Final answer:
A yellow tumor nodule under the skin may be a sign of skin cancer. It is important to monitor any changes in shape, size, and color of skin growths and consult a healthcare professional if there are any concerns.
Step-by-step explanation:
A yellow tumor nodule under the skin may be a sign of skin cancer. Skin cancers are generally asymmetrical, have irregular borders, may be very dark in color, and may have a relatively large diameter. It is important to monitor any changes in shape, size, and color of skin growths and consult a healthcare professional if there are any concerns.