Thanks for posting your query.
Well, without a clinical evaluation it would be difficult to determine the cause of the lump. Possibilities that may need to be considered include enlarged bursa, lipomas
, cysts, growths from underlying connective tissue
I would suggest getting this evaluated by an orthopedician for an accurate diagnosis and appropriate management. may get the X-ray of the area affected and FNAC (fine needle aspiration cytology) of lump under his/her guidance.
Wishing you good health...
Dr Saurabh Gupta.