You are having mole since long time, and now you show black dot on the mole.
Discoloration of pigmented nevus
may be the sign of malignant melanoma
But, there is only black dot in the center of mole...
I think it is not malignant melanoma... But excision biopsy
may be done to rule out cancer.
And it would be treatment also.
Excision under local anaesthesia may be done.
You consult dermatologist
for perfect diagnosis and treatment.
I hope you got my answer.
Dr. Ilyas Patel MD