Contrast-enhanced Ultrasound Features of Renal Hemangiomas: A Retrospective Descriptive Study

This study aimed to investigate the contrast-enhanced ultrasound (CEUS) imaging features of renal hemangiomas and to evaluate their potential role in improving preoperative diagnosis and differential diagnosis.

In this retrospective study, clinical and ultrasound data from 20 patients with surgically confirmed renal hemangiomas (22 lesions) were analyzed. All patients underwent preoperative conventional ultrasound. Among them, 6 patients (7 lesions) additionally underwent CEUS examination within one month before surgery. Standardized ultrasound techniques and equipment were employed, with focused analysis on the enhancement patterns and hemodynamic characteristics observed on CEUS.

The cohort comprised 10 men and 10 women (mean age 50 years). Most lesions (13/22) were located in the renal medulla. On conventional ultrasound, lesions typically appeared as well-defined, round, hypoechoic nodules, with most showing no significant internal flow on color Doppler imaging. In the 6 patients who underwent CEUS, a characteristic pattern of peripheral nodular enhancement in the arterial phase, followed by progressive centripetal filling, was observed. Peak enhancement intensity was generally comparable to that of the surrounding renal parenchyma. Pathologically, anastomosing hemangioma and capillary hemangioma were the most common subtypes (9 cases each), with immunohistochemical profiles (CD31/CD34 positive, low Ki-67) consistent with benign behavior. This study reveals a preliminary CEUS pattern of renal hemangiomas characterized by peripheral nodular enhancement with progressive centripetal filling, which may aid in differentiating these rare benign tumors from renal cell carcinoma and help avoid unnecessary surgery. The small sample size is a major limitation, and these findings require validation in larger prospective studies.

This study reveals a preliminary CEUS pattern of renal hemangiomas characterized by peripheral nodular enhancement with progressive centripetal filling, which may aid in differentiating these rare benign tumors from renal cell carcinoma, potentially helping to avoid unnecessary surgery. The small sample size is a major limitation, and these findings require validation in larger prospective studies.

The combination of conventional ultrasound and CEUS may enhance the preoperative evaluation of renal hemangiomas. CEUS demonstrates distinctive enhancement patterns that can aid in differentiating these rare benign tumors from other renal malignancies. However, these findings are preliminary and require validation in larger-scale studies.