Aortic and iliac thrombosis in a dog with adrenal-dependent hypercortisolism due to bilateral adrenocortical adenoma

Abstract

Hypercortisolism is a common endocrinopathy in dogs; however, in a few cases, bilateral functional adrenocortical adenomas cause spontaneous disease, and thrombotic events are considered uncommon complications. The aim of this report was to describe a case of bilateral adrenocortical adenoma in a dog with hyperadrenocorticism associated with distal aortic and iliac thrombosis, with emphasis on clinical and pathological aspects. A 15-year-old spayed female Dachshund with a previous clinical history of hyperadrenocorticism presented with acute bilateral hindlimb paraparesis. A vertebral thoracolumbar radiography was performed and did not present any evidence of intervertebral disk disease or vertebral abnormalities; however, abdominal ultrasound and vascular Doppler evaluation revealed bilateral adrenal enlargement in addition to an aortic and external iliac artery thrombus. The animal was euthanized. At necropsy, both adrenal glands were enlarged by well-demarcated neoplastic nodules in the parenchyma, and a thrombus caudal to the abdominal aorta bifurcation within the external iliac arteries that extended to the left external iliac artery was noted. Histological evaluation revealed a well-differentiated neoplastic proliferation of cortical epithelial cells, consistent with bilateral adenoma, and muscular necrosis in the pelvic limbs was also observed. Bilateral functional adrenocortical adenoma; although, very rare, should be considered as a cause of hypercortisolism, and aortic thrombosis in dogs should be considered as a possible consequence.