Decembers Case of the Month. Bilateral Adrenomegaly in a Dog.

Patient Information:

Age: 11 years old

Gender: Spayed Female

Breed: Border Collie Mix

Weight: 62.5 lbs

History:

Several weeks duration of intermittent decreased appetite, lethargy, and pu/pd. Labwork showed a mild non regenerative anemia and mild azotemia. A urine cortisol creatinine ratio was not suggestive of hyperadrenocorticism. The patient had recently been treated for a fever and a UTI. Amlodipine was recently started for treatment of hypertension.

Abdominal Ultrasound Findings:

Adrenal Glands

The left adrenal is very enlarged (Lft cd,cr - 20,13 mm), plump in shape, and hyperechoic with multiple partially mineralized nodules.

The right adrenal is very enlarged (Rt cd,cr - 22,19 mm), irregular in shape and mineralized. Invastion into the caudal vena cava is suspected and Doppler blood flow deficits within the caudal vena cava are noted.

Other sonographic findings:

Multiple ill-defined splenic nodules
Mild to moderate diffuse hepatopathy

Chronic renal changes
Biliary debris

Interpretation:

Bilateral adrenomegaly is most commonly seen in dogs associated with pituitary dependent hyperadrenocorticism, however, this patient’s adrenal glands demonstrated multiple abnormal features. The general criteria of malignancy associated with adrenal tumors are a measurement of >1.5 to 2 cm in width, mineralization, and vascular invasion, all of which were visualized in this patient.

Bilateral adrenal tumors are uncommon in dogs, but can occur. Concurrent pituitary dependent AND adrenal dependent hyperadrenocorticism can occur and is also uncommon. Given that this patient’s UCCR was negative, functional adrenal masses are less likely. Other differentials include inactive adrenocortical neoplasia, pheochromocytoma, or metastatic disease from neoplasia elsewhere.

Outcome:

Because of bilateral involvement, surgery was not a feasible option. A University of Tennessee adrenal profile was performed and was abnormal for all hormones with the exception of cortisol. The patient is currently doing well and managed on melatonin and lignans with periodic monitoring of UAs for recurrent UTIs