Hi.. Can understand your concern.. As per your complain a small lump on the inner side of upper lip can be due to trauma to the minor salivary glands or their ducts presents on the inner side of lip leading to spillage of mucous into the adjacent soft tissues causing formation of a small lump known as MUCOCELE.. Many a times mucocele may appear hard due to distension caused by filling of mucous or saliva in it.. When there is some rupture in it and the fluid leaks it gradually becomes softer.. Most of the small mucoceles resolves themselves as they rupture and spill their contents in the mouth and gradually heals without leaving any scar. In case of small multiple mucoceles concentrated salt water gargles can help in shrinkage of the mucoceles and eventually healing.. In case of large chronic cases where mucoceles do not resolve themselves Surgical removal has to be done whereas the chronic cases of small mucoceles can be removed by non invasive procedure known as Laser Ablation.. I would suggest you to consult an Oral Surgeon and get evaluated and treatment can be planned depending upon he cause of the lump which seems most probably to be mucocele. Hope your query is solved.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.