Background: In Germany, renal tumours are detected earlier also due to advancing technology within ultrasound devices and its more widespread application. Ultrasound diagnosis is usually the first imaging procedure available to urologists. For all renal lesions larger than 1 cm in diameter, fat content can be revealed by quantitative measurements within CT/MRI diagnostic modalities to confirm the suspected diagnosis of angiomyolipoma, or in patients with potentially malignant renal lesions referral (with all the their imaging data) to the multidisciplinary tumour team. As a further step, biopsy may be indicated, especially in the case of inflammatory lesions or suspected lymphoma; otherwise patients with a solid tumour are treated within a tumour stage-appropriate urological therapy regime.
Results: Contrast-enhanced ultrasonography (CEUS) is currently unable to distinguish between benign and malignant renal tumours. Nevertheless, this noninvasive method is useful in everyday clinical practice: in excluding renal pseudolesions, in inflammatory lesions, for follow-up of traumatic pseudolesions, and for the differential diagnosis of atypical renal cyst diagnosis versus renal cancer. Contrast-enhanced sonography also reveals the microperfusion of kidney tumors, providing clues for distinguishing between clear cell and papillary types of renal cell carcinoma. The method is also utilised in CEUS-controlled biopsy procedures of renal lesions.
Conclusions: Contrast-enhanced sonography augments CT/MRI imaging with real-time information on the perfusion of the kidney tumour and can be a therapy-relevant aid for the multidisciplinary cancer conference with the ultrasound examinations being presented as video clips for comment thereon.
Keywords: Angiomyolipoma; Differential diagnosis; Kidney neoplasms; Renal cell carcinoma; Renal cysts.