Thank you for the query.
No doctor is able to tell if the mole is benign or malignant without removing it and sending for histopathology. Dermatologist
are able to establish if the mole is in high risk of melanoma
malignum. It can be done with dermatoscope. But the final diagnose can be set only when you do remove it and check for cancer cells under the microscope.
If the mole changes its size, color, gets painful, redness
appears around, gets more prominent, the verges are uneven, the mole is suspicious and should be removed. Otherwise, it should be left alone.
Hope this will help.