Conditions like Enchrondoma are unlikely to recur if properly surgically removed. Given the fact that it has been surgically excised twenty years back, chances are minimal that this is recurrence. It is only the lack of non aggressiveness during surgery could lead to recurrence. Moreover, basal cell carcinoma can also recur on a similar pattern. But, it seems the site is different and there is more of pain. Kindly get the relevant investigations like CT scan, MRI, X ray and other histopathological tests like biopsy and Fine needle aspiration cytology done to rule out malignancy. This would decide the further course of action. Hope this helps.