Welcome and thanks for your question
I would be pleased to help you with your Question
The history suggest that it could be a Dermatofibroma
or a healed Fibrosed Furuncle
The best approach for this bump would be to inject a steroid
in the growth / bump .
It will shrink it in size steadily .
The other alternative would be to take a biopsy
for documentation and pathology study . You will need to book an appointment with the Dermatologist
Thanks and Take care .