The official medical term for a mole is: melanocytic naevus which simply means a collection of pigment skin cells, or melanocytes.

While most moles are benign, there are some real warning signs for moles which are beginning to be cancerous.

These include:

* changes in shape, including a ragged edge to the mole, or an enlargement of the mole
*changes in color, including a difference in color between one area and another within the mole
* itchiness, redness
*bleeding

You should be aware that if you have a large mole, larger than a pencil eraser or a congenital one that is larger than 8 inches in diameter, you are at a higher risk for malignant melanoma.

Also, having greater than 25 moles puts you in a higher risk category so you should always be aware of the state of your moles and monitor them carefully, or have your doctor monitor them very carefully.

https://www.empowher.com/moles/content/cancerous-moles