Cancer of the kidneys classically spreads to the lungs giving rounded deposits that are supposed to look like cannon-balls.
This image contains only one photograph, apart from the X-ray of a man with cannon-ball metastases from a kidney carcinoma. The base picture comes from a leaf with fungus marking the surface with multiple tiny black spots. The fungal spots were selectively copied and pasted on the top layer and given a spray with a white brush to produce the granular almost snowy appearance symbolising fragments of the cancer swept in showers by the blood-stream into the lungs. The remainder of the components of the image are painted on using various brushes in Photoshop, including a “bubble” brush.