Thanks for writing to us.
Without a clinical evaluation it would be difficult to determine the cause of the lump. Possibilities that may need to be considered include enlarged lipomas
, cysts, growths from underlying connective tissue
etc. Ii could be due to muscle pull or spasm.
I would suggest getting this evaluated by an orthopedician for an accurate diagnosis and appropriate management.
I do hope that you have found something helpful and I will be glad to answer any further query.