Renal oncocytoma: contrast-enhanced sonographic features

Area of Science:

• Radiology and Imaging
• Urologic Oncology
• Medical Diagnostics

Background:

• Renal oncocytoma is a benign kidney tumor requiring accurate preoperative diagnosis.
• Conventional sonography has limitations in characterizing renal masses.
• Contrast-enhanced sonography (CES) offers improved visualization of tumor vascularity.

Purpose of the Study:

• To illustrate the characteristic features of renal oncocytoma using contrast-enhanced sonography.
• To evaluate the diagnostic utility of CES in differentiating renal oncocytoma from other renal masses.

Main Methods:

• Retrospective analysis of five pathologically confirmed renal oncocytoma cases.
• Conventional and contrast-enhanced sonographic examinations performed prior to surgery.
• Evaluation of tumor enhancement patterns, perfusion dynamics, and comparison with CT findings.

Main Results:

• Renal oncocytomas appeared as solitary, hypoechoic/isoechoic cortical masses (2-6 cm) with well-defined margins on grayscale sonography.
• Color Doppler showed peripheral and intralesional blood flow signals.
• CES demonstrated early enhancement, hyperenhancement, and rapid washout compared to renal cortex, with central non-enhancing areas and peripheral non-enhancing rims.

Conclusions:

• Contrast-enhanced sonography provides crucial hemodynamic information for diagnosing renal oncocytoma.
• CES aids in the clinical differential diagnosis of this benign renal tumor.
• The characteristic imaging findings on CES can help distinguish oncocytomas from malignant renal neoplasms.