous disease.