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.
Thank you so much. Did you see the pictures too?