Laparoscopic adrenalectomy for management of a functional adrenal tumor in a cat

A 9-year-old castrated male domestic shorthair cat was examined because of hypertension that persisted after resolution of the patient's hyperthyroidism. Bilateral hypertensive retinopathy, a systolic heart murmur, left ventricular hypertrophy, and tachycardia were present.

Biochemical analysis revealed mild hypokalemia, normonatremia, high serum creatine kinase activity, high serum aldosterone concentration, and low plasma renin activity consistent with hyperaldosteronism. Hypercalcemia with an associated high serum parathyroid hormone concentration and an exaggerated low-dose dexamethasone suppression test result were consistent with concurrent hyperparathyroidism and hyperadrenocorticism, respectively. Ultrasonographic examination revealed a markedly enlarged left adrenal gland, an abnormally small right adrenal gland, and 2 nodules in the right thyroid and parathyroid glands.

Laparoscopic left adrenalectomy was performed concurrently with right thyroidectomy and parathyroidectomy. Histologic evaluation revealed an adrenal cortical adenoma, thyroid adenoma, and parathyroid adenoma. The cat recovered from surgery without complications. The hypercalcemia and hypertension resolved after surgery. Follow-up echocardiography revealed improvement in the left ventricular hypertrophy. Ultrasonographic examinations performed up to 26 months after adrenalectomy showed no evidence of regrowth of the adrenal mass. The patient survived for 44 months after adrenalectomy with no signs of recurrent hyperaldosteronism or hyperadrenocorticism.

Laparoscopic adrenalectomy may be a plausible method for the treatment of unilateral functional adrenal neoplasia in feline patients when diagnostic imaging has ruled out intravascular invasion and metastatic disease. In addition, in a feline patient with hyperthyroidism and hypertension, other endocrine glands should be investigated.