Case Of the Month

Aldosterone Secreting Adrenal Tumor in an 11-Year-Old FS DSH Cat: Our Case Of the Month June 2019

The patient was presented for annual exam with a 1-2 month history of decreased appetite. Blood chemistry and CBC found a potassium low at 3.2, chloride low 113, AST high 70, monocytes high 684, and T4/fPL both normal. Repeat bloodwork a month later showed potassium even lower at 2.6. The patient was started on Renacare potassium supplement and abdominal ultrasound was scheduled. The day of the ultrasound, potassium was rechecked and still low at 2.7; Renacare dose was increased and a month later the potassium level was normal.

DX

Enlarged, irregular right adrenal gland.

Outcome

Recommendations based of the ultrasound findings were as follows: Sodium potassium ratio should be evaluated. Blood pressure measurements are also warranted. If hypokalemia is present, Conn’s syndrome may be playing a role in this patient. Right adrenalectomy is recommended. Aldosterone levels warranted given the subnormal potassium. If any inflammatory sediment is present in the urine or proteinuria, renal biopsy could be performed at the time of right adrenalectomy. The patient had surgery and the right adrenal gland was removed; a Tru-cut biopsy of the liver was sampled as well. During right adrenalectomy the right adrenal gland was found to be grossly enlarged, discolored, and adherent to the dorsal surface of the vena cava. The patient was given a Convenia injection and discharged two days after surgery on Onsior and Buprenex along with instructions to discontinue the Renacare, Spironalactone, and Amlodipine. Potassium levels were normal prior to discharge. Biopsy report: Right adrenal gland: adrenal cortical carcinoma. Liver: moderate to marked diffuse hepatocellular swelling. Following surgery, the patient’s blood pressure improved and potassium levels normalized. No chemotherapy was recommended. Blood pressure and potassium levels should be checked every 4 months. Owner reports the patient is doing well at home.

Sampling

A Tru-cut biopsy of the liver was obtained during right adrenalectomy.

Image Interpretation

The right adrenal gland was enlarged in this patient, rounded and mildly heterogeneous, measuring approximately 1.5 cm x 1.5 cm. Strong potential for carcinoma. Capsular expansion was noted without capsular invasion. Both kidneys presented chronic interstitial nephrosis pattern with hyperechhoic, idiopathic medullary rim sign.