Any associated trauma?
Any associated fever ?
Since when is your elbow swollen?
Any associated redness ,warmth in that swollen area?
Is the swelling severe?
Is this swelling in one elbow?
Any associated pain?
Any investigations done so far?
Well this could be due to bursitis or lateral epicondylitis.Since you can feel some chip possible fracture can be there .You should get an X-Ray Lt elbow joint AP and Lateral views .
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I would recommend that you consult an orthopaedic surgeon.
Possibly this swelling is collection of blood .Cause? Infectious? mild trauma on previously injured site.