Subcutaneous rheumatoid nodules (arrow) commonly form over pressure points as in this patient with olecranon bursitis. The nodules may be within subcutaneous tissue overlying the bursae or may be subperiosteal to the extensor surface of the ulna.
By permission of the publisher. From Matteson E, Mason T: Atlas of Rheumatology . Edited by G Hunder. Philadelphia, Current Medicine, 2005.