Thanks for posting a query . I would be pleased to answer the same .
Your condition seems to a wart
or a ganglion
or a epidermal cyst
You will need to get it checked from the Dermatologist
who might suggest electrocautery for the removal of the cyst . If on clinical examination it is a Ganglion , then the Orthopedic doctor will need to be shown . .
Thanks and Take care