A clinical examination is extremely important for correct diagnosis and management of your condition. Any allergic reaction or infection can give rise to lumps. Another possibility is that it is a lipoma.These are fatty lumps which grow between the skin and underlying muscle. They are movable and doughy in consistency. Inflammation of the bony cartilage can also give rise to lumps. Few bony cysts like aneurysmal bony cysts though very rare can also cause lumpy swelling. Other possibilities are cartilaginous haemartoma of the ribs, bronchogenic carcinoma, Ewings sarcoma, fibrous dysplasia etc.Xrays and Ct scan can help to mark the lesion, size and type of the lesion. Depending on the clinical examination findings tests like FNAC, biopsy may be advised if needed. See a primary care physician. He may further refer you to the concerned specialist. Do write to me again.
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