Kidney cancer involves the abnormal growth of cells within the kidney. Imaging techniques like ultrasound are often used to examine the kidneys. While ultrasound can identify abnormal growths that might suggest kidney cancer, it does not provide a definitive diagnosis. It serves as an initial screening tool, indicating a potential issue that requires further investigation.
How Ultrasound Visualizes Kidney Structures
Ultrasound imaging operates by emitting high-frequency sound waves from a transducer, which then travel into the body. These sound waves bounce off internal structures, including the kidneys, and return to the transducer as echoes. A computer processes these echoes to create real-time images on a screen.
When examining the kidneys, sonographers and doctors observe characteristics. They assess the kidney’s overall size and shape, looking for enlargement or distortion. Internal echoes within the kidney are also analyzed to differentiate between fluid-filled structures and solid tissues, to characterize abnormalities. It also provides a dynamic view, allowing evaluation of blood flow within renal structures.
What Ultrasound Can Indicate About Kidney Abnormalities
Ultrasound is effective at detecting abnormalities within the kidneys, such as masses, cysts, and solid lesions. A simple cyst, a fluid-filled sac with smooth walls and no internal echoes, is considered benign and rarely requires further action. These common findings are often discovered incidentally during imaging for other conditions.
Complex cysts or solid masses, however, present characteristics that raise suspicion. Complex cysts might have irregular walls, internal septations (thin divisions), or solid components. Solid masses, appearing as areas of tissue with different echogenicity than the surrounding kidney, are more concerning. While ultrasound can characterize these findings by size, shape, and internal features, it cannot definitively determine if a mass is cancerous, only suggest the likelihood of malignancy based on these characteristics.
Further Steps for Definitive Diagnosis
If an ultrasound reveals a suspicious kidney abnormality, additional steps are required for a definitive diagnosis. Physicians often recommend more advanced imaging techniques for a clearer, more detailed view of the lesion. Cross-sectional imaging modalities such as computed tomography (CT) scans or magnetic resonance imaging (MRI) provide superior anatomical detail and allow for precise characterization of suspicious lesions.
These advanced scans can assess the size, location, and spread of the abnormality more accurately and evaluate surrounding structures. However, even with CT or MRI, a definitive diagnosis of kidney cancer necessitates a biopsy. During a biopsy, a small tissue sample is extracted from the lesion and examined under a microscope by a pathologist, the only way to confirm cancerous cells.