Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems like you have got a ruptured duct of a minor salivary gland leading to spillage of mucous into the soft tissues and causing formation of a lump and is known as a mucocele.. As the lump is painless and persistent you can start doing concentrated salt water rinses for its regression.. In case if it still does not regress consult an Oral Physician and get evaluated and a thorough clinical evaluation can help in diagnosis and in case if it is mucocele surgical removal is advisable.. Hope this information helps.. Thanks and regards. Dr. Honey Nandwani Arora.