Existing mole has crusty wart-like surface

Thank you for your question. Moles can change over time and become more raised, dry, or change colors. However, there are other benign lesions that occur with age that mimic moles and can have a wart like appearance, which are called seborrheic keratosis. I agree with your GP and highly recommend you consult with a board certified dermatologist to have your lesion evaluated. Take care and good luck.