The ulcer looks like a crater

It mostly occurs on the surface of tumors, and there are obvious ulcers, which look like craters and have necrosis in the center. Cancer is often dominated by invasive growth, so the boundary between it and surrounding tissues is unclear. Cancers that occur on the skin and mucosal surfaces are often polypoid in appearance, mushroom-shaped or cauliflower-shaped, and often have necrosis and ulcers on the surface; they are often irregular nodules in the organs and appear as tree roots or crabs. Foot-shaped infiltration into surrounding tissue. Surface infiltration ulcers occur, that is, the formation of crater-like.