<s>[INST] I noticed a hard bone-like lump below my collar bone (i am thinking the top rib) It feels as hard as bone, it is unmoveable, and pretty much has the same contour as a rib but feels a lot different from the right side as it protrudes more, the left side of that area is flat. It starts pretty much on my sternum then extends to the left about 2 inches, then the area is flat again. It feels like it might be wider than a normal rib too. I can t move it around. It is non-painful, but i am not sure since when I have it. I would just like an idea as to what this could be. [/INST] Thanks for your question on Chat Doctor. I can understand your concern. By your history and description, in my opinion, you are mostly having enlarged subcuticular lymph node. In neck, there are many lymph nodes and subcuticular nodes are one of the group. The most common cause for lymph node enlargement is infection and second most common is malignancy. So better to get done ultrasound examination of neck for confirmation of lymph node enlargement. If this is lymph node then fine needle aspiration cytology (FNAC) should be done to establish the diagnosis. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. </s>