<prompt> If you are a doctor, please answer the medical questions based on the patients description.hi i just discovered a lump under the left side of my rib cage it dosent hurt at all not even when i touch it but im still worried it could be something serious like cancer it could just be a rib but im really scared i also smoke which is why i am worried  <response>: Hi.it is best if you consult with a doctor, preferably a general surgeon, for medical and physical examination. Based from your description, it could be a cyst a sebaceous or a gelatinous type, a lipoma fatty deposit or a fibrous fibrous tissue reaction. These lesions can occur anywhere in the body and have the tendency to recur. It could also just be a bony prominence. Diagnostics and management medical and surgical will be directed accordingly. Hope this helps. Good day!! Chat Doctor. 