A patient returns from a Caribbean cruise. He admits to spending "a lot of time sitting at the bar." He presents today, complaining of atraumatic swelling of his right elbow. On examination, he is afebrile, and has a soft, well circumscribed mass over the olecranon. The rest of the examination is unremarkable.
A. lateral epicondylitis.
B. medial epicondylitis.
C. olecranon bursitis.
D. nursemaid's elbow.
E. a dislocated elbow.