Tumor

Growth of cancer cells leads generally to formation of a nodule or tumor; hence cancer is also called a tumor
If it is superficial, it is firm to touch, gets fixed to surrounding tissues and is not freely moveable
However, every nodule is not cancer
Some like warts, cysts, or adenomas are benign and are easily treated
But in order to be sure whether a nodule is cancerous, a bit of the nodule is taken and examined under the microscope, which generally gives a correct diagnosis