Retrospective ultrasonographic evaluation of adrenal lesions in 26 dogs

A review was performed of ultrasonographic findings in 26 dogs with confirmed adrenal lesions. Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated. Histopathologic diagnoses were obtained in all dogs. Adrenal lesions were confirmed as pheochromocytomas (9), adenocarcinomas (6), a poorly differentiated blastoma (1), bilateral adrenal metastases of a carcinoma (1), adenomas--one of which was bilateral--(4) and hyperplasia (6). Size and shape were extremely variable and not specific to lesion type. There was a tendency for pheochromocytomas (7), adenocarcinomas (5) and poorly differentiated blastoma (1) to be rounded masses. Adenomas (4), hyperplasia (7) and adrenal metastases (2) presented predominantly as nodules. No specificity in echogenicity was noted. Mineralization and bilaterality were present in both benign and malignant lesions. Vascular extension or the presence of a thrombus were suggestive but not specific signs of malignancy. Based on our preliminary study, ultrasonography is an effective method for localizing adrenal lesions and is helpful in assessing their extension. However, no definitive differentiation between benign and malignant lesions was possible using ultrasonographic criteria alone.