Thank you so much. Did you see the pictures too?
Hello,
Since the lesion has been present for 12 months, so definitely it needs to be evaluated. It can be due to stucco keratosis(benign cutaneous condition characterized by a skin lesion with a dull or lackluster surface), contact dermatitis to shoes, stasis dermatitis or simple hyperpigmentation.
I would suggest you to consult a dermatologist and get these possibilities evaluated. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.