Thank you for asking Healthcare majic. My name is Dr Ehsan Ullah & I have gone through your query. depending upon nature of this lump, it can be -sebaceous cyst ( Epidermoid Cyst) ; (a swelling in the skin arising in a sebaceous gland,) -Lipoma (a benign tumour of fatty tissue.) Xanthoma (a skin condition in which certain fats build up under the surface of the skin) or it can be just an inflammatory swelling... At ankle regions , Bursitis (inflammation of bursa); when bursa ( a small fluid-filled sac) can get damaged by trauma . Such swellings need a clinical assessment by the physician for diagnosis and treatment . Hope this may help you. Let me know if anything not clear. Thanks.