Contrast-enhanced ultrasound features of adrenal lesions in dogs

Background: The contrast-enhanced ultrasound (CEUS) features of adrenallesions are poorly reported in veterinary literature. Methods: Qualitative and quantitative B-mode ultrasound and CEUS features of 186 benign (adenoma) and malignant (adenocarcinoma and pheochromocytoma)adrenal lesions were evaluated. Results: Adenocarcinomas (n = 72) and pheochromocytomas (n = 32) had mixed echogenicity with B-mode, and a non-homogeneous aspect with a diffusedor peripheral enhancement pattern, hypoperfused areas, intralesional microcirculation and non-homogeneous wash-out with CEUS. Adenomas (n = 82) had mixed echogenicity, isoechogenicity or hypoechogenicity with B-mode, and a homogeneous or non-homogeneous aspect with a diffused enhancement pattern, hypoperfused areas, intralesional microcirculation and homogeneous wash-out with CEUS. With CEUS, a non-homogeneous aspect and the presence of hypoperfused areas and intralesional microcirculation can be used to distinguish between malignant (adenocarcinoma and pheochromocytoma) and benign (adenoma) adrenal lesions. Limitations: Lesions were characterised only bymeans of cytology. Conclusions: CEUS examination is a valuable tool for distinction between benign and malignant adrenal lesions and can potentially differentiatepheochromocytomas fromadenocarcinomas and adenomas.However, cytology and histology are necessary to obtain the final diagnosis.