Mole is a benign skin tumor formed by the aggregation of melanocytes. For most of the moles, the probability of cancer is still relatively small, so to check whether a mole will become cancerous requires patients to observe closely at home. If within a short period of time, you find that your pigmented mole has obvious morphological changes, such as the mole becomes significantly larger, darker or there are some small black spots around the mole, you should highly suspect cancerous changes. In some cases, the nevus may become higher and protrude from the skin, accompanied by tingling, itching, ulceration, oozing, and bleeding, which are also highly suspicious of cancer. After these morphological changes, patients should go to the dermatology department of a regular hospital in time and apply histopathological examination to further confirm the diagnosis.