Incidental adrenal gland masses found on dog abdominal CT scans

Abstract

OBJECTIVE To determine the prevalence and clinical characteristics of incidental adrenal gland masses identified in dogs undergoing abdominal CT. DESIGN Retrospective case series. ANIMALS 270 client-owned dogs. PROCEDURES Medical records of dogs that underwent abdominal CT from June 2013 through June 2014 were reviewed. Patients were excluded if they had undergone CT because of a history or clinical signs of an adrenal gland mass or disease. Information collected included history, signalment, initial complaint, serum alkaline phosphatase activity, urine specific gravity, and whether abdominal ultrasonography was performed. Imaging reports generated by the board-certified radiologist who evaluated the CT images were reviewed. RESULTS Incidental adrenal gland masses were detected in 25 of the 270 (9.3%) dogs. Dogs with incidental adrenal gland masses were significantly older (median, 12.0 years; range, 8.0 to 15.0 years) than dogs without (8.2 years; range, 0.1 to 13.1 years). Dogs examined for neoplasia were significantly more likely to have an incidental adrenal gland mass (22/138 [15.9%]) than were dogs examined for any other reason (3/132 [2.3%]), but these dogs were also significantly older. No other risk factors were identified. Histologic examination was performed in only 3 of the 25 dogs with incidental adrenal gland masses; 2 had cortical adenomas and 1 had a pheochromocytoma and cortical adenoma. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that a clinically important percentage of dogs undergoing abdominal CT will have incidental adrenal gland masses, with incidental masses more likely in older than in younger dogs.