<s>[INST] my baby is 6 months old and I just discovered a lump on his back just on the tip of his right rib cage.  i am frantic and plan on taking him to the doctor tomorrow.  have you heard talk of this before.  also when he lies on his stomach you can see the lump protruding out . [/INST] Hi, dear. I have gone through your question. I can understand your concern. Youmay have some benign lesion or may have some protruding lesion. You should go for ultrasound of that lump and if needed go for fine needle aspiration cytology. Then you should take treatment accordingly. Hope I have answered your question, if you have doubt then I will be happy to answer. Thanks for using health care magic. Wish you a very good health. </s>