A rib is growing is unlikely. What can cause an increase in the bone region or in your cartilage is the appearance of tumors. Tumors occur due to disordered multiplication and growth of cells. Tumors in the ribs are rare and may be benign or malignant, and these may invade other regions of the body (metastases).
Some tumors that can reach the ribs:
- fibrous dysplasia,
Treatment of tumors can be performed with chemotherapy, radiation and surgery depending on the type of tumor. But, first of all, you should seek a doctor to evaluate the possible cause of this problem.