Hi,
Welcome to health care magic,
This lump on lower shin and ankle swelling needs to be visually inspected at least once to make a diagnosis.
Without this examination, it will be slightly difficult for me to go for any further comments.
It could be a lipoma or
cyst on tendon or but again the important thing is to examine it by surgeon's eye and hands for making correct the judgement of its size, shape and consistency,whether it arises from the skin or
subcutaneous tissue.
If it is lipoma (which have likely chances) since it is spongy and firm, is nothing but the growth of fat cells or tissue in a thin, fibrous capsule usually found just below the skin.
It is the most common non-cancerous
soft tissue swelling or lump.
However,It can be surgically removed by simple excision under local anaesthesia if it becomes painful or tender,infected or inflamed repeatedly.
Lipomas are very rarely turned out to be a cancerous or malignant.
So,you must not bother about it.
Occasionally it becomes painful or tender,infected or inflamed or if it is causing a bit discomfort or strange sensation then you can go for surgical excision of that lipoma.
It will hardly take 5 to 10 minutes to get it removed by surgeon under local anaesthesia.
After surgery,your surgeon will send the removed tissue for histo-pathological examination as a part of routine procedure.
So,you should see a surgeon for further evaluation.
Hope this detailed information will help.
Thanks and Regards,